pci_msi.c

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/* pci_msi.c: Sparc64 MSI support common layer.
 *
 * Copyright (C) 2007 David S. Miller ([email protected])
 */
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/slab.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)) {
            unsigned int irq;

            irq = pbm->msi_irq_table[msi - pbm->msi_first];
            generic_handle_irq(irq);
        }

        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 = {
    .name       = "PCI-MSI",
    .irq_mask   = mask_msi_irq,
    .irq_unmask = unmask_msi_irq,
    .irq_enable = unmask_msi_irq,
    .irq_disable    = mask_msi_irq,
    /* XXX affinity XXX */
};

static int sparc64_setup_msi_irq(unsigned int *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;

    *irq_p = irq_alloc(0, 0);
    err = -ENOMEM;
    if (!*irq_p)
        goto out_err;

    irq_set_chip_and_handler_name(*irq_p, &msi_irq, handle_simple_irq,
                      "MSI");

    err = alloc_msi(pbm);
    if (unlikely(err < 0))
        goto out_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] = *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;

    irq_set_msi_desc(*irq_p, entry);
    write_msi_msg(*irq_p, &msg);

    return 0;

out_msi_free:
    free_msi(pbm, msi);

out_irq_free:
    irq_set_chip(*irq_p, NULL);
    irq_free(*irq_p);
    *irq_p = 0;

out_err:
    return err;
}

static void sparc64_teardown_msi_irq(unsigned int 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] == irq)
            break;
    }
    if (i >= pbm->msi_num) {
        printk(KERN_ERR "%s: teardown: No MSI for irq %u\n",
               pbm->name, 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, irq, err);
        return;
    }

    free_msi(pbm, msi_num);

    irq_set_chip(irq, NULL);
    irq_free(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;

        cpumask_copy(&numa_mask, cpumask_of_node(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->op->dev.of_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->op->dev.of_node, "msi-eq-size", &len);
        if (!val || len != 4)
            goto no_msi;

        pbm->msiq_ent_count = *val;

        mqp = of_get_property(pbm->op->dev.of_node,
                      "msi-eq-to-devino", &len);
        if (!mqp)
            mqp = of_get_property(pbm->op->dev.of_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->op->dev.of_node, "#msi", &len);
        if (!val || len != 4)
            goto no_msi;
        pbm->msi_num = *val;

        mrng = of_get_property(pbm->op->dev.of_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->op->dev.of_node, "msi-data-mask", &len);
        if (!val || len != 4)
            goto no_msi;
        pbm->msi_data_mask = *val;

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

        arng = of_get_property(pbm->op->dev.of_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%llx:0x%x] "
               "addr64[0x%llx: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);
}