Archipelago » qemu

/*

 * msi.c

 *

 * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>

 *                    VA Linux Systems Japan K.K.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#include "msi.h"

#include "range.h"

/* Eventually those constants should go to Linux pci_regs.h */

#define PCI_MSI_PENDING_32      0x10

#define PCI_MSI_PENDING_64      0x14

/* PCI_MSI_ADDRESS_LO */

#define PCI_MSI_ADDRESS_LO_MASK         (~0x3)

/* If we get rid of cap allocator, we won't need those. */

#define PCI_MSI_32_SIZEOF       0x0a

#define PCI_MSI_64_SIZEOF       0x0e

#define PCI_MSI_32M_SIZEOF      0x14

#define PCI_MSI_64M_SIZEOF      0x18

#define PCI_MSI_VECTORS_MAX     32

/* Flag for interrupt controller to declare MSI/MSI-X support */

bool msi_supported;

/* If we get rid of cap allocator, we won't need this. */

static inline uint8_t msi_cap_sizeof(uint16_t flags)

{

    switch (flags & (PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT)) {

    case PCI_MSI_FLAGS_MASKBIT | PCI_MSI_FLAGS_64BIT:

        return PCI_MSI_64M_SIZEOF;

    case PCI_MSI_FLAGS_64BIT:

        return PCI_MSI_64_SIZEOF;

    case PCI_MSI_FLAGS_MASKBIT:

        return PCI_MSI_32M_SIZEOF;

    case 0:

        return PCI_MSI_32_SIZEOF;

    default:

        abort();

        break;

    }

    return 0;

}

//#define MSI_DEBUG

#ifdef MSI_DEBUG

# define MSI_DPRINTF(fmt, ...)                                          \

    fprintf(stderr, "%s:%d " fmt, __func__, __LINE__, ## __VA_ARGS__)

#else

# define MSI_DPRINTF(fmt, ...)  do { } while (0)

#endif

#define MSI_DEV_PRINTF(dev, fmt, ...)                                   \

    MSI_DPRINTF("%s:%x " fmt, (dev)->name, (dev)->devfn, ## __VA_ARGS__)

static inline unsigned int msi_nr_vectors(uint16_t flags)

{

    return 1U <<

        ((flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1));

}

static inline uint8_t msi_flags_off(const PCIDevice* dev)

{

    return dev->msi_cap + PCI_MSI_FLAGS;

}

static inline uint8_t msi_address_lo_off(const PCIDevice* dev)

{

    return dev->msi_cap + PCI_MSI_ADDRESS_LO;

}

static inline uint8_t msi_address_hi_off(const PCIDevice* dev)

{

    return dev->msi_cap + PCI_MSI_ADDRESS_HI;

}

static inline uint8_t msi_data_off(const PCIDevice* dev, bool msi64bit)

{

    return dev->msi_cap + (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32);

}

static inline uint8_t msi_mask_off(const PCIDevice* dev, bool msi64bit)

{

    return dev->msi_cap + (msi64bit ? PCI_MSI_MASK_64 : PCI_MSI_MASK_32);

}

static inline uint8_t msi_pending_off(const PCIDevice* dev, bool msi64bit)

{

    return dev->msi_cap + (msi64bit ? PCI_MSI_PENDING_64 : PCI_MSI_PENDING_32);

}

bool msi_enabled(const PCIDevice *dev)

{

    return msi_present(dev) &&

        (pci_get_word(dev->config + msi_flags_off(dev)) &

         PCI_MSI_FLAGS_ENABLE);

}

int msi_init(struct PCIDevice *dev, uint8_t offset,

             unsigned int nr_vectors, bool msi64bit, bool msi_per_vector_mask)

{

    unsigned int vectors_order;

    uint16_t flags;

    uint8_t cap_size;

    int config_offset;

    if (!msi_supported) {

        return -ENOTSUP;

    }

    MSI_DEV_PRINTF(dev,

                   "init offset: 0x%"PRIx8" vector: %"PRId8

                   " 64bit %d mask %d\n",

                   offset, nr_vectors, msi64bit, msi_per_vector_mask);

    assert(!(nr_vectors & (nr_vectors - 1)));   /* power of 2 */

    assert(nr_vectors > 0);

    assert(nr_vectors <= PCI_MSI_VECTORS_MAX);

    /* the nr of MSI vectors is up to 32 */

    vectors_order = ffs(nr_vectors) - 1;

    flags = vectors_order << (ffs(PCI_MSI_FLAGS_QMASK) - 1);

    if (msi64bit) {

        flags |= PCI_MSI_FLAGS_64BIT;

    }

    if (msi_per_vector_mask) {

        flags |= PCI_MSI_FLAGS_MASKBIT;

    }

    cap_size = msi_cap_sizeof(flags);

    config_offset = pci_add_capability(dev, PCI_CAP_ID_MSI, offset, cap_size);

    if (config_offset < 0) {

        return config_offset;

    }

    dev->msi_cap = config_offset;

    dev->cap_present |= QEMU_PCI_CAP_MSI;

    pci_set_word(dev->config + msi_flags_off(dev), flags);

    pci_set_word(dev->wmask + msi_flags_off(dev),

                 PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);

    pci_set_long(dev->wmask + msi_address_lo_off(dev),

                 PCI_MSI_ADDRESS_LO_MASK);

    if (msi64bit) {

        pci_set_long(dev->wmask + msi_address_hi_off(dev), 0xffffffff);

    }

    pci_set_word(dev->wmask + msi_data_off(dev, msi64bit), 0xffff);

    if (msi_per_vector_mask) {

        /* Make mask bits 0 to nr_vectors - 1 writable. */

        pci_set_long(dev->wmask + msi_mask_off(dev, msi64bit),

                     0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors));

    }

    return config_offset;

}

void msi_uninit(struct PCIDevice *dev)

{

    uint16_t flags;

    uint8_t cap_size;

    if (!(dev->cap_present & QEMU_PCI_CAP_MSI)) {

        return;

    }

    flags = pci_get_word(dev->config + msi_flags_off(dev));

    cap_size = msi_cap_sizeof(flags);

    pci_del_capability(dev, PCI_CAP_ID_MSI, cap_size);

    dev->cap_present &= ~QEMU_PCI_CAP_MSI;

    MSI_DEV_PRINTF(dev, "uninit\n");

}

void msi_reset(PCIDevice *dev)

{

    uint16_t flags;

    bool msi64bit;

    if (!msi_present(dev)) {

        return;

    }

    flags = pci_get_word(dev->config + msi_flags_off(dev));

    flags &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE);

    msi64bit = flags & PCI_MSI_FLAGS_64BIT;

    pci_set_word(dev->config + msi_flags_off(dev), flags);

    pci_set_long(dev->config + msi_address_lo_off(dev), 0);

    if (msi64bit) {

        pci_set_long(dev->config + msi_address_hi_off(dev), 0);

    }

    pci_set_word(dev->config + msi_data_off(dev, msi64bit), 0);

    if (flags & PCI_MSI_FLAGS_MASKBIT) {

        pci_set_long(dev->config + msi_mask_off(dev, msi64bit), 0);

        pci_set_long(dev->config + msi_pending_off(dev, msi64bit), 0);

    }

    MSI_DEV_PRINTF(dev, "reset\n");

}

static bool msi_is_masked(const PCIDevice *dev, unsigned int vector)

{

    uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));

    uint32_t mask;

    assert(vector < PCI_MSI_VECTORS_MAX);

    if (!(flags & PCI_MSI_FLAGS_MASKBIT)) {

        return false;

    }

    mask = pci_get_long(dev->config +

                        msi_mask_off(dev, flags & PCI_MSI_FLAGS_64BIT));

    return mask & (1U << vector);

}

void msi_notify(PCIDevice *dev, unsigned int vector)

{

    uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));

    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;

    unsigned int nr_vectors = msi_nr_vectors(flags);

    uint64_t address;

    uint32_t data;

    assert(vector < nr_vectors);

    if (msi_is_masked(dev, vector)) {

        assert(flags & PCI_MSI_FLAGS_MASKBIT);

        pci_long_test_and_set_mask(

            dev->config + msi_pending_off(dev, msi64bit), 1U << vector);

        MSI_DEV_PRINTF(dev, "pending vector 0x%x\n", vector);

        return;

    }

    if (msi64bit) {

        address = pci_get_quad(dev->config + msi_address_lo_off(dev));

    } else {

        address = pci_get_long(dev->config + msi_address_lo_off(dev));

    }

    /* upper bit 31:16 is zero */

    data = pci_get_word(dev->config + msi_data_off(dev, msi64bit));

    if (nr_vectors > 1) {

        data &= ~(nr_vectors - 1);

        data |= vector;

    }

    MSI_DEV_PRINTF(dev,

                   "notify vector 0x%x"

                   " address: 0x%"PRIx64" data: 0x%"PRIx32"\n",

                   vector, address, data);

    stl_le_phys(address, data);

}

/* call this function after updating configs by pci_default_write_config(). */

void msi_write_config(PCIDevice *dev, uint32_t addr, uint32_t val, int len)

{

    uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));

    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;

    bool msi_per_vector_mask = flags & PCI_MSI_FLAGS_MASKBIT;

    unsigned int nr_vectors;

    uint8_t log_num_vecs;

    uint8_t log_max_vecs;

    unsigned int vector;

    uint32_t pending;

    if (!msi_present(dev) ||

        !ranges_overlap(addr, len, dev->msi_cap, msi_cap_sizeof(flags))) {

        return;

    }

#ifdef MSI_DEBUG

    MSI_DEV_PRINTF(dev, "addr 0x%"PRIx32" val 0x%"PRIx32" len %d\n",

                   addr, val, len);

    MSI_DEV_PRINTF(dev, "ctrl: 0x%"PRIx16" address: 0x%"PRIx32,

                   flags,

                   pci_get_long(dev->config + msi_address_lo_off(dev)));

    if (msi64bit) {

        fprintf(stderr, " address-hi: 0x%"PRIx32,

                pci_get_long(dev->config + msi_address_hi_off(dev)));

    }

    fprintf(stderr, " data: 0x%"PRIx16,

            pci_get_word(dev->config + msi_data_off(dev, msi64bit)));

    if (flags & PCI_MSI_FLAGS_MASKBIT) {

        fprintf(stderr, " mask 0x%"PRIx32" pending 0x%"PRIx32,

                pci_get_long(dev->config + msi_mask_off(dev, msi64bit)),

                pci_get_long(dev->config + msi_pending_off(dev, msi64bit)));

    }

    fprintf(stderr, "\n");

#endif

    if (!(flags & PCI_MSI_FLAGS_ENABLE)) {

        return;

    }

    /*

     * Now MSI is enabled, clear INTx# interrupts.

     * the driver is prohibited from writing enable bit to mask

     * a service request. But the guest OS could do this.

     * So we just discard the interrupts as moderate fallback.

     *

     * 6.8.3.3. Enabling Operation

     *   While enabled for MSI or MSI-X operation, a function is prohibited

     *   from using its INTx# pin (if implemented) to request

     *   service (MSI, MSI-X, and INTx# are mutually exclusive).

     */

    pci_device_deassert_intx(dev);

    /*

     * nr_vectors might be set bigger than capable. So clamp it.

     * This is not legal by spec, so we can do anything we like,

     * just don't crash the host

     */

    log_num_vecs =

        (flags & PCI_MSI_FLAGS_QSIZE) >> (ffs(PCI_MSI_FLAGS_QSIZE) - 1);

    log_max_vecs =

        (flags & PCI_MSI_FLAGS_QMASK) >> (ffs(PCI_MSI_FLAGS_QMASK) - 1);

    if (log_num_vecs > log_max_vecs) {

        flags &= ~PCI_MSI_FLAGS_QSIZE;

        flags |= log_max_vecs << (ffs(PCI_MSI_FLAGS_QSIZE) - 1);

        pci_set_word(dev->config + msi_flags_off(dev), flags);

    }

    if (!msi_per_vector_mask) {

        /* if per vector masking isn't supported,

           there is no pending interrupt. */

        return;

    }

    nr_vectors = msi_nr_vectors(flags);

    /* This will discard pending interrupts, if any. */

    pending = pci_get_long(dev->config + msi_pending_off(dev, msi64bit));

    pending &= 0xffffffff >> (PCI_MSI_VECTORS_MAX - nr_vectors);

    pci_set_long(dev->config + msi_pending_off(dev, msi64bit), pending);

    /* deliver pending interrupts which are unmasked */

    for (vector = 0; vector < nr_vectors; ++vector) {

        if (msi_is_masked(dev, vector) || !(pending & (1U << vector))) {

            continue;

        }

        pci_long_test_and_clear_mask(

            dev->config + msi_pending_off(dev, msi64bit), 1U << vector);

        msi_notify(dev, vector);

    }

}

unsigned int msi_nr_vectors_allocated(const PCIDevice *dev)

{

    uint16_t flags = pci_get_word(dev->config + msi_flags_off(dev));

    return msi_nr_vectors(flags);

}