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pci_msi.c

/* pci_msi.c: Sparc64 MSI support common layer.
 *
 * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
 */
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/irq.h>

#include "pci_impl.h"

static irqreturn_t sparc64_msiq_interrupt(int irq, void *cookie)
{
      struct sparc64_msiq_cookie *msiq_cookie = cookie;
      struct pci_pbm_info *pbm = msiq_cookie->pbm;
      unsigned long msiqid = msiq_cookie->msiqid;
      const struct sparc64_msiq_ops *ops;
      unsigned long orig_head, head;
      int err;

      ops = pbm->msi_ops;

      err = ops->get_head(pbm, msiqid, &head);
      if (unlikely(err < 0))
            goto err_get_head;

      orig_head = head;
      for (;;) {
            unsigned long msi;

            err = ops->dequeue_msi(pbm, msiqid, &head, &msi);
            if (likely(err > 0)) {
                  struct irq_desc *desc;
                  unsigned int virt_irq;

                  virt_irq = pbm->msi_irq_table[msi - pbm->msi_first];
                  desc = irq_desc + virt_irq;

                  desc->handle_irq(virt_irq, desc);
            }

            if (unlikely(err < 0))
                  goto err_dequeue;

            if (err == 0)
                  break;
      }
      if (likely(head != orig_head)) {
            err = ops->set_head(pbm, msiqid, head);
            if (unlikely(err < 0))
                  goto err_set_head;
      }
      return IRQ_HANDLED;

err_get_head:
      printk(KERN_EMERG "MSI: Get head on msiqid[%lu] gives error %d\n",
             msiqid, err);
      goto err_out;

err_dequeue:
      printk(KERN_EMERG "MSI: Dequeue head[%lu] from msiqid[%lu] "
             "gives error %d\n",
             head, msiqid, err);
      goto err_out;

err_set_head:
      printk(KERN_EMERG "MSI: Set head[%lu] on msiqid[%lu] "
             "gives error %d\n",
             head, msiqid, err);
      goto err_out;

err_out:
      return IRQ_NONE;
}

static u32 pick_msiq(struct pci_pbm_info *pbm)
{
      static DEFINE_SPINLOCK(rotor_lock);
      unsigned long flags;
      u32 ret, rotor;

      spin_lock_irqsave(&rotor_lock, flags);

      rotor = pbm->msiq_rotor;
      ret = pbm->msiq_first + rotor;

      if (++rotor >= pbm->msiq_num)
            rotor = 0;
      pbm->msiq_rotor = rotor;

      spin_unlock_irqrestore(&rotor_lock, flags);

      return ret;
}


static int alloc_msi(struct pci_pbm_info *pbm)
{
      int i;

      for (i = 0; i < pbm->msi_num; i++) {
            if (!test_and_set_bit(i, pbm->msi_bitmap))
                  return i + pbm->msi_first;
      }

      return -ENOENT;
}

static void free_msi(struct pci_pbm_info *pbm, int msi_num)
{
      msi_num -= pbm->msi_first;
      clear_bit(msi_num, pbm->msi_bitmap);
}

static struct irq_chip msi_irq = {
      .typename   = "PCI-MSI",
      .mask       = mask_msi_irq,
      .unmask           = unmask_msi_irq,
      .enable           = unmask_msi_irq,
      .disable    = mask_msi_irq,
      /* XXX affinity XXX */
};

static int sparc64_setup_msi_irq(unsigned int *virt_irq_p,
                         struct pci_dev *pdev,
                         struct msi_desc *entry)
{
      struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
      const struct sparc64_msiq_ops *ops = pbm->msi_ops;
      struct msi_msg msg;
      int msi, err;
      u32 msiqid;

      *virt_irq_p = virt_irq_alloc(0, 0);
      err = -ENOMEM;
      if (!*virt_irq_p)
            goto out_err;

      set_irq_chip_and_handler_name(*virt_irq_p, &msi_irq,
                              handle_simple_irq, "MSI");

      err = alloc_msi(pbm);
      if (unlikely(err < 0))
            goto out_virt_irq_free;

      msi = err;

      msiqid = pick_msiq(pbm);

      err = ops->msi_setup(pbm, msiqid, msi,
                       (entry->msi_attrib.is_64 ? 1 : 0));
      if (err)
            goto out_msi_free;

      pbm->msi_irq_table[msi - pbm->msi_first] = *virt_irq_p;

      if (entry->msi_attrib.is_64) {
            msg.address_hi = pbm->msi64_start >> 32;
            msg.address_lo = pbm->msi64_start & 0xffffffff;
      } else {
            msg.address_hi = 0;
            msg.address_lo = pbm->msi32_start;
      }
      msg.data = msi;

      set_irq_msi(*virt_irq_p, entry);
      write_msi_msg(*virt_irq_p, &msg);

      return 0;

out_msi_free:
      free_msi(pbm, msi);

out_virt_irq_free:
      set_irq_chip(*virt_irq_p, NULL);
      virt_irq_free(*virt_irq_p);
      *virt_irq_p = 0;

out_err:
      return err;
}

static void sparc64_teardown_msi_irq(unsigned int virt_irq,
                             struct pci_dev *pdev)
{
      struct pci_pbm_info *pbm = pdev->dev.archdata.host_controller;
      const struct sparc64_msiq_ops *ops = pbm->msi_ops;
      unsigned int msi_num;
      int i, err;

      for (i = 0; i < pbm->msi_num; i++) {
            if (pbm->msi_irq_table[i] == virt_irq)
                  break;
      }
      if (i >= pbm->msi_num) {
            printk(KERN_ERR "%s: teardown: No MSI for irq %u\n",
                   pbm->name, virt_irq);
            return;
      }

      msi_num = pbm->msi_first + i;
      pbm->msi_irq_table[i] = ~0U;

      err = ops->msi_teardown(pbm, msi_num);
      if (err) {
            printk(KERN_ERR "%s: teardown: ops->teardown() on MSI %u, "
                   "irq %u, gives error %d\n",
                   pbm->name, msi_num, virt_irq, err);
            return;
      }

      free_msi(pbm, msi_num);

      set_irq_chip(virt_irq, NULL);
      virt_irq_free(virt_irq);
}

static int msi_bitmap_alloc(struct pci_pbm_info *pbm)
{
      unsigned long size, bits_per_ulong;

      bits_per_ulong = sizeof(unsigned long) * 8;
      size = (pbm->msi_num + (bits_per_ulong - 1)) & ~(bits_per_ulong - 1);
      size /= 8;
      BUG_ON(size % sizeof(unsigned long));

      pbm->msi_bitmap = kzalloc(size, GFP_KERNEL);
      if (!pbm->msi_bitmap)
            return -ENOMEM;

      return 0;
}

static void msi_bitmap_free(struct pci_pbm_info *pbm)
{
      kfree(pbm->msi_bitmap);
      pbm->msi_bitmap = NULL;
}

static int msi_table_alloc(struct pci_pbm_info *pbm)
{
      int size, i;

      size = pbm->msiq_num * sizeof(struct sparc64_msiq_cookie);
      pbm->msiq_irq_cookies = kzalloc(size, GFP_KERNEL);
      if (!pbm->msiq_irq_cookies)
            return -ENOMEM;

      for (i = 0; i < pbm->msiq_num; i++) {
            struct sparc64_msiq_cookie *p;

            p = &pbm->msiq_irq_cookies[i];
            p->pbm = pbm;
            p->msiqid = pbm->msiq_first + i;
      }

      size = pbm->msi_num * sizeof(unsigned int);
      pbm->msi_irq_table = kzalloc(size, GFP_KERNEL);
      if (!pbm->msi_irq_table) {
            kfree(pbm->msiq_irq_cookies);
            pbm->msiq_irq_cookies = NULL;
            return -ENOMEM;
      }

      return 0;
}

static void msi_table_free(struct pci_pbm_info *pbm)
{
      kfree(pbm->msiq_irq_cookies);
      pbm->msiq_irq_cookies = NULL;

      kfree(pbm->msi_irq_table);
      pbm->msi_irq_table = NULL;
}

static int bringup_one_msi_queue(struct pci_pbm_info *pbm,
                         const struct sparc64_msiq_ops *ops,
                         unsigned long msiqid,
                         unsigned long devino)
{
      int irq = ops->msiq_build_irq(pbm, msiqid, devino);
      int err, nid;

      if (irq < 0)
            return irq;

      nid = pbm->numa_node;
      if (nid != -1) {
            cpumask_t numa_mask = node_to_cpumask(nid);

            irq_set_affinity(irq, numa_mask);
      }
      err = request_irq(irq, sparc64_msiq_interrupt, 0,
                    "MSIQ",
                    &pbm->msiq_irq_cookies[msiqid - pbm->msiq_first]);
      if (err)
            return err;

      return 0;
}

static int sparc64_bringup_msi_queues(struct pci_pbm_info *pbm,
                              const struct sparc64_msiq_ops *ops)
{
      int i;

      for (i = 0; i < pbm->msiq_num; i++) {
            unsigned long msiqid = i + pbm->msiq_first;
            unsigned long devino = i + pbm->msiq_first_devino;
            int err;

            err = bringup_one_msi_queue(pbm, ops, msiqid, devino);
            if (err)
                  return err;
      }

      return 0;
}

void sparc64_pbm_msi_init(struct pci_pbm_info *pbm,
                    const struct sparc64_msiq_ops *ops)
{
      const u32 *val;
      int len;

      val = of_get_property(pbm->prom_node, "#msi-eqs", &len);
      if (!val || len != 4)
            goto no_msi;
      pbm->msiq_num = *val;
      if (pbm->msiq_num) {
            const struct msiq_prop {
                  u32 first_msiq;
                  u32 num_msiq;
                  u32 first_devino;
            } *mqp;
            const struct msi_range_prop {
                  u32 first_msi;
                  u32 num_msi;
            } *mrng;
            const struct addr_range_prop {
                  u32 msi32_high;
                  u32 msi32_low;
                  u32 msi32_len;
                  u32 msi64_high;
                  u32 msi64_low;
                  u32 msi64_len;
            } *arng;

            val = of_get_property(pbm->prom_node, "msi-eq-size", &len);
            if (!val || len != 4)
                  goto no_msi;

            pbm->msiq_ent_count = *val;

            mqp = of_get_property(pbm->prom_node,
                              "msi-eq-to-devino", &len);
            if (!mqp)
                  mqp = of_get_property(pbm->prom_node,
                                    "msi-eq-devino", &len);
            if (!mqp || len != sizeof(struct msiq_prop))
                  goto no_msi;

            pbm->msiq_first = mqp->first_msiq;
            pbm->msiq_first_devino = mqp->first_devino;

            val = of_get_property(pbm->prom_node, "#msi", &len);
            if (!val || len != 4)
                  goto no_msi;
            pbm->msi_num = *val;

            mrng = of_get_property(pbm->prom_node, "msi-ranges", &len);
            if (!mrng || len != sizeof(struct msi_range_prop))
                  goto no_msi;
            pbm->msi_first = mrng->first_msi;

            val = of_get_property(pbm->prom_node, "msi-data-mask", &len);
            if (!val || len != 4)
                  goto no_msi;
            pbm->msi_data_mask = *val;

            val = of_get_property(pbm->prom_node, "msix-data-width", &len);
            if (!val || len != 4)
                  goto no_msi;
            pbm->msix_data_width = *val;

            arng = of_get_property(pbm->prom_node, "msi-address-ranges",
                               &len);
            if (!arng || len != sizeof(struct addr_range_prop))
                  goto no_msi;
            pbm->msi32_start = ((u64)arng->msi32_high << 32) |
                  (u64) arng->msi32_low;
            pbm->msi64_start = ((u64)arng->msi64_high << 32) |
                  (u64) arng->msi64_low;
            pbm->msi32_len = arng->msi32_len;
            pbm->msi64_len = arng->msi64_len;

            if (msi_bitmap_alloc(pbm))
                  goto no_msi;

            if (msi_table_alloc(pbm)) {
                  msi_bitmap_free(pbm);
                  goto no_msi;
            }

            if (ops->msiq_alloc(pbm)) {
                  msi_table_free(pbm);
                  msi_bitmap_free(pbm);
                  goto no_msi;
            }

            if (sparc64_bringup_msi_queues(pbm, ops)) {
                  ops->msiq_free(pbm);
                  msi_table_free(pbm);
                  msi_bitmap_free(pbm);
                  goto no_msi;
            }

            printk(KERN_INFO "%s: MSI Queue first[%u] num[%u] count[%u] "
                   "devino[0x%x]\n",
                   pbm->name,
                   pbm->msiq_first, pbm->msiq_num,
                   pbm->msiq_ent_count,
                   pbm->msiq_first_devino);
            printk(KERN_INFO "%s: MSI first[%u] num[%u] mask[0x%x] "
                   "width[%u]\n",
                   pbm->name,
                   pbm->msi_first, pbm->msi_num, pbm->msi_data_mask,
                   pbm->msix_data_width);
            printk(KERN_INFO "%s: MSI addr32[0x%lx:0x%x] "
                   "addr64[0x%lx:0x%x]\n",
                   pbm->name,
                   pbm->msi32_start, pbm->msi32_len,
                   pbm->msi64_start, pbm->msi64_len);
            printk(KERN_INFO "%s: MSI queues at RA [%016lx]\n",
                   pbm->name,
                   __pa(pbm->msi_queues));

            pbm->msi_ops = ops;
            pbm->setup_msi_irq = sparc64_setup_msi_irq;
            pbm->teardown_msi_irq = sparc64_teardown_msi_irq;
      }
      return;

no_msi:
      pbm->msiq_num = 0;
      printk(KERN_INFO "%s: No MSI support.\n", pbm->name);
}

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