FreeBSD/Linux Kernel Cross Reference
sys/powerpc/powerpc/busdma_machdep.c

     /*-
      * Copyright (c) 2002 Peter Grehan
      * Copyright (c) 1997, 1998 Justin T. Gibbs.
      * All rights reserved.
      *
      * 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,
     *    without modification, immediately at the beginning of the file.
     * 2. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
     *
     *   From i386/busdma_machdep.c,v 1.26 2002/04/19 22:58:09 alfred
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD: releng/8.0/sys/powerpc/powerpc/busdma_machdep.c 192533 2009-05-21 12:05:15Z raj $");
    
    /*
     * Bus dma support routines
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/bus.h>
    #include <sys/interrupt.h>
    #include <sys/lock.h>
    #include <sys/proc.h>
    #include <sys/mutex.h>
    #include <sys/mbuf.h>
    #include <sys/uio.h>
    
    #include <vm/vm.h>
    #include <vm/vm_page.h>
    #include <vm/vm_map.h>
    
    #include <machine/atomic.h>
    #include <machine/bus.h>
    #include <machine/cpufunc.h>
    
    struct bus_dma_tag {
            bus_dma_tag_t     parent;
            bus_size_t        alignment;
            bus_size_t        boundary;
            bus_addr_t        lowaddr;
            bus_addr_t        highaddr;
            bus_dma_filter_t *filter;
            void             *filterarg;
            bus_size_t        maxsize;
            u_int             nsegments;
            bus_size_t        maxsegsz;
            int               flags;
            int               ref_count;
            int               map_count;
            bus_dma_lock_t   *lockfunc;
            void             *lockfuncarg;
    };
    
    struct bus_dmamap {
            bus_dma_tag_t          dmat;
            void                  *buf;             /* unmapped buffer pointer */
            bus_size_t             buflen;          /* unmapped buffer length */
            bus_dmamap_callback_t *callback;
            void                  *callback_arg;
    };
    
    /*
     * Convenience function for manipulating driver locks from busdma (during
     * busdma_swi, for example).  Drivers that don't provide their own locks
     * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
     * non-mutex locking scheme don't have to use this at all.
     */
    void
    busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
    {
            struct mtx *dmtx;
    
            dmtx = (struct mtx *)arg;
            switch (op) {
            case BUS_DMA_LOCK:
                    mtx_lock(dmtx);
                    break;
            case BUS_DMA_UNLOCK:
                    mtx_unlock(dmtx);
                   break;
           default:
                   panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
           }
   }
   
   /*
    * dflt_lock should never get called.  It gets put into the dma tag when
    * lockfunc == NULL, which is only valid if the maps that are associated
    * with the tag are meant to never be defered.
    * XXX Should have a way to identify which driver is responsible here.
    */
   static void
   dflt_lock(void *arg, bus_dma_lock_op_t op)
   {
   #ifdef INVARIANTS
           panic("driver error: busdma dflt_lock called");
   #else
           printf("DRIVER_ERROR: busdma dflt_lock called\n");
   #endif
   }
   
   /*
    * Allocate a device specific dma_tag.
    */
   int
   bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
       bus_size_t boundary, bus_addr_t lowaddr, bus_addr_t highaddr,
       bus_dma_filter_t *filter, void *filterarg, bus_size_t maxsize,
       int nsegments, bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
       void *lockfuncarg, bus_dma_tag_t *dmat)
   {
           bus_dma_tag_t newtag;
           int error = 0;
   
           /* Return a NULL tag on failure */
           *dmat = NULL;
   
           newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
           if (newtag == NULL)
                   return (ENOMEM);
   
           newtag->parent = parent;
           newtag->alignment = alignment;
           newtag->boundary = boundary;
           newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
           newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
           newtag->filter = filter;
           newtag->filterarg = filterarg;
           newtag->maxsize = maxsize;
           newtag->nsegments = nsegments;
           newtag->maxsegsz = maxsegsz;
           newtag->flags = flags;
           newtag->ref_count = 1; /* Count ourself */
           newtag->map_count = 0;
           if (lockfunc != NULL) {
                   newtag->lockfunc = lockfunc;
                   newtag->lockfuncarg = lockfuncarg;
           } else {
                   newtag->lockfunc = dflt_lock;
                   newtag->lockfuncarg = NULL;
           }
   
           /*
            * Take into account any restrictions imposed by our parent tag
            */
           if (parent != NULL) {
                   newtag->lowaddr = min(parent->lowaddr, newtag->lowaddr);
                   newtag->highaddr = max(parent->highaddr, newtag->highaddr);
                   if (newtag->boundary == 0)
                           newtag->boundary = parent->boundary;
                   else if (parent->boundary != 0)
                           newtag->boundary = MIN(parent->boundary,
                                                  newtag->boundary);
                   if (newtag->filter == NULL) {
                           /*
                            * Short circuit looking at our parent directly
                            * since we have encapsulated all of its information
                            */
                           newtag->filter = parent->filter;
                           newtag->filterarg = parent->filterarg;
                           newtag->parent = parent->parent;
                   }
                   if (newtag->parent != NULL)
                           atomic_add_int(&parent->ref_count, 1);
           }
   
           *dmat = newtag;
           return (error);
   }
   
   int
   bus_dma_tag_destroy(bus_dma_tag_t dmat)
   {
           if (dmat != NULL) {
                   
                   if (dmat->map_count != 0)
                           return (EBUSY);
                   
                   while (dmat != NULL) {
                           bus_dma_tag_t parent;
                           
                           parent = dmat->parent;
                           atomic_subtract_int(&dmat->ref_count, 1);
                           if (dmat->ref_count == 0) {
                                   free(dmat, M_DEVBUF);
                                   /*
                                    * Last reference count, so
                                    * release our reference
                                    * count on our parent.
                                    */
                                   dmat = parent;
                           } else
                                   dmat = NULL;
                   }
           }
           return (0);
   }
   
   /*
    * Allocate a handle for mapping from kva/uva/physical
    * address space into bus device space.
    */
   int
   bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
   {
           *mapp = NULL;
           dmat->map_count++;
   
           return (0);
   }
   
   /*
    * Destroy a handle for mapping from kva/uva/physical
    * address space into bus device space.
    */
   int
   bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
   {
           if (map != NULL) {
                   panic("dmamap_destroy: NULL?\n");
           }
           dmat->map_count--;
           return (0);
   }
   
   /*
    * Allocate a piece of memory that can be efficiently mapped into
    * bus device space based on the constraints lited in the dma tag.
    * A dmamap to for use with dmamap_load is also allocated.
    */
   int
   bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
       bus_dmamap_t *mapp)
   {
           int mflags;
   
           if (flags & BUS_DMA_NOWAIT)
                   mflags = M_NOWAIT;
           else
                   mflags = M_WAITOK;
           if (flags & BUS_DMA_ZERO)
                   mflags |= M_ZERO;
   
           *mapp = NULL;
   
           /* 
            * XXX:
            * (dmat->alignment < dmat->maxsize) is just a quick hack; the exact
            * alignment guarantees of malloc need to be nailed down, and the
            * code below should be rewritten to take that into account.
            *
            * In the meantime, we'll return an error if malloc gets it wrong.
            */
           if (dmat->maxsize <= PAGE_SIZE &&
               dmat->alignment < dmat->maxsize) {
                   *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
           } else {
                   /*
                    * XXX Use Contigmalloc until it is merged into this facility
                    *     and handles multi-seg allocations.  Nobody is doing
                    *     multi-seg allocations yet though.
                    */
                   *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
                       0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
                       dmat->boundary);
           }
   
           if (*vaddr == NULL)
                   return (ENOMEM);
   
           if ((uintptr_t)*vaddr % dmat->alignment)
                   printf("XXX: %s: alignment not respected!\n", __func__);
   
           return (0);
   }
   
   /*
    * Free a piece of memory and it's allocated dmamap, that was allocated
    * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
    */
   void
   bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
   {
           if (map != NULL)
                   panic("bus_dmamem_free: Invalid map freed\n");
           if (dmat->maxsize <= PAGE_SIZE &&
               dmat->alignment < dmat->maxsize)
                   free(vaddr, M_DEVBUF);
           else
                   contigfree(vaddr, dmat->maxsize, M_DEVBUF);
   }
   
   /*
    * Utility function to load a linear buffer.  lastaddrp holds state
    * between invocations (for multiple-buffer loads).  segp contains
    * the starting segment on entrance, and the ending segment on exit.
    * first indicates if this is the first invocation of this function.
    */
   static int
   bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t segs[],
       void *buf, bus_size_t buflen, struct thread *td, int flags,
       vm_offset_t *lastaddrp, int *segp, int first)
   {
           bus_size_t sgsize;
           bus_addr_t curaddr, lastaddr, baddr, bmask;
           vm_offset_t vaddr = (vm_offset_t)buf;
           int seg;
           pmap_t pmap;
   
           if (td != NULL)
                   pmap = vmspace_pmap(td->td_proc->p_vmspace);
           else
                   pmap = NULL;
   
           lastaddr = *lastaddrp;
           bmask = ~(dmat->boundary - 1);
   
           for (seg = *segp; buflen > 0 ; ) {
                   /*
                    * Get the physical address for this segment.
                    */
                   if (pmap)
                           curaddr = pmap_extract(pmap, vaddr);
                   else
                           curaddr = pmap_kextract(vaddr);
   
                   /*
                    * Compute the segment size, and adjust counts.
                    */
                   sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
                   if (sgsize > dmat->maxsegsz)
                           sgsize = dmat->maxsegsz;
                   if (buflen < sgsize)
                           sgsize = buflen;
   
                   /*
                    * Make sure we don't cross any boundaries.
                    */
                   if (dmat->boundary > 0) {
                           baddr = (curaddr + dmat->boundary) & bmask;
                           if (sgsize > (baddr - curaddr))
                                   sgsize = (baddr - curaddr);
                   }
   
                   /*
                    * Insert chunk into a segment, coalescing with
                    * the previous segment if possible.
                    */
                   if (first) {
                           segs[seg].ds_addr = curaddr;
                           segs[seg].ds_len = sgsize;
                           first = 0;
                   } else {
                           if (curaddr == lastaddr &&
                               (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
                               (dmat->boundary == 0 ||
                                (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
                                   segs[seg].ds_len += sgsize;
                           else {
                                   if (++seg >= dmat->nsegments)
                                           break;
                                   segs[seg].ds_addr = curaddr;
                                   segs[seg].ds_len = sgsize;
                           }
                   }
   
                   lastaddr = curaddr + sgsize;
                   vaddr += sgsize;
                   buflen -= sgsize;
           }
   
           *segp = seg;
           *lastaddrp = lastaddr;
   
           /*
            * Did we fit?
            */
           return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
   }
   
   /*
    * Map the buffer buf into bus space using the dmamap map.
    */
   int
   bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
       bus_size_t buflen, bus_dmamap_callback_t *callback,
       void *callback_arg, int flags)
   {
   #ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
           bus_dma_segment_t       dm_segments[dmat->nsegments];
   #else
           bus_dma_segment_t       dm_segments[BUS_DMAMAP_NSEGS];
   #endif
           vm_offset_t             lastaddr;
           int                     error, nsegs;
   
           if (map != NULL)
                   panic("bus_dmamap_load: Invalid map\n");
   
           lastaddr = (vm_offset_t)0;
           nsegs = 0;      
           error = bus_dmamap_load_buffer(dmat, dm_segments, buf, buflen,
               NULL, flags, &lastaddr, &nsegs, 1);
   
           if (error == 0)
                   (*callback)(callback_arg, dm_segments, nsegs + 1, 0);
           else
                   (*callback)(callback_arg, NULL, 0, error);
   
           return (0);
   }
   
   /*
    * Like bus_dmamap_load(), but for mbufs.
    */
   int
   bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
       bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
   {
   #ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
           bus_dma_segment_t dm_segments[dmat->nsegments];
   #else
           bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
   #endif
           int nsegs = 0, error = 0;
   
           M_ASSERTPKTHDR(m0);
   
           if (m0->m_pkthdr.len <= dmat->maxsize) {
                   int first = 1;
                   vm_offset_t lastaddr = 0;
                   struct mbuf *m;
   
                   for (m = m0; m != NULL && error == 0; m = m->m_next) {
                           if (m->m_len > 0) {
                                   error = bus_dmamap_load_buffer(dmat,
                                       dm_segments, m->m_data, m->m_len, NULL,
                                       flags, &lastaddr, &nsegs, first);
                                   first = 0;
                           }
                   }
           } else {
                   error = EINVAL;
           }
   
           if (error) {
                   /* 
                    * force "no valid mappings" on error in callback.
                    */
                   (*callback)(callback_arg, dm_segments, 0, 0, error);
           } else {
                   (*callback)(callback_arg, dm_segments, nsegs+1,
                       m0->m_pkthdr.len, error);
           }
           return (error);
   }
   
   int
   bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
       bus_dma_segment_t *segs, int *nsegs, int flags)
   {
           int error = 0;
   
           M_ASSERTPKTHDR(m0);
   
           *nsegs = 0;
   
           if (m0->m_pkthdr.len <= dmat->maxsize) {
                   int first = 1;
                   vm_offset_t lastaddr = 0;
                   struct mbuf *m;
   
                   for (m = m0; m != NULL && error == 0; m = m->m_next) {
                           if (m->m_len > 0) {
                                   error = bus_dmamap_load_buffer(dmat,
                                       segs, m->m_data, m->m_len, NULL,
                                       flags, &lastaddr, nsegs, first);
                                   first = 0;
                           }
                   }
                   ++*nsegs;
           } else {
                   error = EINVAL;
           }
   
           return (error);
   }
   
   /*
    * Like bus_dmamap_load(), but for uios.
    */
   int
   bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
       bus_dmamap_callback2_t *callback, void *callback_arg, int flags)
   {
           vm_offset_t lastaddr;
   #ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
           bus_dma_segment_t dm_segments[dmat->nsegments];
   #else
           bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
   #endif
           int nsegs, i, error, first;
           bus_size_t resid;
           struct iovec *iov;
           struct thread *td = NULL;
   
           resid = uio->uio_resid;
           iov = uio->uio_iov;
   
           if (uio->uio_segflg == UIO_USERSPACE) {
                   td = uio->uio_td;
                   KASSERT(td != NULL,
                       ("bus_dmamap_load_uio: USERSPACE but no proc"));
           }
   
           first = 1;
           nsegs = error = 0;
           for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
                   /*
                    * Now at the first iovec to load.  Load each iovec
                    * until we have exhausted the residual count.
                    */
                   bus_size_t minlen =
                       resid < iov[i].iov_len ? resid : iov[i].iov_len;
                   caddr_t addr = (caddr_t) iov[i].iov_base;
   
                   if (minlen > 0) {
                           error = bus_dmamap_load_buffer(dmat, dm_segments, addr,
                               minlen, td, flags, &lastaddr, &nsegs, first);
   
                           first = 0;
   
                           resid -= minlen;
                   }
           }
   
           if (error) {
                   /* 
                    * force "no valid mappings" on error in callback.
                    */
                   (*callback)(callback_arg, dm_segments, 0, 0, error);
           } else {
                   (*callback)(callback_arg, dm_segments, nsegs+1,
                       uio->uio_resid, error);
           }
   
           return (error);
   }
   
   /*
    * Release the mapping held by map. A no-op on PowerPC.
    */
   void
   _bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
   {
   
           return;
   }
   
   void
   _bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
   {
   
           return;
   }

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