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/*
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* MSI-X device support
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*
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* This module includes support for MSI-X in pci devices.
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*
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* Author: Michael S. Tsirkin <mst@redhat.com>
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*
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* Copyright (c) 2009, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*/
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#include "hw.h" |
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#include "msix.h" |
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#include "pci.h" |
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#include "range.h" |
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#define MSIX_CAP_LENGTH 12 |
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/* MSI enable bit and maskall bit are in byte 1 in FLAGS register */
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#define MSIX_CONTROL_OFFSET (PCI_MSIX_FLAGS + 1) |
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#define MSIX_ENABLE_MASK (PCI_MSIX_FLAGS_ENABLE >> 8) |
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#define MSIX_MASKALL_MASK (PCI_MSIX_FLAGS_MASKALL >> 8) |
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/* How much space does an MSIX table need. */
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/* The spec requires giving the table structure
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* a 4K aligned region all by itself. */
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#define MSIX_PAGE_SIZE 0x1000 |
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/* Reserve second half of the page for pending bits */
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#define MSIX_PAGE_PENDING (MSIX_PAGE_SIZE / 2) |
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#define MSIX_MAX_ENTRIES 32 |
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/* Flag for interrupt controller to declare MSI-X support */
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int msix_supported;
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/* Add MSI-X capability to the config space for the device. */
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/* Given a bar and its size, add MSI-X table on top of it
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* and fill MSI-X capability in the config space.
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* Original bar size must be a power of 2 or 0.
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* New bar size is returned. */
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static int msix_add_config(struct PCIDevice *pdev, unsigned short nentries, |
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unsigned bar_nr, unsigned bar_size) |
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{ |
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int config_offset;
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uint8_t *config; |
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uint32_t new_size; |
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if (nentries < 1 || nentries > PCI_MSIX_FLAGS_QSIZE + 1) |
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return -EINVAL;
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if (bar_size > 0x80000000) |
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return -ENOSPC;
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/* Add space for MSI-X structures */
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if (!bar_size) {
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new_size = MSIX_PAGE_SIZE; |
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} else if (bar_size < MSIX_PAGE_SIZE) { |
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bar_size = MSIX_PAGE_SIZE; |
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new_size = MSIX_PAGE_SIZE * 2;
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} else {
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new_size = bar_size * 2;
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} |
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pdev->msix_bar_size = new_size; |
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config_offset = pci_add_capability(pdev, PCI_CAP_ID_MSIX, |
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0, MSIX_CAP_LENGTH);
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if (config_offset < 0) |
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return config_offset;
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config = pdev->config + config_offset; |
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pci_set_word(config + PCI_MSIX_FLAGS, nentries - 1);
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/* Table on top of BAR */
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pci_set_long(config + PCI_MSIX_TABLE, bar_size | bar_nr); |
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/* Pending bits on top of that */
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pci_set_long(config + PCI_MSIX_PBA, (bar_size + MSIX_PAGE_PENDING) | |
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bar_nr); |
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pdev->msix_cap = config_offset; |
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/* Make flags bit writable. */
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pdev->wmask[config_offset + MSIX_CONTROL_OFFSET] |= MSIX_ENABLE_MASK | |
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MSIX_MASKALL_MASK; |
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return 0; |
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} |
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static uint64_t msix_mmio_read(void *opaque, target_phys_addr_t addr, |
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unsigned size)
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{ |
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PCIDevice *dev = opaque; |
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unsigned int offset = addr & (MSIX_PAGE_SIZE - 1) & ~0x3; |
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void *page = dev->msix_table_page;
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return pci_get_long(page + offset);
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} |
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static uint8_t msix_pending_mask(int vector) |
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{ |
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return 1 << (vector % 8); |
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} |
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static uint8_t *msix_pending_byte(PCIDevice *dev, int vector) |
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{ |
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return dev->msix_table_page + MSIX_PAGE_PENDING + vector / 8; |
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} |
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static int msix_is_pending(PCIDevice *dev, int vector) |
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{ |
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return *msix_pending_byte(dev, vector) & msix_pending_mask(vector);
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} |
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static void msix_set_pending(PCIDevice *dev, int vector) |
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{ |
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*msix_pending_byte(dev, vector) |= msix_pending_mask(vector); |
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} |
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static void msix_clr_pending(PCIDevice *dev, int vector) |
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{ |
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*msix_pending_byte(dev, vector) &= ~msix_pending_mask(vector); |
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} |
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static int msix_function_masked(PCIDevice *dev) |
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{ |
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return dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK;
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} |
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static int msix_is_masked(PCIDevice *dev, int vector) |
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{ |
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unsigned offset =
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vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; |
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return msix_function_masked(dev) ||
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dev->msix_table_page[offset] & PCI_MSIX_ENTRY_CTRL_MASKBIT; |
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} |
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static void msix_handle_mask_update(PCIDevice *dev, int vector) |
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{ |
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if (!msix_is_masked(dev, vector) && msix_is_pending(dev, vector)) {
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msix_clr_pending(dev, vector); |
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msix_notify(dev, vector); |
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} |
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} |
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/* Handle MSI-X capability config write. */
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void msix_write_config(PCIDevice *dev, uint32_t addr,
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uint32_t val, int len)
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{ |
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unsigned enable_pos = dev->msix_cap + MSIX_CONTROL_OFFSET;
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int vector;
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if (!range_covers_byte(addr, len, enable_pos)) {
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return;
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} |
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if (!msix_enabled(dev)) {
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return;
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} |
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pci_device_deassert_intx(dev); |
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if (msix_function_masked(dev)) {
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return;
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} |
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for (vector = 0; vector < dev->msix_entries_nr; ++vector) { |
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msix_handle_mask_update(dev, vector); |
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} |
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} |
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static void msix_mmio_write(void *opaque, target_phys_addr_t addr, |
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uint64_t val, unsigned size)
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{ |
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PCIDevice *dev = opaque; |
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unsigned int offset = addr & (MSIX_PAGE_SIZE - 1) & ~0x3; |
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int vector = offset / PCI_MSIX_ENTRY_SIZE;
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pci_set_long(dev->msix_table_page + offset, val); |
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msix_handle_mask_update(dev, vector); |
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} |
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static const MemoryRegionOps msix_mmio_ops = { |
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.read = msix_mmio_read, |
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.write = msix_mmio_write, |
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.endianness = DEVICE_NATIVE_ENDIAN, |
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.valid = { |
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.min_access_size = 4,
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.max_access_size = 4,
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}, |
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}; |
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static void msix_mmio_setup(PCIDevice *d, MemoryRegion *bar) |
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{ |
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uint8_t *config = d->config + d->msix_cap; |
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uint32_t table = pci_get_long(config + PCI_MSIX_TABLE); |
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uint32_t offset = table & ~(MSIX_PAGE_SIZE - 1);
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/* TODO: for assigned devices, we'll want to make it possible to map
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* pending bits separately in case they are in a separate bar. */
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memory_region_add_subregion(bar, offset, &d->msix_mmio); |
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} |
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static void msix_mask_all(struct PCIDevice *dev, unsigned nentries) |
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{ |
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int vector;
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for (vector = 0; vector < nentries; ++vector) { |
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unsigned offset =
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vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; |
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dev->msix_table_page[offset] |= PCI_MSIX_ENTRY_CTRL_MASKBIT; |
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} |
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} |
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/* Initialize the MSI-X structures. Note: if MSI-X is supported, BAR size is
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* modified, it should be retrieved with msix_bar_size. */
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int msix_init(struct PCIDevice *dev, unsigned short nentries, |
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MemoryRegion *bar, |
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unsigned bar_nr, unsigned bar_size) |
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{ |
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int ret;
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/* Nothing to do if MSI is not supported by interrupt controller */
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if (!msix_supported)
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return -ENOTSUP;
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if (nentries > MSIX_MAX_ENTRIES)
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return -EINVAL;
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dev->msix_entry_used = g_malloc0(MSIX_MAX_ENTRIES * |
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sizeof *dev->msix_entry_used);
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dev->msix_table_page = g_malloc0(MSIX_PAGE_SIZE); |
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msix_mask_all(dev, nentries); |
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memory_region_init_io(&dev->msix_mmio, &msix_mmio_ops, dev, |
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"msix", MSIX_PAGE_SIZE);
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dev->msix_entries_nr = nentries; |
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ret = msix_add_config(dev, nentries, bar_nr, bar_size); |
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if (ret)
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goto err_config;
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dev->cap_present |= QEMU_PCI_CAP_MSIX; |
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msix_mmio_setup(dev, bar); |
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return 0; |
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err_config:
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dev->msix_entries_nr = 0;
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memory_region_destroy(&dev->msix_mmio); |
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g_free(dev->msix_table_page); |
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dev->msix_table_page = NULL;
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g_free(dev->msix_entry_used); |
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dev->msix_entry_used = NULL;
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return ret;
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} |
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static void msix_free_irq_entries(PCIDevice *dev) |
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{ |
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int vector;
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for (vector = 0; vector < dev->msix_entries_nr; ++vector) { |
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dev->msix_entry_used[vector] = 0;
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msix_clr_pending(dev, vector); |
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} |
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} |
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/* Clean up resources for the device. */
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int msix_uninit(PCIDevice *dev, MemoryRegion *bar)
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{ |
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if (!(dev->cap_present & QEMU_PCI_CAP_MSIX))
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return 0; |
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pci_del_capability(dev, PCI_CAP_ID_MSIX, MSIX_CAP_LENGTH); |
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dev->msix_cap = 0;
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msix_free_irq_entries(dev); |
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dev->msix_entries_nr = 0;
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memory_region_del_subregion(bar, &dev->msix_mmio); |
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memory_region_destroy(&dev->msix_mmio); |
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g_free(dev->msix_table_page); |
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dev->msix_table_page = NULL;
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g_free(dev->msix_entry_used); |
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dev->msix_entry_used = NULL;
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dev->cap_present &= ~QEMU_PCI_CAP_MSIX; |
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return 0; |
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} |
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void msix_save(PCIDevice *dev, QEMUFile *f)
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{ |
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unsigned n = dev->msix_entries_nr;
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if (!(dev->cap_present & QEMU_PCI_CAP_MSIX)) {
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return;
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} |
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qemu_put_buffer(f, dev->msix_table_page, n * PCI_MSIX_ENTRY_SIZE); |
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qemu_put_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8); |
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} |
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/* Should be called after restoring the config space. */
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void msix_load(PCIDevice *dev, QEMUFile *f)
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{ |
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unsigned n = dev->msix_entries_nr;
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if (!(dev->cap_present & QEMU_PCI_CAP_MSIX)) {
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return;
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} |
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msix_free_irq_entries(dev); |
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qemu_get_buffer(f, dev->msix_table_page, n * PCI_MSIX_ENTRY_SIZE); |
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qemu_get_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8); |
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} |
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/* Does device support MSI-X? */
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int msix_present(PCIDevice *dev)
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{ |
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return dev->cap_present & QEMU_PCI_CAP_MSIX;
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} |
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/* Is MSI-X enabled? */
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int msix_enabled(PCIDevice *dev)
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{ |
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return (dev->cap_present & QEMU_PCI_CAP_MSIX) &&
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(dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & |
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MSIX_ENABLE_MASK); |
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} |
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/* Size of bar where MSI-X table resides, or 0 if MSI-X not supported. */
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uint32_t msix_bar_size(PCIDevice *dev) |
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{ |
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return (dev->cap_present & QEMU_PCI_CAP_MSIX) ?
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dev->msix_bar_size : 0;
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} |
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/* Send an MSI-X message */
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void msix_notify(PCIDevice *dev, unsigned vector) |
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{ |
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uint8_t *table_entry = dev->msix_table_page + vector * PCI_MSIX_ENTRY_SIZE; |
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uint64_t address; |
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uint32_t data; |
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if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector])
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return;
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if (msix_is_masked(dev, vector)) {
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msix_set_pending(dev, vector); |
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return;
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} |
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address = pci_get_quad(table_entry + PCI_MSIX_ENTRY_LOWER_ADDR); |
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data = pci_get_long(table_entry + PCI_MSIX_ENTRY_DATA); |
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stl_le_phys(address, data); |
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} |
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void msix_reset(PCIDevice *dev)
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{ |
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if (!(dev->cap_present & QEMU_PCI_CAP_MSIX))
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return;
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msix_free_irq_entries(dev); |
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dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &= |
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~dev->wmask[dev->msix_cap + MSIX_CONTROL_OFFSET]; |
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memset(dev->msix_table_page, 0, MSIX_PAGE_SIZE);
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msix_mask_all(dev, dev->msix_entries_nr); |
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} |
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/* PCI spec suggests that devices make it possible for software to configure
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* less vectors than supported by the device, but does not specify a standard
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* mechanism for devices to do so.
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*
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* We support this by asking devices to declare vectors software is going to
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* actually use, and checking this on the notification path. Devices that
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* don't want to follow the spec suggestion can declare all vectors as used. */
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/* Mark vector as used. */
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int msix_vector_use(PCIDevice *dev, unsigned vector) |
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{ |
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if (vector >= dev->msix_entries_nr)
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return -EINVAL;
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dev->msix_entry_used[vector]++; |
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return 0; |
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} |
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/* Mark vector as unused. */
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void msix_vector_unuse(PCIDevice *dev, unsigned vector) |
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{ |
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if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector]) {
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return;
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} |
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if (--dev->msix_entry_used[vector]) {
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return;
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} |
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msix_clr_pending(dev, vector); |
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} |
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void msix_unuse_all_vectors(PCIDevice *dev)
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{ |
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if (!(dev->cap_present & QEMU_PCI_CAP_MSIX))
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return;
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msix_free_irq_entries(dev); |
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} |