FreeBSD/Linux Kernel Cross Reference
sys/dev/ocs_fc/ocs_utils.c

     /*-
      * Copyright (c) 2017 Broadcom. All rights reserved.
      * The term "Broadcom" refers to Broadcom Limited and/or its subsidiaries.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions are met:
      *
      * 1. Redistributions of source code must retain the above copyright notice,
      *    this list of conditions and the following disclaimer.
     *
     * 2. Redistributions in binary form must reproduce the above copyright notice,
     *    this list of conditions and the following disclaimer in the documentation
     *    and/or other materials provided with the distribution.
     *
     * 3. Neither the name of the copyright holder nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     * POSSIBILITY OF SUCH DAMAGE.
     *
     * $FreeBSD$
     */
    
    /**
     * @file
     *
     */
    
    #include "ocs.h"
    #include "ocs_os.h"
    
    #define DEFAULT_SLAB_LEN                (64*1024)
    
    struct ocs_array_s {
            ocs_os_handle_t os;
    
            uint32_t size;
            uint32_t count;
    
            uint32_t n_rows;
            uint32_t elems_per_row;
            uint32_t bytes_per_row;
    
            void **array_rows;
            uint32_t array_rows_len;
    };
    
    static uint32_t slab_len = DEFAULT_SLAB_LEN;
    
    /**
     * @brief Set array slab allocation length
     *
     * The slab length is the maximum allocation length that the array uses.
     * The default 64k slab length may be overridden using this function.
     *
     * @param len new slab length.
     *
     * @return none
     */
    void
    ocs_array_set_slablen(uint32_t len)
    {
            slab_len = len;
    }
    
    /**
     * @brief Allocate an array object
     *
     * An array object of size and number of elements is allocated
     *
     * @param os OS handle
     * @param size size of array elements in bytes
     * @param count number of elements in array
     *
     * @return pointer to array object or NULL
     */
    ocs_array_t *
    ocs_array_alloc(ocs_os_handle_t os, uint32_t size, uint32_t count)
    {
            ocs_array_t *array = NULL;
            uint32_t i;
    
            /* Fail if the item size exceeds slab_len - caller should increase slab_size,
             * or not use this API.
             */
            if (size > slab_len) {
                    ocs_log_err(NULL, "Error: size exceeds slab length\n");
                    return NULL;
            }
   
           array = ocs_malloc(os, sizeof(*array), OCS_M_ZERO | OCS_M_NOWAIT);
           if (array == NULL) {
                   return NULL;
           }
   
           array->os = os;
           array->size = size;
           array->count = count;
           array->elems_per_row = slab_len / size;
           array->n_rows = (count + array->elems_per_row - 1) / array->elems_per_row;
           array->bytes_per_row = array->elems_per_row * array->size;
   
           array->array_rows_len = array->n_rows * sizeof(*array->array_rows);
           array->array_rows = ocs_malloc(os, array->array_rows_len, OCS_M_ZERO | OCS_M_NOWAIT);
           if (array->array_rows == NULL) {
                   ocs_array_free(array);
                   return NULL;
           }
           for (i = 0; i < array->n_rows; i++) {
                   array->array_rows[i] = ocs_malloc(os, array->bytes_per_row, OCS_M_ZERO | OCS_M_NOWAIT);
                   if (array->array_rows[i] == NULL) {
                           ocs_array_free(array);
                           return NULL;
                   }
           }
   
           return array;
   }
   
   /**
    * @brief Free an array object
    *
    * Frees a prevously allocated array object
    *
    * @param array pointer to array object
    *
    * @return none
    */
   void
   ocs_array_free(ocs_array_t *array)
   {
           uint32_t i;
   
           if (array != NULL) {
                   if (array->array_rows != NULL) {
                           for (i = 0; i < array->n_rows; i++) {
                                   if (array->array_rows[i] != NULL) {
                                           ocs_free(array->os, array->array_rows[i], array->bytes_per_row);
                                   }
                           }
                           ocs_free(array->os, array->array_rows, array->array_rows_len);
                   }
                   ocs_free(array->os, array, sizeof(*array));
           }
   }
   
   /**
    * @brief Return reference to an element of an array object
    *
    * Return the address of an array element given an index
    *
    * @param array pointer to array object
    * @param idx array element index
    *
    * @return rointer to array element, or NULL if index out of range
    */
   void *ocs_array_get(ocs_array_t *array, uint32_t idx)
   {
           void *entry = NULL;
   
           if (idx < array->count) {
                   uint32_t row = idx / array->elems_per_row;
                   uint32_t offset = idx % array->elems_per_row;
                   entry = ((uint8_t*)array->array_rows[row]) + (offset * array->size);
           }
           return entry;
   }
   
   /**
    * @brief Return number of elements in an array
    *
    * Return the number of elements in an array
    *
    * @param array pointer to array object
    *
    * @return returns count of elements in an array
    */
   uint32_t
   ocs_array_get_count(ocs_array_t *array)
   {
           return array->count;
   }
   
   /**
    * @brief Return size of array elements in bytes
    *
    * Returns the size in bytes of each array element
    *
    * @param array pointer to array object
    *
    * @return size of array element
    */
   uint32_t
   ocs_array_get_size(ocs_array_t *array)
   {
           return array->size;
   }
   
   /**
    * @brief Void pointer array structure
    *
    * This structure describes an object consisting of an array of void
    * pointers.   The object is allocated with a maximum array size, entries
    * are then added to the array with while maintaining an entry count.   A set of
    * iterator APIs are included to allow facilitate cycling through the array
    * entries in a circular fashion.
    *
    */
   struct ocs_varray_s {
           ocs_os_handle_t os;
           uint32_t array_count;                   /*>> maximum entry count in array */
           void **array;                           /*>> pointer to allocated array memory */
           uint32_t entry_count;                   /*>> number of entries added to the array */
           uint32_t next_index;                    /*>> iterator next index */
           ocs_lock_t lock;                        /*>> iterator lock */
   };
   
   /**
    * @brief Allocate a void pointer array
    *
    * A void pointer array of given length is allocated.
    *
    * @param os OS handle
    * @param array_count Array size
    *
    * @return returns a pointer to the ocs_varray_t object, other NULL on error
    */
   ocs_varray_t *
   ocs_varray_alloc(ocs_os_handle_t os, uint32_t array_count)
   {
           ocs_varray_t *va;
   
           va = ocs_malloc(os, sizeof(*va), OCS_M_ZERO | OCS_M_NOWAIT);
           if (va != NULL) {
                   va->os = os;
                   va->array_count = array_count;
                   va->array = ocs_malloc(os, sizeof(*va->array) * va->array_count, OCS_M_ZERO | OCS_M_NOWAIT);
                   if (va->array != NULL) {
                           va->next_index = 0;
                           ocs_lock_init(os, &va->lock, "varray:%p", va);
                   } else {
                           ocs_free(os, va, sizeof(*va));
                           va = NULL;
                   }
           }
           return va;
   }
   
   /**
    * @brief Free a void pointer array
    *
    * The void pointer array object is free'd
    *
    * @param va Pointer to void pointer array
    *
    * @return none
    */
   void
   ocs_varray_free(ocs_varray_t *va)
   {
           if (va != NULL) {
                   ocs_lock_free(&va->lock);
                   if (va->array != NULL) {
                           ocs_free(va->os, va->array, sizeof(*va->array) * va->array_count);
                   }
                   ocs_free(va->os, va, sizeof(*va));
           }
   }
   
   /**
    * @brief Add an entry to a void pointer array
    *
    * An entry is added to the void pointer array
    *
    * @param va Pointer to void pointer array
    * @param entry Pointer to entry to add
    *
    * @return returns 0 if entry was added, -1 if there is no more space in the array
    */
   int32_t
   ocs_varray_add(ocs_varray_t *va, void *entry)
   {
           uint32_t rc = -1;
   
           ocs_lock(&va->lock);
                   if (va->entry_count < va->array_count) {
                           va->array[va->entry_count++] = entry;
                           rc = 0;
                   }
           ocs_unlock(&va->lock);
   
           return rc;
   }
   
   /**
    * @brief Reset the void pointer array iterator
    *
    * The next index value of the void pointer array iterator is cleared.
    *
    * @param va Pointer to void pointer array
    *
    * @return none
    */
   void
   ocs_varray_iter_reset(ocs_varray_t *va)
   {
           ocs_lock(&va->lock);
                   va->next_index = 0;
           ocs_unlock(&va->lock);
   }
   
   /**
    * @brief Return next entry from a void pointer array
    *
    * The next entry in the void pointer array is returned.
    *
    * @param va Pointer to void point array
    *
    * Note: takes the void pointer array lock
    *
    * @return returns next void pointer entry
    */
   void *
   ocs_varray_iter_next(ocs_varray_t *va)
   {
           void *rval = NULL;
   
           if (va != NULL) {
                   ocs_lock(&va->lock);
                           rval = _ocs_varray_iter_next(va);
                   ocs_unlock(&va->lock);
           }
           return rval;
   }
   
   /**
    * @brief Return next entry from a void pointer array
    *
    * The next entry in the void pointer array is returned.
    *
    * @param va Pointer to void point array
    *
    * Note: doesn't take the void pointer array lock
    *
    * @return returns next void pointer entry
    */
   void *
   _ocs_varray_iter_next(ocs_varray_t *va)
   {
           void *rval;
   
           rval = va->array[va->next_index];
           if (++va->next_index >= va->entry_count) {
                   va->next_index = 0;
           }
           return rval;
   }
   
   /**
    * @brief Take void pointer array lock
    *
    * Takes the lock for the given void pointer array
    *
    * @param va Pointer to void pointer array
    *
    * @return none
    */
   void
   ocs_varray_lock(ocs_varray_t *va)
   {
           ocs_lock(&va->lock);
   }
   
   /**
    * @brief Release void pointer array lock
    *
    * Releases the lock for the given void pointer array
    *
    * @param va Pointer to void pointer array
    *
    * @return none
    */
   void
   ocs_varray_unlock(ocs_varray_t *va)
   {
           ocs_unlock(&va->lock);
   }
   
   /**
    * @brief Return entry count for a void pointer array
    *
    * The entry count for a void pointer array is returned
    *
    * @param va Pointer to void pointer array
    *
    * @return returns entry count
    */
   uint32_t
   ocs_varray_get_count(ocs_varray_t *va)
   {
           uint32_t rc;
   
           ocs_lock(&va->lock);
                   rc = va->entry_count;
           ocs_unlock(&va->lock);
           return rc;
   }
   
   struct ocs_cbuf_s {
           ocs_os_handle_t os;             /*<< OS handle */
           uint32_t entry_count;           /*<< entry count */
           void **array;                   /*<< pointer to array of cbuf pointers */
           uint32_t pidx;                  /*<< producer index */
           uint32_t cidx;                  /*<< consumer index */
           ocs_lock_t cbuf_plock;          /*<< idx lock */
           ocs_lock_t cbuf_clock;          /*<< idx lock */
           ocs_sem_t cbuf_psem;            /*<< cbuf producer counting semaphore */
           ocs_sem_t cbuf_csem;            /*<< cbuf consumer counting semaphore */
   };
   
   /**
    * @brief Initialize a circular buffer queue
    *
    * A circular buffer with producer/consumer API is allocated
    *
    * @param os OS handle
    * @param entry_count count of entries
    *
    * @return returns pointer to circular buffer, or NULL
    */
   ocs_cbuf_t*
   ocs_cbuf_alloc(ocs_os_handle_t os, uint32_t entry_count)
   {
           ocs_cbuf_t *cbuf;
   
           cbuf = ocs_malloc(os, sizeof(*cbuf), OCS_M_NOWAIT | OCS_M_ZERO);
           if (cbuf == NULL) {
                   return NULL;
           }
   
           cbuf->os = os;
           cbuf->entry_count = entry_count;
           cbuf->pidx = 0;
           cbuf->cidx = 0;
   
           ocs_lock_init(NULL, &cbuf->cbuf_clock, "cbuf_c:%p", cbuf);
           ocs_lock_init(NULL, &cbuf->cbuf_plock, "cbuf_p:%p", cbuf);
           ocs_sem_init(&cbuf->cbuf_csem, 0, "cbuf:%p", cbuf);
           ocs_sem_init(&cbuf->cbuf_psem, cbuf->entry_count, "cbuf:%p", cbuf);
   
           cbuf->array = ocs_malloc(os, entry_count * sizeof(*cbuf->array), OCS_M_NOWAIT | OCS_M_ZERO);
           if (cbuf->array == NULL) {
                   ocs_cbuf_free(cbuf);
                   return NULL;
           }
   
           return cbuf;
   }
   
   /**
    * @brief Free a circular buffer
    *
    * The memory resources of a circular buffer are free'd
    *
    * @param cbuf pointer to circular buffer
    *
    * @return none
    */
   void
   ocs_cbuf_free(ocs_cbuf_t *cbuf)
   {
           if (cbuf != NULL) {
                   if (cbuf->array != NULL) {
                           ocs_free(cbuf->os, cbuf->array, sizeof(*cbuf->array) * cbuf->entry_count);
                   }
                   ocs_lock_free(&cbuf->cbuf_clock);
                   ocs_lock_free(&cbuf->cbuf_plock);
                   ocs_free(cbuf->os, cbuf, sizeof(*cbuf));
           }
   }
   
   /**
    * @brief Get pointer to buffer
    *
    * Wait for a buffer to become available, and return a pointer to the buffer.
    *
    * @param cbuf pointer to circular buffer
    * @param timeout_usec timeout in microseconds
    *
    * @return pointer to buffer, or NULL if timeout
    */
   void*
   ocs_cbuf_get(ocs_cbuf_t *cbuf, int32_t timeout_usec)
   {
           void *ret = NULL;
   
           if (likely(ocs_sem_p(&cbuf->cbuf_csem, timeout_usec) == 0)) {
                   ocs_lock(&cbuf->cbuf_clock);
                           ret = cbuf->array[cbuf->cidx];
                           if (unlikely(++cbuf->cidx >= cbuf->entry_count)) {
                                   cbuf->cidx = 0;
                           }
                   ocs_unlock(&cbuf->cbuf_clock);
                   ocs_sem_v(&cbuf->cbuf_psem);
           }
           return ret;
   }
   
   /**
    * @brief write a buffer
    *
    * The buffer is written to the circular buffer.
    *
    * @param cbuf pointer to circular buffer
    * @param elem pointer to entry
    *
    * @return returns 0 for success, a negative error code value for failure.
    */
   int32_t
   ocs_cbuf_put(ocs_cbuf_t *cbuf, void *elem)
   {
           int32_t rc = 0;
   
           if (likely(ocs_sem_p(&cbuf->cbuf_psem, -1) == 0)) {
                   ocs_lock(&cbuf->cbuf_plock);
                           cbuf->array[cbuf->pidx] = elem;
                           if (unlikely(++cbuf->pidx >= cbuf->entry_count)) {
                                   cbuf->pidx = 0;
                           }
                   ocs_unlock(&cbuf->cbuf_plock);
                   ocs_sem_v(&cbuf->cbuf_csem);
           } else {
                   rc = -1;
           }
           return rc;
   }
   
   /**
    * @brief Prime a circular buffer data
    *
    * Post array buffers to a circular buffer
    *
    * @param cbuf pointer to circular buffer
    * @param array pointer to buffer array
    *
    * @return returns 0 for success, a negative error code value for failure.
    */
   int32_t
   ocs_cbuf_prime(ocs_cbuf_t *cbuf, ocs_array_t *array)
   {
           uint32_t i;
           uint32_t count = MIN(ocs_array_get_count(array), cbuf->entry_count);
   
           for (i = 0; i < count; i++) {
                   ocs_cbuf_put(cbuf, ocs_array_get(array, i));
           }
           return 0;
   }
   
   /**
    * @brief Generate driver dump start of file information
    *
    * The start of file information is added to 'textbuf'
    *
    * @param textbuf pointer to driver dump text buffer
    *
    * @return none
    */
   
   void
   ocs_ddump_startfile(ocs_textbuf_t *textbuf)
   {
           ocs_textbuf_printf(textbuf, "<?xml version=\"1.0\" encoding=\"ISO-8859-1\" ?>\n");
   }
   
   /**
    * @brief Generate driver dump end of file information
    *
    * The end of file information is added to 'textbuf'
    *
    * @param textbuf pointer to driver dump text buffer
    *
    * @return none
    */
   
   void
   ocs_ddump_endfile(ocs_textbuf_t *textbuf)
   {
   }
   
   /**
    * @brief Generate driver dump section start data
    *
    * The driver section start information is added to textbuf
    *
    * @param textbuf pointer to text buffer
    * @param name name of section
    * @param instance instance number of this section
    *
    * @return none
    */
   
   void
   ocs_ddump_section(ocs_textbuf_t *textbuf, const char *name, uint32_t instance)
   {
           ocs_textbuf_printf(textbuf, "<%s type=\"section\" instance=\"%d\">\n", name, instance);
   }
   
   /**
    * @brief Generate driver dump section end data
    *
    * The driver section end information is added to textbuf
    *
    * @param textbuf pointer to text buffer
    * @param name name of section
    * @param instance instance number of this section
    *
    * @return none
    */
   
   void
   ocs_ddump_endsection(ocs_textbuf_t *textbuf, const char *name, uint32_t instance)
   {
           ocs_textbuf_printf(textbuf, "</%s>\n", name);
   }
   
   /**
    * @brief Generate driver dump data for a given value
    *
    * A value is added to textbuf
    *
    * @param textbuf pointer to text buffer
    * @param name name of variable
    * @param fmt snprintf format specifier
    *
    * @return none
    */
   
   void
   ocs_ddump_value(ocs_textbuf_t *textbuf, const char *name, const char *fmt, ...)
   {
           va_list ap;
           char valuebuf[64];
   
           va_start(ap, fmt);
           vsnprintf(valuebuf, sizeof(valuebuf), fmt, ap);
           va_end(ap);
   
           ocs_textbuf_printf(textbuf, "<%s>%s</%s>\n", name, valuebuf, name);
   }
   
   /**
    * @brief Generate driver dump data for an arbitrary buffer of DWORDS
    *
    * A status value is added to textbuf
    *
    * @param textbuf pointer to text buffer
    * @param name name of status variable
    * @param instance instance number of this section
    * @param buffer buffer to print
    * @param size size of buffer in bytes
    *
    * @return none
    */
   
   void
   ocs_ddump_buffer(ocs_textbuf_t *textbuf, const char *name, uint32_t instance, void *buffer, uint32_t size)
   {
           uint32_t *dword;
           uint32_t i;
           uint32_t count;
   
           count = size / sizeof(uint32_t);
   
           if (count == 0) {
                   return;
           }
   
           ocs_textbuf_printf(textbuf, "<%s type=\"buffer\" instance=\"%d\">\n", name, instance);
   
           dword = buffer;
           for (i = 0; i < count; i++) {
   #define OCS_NEWLINE_MOD 8
                   ocs_textbuf_printf(textbuf, "%08x ", *dword++);
                   if ((i % OCS_NEWLINE_MOD) == (OCS_NEWLINE_MOD - 1)) {
                           ocs_textbuf_printf(textbuf, "\n");
                   }
           }
   
           ocs_textbuf_printf(textbuf, "</%s>\n", name);
   }
   
   /**
    * @brief Generate driver dump for queue
    *
    * Add queue elements to text buffer
    *
    * @param textbuf pointer to driver dump text buffer
    * @param q_addr address of start of queue
    * @param size size of each queue entry
    * @param length number of queue entries in the queue
    * @param index current index of queue
    * @param qentries number of most recent queue entries to dump
    *
    * @return none
    */
   
   void
   ocs_ddump_queue_entries(ocs_textbuf_t *textbuf, void *q_addr, uint32_t size,
                           uint32_t length, int32_t index, uint32_t qentries)
   {
           uint32_t i;
           uint32_t j;
           uint8_t *entry;
           uint32_t *dword;
           uint32_t entry_count = 0;
           uint32_t entry_words = size / sizeof(uint32_t);
   
           if ((qentries == (uint32_t)-1) || (qentries > length)) {
                   /* if qentries is -1 or larger than queue size, dump entire queue */
                   entry_count = length;
                   index = 0;
           } else {
                   entry_count = qentries;
   
                   index -= (qentries - 1);
                   if (index < 0) {
                           index += length;
                   }
           }
   #define OCS_NEWLINE_MOD 8
           ocs_textbuf_printf(textbuf, "<qentries>\n");
           for (i = 0; i < entry_count; i++){
                   entry = q_addr;
                   entry += index * size;
                   dword = (uint32_t *)entry;
   
                   ocs_textbuf_printf(textbuf, "[%04x] ", index);
                   for (j = 0; j < entry_words; j++) {
                           ocs_textbuf_printf(textbuf, "%08x ", *dword++);
                           if (((j+1) == entry_words) ||
                               ((j % OCS_NEWLINE_MOD) == (OCS_NEWLINE_MOD - 1))) {
                                   ocs_textbuf_printf(textbuf, "\n");
                                   if ((j+1) < entry_words) {
                                           ocs_textbuf_printf(textbuf, "       ");
                                   }
                           }
                   }
   
                   index++;
                   if ((uint32_t)index >= length) {
                           index = 0;
                   }
           }
           ocs_textbuf_printf(textbuf, "</qentries>\n");
   }
   
   #define OCS_DEBUG_ENABLE(x)     (x ? ~0 : 0)
   
   #define OCS_DEBUG_MASK \
           (OCS_DEBUG_ENABLE(1)    & OCS_DEBUG_ALWAYS)  | \
           (OCS_DEBUG_ENABLE(0)    & OCS_DEBUG_ENABLE_MQ_DUMP) | \
           (OCS_DEBUG_ENABLE(0)    & OCS_DEBUG_ENABLE_CQ_DUMP) | \
           (OCS_DEBUG_ENABLE(0)    & OCS_DEBUG_ENABLE_WQ_DUMP) | \
           (OCS_DEBUG_ENABLE(0)    & OCS_DEBUG_ENABLE_EQ_DUMP) | \
           (OCS_DEBUG_ENABLE(0)    & OCS_DEBUG_ENABLE_SPARAM_DUMP)
   
   static uint32_t ocs_debug_mask = OCS_DEBUG_MASK;
   
   static int
   _isprint(int c) {
           return ((c > 32) && (c < 127));
   }
   
   /**
    * @ingroup debug
    * @brief enable debug options
    *
    * Enables debug options by or-ing in <b>mask</b> into the currently enabled
    * debug mask.
    *
    * @param mask mask bits to enable
    *
    * @return none
    */
   
   void ocs_debug_enable(uint32_t mask) {
           ocs_debug_mask |= mask;
   }
   
   /**
    * @ingroup debug
    * @brief disable debug options
    *
    * Disables debug options by clearing bits in <b>mask</b> into the currently enabled
    * debug mask.
    *
    * @param mask mask bits to enable
    *
    * @return none
    */
   
   void ocs_debug_disable(uint32_t mask) {
           ocs_debug_mask &= ~mask;
   }
   
   /**
    * @ingroup debug
    * @brief return true if debug bits are enabled
    *
    * Returns true if the request debug bits are set.
    *
    * @param mask debug bit mask
    *
    * @return true if corresponding bits are set
    *
    * @note Passing in a mask value of zero always returns true
    */
   
   int ocs_debug_is_enabled(uint32_t mask) {
           return (ocs_debug_mask & mask) == mask;
   }
   
   /**
    * @ingroup debug
    * @brief Dump 32 bit hex/ascii data
    *
    * Dumps using ocs_log a buffer of data as 32 bit hex and ascii
    *
    * @param mask debug enable bits
    * @param os os handle
    * @param label text label for the display (may be NULL)
    * @param buf pointer to data buffer
    * @param buf_length length of data buffer
    *
    * @return none
    *
    */
   
   void
   ocs_dump32(uint32_t mask, ocs_os_handle_t os, const char *label, void *buf, uint32_t buf_length)
   {
           uint32_t word_count = buf_length / sizeof(uint32_t);
           uint32_t i;
           uint32_t columns = 8;
           uint32_t n;
           uint32_t *wbuf;
           char *cbuf;
           uint32_t addr = 0;
           char linebuf[200];
           char *pbuf = linebuf;
   
           if (!ocs_debug_is_enabled(mask))
                   return;
   
           if (label)
                   ocs_log_debug(os, "%s\n", label);
   
           wbuf = buf;
           while (word_count > 0) {
                   pbuf = linebuf;
                   pbuf += ocs_snprintf(pbuf, sizeof(linebuf) - (pbuf-linebuf), "%08X:  ", addr);
   
                   n = word_count;
                   if (n > columns)
                           n = columns;
   
                   for (i = 0; i < n; i ++)
                           pbuf += ocs_snprintf(pbuf, sizeof(linebuf) - (pbuf-linebuf), "%08X ", wbuf[i]);
   
                   for (; i < columns; i ++)
                           pbuf += ocs_snprintf(pbuf, sizeof(linebuf) - (pbuf-linebuf), "%8s ", "");
   
                   pbuf += ocs_snprintf(pbuf, sizeof(linebuf) - (pbuf-linebuf), "    ");
                   cbuf = (char*)wbuf;
                   for (i = 0; i < n*sizeof(uint32_t); i ++)
                           pbuf += ocs_snprintf(pbuf, sizeof(linebuf) - (pbuf-linebuf), "%c", _isprint(cbuf[i]) ? cbuf[i] : '.');
                   pbuf += ocs_snprintf(pbuf, sizeof(linebuf) - (pbuf-linebuf), "\n");
   
                   ocs_log_debug(os, "%s", linebuf);
   
                   wbuf += n;
                   word_count -= n;
                   addr += n*sizeof(uint32_t);
           }
   }
   
   #if defined(OCS_DEBUG_QUEUE_HISTORY)
   
   /* each bit corresponds to word to capture */
   #define OCS_Q_HIST_WQE_WORD_MASK_DEFAULT        (BIT(4) | BIT(6) | BIT(7) | BIT(9) | BIT(12))
   #define OCS_Q_HIST_TRECV_CONT_WQE_WORD_MASK     (BIT(4) | BIT(5) | BIT(6) | BIT(7) | BIT(9) | BIT(12))
   #define OCS_Q_HIST_IWRITE_WQE_WORD_MASK         (BIT(4) | BIT(5) | BIT(6) | BIT(7) | BIT(9))
   #define OCS_Q_HIST_IREAD_WQE_WORD_MASK          (BIT(4) | BIT(6) | BIT(7) | BIT(9))
   #define OCS_Q_HIST_ABORT_WQE_WORD_MASK          (BIT(3) | BIT(7) | BIT(8) | BIT(9))
   #define OCS_Q_HIST_WCQE_WORD_MASK               (BIT(0) | BIT(3))
   #define OCS_Q_HIST_WCQE_WORD_MASK_ERR           (BIT(0) | BIT(1) | BIT(2) | BIT(3))
   #define OCS_Q_HIST_CQXABT_WORD_MASK             (BIT(0) | BIT(1) | BIT(2) | BIT(3))
   
   /* if set, will provide extra queue information in each entry */
   #define OCS_Q_HIST_ENABLE_Q_INFO        0
   uint8_t ocs_queue_history_q_info_enabled(void)
   {
           return OCS_Q_HIST_ENABLE_Q_INFO;
   }
   
   /* if set, will provide timestamps in each entry */
   #define OCS_Q_HIST_ENABLE_TIMESTAMPS    0
   uint8_t ocs_queue_history_timestamp_enabled(void)
   {
           return OCS_Q_HIST_ENABLE_TIMESTAMPS;
   }
   
   /* Add WQEs and masks to override default WQE mask */
   ocs_q_hist_wqe_mask_t ocs_q_hist_wqe_masks[] = {
           /* WQE command   Word mask */
           {SLI4_WQE_ABORT, OCS_Q_HIST_ABORT_WQE_WORD_MASK},
           {SLI4_WQE_FCP_IREAD64, OCS_Q_HIST_IREAD_WQE_WORD_MASK},
           {SLI4_WQE_FCP_IWRITE64, OCS_Q_HIST_IWRITE_WQE_WORD_MASK},
           {SLI4_WQE_FCP_CONT_TRECEIVE64, OCS_Q_HIST_TRECV_CONT_WQE_WORD_MASK},
   };
   
   /* CQE masks */
   ocs_q_hist_cqe_mask_t ocs_q_hist_cqe_masks[] = {
           /* CQE type     Q_hist_type             mask (success)  mask (non-success) */
           {SLI_QENTRY_WQ, OCS_Q_HIST_TYPE_CWQE,   OCS_Q_HIST_WCQE_WORD_MASK, OCS_Q_HIST_WCQE_WORD_MASK_ERR},
           {SLI_QENTRY_XABT, OCS_Q_HIST_TYPE_CXABT, OCS_Q_HIST_CQXABT_WORD_MASK, OCS_Q_HIST_WCQE_WORD_MASK},
   };
   
   static uint32_t ocs_q_hist_get_wqe_mask(sli4_generic_wqe_t *wqe)
   {
           uint32_t i;
           for (i = 0; i < ARRAY_SIZE(ocs_q_hist_wqe_masks); i++) {
                   if (ocs_q_hist_wqe_masks[i].command == wqe->command) {
                           return ocs_q_hist_wqe_masks[i].mask;
                   }
           }
           /* return default WQE mask */
           return OCS_Q_HIST_WQE_WORD_MASK_DEFAULT;
   }
   
   /**
    * @ingroup debug
    * @brief Initialize resources for queue history
    *
    * @param os os handle
    * @param q_hist Pointer to the queue history object.
    *
    * @return none
    */
   void
   ocs_queue_history_init(ocs_t *ocs, ocs_hw_q_hist_t *q_hist)
   {
           q_hist->ocs = ocs;
           if (q_hist->q_hist != NULL) {
                   /* Setup is already done */
                   ocs_log_debug(ocs, "q_hist not NULL, skipping init\n");
                   return;
           }
   
           q_hist->q_hist = ocs_malloc(ocs, sizeof(*q_hist->q_hist)*OCS_Q_HIST_SIZE, OCS_M_ZERO | OCS_M_NOWAIT);
   
           if (q_hist->q_hist == NULL) {
                   ocs_log_err(ocs, "Could not allocate queue history buffer\n");
           } else {
                   ocs_lock_init(ocs, &q_hist->q_hist_lock, "queue history lock[%d]", ocs_instance(ocs));
           }
   
           q_hist->q_hist_index = 0;
   }
   
   /**
    * @ingroup debug
    * @brief Free resources for queue history
    *
    * @param q_hist Pointer to the queue history object.
    *
    * @return none
    */
   void
   ocs_queue_history_free(ocs_hw_q_hist_t *q_hist)
   {
           ocs_t *ocs = q_hist->ocs;
   
           if (q_hist->q_hist != NULL) {
                   ocs_free(ocs, q_hist->q_hist, sizeof(*q_hist->q_hist)*OCS_Q_HIST_SIZE);
                   ocs_lock_free(&q_hist->q_hist_lock);
                   q_hist->q_hist = NULL;
           }
  }
  
  static void
  ocs_queue_history_add_q_info(ocs_hw_q_hist_t *q_hist, uint32_t qid, uint32_t qindex)
  {
          if (ocs_queue_history_q_info_enabled()) {
                  /* write qid, index */
                  q_hist->q_hist[q_hist->q_hist_index] = (qid << 16) | qindex;
                  q_hist->q_hist_index++;
                  q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
          }
  }
  
  static void
  ocs_queue_history_add_timestamp(ocs_hw_q_hist_t *q_hist)
  {
          if (ocs_queue_history_timestamp_enabled()) {
                  /* write tsc */
                  uint64_t tsc_value;
                  tsc_value = get_cyclecount();
                  q_hist->q_hist[q_hist->q_hist_index] = ((tsc_value >> 32 ) & 0xFFFFFFFF);
                  q_hist->q_hist_index++;
                  q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                  q_hist->q_hist[q_hist->q_hist_index] = (tsc_value & 0xFFFFFFFF);
                  q_hist->q_hist_index++;
                  q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
          }
  }
  
  /**
   * @ingroup debug
   * @brief Log work queue entry (WQE) into history array
   *
   * @param q_hist Pointer to the queue history object.
   * @param entryw Work queue entry in words
   * @param qid Queue ID
   * @param qindex Queue index
   *
   * @return none
   */
  void
  ocs_queue_history_wq(ocs_hw_q_hist_t *q_hist, uint32_t *entryw, uint32_t qid, uint32_t qindex)
  {
          int i;
          ocs_q_hist_ftr_t ftr;
          uint32_t wqe_word_mask = ocs_q_hist_get_wqe_mask((sli4_generic_wqe_t *)entryw);
  
          if (q_hist->q_hist == NULL) {
                  /* Can't save anything */
                  return;
          }
  
          ftr.word = 0;
          ftr.s.type = OCS_Q_HIST_TYPE_WQE;
          ocs_lock(&q_hist->q_hist_lock);
                  /* Capture words in reverse order since we'll be interpretting them LIFO */
                  for (i = ((sizeof(wqe_word_mask)*8) - 1); i >= 0; i--){
                          if ((wqe_word_mask >> i) & 1) {
                                  q_hist->q_hist[q_hist->q_hist_index] = entryw[i];
                                  q_hist->q_hist_index++;
                                  q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                          }
                  }
  
                  ocs_queue_history_add_q_info(q_hist, qid, qindex);
                  ocs_queue_history_add_timestamp(q_hist);
  
                  /* write footer */
                  if (wqe_word_mask) {
                          ftr.s.mask = wqe_word_mask;
                          q_hist->q_hist[q_hist->q_hist_index] = ftr.word;
                          q_hist->q_hist_index++;
                          q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                  }
  
          ocs_unlock(&q_hist->q_hist_lock);
  }
  
  /**
   * @ingroup debug
   * @brief Log misc words
   *
   * @param q_hist Pointer to the queue history object.
   * @param entryw array of words
   * @param num_words number of words in entryw
   *
   * @return none
   */
  void
  ocs_queue_history_misc(ocs_hw_q_hist_t *q_hist, uint32_t *entryw, uint32_t num_words)
  {
          int i;
          ocs_q_hist_ftr_t ftr;
          uint32_t mask = 0;
  
          if (q_hist->q_hist == NULL) {
                  /* Can't save anything */
                  return;
          }
  
          ftr.word = 0;
          ftr.s.type = OCS_Q_HIST_TYPE_MISC;
          ocs_lock(&q_hist->q_hist_lock);
                  /* Capture words in reverse order since we'll be interpretting them LIFO */
                  for (i = num_words-1; i >= 0; i--) {
                          q_hist->q_hist[q_hist->q_hist_index] = entryw[i];
                          q_hist->q_hist_index++;
                          q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                          mask |= BIT(i);
                  }
  
                  ocs_queue_history_add_timestamp(q_hist);
  
                  /* write footer */
                  if (num_words) {
                          ftr.s.mask = mask;
                          q_hist->q_hist[q_hist->q_hist_index] = ftr.word;
                          q_hist->q_hist_index++;
                          q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                  }
  
          ocs_unlock(&q_hist->q_hist_lock);
  }
  
  /**
   * @ingroup debug
   * @brief Log work queue completion (CQE) entry into history
   *        array
   *
   * @param q_hist Pointer to the queue history object.
   * @param ctype Type of completion entry
   * @param entryw Completion queue entry in words
   * @param status Completion queue status
   * @param qid Queue ID
   * @param qindex Queue index
   *
   * @return none
   */
  void
  ocs_queue_history_cqe(ocs_hw_q_hist_t *q_hist, uint8_t ctype, uint32_t *entryw, uint8_t status, uint32_t qid, uint32_t qindex)
  {
          int i;
          unsigned j;
          uint32_t cqe_word_mask = 0;
          ocs_q_hist_ftr_t ftr;
  
          if (q_hist->q_hist == NULL) {
                  /* Can't save anything */
                  return;
          }
  
          ftr.word = 0;
          for (j = 0; j < ARRAY_SIZE(ocs_q_hist_cqe_masks); j++) {
                  if (ocs_q_hist_cqe_masks[j].ctype == ctype) {
                          ftr.s.type = ocs_q_hist_cqe_masks[j].type;
                          if (status != 0) {
                                  cqe_word_mask = ocs_q_hist_cqe_masks[j].mask_err;
                          } else {
                                  cqe_word_mask = ocs_q_hist_cqe_masks[j].mask;
                          }
                  }
          }
          ocs_lock(&q_hist->q_hist_lock);
                  /* Capture words in reverse order since we'll be interpretting them LIFO */
                  for (i = ((sizeof(cqe_word_mask)*8) - 1); i >= 0; i--){
                          if ((cqe_word_mask >> i) & 1) {
                                  q_hist->q_hist[q_hist->q_hist_index] = entryw[i];
                                  q_hist->q_hist_index++;
                                  q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                          }
                  }
                  ocs_queue_history_add_q_info(q_hist, qid, qindex);
                  ocs_queue_history_add_timestamp(q_hist);
  
                  /* write footer */
                  if (cqe_word_mask) {
                          ftr.s.mask = cqe_word_mask;
                          q_hist->q_hist[q_hist->q_hist_index] = ftr.word;
                          q_hist->q_hist_index++;
                          q_hist->q_hist_index = q_hist->q_hist_index % OCS_Q_HIST_SIZE;
                  }
  
          ocs_unlock(&q_hist->q_hist_lock);
  }
  
  /**
   * @brief Get previous index
   *
   * @param index Index from which previous index is derived.
   */
  uint32_t
  ocs_queue_history_prev_index(uint32_t index)
  {
          if (index == 0) {
                  return OCS_Q_HIST_SIZE - 1;
          } else {
                  return index - 1;
          }
  }
  
  #endif /* OCS_DEBUG_QUEUE_HISTORY */
  
  /**
   * @brief Display service parameters
   *
   * <description>
   *
   * @param prelabel leading display label
   * @param reqlabel display label
   * @param dest destination 0=ocs_log, 1=textbuf
   * @param textbuf text buffer destination (if dest==1)
   * @param sparams pointer to service parameter
   *
   * @return none
   */
  
  void
  ocs_display_sparams(const char *prelabel, const char *reqlabel, int dest, void *textbuf, void *sparams)
  {
          char label[64];
  
          if (sparams == NULL) {
                  return;
          }
  
          switch(dest) {
          case 0:
                  if (prelabel != NULL) {
                          ocs_snprintf(label, sizeof(label), "[%s] sparam: %s", prelabel, reqlabel);
                  } else {
                          ocs_snprintf(label, sizeof(label), "sparam: %s", reqlabel);
                  }
  
                  ocs_dump32(OCS_DEBUG_ENABLE_SPARAM_DUMP, NULL, label, sparams, sizeof(fc_plogi_payload_t));
                  break;
          case 1:
                  ocs_ddump_buffer((ocs_textbuf_t*) textbuf, reqlabel, 0, sparams, sizeof(fc_plogi_payload_t));
                  break;
          }
  }
  
  /**
   * @brief Calculate the T10 PI CRC guard value for a block.
   *
   * @param buffer Pointer to the data buffer.
   * @param size Number of bytes.
   * @param crc Previously-calculated CRC, or 0 for a new block.
   *
   * @return Returns the calculated CRC, which may be passed back in for partial blocks.
   *
   */
  
  uint16_t
  ocs_scsi_dif_calc_crc(const uint8_t *buffer, uint32_t size, uint16_t crc)
  {
          return t10crc16(buffer, size, crc);
  }
  
  /**
   * @brief Calculate the IP-checksum guard value for a block.
   *
   * @param addrlen array of address length pairs
   * @param addrlen_count number of entries in the addrlen[] array
   *
   * Algorithm:
   *    Sum all all the 16-byte words in the block
   *    Add in the "carry", which is everything in excess of 16-bits
   *    Flip all the bits
   *
   * @return Returns the calculated checksum
   */
  
  uint16_t
  ocs_scsi_dif_calc_checksum(ocs_scsi_vaddr_len_t addrlen[], uint32_t addrlen_count)
  {
          uint32_t i, j;
          uint16_t checksum;
          uint32_t intermediate; /* Use an intermediate to hold more than 16 bits during calculations */
          uint32_t count;
          uint16_t *buffer;
  
          intermediate = 0;
          for (j = 0; j < addrlen_count; j++) {
                  buffer = addrlen[j].vaddr;
                  count = addrlen[j].length / 2;
                  for (i=0; i < count; i++) {
                          intermediate += buffer[i];
                  }
          }
  
          /* Carry is everything over 16 bits */
          intermediate += ((intermediate & 0xffff0000) >> 16);
  
          /* Flip all the bits */
          intermediate = ~intermediate;
  
          checksum = intermediate;
  
          return checksum;
  }
  
  /**
   * @brief Return blocksize given SCSI API DIF block size
   *
   * Given the DIF block size enumerated value, return the block size value. (e.g.
   * OCS_SCSI_DIF_BLK_SIZE_512 returns 512)
   *
   * @param dif_info Pointer to SCSI API DIF info block
   *
   * @return returns block size, or 0 if SCSI API DIF blocksize is invalid
   */
  
  uint32_t
  ocs_scsi_dif_blocksize(ocs_scsi_dif_info_t *dif_info)
  {
          uint32_t blocksize = 0;
  
          switch(dif_info->blk_size) {
          case OCS_SCSI_DIF_BK_SIZE_512:  blocksize = 512; break;
          case OCS_SCSI_DIF_BK_SIZE_1024: blocksize = 1024; break;
          case OCS_SCSI_DIF_BK_SIZE_2048: blocksize = 2048; break;
          case OCS_SCSI_DIF_BK_SIZE_4096: blocksize = 4096; break;
          case OCS_SCSI_DIF_BK_SIZE_520:  blocksize = 520; break;
          case OCS_SCSI_DIF_BK_SIZE_4104: blocksize = 4104; break;
          default:
                  break;
          }
  
          return blocksize;
  }
  
  /**
   * @brief Set SCSI API DIF blocksize
   *
   * Given a blocksize value (512, 1024, etc.), set the SCSI API DIF blocksize
   * in the DIF info block
   *
   * @param dif_info Pointer to the SCSI API DIF info block
   * @param blocksize Block size
   *
   * @return returns 0 for success, a negative error code value for failure.
   */
  
  int32_t
  ocs_scsi_dif_set_blocksize(ocs_scsi_dif_info_t *dif_info, uint32_t blocksize)
  {
          int32_t rc = 0;
  
          switch(blocksize) {
          case 512:       dif_info->blk_size = OCS_SCSI_DIF_BK_SIZE_512; break;
          case 1024:      dif_info->blk_size = OCS_SCSI_DIF_BK_SIZE_1024; break;
          case 2048:      dif_info->blk_size = OCS_SCSI_DIF_BK_SIZE_2048; break;
          case 4096:      dif_info->blk_size = OCS_SCSI_DIF_BK_SIZE_4096; break;
          case 520:       dif_info->blk_size = OCS_SCSI_DIF_BK_SIZE_520; break;
          case 4104:      dif_info->blk_size = OCS_SCSI_DIF_BK_SIZE_4104; break;
          default:
                  rc = -1;
                  break;
          }
          return rc;
  
  }
  
  /**
   * @brief Return memory block size given SCSI DIF API
   *
   * The blocksize in memory for the DIF transfer is returned, given the SCSI DIF info
   * block and the direction of transfer.
   *
   * @param dif_info Pointer to DIF info block
   * @param wiretomem Transfer direction, 1 is wire to memory, 0 is memory to wire
   *
   * @return Memory blocksize, or negative error value
   *
   * WARNING: the order of initialization of the adj[] arrays MUST match the declarations
   * of OCS_SCSI_DIF_OPER_*
   */
  
  int32_t
  ocs_scsi_dif_mem_blocksize(ocs_scsi_dif_info_t *dif_info, int wiretomem)
  {
          uint32_t blocksize;
          uint8_t wiretomem_adj[] = {
                  0,              /* OCS_SCSI_DIF_OPER_DISABLED, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CRC, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_SCSI_DIF_OPER_IN_RAW_OUT_RAW, */
          uint8_t memtowire_adj[] = {
                  0,              /* OCS_SCSI_DIF_OPER_DISABLED, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CRC, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_NODIF, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_SCSI_DIF_OPER_IN_RAW_OUT_RAW, */
  
          blocksize = ocs_scsi_dif_blocksize(dif_info);
          if (blocksize == 0) {
                  return -1;
          }
  
          if (wiretomem) {
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(wiretomem_adj), 0);
                  blocksize += wiretomem_adj[dif_info->dif_oper];
          } else {        /* mem to wire */
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(memtowire_adj), 0);
                  blocksize += memtowire_adj[dif_info->dif_oper];
          }
          return blocksize;
  }
  
  /**
   * @brief Return wire block size given SCSI DIF API
   *
   * The blocksize on the wire for the DIF transfer is returned, given the SCSI DIF info
   * block and the direction of transfer.
   *
   * @param dif_info Pointer to DIF info block
   * @param wiretomem Transfer direction, 1 is wire to memory, 0 is memory to wire
   *
   * @return Wire blocksize or negative error value
   *
   * WARNING: the order of initialization of the adj[] arrays MUST match the declarations
   * of OCS_SCSI_DIF_OPER_*
   */
  
  int32_t
  ocs_scsi_dif_wire_blocksize(ocs_scsi_dif_info_t *dif_info, int wiretomem)
  {
          uint32_t blocksize;
          uint8_t wiretomem_adj[] = {
                  0,              /* OCS_SCSI_DIF_OPER_DISABLED, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CRC, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_NODIF, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_SCSI_DIF_OPER_IN_RAW_OUT_RAW, */
          uint8_t memtowire_adj[] = {
                  0,              /* OCS_SCSI_DIF_OPER_DISABLED, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CRC, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  0,              /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_SCSI_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_SCSI_DIF_OPER_IN_RAW_OUT_RAW, */
  
          blocksize = ocs_scsi_dif_blocksize(dif_info);
          if (blocksize == 0) {
                  return -1;
          }
  
          if (wiretomem) {
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(wiretomem_adj), 0);
                  blocksize += wiretomem_adj[dif_info->dif_oper];
          } else {        /* mem to wire */
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(memtowire_adj), 0);
                  blocksize += memtowire_adj[dif_info->dif_oper];
          }
  
          return blocksize;
  }
  /**
   * @brief Return blocksize given HW API DIF block size
   *
   * Given the DIF block size enumerated value, return the block size value. (e.g.
   * OCS_SCSI_DIF_BLK_SIZE_512 returns 512)
   *
   * @param dif_info Pointer to HW API DIF info block
   *
   * @return returns block size, or 0 if HW API DIF blocksize is invalid
   */
  
  uint32_t
  ocs_hw_dif_blocksize(ocs_hw_dif_info_t *dif_info)
  {
          uint32_t blocksize = 0;
  
          switch(dif_info->blk_size) {
          case OCS_HW_DIF_BK_SIZE_512:    blocksize = 512; break;
          case OCS_HW_DIF_BK_SIZE_1024:   blocksize = 1024; break;
          case OCS_HW_DIF_BK_SIZE_2048:   blocksize = 2048; break;
          case OCS_HW_DIF_BK_SIZE_4096:   blocksize = 4096; break;
          case OCS_HW_DIF_BK_SIZE_520:    blocksize = 520; break;
          case OCS_HW_DIF_BK_SIZE_4104:   blocksize = 4104; break;
          default:
                  break;
          }
  
          return blocksize;
  }
  
  /**
   * @brief Return memory block size given HW DIF API
   *
   * The blocksize in memory for the DIF transfer is returned, given the HW DIF info
   * block and the direction of transfer.
   *
   * @param dif_info Pointer to DIF info block
   * @param wiretomem Transfer direction, 1 is wire to memory, 0 is memory to wire
   *
   * @return Memory blocksize, or negative error value
   *
   * WARNING: the order of initialization of the adj[] arrays MUST match the declarations
   * of OCS_HW_DIF_OPER_*
   */
  
  int32_t
  ocs_hw_dif_mem_blocksize(ocs_hw_dif_info_t *dif_info, int wiretomem)
  {
          uint32_t blocksize;
          uint8_t wiretomem_adj[] = {
                  0,              /* OCS_HW_DIF_OPER_DISABLED, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CRC, */
                  0,              /* OCS_HW_DIF_OPER_IN_CRC_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  0,              /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_HW_DIF_OPER_IN_RAW_OUT_RAW, */
          uint8_t memtowire_adj[] = {
                  0,              /* OCS_HW_DIF_OPER_DISABLED, */
                  0,              /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CRC, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_NODIF, */
                  0,              /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_HW_DIF_OPER_IN_RAW_OUT_RAW, */
  
          blocksize = ocs_hw_dif_blocksize(dif_info);
          if (blocksize == 0) {
                  return -1;
          }
  
          if (wiretomem) {
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(wiretomem_adj), 0);
                  blocksize += wiretomem_adj[dif_info->dif_oper];
          } else {        /* mem to wire */
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(memtowire_adj), 0);
                  blocksize += memtowire_adj[dif_info->dif_oper];
          }
          return blocksize;
  }
  
  /**
   * @brief Return wire block size given HW DIF API
   *
   * The blocksize on the wire for the DIF transfer is returned, given the HW DIF info
   * block and the direction of transfer.
   *
   * @param dif_info Pointer to DIF info block
   * @param wiretomem Transfer direction, 1 is wire to memory, 0 is memory to wire
   *
   * @return Wire blocksize or negative error value
   *
   * WARNING: the order of initialization of the adj[] arrays MUST match the declarations
   * of OCS_HW_DIF_OPER_*
   */
  
  int32_t
  ocs_hw_dif_wire_blocksize(ocs_hw_dif_info_t *dif_info, int wiretomem)
  {
          uint32_t blocksize;
          uint8_t wiretomem_adj[] = {
                  0,              /* OCS_HW_DIF_OPER_DISABLED, */
                  0,              /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CRC, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_NODIF, */
                  0,              /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_HW_DIF_OPER_IN_RAW_OUT_RAW, */
          uint8_t memtowire_adj[] = {
                  0,              /* OCS_HW_DIF_OPER_DISABLED, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CRC, */
                  0,              /* OCS_HW_DIF_OPER_IN_CRC_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_NODIF_OUT_CHKSUM, */
                  0,              /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_NODIF, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CRC, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CRC_OUT_CHKSUM, */
                  DIF_SIZE,       /* OCS_HW_DIF_OPER_IN_CHKSUM_OUT_CRC, */
                  DIF_SIZE};      /* OCS_HW_DIF_OPER_IN_RAW_OUT_RAW, */
  
          blocksize = ocs_hw_dif_blocksize(dif_info);
          if (blocksize == 0) {
                  return -1;
          }
  
          if (wiretomem) {
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(wiretomem_adj), 0);
                  blocksize += wiretomem_adj[dif_info->dif_oper];
          } else {        /* mem to wire */
                  ocs_assert(dif_info->dif_oper < ARRAY_SIZE(memtowire_adj), 0);
                  blocksize += memtowire_adj[dif_info->dif_oper];
          }
  
          return blocksize;
  }
  
  static int32_t ocs_segment_remaining(ocs_textbuf_segment_t *segment);
  static ocs_textbuf_segment_t *ocs_textbuf_segment_alloc(ocs_textbuf_t *textbuf);
  static void ocs_textbuf_segment_free(ocs_t *ocs, ocs_textbuf_segment_t *segment);
  static ocs_textbuf_segment_t *ocs_textbuf_get_segment(ocs_textbuf_t *textbuf, uint32_t idx);
  
  uint8_t *
  ocs_textbuf_get_buffer(ocs_textbuf_t *textbuf)
  {
          return ocs_textbuf_ext_get_buffer(textbuf, 0);
  }
  
  int32_t
  ocs_textbuf_get_length(ocs_textbuf_t *textbuf)
  {
          return ocs_textbuf_ext_get_length(textbuf, 0);
  }
  
  int32_t
  ocs_textbuf_get_written(ocs_textbuf_t *textbuf)
  {
          uint32_t idx;
          int32_t n;
          int32_t total = 0;
  
          for (idx = 0; (n = ocs_textbuf_ext_get_written(textbuf, idx)) >= 0; idx++) {
                  total += n;
          }
          return total;
  }
  
  uint8_t *ocs_textbuf_ext_get_buffer(ocs_textbuf_t *textbuf, uint32_t idx)
  {
          ocs_textbuf_segment_t *segment = ocs_textbuf_get_segment(textbuf, idx);
          if (segment == NULL) {
                  return NULL;
          }
          return segment->buffer;
  }
  
  int32_t ocs_textbuf_ext_get_length(ocs_textbuf_t *textbuf, uint32_t idx)
  {
          ocs_textbuf_segment_t *segment = ocs_textbuf_get_segment(textbuf, idx);
          if (segment == NULL) {
                  return -1;
          }
          return segment->buffer_length;
  }
  
  int32_t ocs_textbuf_ext_get_written(ocs_textbuf_t *textbuf, uint32_t idx)
  {
          ocs_textbuf_segment_t *segment = ocs_textbuf_get_segment(textbuf, idx);
          if (segment == NULL) {
                  return -1;
          }
          return segment->buffer_written;
  }
  
  uint32_t
  ocs_textbuf_initialized(ocs_textbuf_t *textbuf)
  {
          return (textbuf->ocs != NULL);
  }
  
  int32_t
  ocs_textbuf_alloc(ocs_t *ocs, ocs_textbuf_t *textbuf, uint32_t length)
  {
          ocs_memset(textbuf, 0, sizeof(*textbuf));
  
          textbuf->ocs = ocs;
          ocs_list_init(&textbuf->segment_list, ocs_textbuf_segment_t, link);
  
          if (length > OCS_TEXTBUF_MAX_ALLOC_LEN) {
                  textbuf->allocation_length = OCS_TEXTBUF_MAX_ALLOC_LEN;
          } else {
                  textbuf->allocation_length = length;
          }
  
          /* mark as extendable */
          textbuf->extendable = TRUE;
  
          /* save maximum allocation length */
          textbuf->max_allocation_length = length;
  
          /* Add first segment */
          return (ocs_textbuf_segment_alloc(textbuf) == NULL) ? -1 : 0;
  }
  
  static ocs_textbuf_segment_t *
  ocs_textbuf_segment_alloc(ocs_textbuf_t *textbuf)
  {
          ocs_textbuf_segment_t *segment = NULL;
  
          if (textbuf->extendable) {
                  segment = ocs_malloc(textbuf->ocs, sizeof(*segment), OCS_M_ZERO | OCS_M_NOWAIT);
                  if (segment != NULL) {
                          segment->buffer = ocs_malloc(textbuf->ocs, textbuf->allocation_length, OCS_M_ZERO | OCS_M_NOWAIT);
                          if (segment->buffer != NULL) {
                                  segment->buffer_length = textbuf->allocation_length;
                                  segment->buffer_written = 0;
                                  ocs_list_add_tail(&textbuf->segment_list, segment);
                                  textbuf->total_allocation_length += textbuf->allocation_length;
  
                                  /* If we've allocated our limit, then mark as not extendable */
                                  if (textbuf->total_allocation_length >= textbuf->max_allocation_length) {
                                          textbuf->extendable = 0;
                                  }
  
                          } else {
                                  ocs_textbuf_segment_free(textbuf->ocs, segment);
                                  segment = NULL;
                          }
                  }
          }
          return segment;
  }
  
  static void
  ocs_textbuf_segment_free(ocs_t *ocs, ocs_textbuf_segment_t *segment)
  {
          if (segment) {
                  if (segment->buffer && !segment->user_allocated) {
                          ocs_free(ocs, segment->buffer, segment->buffer_length);
                  }
                  ocs_free(ocs, segment, sizeof(*segment));
          }
  }
  
  static ocs_textbuf_segment_t *
  ocs_textbuf_get_segment(ocs_textbuf_t *textbuf, uint32_t idx)
  {
          uint32_t i;
          ocs_textbuf_segment_t *segment;
  
          if (ocs_textbuf_initialized(textbuf)) {
                  i = 0;
                  ocs_list_foreach(&textbuf->segment_list, segment) {
                          if (i == idx) {
                                  return segment;
                          }
                          i++;
                  }
          }
          return NULL;
  }
  
  int32_t
  ocs_textbuf_init(ocs_t *ocs, ocs_textbuf_t *textbuf, void *buffer, uint32_t length)
  {
          int32_t rc = -1;
          ocs_textbuf_segment_t *segment;
  
          ocs_memset(textbuf, 0, sizeof(*textbuf));
  
          textbuf->ocs = ocs;
          ocs_list_init(&textbuf->segment_list, ocs_textbuf_segment_t, link);
          segment = ocs_malloc(ocs, sizeof(*segment), OCS_M_ZERO | OCS_M_NOWAIT);
          if (segment) {
                  segment->buffer = buffer;
                  segment->buffer_length = length;
                  segment->buffer_written = 0;
                  segment->user_allocated = 1;
                  ocs_list_add_tail(&textbuf->segment_list, segment);
                  rc = 0;
          }
  
          return rc;
  }
  
  void
  ocs_textbuf_free(ocs_t *ocs, ocs_textbuf_t *textbuf)
  {
          ocs_textbuf_segment_t *segment;
          ocs_textbuf_segment_t *n;
  
          if (ocs_textbuf_initialized(textbuf)) {
                  ocs_list_foreach_safe(&textbuf->segment_list, segment, n) {
                          ocs_list_remove(&textbuf->segment_list, segment);
                          ocs_textbuf_segment_free(ocs, segment);
                  }
  
                  ocs_memset(textbuf, 0, sizeof(*textbuf));
          }
  }
  
  void
  ocs_textbuf_printf(ocs_textbuf_t *textbuf, const char *fmt, ...)
  {
          va_list ap;
  
          if (ocs_textbuf_initialized(textbuf)) {
                  va_start(ap, fmt);
                  ocs_textbuf_vprintf(textbuf, fmt, ap);
                  va_end(ap);
          }
  }
  
  void
  ocs_textbuf_vprintf(ocs_textbuf_t *textbuf, const char *fmt, va_list ap)
  {
          int avail;
          int written;
          ocs_textbuf_segment_t *segment;
          va_list save_ap;
  
          if (!ocs_textbuf_initialized(textbuf)) {
                  return;
          }
  
          va_copy(save_ap, ap);
  
          /* fetch last segment */
          segment = ocs_list_get_tail(&textbuf->segment_list);
  
          avail = ocs_segment_remaining(segment);
          if (avail == 0) {
                  if ((segment = ocs_textbuf_segment_alloc(textbuf)) == NULL) {
                          goto out;
                  }
                  avail = ocs_segment_remaining(segment);
          }
  
          written = ocs_vsnprintf(segment->buffer + segment->buffer_written, avail, fmt, ap);
  
          /* See if data was truncated */
          if (written >= avail) {
                  written = avail;
  
                  if (textbuf->extendable) {
                          /* revert the partially written data */
                          *(segment->buffer + segment->buffer_written) = 0;
  
                          /* Allocate a new segment */
                          if ((segment = ocs_textbuf_segment_alloc(textbuf)) == NULL) {
                                  ocs_log_err(textbuf->ocs, "alloc segment failed\n");
                                  goto out;
                          }
                          avail = ocs_segment_remaining(segment);
  
                          /* Retry the write */
                          written = ocs_vsnprintf(segment->buffer + segment->buffer_written, avail, fmt, save_ap);
                  }
          }
          segment->buffer_written += written;
  
  out:
          va_end(save_ap);
  }
  
  void
  ocs_textbuf_putc(ocs_textbuf_t *textbuf, uint8_t c)
  {
          ocs_textbuf_segment_t *segment;
  
          if (ocs_textbuf_initialized(textbuf)) {
                  segment = ocs_list_get_tail(&textbuf->segment_list);
  
                  if (ocs_segment_remaining(segment)) {
                          *(segment->buffer + segment->buffer_written++) = c;
                  }
                  if (ocs_segment_remaining(segment) == 0) {
                          ocs_textbuf_segment_alloc(textbuf);
                  }
          }
  }
  
  void
  ocs_textbuf_puts(ocs_textbuf_t *textbuf, char *s)
  {
          if (ocs_textbuf_initialized(textbuf)) {
                  while(*s) {
                          ocs_textbuf_putc(textbuf, *s++);
                  }
          }
  }
  
  void
  ocs_textbuf_buffer(ocs_textbuf_t *textbuf, uint8_t *buffer, uint32_t buffer_length)
  {
          char *s;
  
          if (!ocs_textbuf_initialized(textbuf)) {
                  return;
          }
  
          s = (char*) buffer;
          while(*s) {
                  /*
                   * XML escapes
                   *
                   * "   &quot;
                   * '   &apos;
                   * <   &lt;
                   * >   &gt;
                   * &   &amp;
                   */
  
                  switch(*s) {
                  case '"':       ocs_textbuf_puts(textbuf, "&quot;"); break;
                  case '\'':      ocs_textbuf_puts(textbuf, "&apos;"); break;
                  case '<':       ocs_textbuf_puts(textbuf, "&lt;"); break;
                  case '>':       ocs_textbuf_puts(textbuf, "&gt;"); break;
                  case '&':       ocs_textbuf_puts(textbuf, "&amp;"); break;
                  default:        ocs_textbuf_putc(textbuf, *s); break;
                  }
                  s++;
          }
  
  }
  
  void
  ocs_textbuf_copy(ocs_textbuf_t *textbuf, uint8_t *buffer, uint32_t buffer_length)
  {
          char *s;
  
          if (!ocs_textbuf_initialized(textbuf)) {
                  return;
          }
  
          s = (char*) buffer;
          while(*s) {
                  ocs_textbuf_putc(textbuf, *s++);
          }
  
  }
  
  int32_t
  ocs_textbuf_remaining(ocs_textbuf_t *textbuf)
  {
          if (ocs_textbuf_initialized(textbuf)) {
                  return ocs_segment_remaining(ocs_list_get_head(&textbuf->segment_list));
          } else {
                  return 0;
          }
  }
  
  static int32_t
  ocs_segment_remaining(ocs_textbuf_segment_t *segment)
  {
          return segment->buffer_length - segment->buffer_written;
  }
  
  void
  ocs_textbuf_reset(ocs_textbuf_t *textbuf)
  {
          uint32_t i = 0;
          ocs_textbuf_segment_t *segment;
          ocs_textbuf_segment_t *n;
  
          if (ocs_textbuf_initialized(textbuf)) {
                  /* zero written on the first segment, free the rest */
                  ocs_list_foreach_safe(&textbuf->segment_list, segment, n) {
                          if (i++ == 0) {
                                  segment->buffer_written = 0;
                          } else {
                                  ocs_list_remove(&textbuf->segment_list, segment);
                                  ocs_textbuf_segment_free(textbuf->ocs, segment);
                          }
                  }
          }
  }
  
  /**
   * @brief Sparse Vector API.
   *
   * This is a trimmed down sparse vector implementation tuned to the problem of
   * 24-bit FC_IDs. In this case, the 24-bit index value is broken down in three
   * 8-bit values. These values are used to index up to three 256 element arrays.
   * Arrays are allocated, only when needed. @n @n
   * The lookup can complete in constant time (3 indexed array references). @n @n
   * A typical use case would be that the fabric/directory FC_IDs would cause two rows to be
   * allocated, and the fabric assigned remote nodes would cause two rows to be allocated, with
   * the root row always allocated. This gives five rows of 256 x sizeof(void*),
   * resulting in 10k.
   */
  
  /**
   * @ingroup spv
   * @brief Allocate a new sparse vector row.
   *
   * @param os OS handle
   * @param rowcount Count of rows.
   *
   * @par Description
   * A new sparse vector row is allocated.
   *
   * @param rowcount Number of elements in a row.
   *
   * @return Returns the pointer to a row.
   */
  static void
  **spv_new_row(ocs_os_handle_t os, uint32_t rowcount)
  {
          return ocs_malloc(os, sizeof(void*) * rowcount, OCS_M_ZERO | OCS_M_NOWAIT);
  }
  
  /**
   * @ingroup spv
   * @brief Delete row recursively.
   *
   * @par Description
   * This function recursively deletes the rows in this sparse vector
   *
   * @param os OS handle
   * @param a Pointer to the row.
   * @param n Number of elements in the row.
   * @param depth Depth of deleting.
   *
   * @return None.
   */
  static void
  _spv_del(ocs_os_handle_t os, void **a, uint32_t n, uint32_t depth)
  {
          if (a) {
                  if (depth) {
                          uint32_t i;
  
                          for (i = 0; i < n; i ++) {
                                  _spv_del(os, a[i], n, depth-1);
                          }
  
                          ocs_free(os, a, SPV_ROWLEN*sizeof(*a));
                  }
          }
  }
  
  /**
   * @ingroup spv
   * @brief Delete a sparse vector.
   *
   * @par Description
   * The sparse vector is freed.
   *
   * @param spv Pointer to the sparse vector object.
   */
  void
  spv_del(sparse_vector_t spv)
  {
          if (spv) {
                  _spv_del(spv->os, spv->array, SPV_ROWLEN, SPV_DIM);
                  ocs_free(spv->os, spv, sizeof(*spv));
          }
  }
  
  /**
   * @ingroup spv
   * @brief Instantiate a new sparse vector object.
   *
   * @par Description
   * A new sparse vector is allocated.
   *
   * @param os OS handle
   *
   * @return Returns the pointer to the sparse vector, or NULL.
   */
  sparse_vector_t
  spv_new(ocs_os_handle_t os)
  {
          sparse_vector_t spv;
          uint32_t i;
  
          spv = ocs_malloc(os, sizeof(*spv), OCS_M_ZERO | OCS_M_NOWAIT);
          if (!spv) {
                  return NULL;
          }
  
          spv->os = os;
          spv->max_idx = 1;
          for (i = 0; i < SPV_DIM; i ++) {
                  spv->max_idx *= SPV_ROWLEN;
          }
  
          return spv;
  }
  
  /**
   * @ingroup spv
   * @brief Return the address of a cell.
   *
   * @par Description
   * Returns the address of a cell, allocates sparse rows as needed if the
   *         alloc_new_rows parameter is set.
   *
   * @param sv Pointer to the sparse vector.
   * @param idx Index of which to return the address.
   * @param alloc_new_rows If TRUE, then new rows may be allocated to set values,
   *                       Set to FALSE for retrieving values.
   *
   * @return Returns the pointer to the cell, or NULL.
   */
  static void
  *spv_new_cell(sparse_vector_t sv, uint32_t idx, uint8_t alloc_new_rows)
  {
          uint32_t a = (idx >> 16) & 0xff;
          uint32_t b = (idx >>  8) & 0xff;
          uint32_t c = (idx >>  0) & 0xff;
          void **p;
  
          if (idx >= sv->max_idx) {
                  return NULL;
          }
  
          if (sv->array == NULL) {
                  sv->array = (alloc_new_rows ? spv_new_row(sv->os, SPV_ROWLEN) : NULL);
                  if (sv->array == NULL) {
                          return NULL;
                  }
          }
          p = sv->array;
          if (p[a] == NULL) {
                  p[a] = (alloc_new_rows ? spv_new_row(sv->os, SPV_ROWLEN) : NULL);
                  if (p[a] == NULL) {
                          return NULL;
                  }
          }
          p = p[a];
          if (p[b] == NULL) {
                  p[b] = (alloc_new_rows ? spv_new_row(sv->os, SPV_ROWLEN) : NULL);
                  if (p[b] == NULL) {
                          return NULL;
                  }
          }
          p = p[b];
  
          return &p[c];
  }
  
  /**
   * @ingroup spv
   * @brief Set the sparse vector cell value.
   *
   * @par Description
   * Sets the sparse vector at @c idx to @c value.
   *
   * @param sv Pointer to the sparse vector.
   * @param idx Index of which to store.
   * @param value Value to store.
   *
   * @return None.
   */
  void
  spv_set(sparse_vector_t sv, uint32_t idx, void *value)
  {
          void **ref = spv_new_cell(sv, idx, TRUE);
          if (ref) {
                  *ref = value;
          }
  }
  
  /**
   * @ingroup spv
   * @brief Return the sparse vector cell value.
   *
   * @par Description
   * Returns the value at @c idx.
   *
   * @param sv Pointer to the sparse vector.
   * @param idx Index of which to return the value.
   *
   * @return Returns the cell value, or NULL.
   */
  void
  *spv_get(sparse_vector_t sv, uint32_t idx)
  {
          void **ref = spv_new_cell(sv, idx, FALSE);
          if (ref) {
                  return *ref;
          }
          return NULL;
  }
  
  /*****************************************************************/
  /*                                                               */
  /* CRC LOOKUP TABLE                                              */
  /* ================                                              */
  /* The following CRC lookup table was generated automagically    */
  /* by the Rocksoft^tm Model CRC Algorithm Table Generation       */
  /* Program V1.0 using the following model parameters:            */
  /*                                                               */
  /*    Width   : 2 bytes.                                         */
  /*    Poly    : 0x8BB7                                           */
  /*    Reverse : FALSE.                                           */
  /*                                                               */
  /* For more information on the Rocksoft^tm Model CRC Algorithm,  */
  /* see the document titled "A Painless Guide to CRC Error        */
  /* Detection Algorithms" by Ross Williams                        */
  /* (ross@guest.adelaide.edu.au.). This document is likely to be  */
  /* in the FTP archive "ftp.adelaide.edu.au/pub/rocksoft".        */
  /*                                                               */
  /*****************************************************************/
  /*
   * Emulex Inc, changes:
   * - minor syntax changes for successful compilation with contemporary
   *   C compilers, and OCS SDK API
   * - crctable[] generated using Rocksoft public domain code
   *
   * Used in the Emulex SDK, the generated file crctable.out is cut and pasted into
   * applicable SDK sources.
   */
  
  static unsigned short crctable[256] =
  {
   0x0000, 0x8BB7, 0x9CD9, 0x176E, 0xB205, 0x39B2, 0x2EDC, 0xA56B,
   0xEFBD, 0x640A, 0x7364, 0xF8D3, 0x5DB8, 0xD60F, 0xC161, 0x4AD6,
   0x54CD, 0xDF7A, 0xC814, 0x43A3, 0xE6C8, 0x6D7F, 0x7A11, 0xF1A6,
   0xBB70, 0x30C7, 0x27A9, 0xAC1E, 0x0975, 0x82C2, 0x95AC, 0x1E1B,
   0xA99A, 0x222D, 0x3543, 0xBEF4, 0x1B9F, 0x9028, 0x8746, 0x0CF1,
   0x4627, 0xCD90, 0xDAFE, 0x5149, 0xF422, 0x7F95, 0x68FB, 0xE34C,
   0xFD57, 0x76E0, 0x618E, 0xEA39, 0x4F52, 0xC4E5, 0xD38B, 0x583C,
   0x12EA, 0x995D, 0x8E33, 0x0584, 0xA0EF, 0x2B58, 0x3C36, 0xB781,
   0xD883, 0x5334, 0x445A, 0xCFED, 0x6A86, 0xE131, 0xF65F, 0x7DE8,
   0x373E, 0xBC89, 0xABE7, 0x2050, 0x853B, 0x0E8C, 0x19E2, 0x9255,
   0x8C4E, 0x07F9, 0x1097, 0x9B20, 0x3E4B, 0xB5FC, 0xA292, 0x2925,
   0x63F3, 0xE844, 0xFF2A, 0x749D, 0xD1F6, 0x5A41, 0x4D2F, 0xC698,
   0x7119, 0xFAAE, 0xEDC0, 0x6677, 0xC31C, 0x48AB, 0x5FC5, 0xD472,
   0x9EA4, 0x1513, 0x027D, 0x89CA, 0x2CA1, 0xA716, 0xB078, 0x3BCF,
   0x25D4, 0xAE63, 0xB90D, 0x32BA, 0x97D1, 0x1C66, 0x0B08, 0x80BF,
   0xCA69, 0x41DE, 0x56B0, 0xDD07, 0x786C, 0xF3DB, 0xE4B5, 0x6F02,
   0x3AB1, 0xB106, 0xA668, 0x2DDF, 0x88B4, 0x0303, 0x146D, 0x9FDA,
   0xD50C, 0x5EBB, 0x49D5, 0xC262, 0x6709, 0xECBE, 0xFBD0, 0x7067,
   0x6E7C, 0xE5CB, 0xF2A5, 0x7912, 0xDC79, 0x57CE, 0x40A0, 0xCB17,
   0x81C1, 0x0A76, 0x1D18, 0x96AF, 0x33C4, 0xB873, 0xAF1D, 0x24AA,
   0x932B, 0x189C, 0x0FF2, 0x8445, 0x212E, 0xAA99, 0xBDF7, 0x3640,
   0x7C96, 0xF721, 0xE04F, 0x6BF8, 0xCE93, 0x4524, 0x524A, 0xD9FD,
   0xC7E6, 0x4C51, 0x5B3F, 0xD088, 0x75E3, 0xFE54, 0xE93A, 0x628D,
   0x285B, 0xA3EC, 0xB482, 0x3F35, 0x9A5E, 0x11E9, 0x0687, 0x8D30,
   0xE232, 0x6985, 0x7EEB, 0xF55C, 0x5037, 0xDB80, 0xCCEE, 0x4759,
   0x0D8F, 0x8638, 0x9156, 0x1AE1, 0xBF8A, 0x343D, 0x2353, 0xA8E4,
   0xB6FF, 0x3D48, 0x2A26, 0xA191, 0x04FA, 0x8F4D, 0x9823, 0x1394,
   0x5942, 0xD2F5, 0xC59B, 0x4E2C, 0xEB47, 0x60F0, 0x779E, 0xFC29,
   0x4BA8, 0xC01F, 0xD771, 0x5CC6, 0xF9AD, 0x721A, 0x6574, 0xEEC3,
   0xA415, 0x2FA2, 0x38CC, 0xB37B, 0x1610, 0x9DA7, 0x8AC9, 0x017E,
   0x1F65, 0x94D2, 0x83BC, 0x080B, 0xAD60, 0x26D7, 0x31B9, 0xBA0E,
   0xF0D8, 0x7B6F, 0x6C01, 0xE7B6, 0x42DD, 0xC96A, 0xDE04, 0x55B3
  };
  
  /*****************************************************************/
  /*                   End of CRC Lookup Table                     */
  /*****************************************************************/
  
  /**
   * @brief Calculate the T10 PI CRC guard value for a block.
   *
   * Code based on Rocksoft's public domain CRC code, refer to
   * http://www.ross.net/crc/download/crc_v3.txt.  Minimally altered
   * to work with the ocs_dif API.
   *
   * @param blk_adr Pointer to the data buffer.
   * @param blk_len Number of bytes.
   * @param crc Previously-calculated CRC, or crcseed for a new block.
   *
   * @return Returns the calculated CRC, which may be passed back in for partial blocks.
   *
   */
  
  unsigned short
  t10crc16(const unsigned char *blk_adr, unsigned long blk_len, unsigned short crc)
  {
          if (blk_len > 0) {
                  while (blk_len--) {
                          crc = crctable[((crc>>8) ^ *blk_adr++) & 0xFFL] ^ (crc << 8);
                  }
          }
          return crc;
  }
  
  struct ocs_ramlog_s {
          uint32_t initialized;
          uint32_t textbuf_count;
          uint32_t textbuf_base;
          ocs_textbuf_t *textbufs;
          uint32_t cur_textbuf_idx;
          ocs_textbuf_t *cur_textbuf;
          ocs_lock_t lock;
  };
  
  static uint32_t ocs_ramlog_next_idx(ocs_ramlog_t *ramlog, uint32_t idx);
  
  /**
   * @brief Allocate a ramlog buffer.
   *
   * Initialize a RAM logging buffer with text buffers totalling buffer_len.
   *
   * @param ocs Pointer to driver structure.
   * @param buffer_len Total length of RAM log buffers.
   * @param buffer_count Number of text buffers to allocate (totalling buffer-len).
   *
   * @return Returns pointer to ocs_ramlog_t instance, or NULL.
   */
  ocs_ramlog_t *
  ocs_ramlog_init(ocs_t *ocs, uint32_t buffer_len, uint32_t buffer_count)
  {
          uint32_t i;
          uint32_t rc;
          ocs_ramlog_t *ramlog;
  
          ramlog = ocs_malloc(ocs, sizeof(*ramlog), OCS_M_ZERO | OCS_M_NOWAIT);
          if (ramlog == NULL) {
                  ocs_log_err(ocs, "ocs_malloc ramlog failed\n");
                  return NULL;
          }
  
          ramlog->textbuf_count = buffer_count;
  
          ramlog->textbufs = ocs_malloc(ocs, sizeof(*ramlog->textbufs)*buffer_count, OCS_M_ZERO | OCS_M_NOWAIT);
          if (ramlog->textbufs == NULL) {
                  ocs_log_err(ocs, "ocs_malloc textbufs failed\n");
                  ocs_ramlog_free(ocs, ramlog);
                  return NULL;
          }
  
          for (i = 0; i < buffer_count; i ++) {
                  rc = ocs_textbuf_alloc(ocs, &ramlog->textbufs[i], buffer_len);
                  if (rc) {
                          ocs_log_err(ocs, "ocs_textbuf_alloc failed\n");
                          ocs_ramlog_free(ocs, ramlog);
                          return NULL;
                  }
          }
  
          ramlog->cur_textbuf_idx = 0;
          ramlog->textbuf_base = 1;
          ramlog->cur_textbuf = &ramlog->textbufs[0];
          ramlog->initialized = TRUE;
          ocs_lock_init(ocs, &ramlog->lock, "ramlog_lock[%d]", ocs_instance(ocs));
          return ramlog;
  }
  
  /**
   * @brief Free a ramlog buffer.
   *
   * A previously allocated RAM logging buffer is freed.
   *
   * @param ocs Pointer to driver structure.
   * @param ramlog Pointer to RAM logging buffer structure.
   *
   * @return None.
   */
  
  void
  ocs_ramlog_free(ocs_t *ocs, ocs_ramlog_t *ramlog)
  {
          uint32_t i;
  
          if (ramlog != NULL) {
                  ocs_lock_free(&ramlog->lock);
                  if (ramlog->textbufs) {
                          for (i = 0; i < ramlog->textbuf_count; i ++) {
                                  ocs_textbuf_free(ocs, &ramlog->textbufs[i]);
                          }
  
                          ocs_free(ocs, ramlog->textbufs, ramlog->textbuf_count*sizeof(*ramlog->textbufs));
                          ramlog->textbufs = NULL;
                  }
                  ocs_free(ocs, ramlog, sizeof(*ramlog));
          }
  }
  
  /**
   * @brief Clear a ramlog buffer.
   *
   * The text in the start of day and/or recent ramlog text buffers is cleared.
   *
   * @param ocs Pointer to driver structure.
   * @param ramlog Pointer to RAM logging buffer structure.
   * @param clear_start_of_day Clear the start of day (driver init) portion of the ramlog.
   * @param clear_recent Clear the recent messages portion of the ramlog.
   *
   * @return None.
   */
  
  void
  ocs_ramlog_clear(ocs_t *ocs, ocs_ramlog_t *ramlog, int clear_start_of_day, int clear_recent)
  {
          uint32_t i;
  
          if (clear_recent) {
                  for (i = ramlog->textbuf_base; i < ramlog->textbuf_count; i ++) {
                          ocs_textbuf_reset(&ramlog->textbufs[i]);
                  }
                  ramlog->cur_textbuf_idx = 1;
          }
          if (clear_start_of_day && ramlog->textbuf_base) {
                  ocs_textbuf_reset(&ramlog->textbufs[0]);
                  /* Set textbuf_base to 0, so that all buffers are available for
                   * recent logs
                   */
                  ramlog->textbuf_base = 0;
          }
  }
  
  /**
   * @brief Append formatted printf data to a ramlog buffer.
   *
   * Formatted data is appended to a RAM logging buffer.
   *
   * @param os Pointer to driver structure.
   * @param fmt Pointer to printf style format specifier.
   *
   * @return Returns 0 on success, or a negative error code value on failure.
   */
  
  int32_t
  ocs_ramlog_printf(void *os, const char *fmt, ...)
  {
          ocs_t *ocs = os;
          va_list ap;
          int32_t res;
  
          if (ocs == NULL || ocs->ramlog == NULL) {
                  return -1;
          }
  
          va_start(ap, fmt);
          res = ocs_ramlog_vprintf(ocs->ramlog, fmt, ap);
          va_end(ap);
  
          return res;
  }
  
  /**
   * @brief Append formatted text to a ramlog using variable arguments.
   *
   * Formatted data is appended to the RAM logging buffer, using variable arguments.
   *
   * @param ramlog Pointer to RAM logging buffer.
   * @param fmt Pointer to printf style formatting string.
   * @param ap Variable argument pointer.
   *
   * @return Returns 0 on success, or a negative error code value on failure.
   */
  
  int32_t
  ocs_ramlog_vprintf(ocs_ramlog_t *ramlog, const char *fmt, va_list ap)
  {
          if (ramlog == NULL || !ramlog->initialized) {
                  return -1;
          }
  
          /* check the current text buffer, if it is almost full (less than 120 characaters), then
           * roll to the next one.
           */
          ocs_lock(&ramlog->lock);
          if (ocs_textbuf_remaining(ramlog->cur_textbuf) < 120) {
                  ramlog->cur_textbuf_idx = ocs_ramlog_next_idx(ramlog, ramlog->cur_textbuf_idx);
                  ramlog->cur_textbuf = &ramlog->textbufs[ramlog->cur_textbuf_idx];
                  ocs_textbuf_reset(ramlog->cur_textbuf);
          }
  
          ocs_textbuf_vprintf(ramlog->cur_textbuf, fmt, ap);
          ocs_unlock(&ramlog->lock);
  
          return 0;
  }
  
  /**
   * @brief Return next ramlog buffer index.
   *
   * Given a RAM logging buffer index, return the next index.
   *
   * @param ramlog Pointer to RAM logging buffer.
   * @param idx Index value.
   *
   * @return Returns next index value.
   */
  
  static uint32_t
  ocs_ramlog_next_idx(ocs_ramlog_t *ramlog, uint32_t idx)
  {
          idx = idx + 1;
  
          if (idx >= ramlog->textbuf_count) {
                  idx = ramlog->textbuf_base;
          }
  
          return idx;
  }
  
  /**
   * @brief Perform ramlog buffer driver dump.
   *
   * The RAM logging buffer is appended to the driver dump data.
   *
   * @param textbuf Pointer to the driver dump text buffer.
   * @param ramlog Pointer to the RAM logging buffer.
   *
   * @return Returns 0 on success, or a negative error code value on failure.
   */
  
  int32_t
  ocs_ddump_ramlog(ocs_textbuf_t *textbuf, ocs_ramlog_t *ramlog)
  {
          uint32_t i;
          ocs_textbuf_t *rltextbuf;
          int idx;
  
          if ((ramlog == NULL) || (ramlog->textbufs == NULL)) {
                  return -1;
          }
  
          ocs_ddump_section(textbuf, "driver-log", 0);
  
          /* Dump the start of day buffer */
          ocs_ddump_section(textbuf, "startofday", 0);
          /* If textbuf_base is 0, then all buffers are used for recent */
          if (ramlog->textbuf_base) {
                  rltextbuf = &ramlog->textbufs[0];
                  ocs_textbuf_buffer(textbuf, ocs_textbuf_get_buffer(rltextbuf), ocs_textbuf_get_written(rltextbuf));
          }
          ocs_ddump_endsection(textbuf, "startofday", 0);
  
          /* Dump the most recent buffers */
          ocs_ddump_section(textbuf, "recent", 0);
  
          /* start with the next textbuf */
          idx = ocs_ramlog_next_idx(ramlog, ramlog->textbuf_count);
  
          for (i = ramlog->textbuf_base; i < ramlog->textbuf_count; i ++) {
                  rltextbuf = &ramlog->textbufs[idx];
                  ocs_textbuf_buffer(textbuf, ocs_textbuf_get_buffer(rltextbuf), ocs_textbuf_get_written(rltextbuf));
                  idx = ocs_ramlog_next_idx(ramlog, idx);
          }
          ocs_ddump_endsection(textbuf, "recent", 0);
          ocs_ddump_endsection(textbuf, "driver-log", 0);
  
          return 0;
  }
  
  struct ocs_pool_s {
          ocs_os_handle_t os;
          ocs_array_t *a;
          ocs_list_t freelist;
          uint32_t use_lock:1;
          ocs_lock_t lock;
  };
  
  typedef struct {
          ocs_list_link_t link;
  } pool_hdr_t;
  
  /**
   * @brief Allocate a memory pool.
   *
   * A memory pool of given size and item count is allocated.
   *
   * @param os OS handle.
   * @param size Size in bytes of item.
   * @param count Number of items in a memory pool.
   * @param use_lock TRUE to enable locking of pool.
   *
   * @return Returns pointer to allocated memory pool, or NULL.
   */
  ocs_pool_t *
  ocs_pool_alloc(ocs_os_handle_t os, uint32_t size, uint32_t count, uint32_t use_lock)
  {
          ocs_pool_t *pool;
          uint32_t i;
  
          pool = ocs_malloc(os, sizeof(*pool), OCS_M_ZERO | OCS_M_NOWAIT);
          if (pool == NULL) {
                  return NULL;
          }
  
          pool->os = os;
          pool->use_lock = use_lock;
  
          /* Allocate an array where each array item is the size of a pool_hdr_t plus
           * the requested memory item size (size)
           */
          pool->a = ocs_array_alloc(os, size + sizeof(pool_hdr_t), count);
          if (pool->a == NULL) {
                  ocs_pool_free(pool);
                  return NULL;
          }
  
          ocs_list_init(&pool->freelist, pool_hdr_t, link);
          for (i = 0; i < count; i++) {
                  ocs_list_add_tail(&pool->freelist, ocs_array_get(pool->a, i));
          }
  
          if (pool->use_lock) {
                  ocs_lock_init(os, &pool->lock, "ocs_pool:%p", pool);
          }
  
          return pool;
  }
  
  /**
   * @brief Reset a memory pool.
   *
   * Place all pool elements on the free list, and zero them.
   *
   * @param pool Pointer to the pool object.
   *
   * @return None.
   */
  void
  ocs_pool_reset(ocs_pool_t *pool)
  {
          uint32_t i;
          uint32_t count = ocs_array_get_count(pool->a);
          uint32_t size = ocs_array_get_size(pool->a);
  
          if (pool->use_lock) {
                  ocs_lock(&pool->lock);
          }
  
          /*
           * Remove all the entries from the free list, otherwise we will
           * encountered linked list asserts when they are re-added.
           */
          while (!ocs_list_empty(&pool->freelist)) {
                  ocs_list_remove_head(&pool->freelist);
          }
  
          /* Reset the free list */
          ocs_list_init(&pool->freelist, pool_hdr_t, link);
  
          /* Return all elements to the free list and zero the elements */
          for (i = 0; i < count; i++) {
                  ocs_memset(ocs_pool_get_instance(pool, i), 0, size - sizeof(pool_hdr_t));
                  ocs_list_add_tail(&pool->freelist, ocs_array_get(pool->a, i));
          }
          if (pool->use_lock) {
                  ocs_unlock(&pool->lock);
          }
  
  }
  
  /**
   * @brief Free a previously allocated memory pool.
   *
   * The memory pool is freed.
   *
   * @param pool Pointer to memory pool.
   *
   * @return None.
   */
  void
  ocs_pool_free(ocs_pool_t *pool)
  {
          if (pool != NULL) {
                  if (pool->a != NULL) {
                          ocs_array_free(pool->a);
                  }
                  if (pool->use_lock) {
                          ocs_lock_free(&pool->lock);
                  }
                  ocs_free(pool->os, pool, sizeof(*pool));
          }
  }
  
  /**
   * @brief Allocate a memory pool item
   *
   * A memory pool item is taken from the free list and returned.
   *
   * @param pool Pointer to memory pool.
   *
   * @return Pointer to allocated item, otherwise NULL if there are no unallocated
   *         items.
   */
  void *
  ocs_pool_get(ocs_pool_t *pool)
  {
          pool_hdr_t *h;
          void *item = NULL;
  
          if (pool->use_lock) {
                  ocs_lock(&pool->lock);
          }
  
          h = ocs_list_remove_head(&pool->freelist);
  
          if (h != NULL) {
                  /* Return the array item address offset by the size of pool_hdr_t */
                  item = &h[1];
          }
  
          if (pool->use_lock) {
                  ocs_unlock(&pool->lock);
          }
          return item;
  }
  
  /**
   * @brief free memory pool item
   *
   * A memory pool item is freed.
   *
   * @param pool Pointer to memory pool.
   * @param item Pointer to item to free.
   *
   * @return None.
   */
  void
  ocs_pool_put(ocs_pool_t *pool, void *item)
  {
          pool_hdr_t *h;
  
          if (pool->use_lock) {
                  ocs_lock(&pool->lock);
          }
  
          /* Fetch the address of the array item, which is the item address negatively offset
           * by size of pool_hdr_t (note the index of [-1]
           */
          h = &((pool_hdr_t*)item)[-1];
  
          ocs_list_add_tail(&pool->freelist, h);
  
          if (pool->use_lock) {
                  ocs_unlock(&pool->lock);
          }
  
  }
  
  /**
   * @brief Return memory pool item count.
   *
   * Returns the allocated number of items.
   *
   * @param pool Pointer to memory pool.
   *
   * @return Returns count of allocated items.
   */
  uint32_t
  ocs_pool_get_count(ocs_pool_t *pool)
  {
          uint32_t count;
          if (pool->use_lock) {
                  ocs_lock(&pool->lock);
          }
          count = ocs_array_get_count(pool->a);
          if (pool->use_lock) {
                  ocs_unlock(&pool->lock);
          }
          return count;
  }
  
  /**
   * @brief Return item given an index.
   *
   * A pointer to a memory pool item is returned given an index.
   *
   * @param pool Pointer to memory pool.
   * @param idx Index.
   *
   * @return Returns pointer to item, or NULL if index is invalid.
   */
  void *
  ocs_pool_get_instance(ocs_pool_t *pool, uint32_t idx)
  {
          pool_hdr_t *h = ocs_array_get(pool->a, idx);
  
          if (h == NULL) {
                  return NULL;
          }
          return &h[1];
  }
  
  /**
   * @brief Return count of free objects in a pool.
   *
   * The number of objects on a pool's free list.
   *
   * @param pool Pointer to memory pool.
   *
   * @return Returns count of objects on free list.
   */
  uint32_t
  ocs_pool_get_freelist_count(ocs_pool_t *pool)
  {
          uint32_t count = 0;
          void *item;
  
          if (pool->use_lock) {
                  ocs_lock(&pool->lock);
          }
  
          ocs_list_foreach(&pool->freelist, item) {
                  count++;
          }
  
          if (pool->use_lock) {
                  ocs_unlock(&pool->lock);
          }
          return count;
  }

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