FreeBSD/Linux Kernel Cross Reference
sys/x86/x86/msi.c

     /*-
      * Copyright (c) 2006 Yahoo!, Inc.
      * All rights reserved.
      * Written by: John Baldwin <jhb@FreeBSD.org>
      *
      * 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 author nor the names of any co-contributors
     *    may 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.
     */
    
    /*
     * Support for PCI Message Signalled Interrupts (MSI).  MSI interrupts on
     * x86 are basically APIC messages that the northbridge delivers directly
     * to the local APICs as if they had come from an I/O APIC.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/mutex.h>
    #include <sys/sx.h>
    #include <sys/systm.h>
    #include <machine/apicreg.h>
    #include <machine/cputypes.h>
    #include <machine/md_var.h>
    #include <machine/frame.h>
    #include <machine/intr_machdep.h>
    #include <machine/apicvar.h>
    #include <machine/specialreg.h>
    #include <dev/pci/pcivar.h>
    
    /* Fields in address for Intel MSI messages. */
    #define MSI_INTEL_ADDR_DEST             0x000ff000
    #define MSI_INTEL_ADDR_RH               0x00000008
    # define MSI_INTEL_ADDR_RH_ON           0x00000008
    # define MSI_INTEL_ADDR_RH_OFF          0x00000000
    #define MSI_INTEL_ADDR_DM               0x00000004
    # define MSI_INTEL_ADDR_DM_PHYSICAL     0x00000000
    # define MSI_INTEL_ADDR_DM_LOGICAL      0x00000004
    
    /* Fields in data for Intel MSI messages. */
    #define MSI_INTEL_DATA_TRGRMOD          IOART_TRGRMOD   /* Trigger mode. */
    # define MSI_INTEL_DATA_TRGREDG         IOART_TRGREDG
    # define MSI_INTEL_DATA_TRGRLVL         IOART_TRGRLVL
    #define MSI_INTEL_DATA_LEVEL            0x00004000      /* Polarity. */
    # define MSI_INTEL_DATA_DEASSERT        0x00000000
    # define MSI_INTEL_DATA_ASSERT          0x00004000
    #define MSI_INTEL_DATA_DELMOD           IOART_DELMOD    /* Delivery mode. */
    # define MSI_INTEL_DATA_DELFIXED        IOART_DELFIXED
    # define MSI_INTEL_DATA_DELLOPRI        IOART_DELLOPRI
    # define MSI_INTEL_DATA_DELSMI          IOART_DELSMI
    # define MSI_INTEL_DATA_DELNMI          IOART_DELNMI
    # define MSI_INTEL_DATA_DELINIT         IOART_DELINIT
    # define MSI_INTEL_DATA_DELEXINT        IOART_DELEXINT
    #define MSI_INTEL_DATA_INTVEC           IOART_INTVEC    /* Interrupt vector. */
    
    /*
     * Build Intel MSI message and data values from a source.  AMD64 systems
     * seem to be compatible, so we use the same function for both.
     */
    #define INTEL_ADDR(msi)                                                 \
            (MSI_INTEL_ADDR_BASE | (msi)->msi_cpu << 12 |                   \
                MSI_INTEL_ADDR_RH_OFF | MSI_INTEL_ADDR_DM_PHYSICAL)
    #define INTEL_DATA(msi)                                                 \
            (MSI_INTEL_DATA_TRGREDG | MSI_INTEL_DATA_DELFIXED | (msi)->msi_vector)
    
    static MALLOC_DEFINE(M_MSI, "msi", "PCI MSI");
    
    /*
     * MSI sources are bunched into groups.  This is because MSI forces
     * all of the messages to share the address and data registers and
     * thus certain properties (such as the local APIC ID target on x86).
     * Each group has a 'first' source that contains information global to
     * the group.  These fields are marked with (g) below.
    *
    * Note that local APIC ID is kind of special.  Each message will be
    * assigned an ID by the system; however, a group will use the ID from
    * the first message.
    *
    * For MSI-X, each message is isolated.
    */
   struct msi_intsrc {
           struct intsrc msi_intsrc;
           device_t msi_dev;               /* Owning device. (g) */
           struct msi_intsrc *msi_first;   /* First source in group. */
           u_int msi_irq;                  /* IRQ cookie. */
           u_int msi_msix;                 /* MSI-X message. */
           u_int msi_vector:8;             /* IDT vector. */
           u_int msi_cpu:8;                /* Local APIC ID. (g) */
           u_int msi_count:8;              /* Messages in this group. (g) */
           u_int msi_maxcount:8;           /* Alignment for this group. (g) */
           int *msi_irqs;                  /* Group's IRQ list. (g) */
   };
   
   static void     msi_create_source(void);
   static void     msi_enable_source(struct intsrc *isrc);
   static void     msi_disable_source(struct intsrc *isrc, int eoi);
   static void     msi_eoi_source(struct intsrc *isrc);
   static void     msi_enable_intr(struct intsrc *isrc);
   static void     msi_disable_intr(struct intsrc *isrc);
   static int      msi_vector(struct intsrc *isrc);
   static int      msi_source_pending(struct intsrc *isrc);
   static int      msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
                       enum intr_polarity pol);
   static int      msi_assign_cpu(struct intsrc *isrc, u_int apic_id);
   
   struct pic msi_pic = { msi_enable_source, msi_disable_source, msi_eoi_source,
                          msi_enable_intr, msi_disable_intr, msi_vector,
                          msi_source_pending, NULL, NULL, msi_config_intr,
                          msi_assign_cpu };
   
   static int msi_enabled;
   static int msi_last_irq;
   static struct mtx msi_lock;
   
   static void
   msi_enable_source(struct intsrc *isrc)
   {
   }
   
   static void
   msi_disable_source(struct intsrc *isrc, int eoi)
   {
   
           if (eoi == PIC_EOI)
                   lapic_eoi();
   }
   
   static void
   msi_eoi_source(struct intsrc *isrc)
   {
   
           lapic_eoi();
   }
   
   static void
   msi_enable_intr(struct intsrc *isrc)
   {
           struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
   
           apic_enable_vector(msi->msi_cpu, msi->msi_vector);
   }
   
   static void
   msi_disable_intr(struct intsrc *isrc)
   {
           struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
   
           apic_disable_vector(msi->msi_cpu, msi->msi_vector);
   }
   
   static int
   msi_vector(struct intsrc *isrc)
   {
           struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
   
           return (msi->msi_irq);
   }
   
   static int
   msi_source_pending(struct intsrc *isrc)
   {
   
           return (0);
   }
   
   static int
   msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
       enum intr_polarity pol)
   {
   
           return (ENODEV);
   }
   
   static int
   msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
   {
           struct msi_intsrc *sib, *msi = (struct msi_intsrc *)isrc;
           int old_vector;
           u_int old_id;
           int i, vector;
   
           /*
            * Only allow CPUs to be assigned to the first message for an
            * MSI group.
            */
           if (msi->msi_first != msi)
                   return (EINVAL);
   
           /* Store information to free existing irq. */
           old_vector = msi->msi_vector;
           old_id = msi->msi_cpu;
           if (old_id == apic_id)
                   return (0);
   
           /* Allocate IDT vectors on this cpu. */
           if (msi->msi_count > 1) {
                   KASSERT(msi->msi_msix == 0, ("MSI-X message group"));
                   vector = apic_alloc_vectors(apic_id, msi->msi_irqs,
                       msi->msi_count, msi->msi_maxcount);
           } else
                   vector = apic_alloc_vector(apic_id, msi->msi_irq);
           if (vector == 0)
                   return (ENOSPC);
   
           msi->msi_cpu = apic_id;
           msi->msi_vector = vector;
           if (msi->msi_intsrc.is_handlers > 0)
                   apic_enable_vector(msi->msi_cpu, msi->msi_vector);
           if (bootverbose)
                   printf("msi: Assigning %s IRQ %d to local APIC %u vector %u\n",
                       msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
                       msi->msi_cpu, msi->msi_vector);
           for (i = 1; i < msi->msi_count; i++) {
                   sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
                   sib->msi_cpu = apic_id;
                   sib->msi_vector = vector + i;
                   if (sib->msi_intsrc.is_handlers > 0)
                           apic_enable_vector(sib->msi_cpu, sib->msi_vector);
                   if (bootverbose)
                           printf(
                       "msi: Assigning MSI IRQ %d to local APIC %u vector %u\n",
                               sib->msi_irq, sib->msi_cpu, sib->msi_vector);
           }
           BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
               msi->msi_irq);
   
           /*
            * Free the old vector after the new one is established.  This is done
            * to prevent races where we could miss an interrupt.
            */
           if (msi->msi_intsrc.is_handlers > 0)
                   apic_disable_vector(old_id, old_vector);
           apic_free_vector(old_id, old_vector, msi->msi_irq);
           for (i = 1; i < msi->msi_count; i++) {
                   sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
                   if (sib->msi_intsrc.is_handlers > 0)
                           apic_disable_vector(old_id, old_vector + i);
                   apic_free_vector(old_id, old_vector + i, msi->msi_irqs[i]);
           }
           return (0);
   }
   
   void
   msi_init(void)
   {
   
           /* Check if we have a supported CPU. */
           switch (cpu_vendor_id) {
           case CPU_VENDOR_INTEL:
           case CPU_VENDOR_AMD:
                   break;
           case CPU_VENDOR_CENTAUR:
                   if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
                       CPUID_TO_MODEL(cpu_id) >= 0xf)
                           break;
                   /* FALLTHROUGH */
           default:
                   return;
           }
   
           msi_enabled = 1;
           intr_register_pic(&msi_pic);
           mtx_init(&msi_lock, "msi", NULL, MTX_DEF);
   }
   
   static void
   msi_create_source(void)
   {
           struct msi_intsrc *msi;
           u_int irq;
   
           mtx_lock(&msi_lock);
           if (msi_last_irq >= NUM_MSI_INTS) {
                   mtx_unlock(&msi_lock);
                   return;
           }
           irq = msi_last_irq + FIRST_MSI_INT;
           msi_last_irq++;
           mtx_unlock(&msi_lock);
   
           msi = malloc(sizeof(struct msi_intsrc), M_MSI, M_WAITOK | M_ZERO);
           msi->msi_intsrc.is_pic = &msi_pic;
           msi->msi_irq = irq;
           intr_register_source(&msi->msi_intsrc);
           nexus_add_irq(irq);
   }
   
   /*
    * Try to allocate 'count' interrupt sources with contiguous IDT values.
    */
   int
   msi_alloc(device_t dev, int count, int maxcount, int *irqs)
   {
           struct msi_intsrc *msi, *fsrc;
           u_int cpu;
           int cnt, i, *mirqs, vector;
   
           if (!msi_enabled)
                   return (ENXIO);
   
           if (count > 1)
                   mirqs = malloc(count * sizeof(*mirqs), M_MSI, M_WAITOK);
           else
                   mirqs = NULL;
   again:
           mtx_lock(&msi_lock);
   
           /* Try to find 'count' free IRQs. */
           cnt = 0;
           for (i = FIRST_MSI_INT; i < FIRST_MSI_INT + NUM_MSI_INTS; i++) {
                   msi = (struct msi_intsrc *)intr_lookup_source(i);
   
                   /* End of allocated sources, so break. */
                   if (msi == NULL)
                           break;
   
                   /* If this is a free one, save its IRQ in the array. */
                   if (msi->msi_dev == NULL) {
                           irqs[cnt] = i;
                           cnt++;
                           if (cnt == count)
                                   break;
                   }
           }
   
           /* Do we need to create some new sources? */
           if (cnt < count) {
                   /* If we would exceed the max, give up. */
                   if (i + (count - cnt) > FIRST_MSI_INT + NUM_MSI_INTS) {
                           mtx_unlock(&msi_lock);
                           free(mirqs, M_MSI);
                           return (ENXIO);
                   }
                   mtx_unlock(&msi_lock);
   
                   /* We need count - cnt more sources. */
                   while (cnt < count) {
                           msi_create_source();
                           cnt++;
                   }
                   goto again;
           }
   
           /* Ok, we now have the IRQs allocated. */
           KASSERT(cnt == count, ("count mismatch"));
   
           /* Allocate 'count' IDT vectors. */
           cpu = intr_next_cpu();
           vector = apic_alloc_vectors(cpu, irqs, count, maxcount);
           if (vector == 0) {
                   mtx_unlock(&msi_lock);
                   free(mirqs, M_MSI);
                   return (ENOSPC);
           }
   
           /* Assign IDT vectors and make these messages owned by 'dev'. */
           fsrc = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
           for (i = 0; i < count; i++) {
                   msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
                   msi->msi_cpu = cpu;
                   msi->msi_dev = dev;
                   msi->msi_vector = vector + i;
                   if (bootverbose)
                           printf(
                       "msi: routing MSI IRQ %d to local APIC %u vector %u\n",
                               msi->msi_irq, msi->msi_cpu, msi->msi_vector);
                   msi->msi_first = fsrc;
                   KASSERT(msi->msi_intsrc.is_handlers == 0,
                       ("dead MSI has handlers"));
           }
           fsrc->msi_count = count;
           fsrc->msi_maxcount = maxcount;
           if (count > 1)
                   bcopy(irqs, mirqs, count * sizeof(*mirqs));
           fsrc->msi_irqs = mirqs;
           mtx_unlock(&msi_lock);
   
           return (0);
   }
   
   int
   msi_release(int *irqs, int count)
   {
           struct msi_intsrc *msi, *first;
           int i;
   
           mtx_lock(&msi_lock);
           first = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
           if (first == NULL) {
                   mtx_unlock(&msi_lock);
                   return (ENOENT);
           }
   
           /* Make sure this isn't an MSI-X message. */
           if (first->msi_msix) {
                   mtx_unlock(&msi_lock);
                   return (EINVAL);
           }
   
           /* Make sure this message is allocated to a group. */
           if (first->msi_first == NULL) {
                   mtx_unlock(&msi_lock);
                   return (ENXIO);
           }
   
           /*
            * Make sure this is the start of a group and that we are releasing
            * the entire group.
            */
           if (first->msi_first != first || first->msi_count != count) {
                   mtx_unlock(&msi_lock);
                   return (EINVAL);
           }
           KASSERT(first->msi_dev != NULL, ("unowned group"));
   
           /* Clear all the extra messages in the group. */
           for (i = 1; i < count; i++) {
                   msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
                   KASSERT(msi->msi_first == first, ("message not in group"));
                   KASSERT(msi->msi_dev == first->msi_dev, ("owner mismatch"));
                   msi->msi_first = NULL;
                   msi->msi_dev = NULL;
                   apic_free_vector(msi->msi_cpu, msi->msi_vector, msi->msi_irq);
                   msi->msi_vector = 0;
           }
   
           /* Clear out the first message. */
           first->msi_first = NULL;
           first->msi_dev = NULL;
           apic_free_vector(first->msi_cpu, first->msi_vector, first->msi_irq);
           first->msi_vector = 0;
           first->msi_count = 0;
           first->msi_maxcount = 0;
           free(first->msi_irqs, M_MSI);
           first->msi_irqs = NULL;
   
           mtx_unlock(&msi_lock);
           return (0);
   }
   
   int
   msi_map(int irq, uint64_t *addr, uint32_t *data)
   {
           struct msi_intsrc *msi;
   
           mtx_lock(&msi_lock);
           msi = (struct msi_intsrc *)intr_lookup_source(irq);
           if (msi == NULL) {
                   mtx_unlock(&msi_lock);
                   return (ENOENT);
           }
   
           /* Make sure this message is allocated to a device. */
           if (msi->msi_dev == NULL) {
                   mtx_unlock(&msi_lock);
                   return (ENXIO);
           }
   
           /*
            * If this message isn't an MSI-X message, make sure it's part
            * of a group, and switch to the first message in the
            * group.
            */
           if (!msi->msi_msix) {
                   if (msi->msi_first == NULL) {
                           mtx_unlock(&msi_lock);
                           return (ENXIO);
                   }
                   msi = msi->msi_first;
           }
   
           *addr = INTEL_ADDR(msi);
           *data = INTEL_DATA(msi);
           mtx_unlock(&msi_lock);
           return (0);
   }
   
   int
   msix_alloc(device_t dev, int *irq)
   {
           struct msi_intsrc *msi;
           u_int cpu;
           int i, vector;
   
           if (!msi_enabled)
                   return (ENXIO);
   
   again:
           mtx_lock(&msi_lock);
   
           /* Find a free IRQ. */
           for (i = FIRST_MSI_INT; i < FIRST_MSI_INT + NUM_MSI_INTS; i++) {
                   msi = (struct msi_intsrc *)intr_lookup_source(i);
   
                   /* End of allocated sources, so break. */
                   if (msi == NULL)
                           break;
   
                   /* Stop at the first free source. */
                   if (msi->msi_dev == NULL)
                           break;
           }
   
           /* Do we need to create a new source? */
           if (msi == NULL) {
                   /* If we would exceed the max, give up. */
                   if (i + 1 > FIRST_MSI_INT + NUM_MSI_INTS) {
                           mtx_unlock(&msi_lock);
                           return (ENXIO);
                   }
                   mtx_unlock(&msi_lock);
   
                   /* Create a new source. */
                   msi_create_source();
                   goto again;
           }
   
           /* Allocate an IDT vector. */
           cpu = intr_next_cpu();
           vector = apic_alloc_vector(cpu, i);
           if (vector == 0) {
                   mtx_unlock(&msi_lock);
                   return (ENOSPC);
           }
           if (bootverbose)
                   printf("msi: routing MSI-X IRQ %d to local APIC %u vector %u\n",
                       msi->msi_irq, cpu, vector);
   
           /* Setup source. */
           msi->msi_cpu = cpu;
           msi->msi_dev = dev;
           msi->msi_first = msi;
           msi->msi_vector = vector;
           msi->msi_msix = 1;
           msi->msi_count = 1;
           msi->msi_maxcount = 1;
           msi->msi_irqs = NULL;
   
           KASSERT(msi->msi_intsrc.is_handlers == 0, ("dead MSI-X has handlers"));
           mtx_unlock(&msi_lock);
   
           *irq = i;
           return (0);
   }
   
   int
   msix_release(int irq)
   {
           struct msi_intsrc *msi;
   
           mtx_lock(&msi_lock);
           msi = (struct msi_intsrc *)intr_lookup_source(irq);
           if (msi == NULL) {
                   mtx_unlock(&msi_lock);
                   return (ENOENT);
           }
   
           /* Make sure this is an MSI-X message. */
           if (!msi->msi_msix) {
                   mtx_unlock(&msi_lock);
                   return (EINVAL);
           }
   
           KASSERT(msi->msi_dev != NULL, ("unowned message"));
   
           /* Clear out the message. */
           msi->msi_first = NULL;
           msi->msi_dev = NULL;
           apic_free_vector(msi->msi_cpu, msi->msi_vector, msi->msi_irq);
           msi->msi_vector = 0;
           msi->msi_msix = 0;
           msi->msi_count = 0;
           msi->msi_maxcount = 0;
   
           mtx_unlock(&msi_lock);
           return (0);
   }

Cache object: 5d37dc770bab3059bc79a637635e809a