/* * File: msi.c * Purpose: PCI Message Signaled Interrupt (MSI) * * Copyright (C) 2003-2004 Intel * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com) */ #include <linux/err.h> #include <linux/mm.h> #include <linux/irq.h> #include <linux/interrupt.h> #include <linux/init.h> #include <linux/ioport.h> #include <linux/smp_lock.h> #include <linux/pci.h> #include <linux/proc_fs.h> #include <linux/msi.h> #include <asm/errno.h> #include <asm/io.h> #include <asm/smp.h> #include "pci.h" #include "msi.h" static struct kmem_cache* msi_cachep; static int pci_msi_enable = 1; static int msi_cache_init(void) { msi_cachep = kmem_cache_create("msi_cache", sizeof(struct msi_desc), 0, SLAB_HWCACHE_ALIGN, NULL, NULL); if (!msi_cachep) return -ENOMEM; return 0; } static void msi_set_mask_bit(unsigned int irq, int flag) { struct msi_desc *entry; entry = get_irq_msi(irq); BUG_ON(!entry || !entry->dev); switch (entry->msi_attrib.type) { case PCI_CAP_ID_MSI: if (entry->msi_attrib.maskbit) { int pos; u32 mask_bits; pos = (long)entry->mask_base; pci_read_config_dword(entry->dev, pos, &mask_bits); mask_bits &= ~(1); mask_bits |= flag; pci_write_config_dword(entry->dev, pos, mask_bits); } break; case PCI_CAP_ID_MSIX: { int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET; writel(flag, entry->mask_base + offset); break; } default: BUG(); break; } } void read_msi_msg(unsigned int irq, struct msi_msg *msg) { struct msi_desc *entry = get_irq_msi(irq); switch(entry->msi_attrib.type) { case PCI_CAP_ID_MSI: { struct pci_dev *dev = entry->dev; int pos = entry->msi_attrib.pos; u16 data; pci_read_config_dword(dev, msi_lower_address_reg(pos), &msg->address_lo); if (entry->msi_attrib.is_64) { pci_read_config_dword(dev, msi_upper_address_reg(pos), &msg->address_hi); pci_read_config_word(dev, msi_data_reg(pos, 1), &data); } else { msg->address_hi = 0; pci_read_config_word(dev, msi_data_reg(pos, 1), &data); } msg->data = data; break; } case PCI_CAP_ID_MSIX: { void __iomem *base; base = entry->mask_base + entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET); msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET); msg->data = readl(base + PCI_MSIX_ENTRY_DATA_OFFSET); break; } default: BUG(); } } void write_msi_msg(unsigned int irq, struct msi_msg *msg) { struct msi_desc *entry = get_irq_msi(irq); switch (entry->msi_attrib.type) { case PCI_CAP_ID_MSI: { struct pci_dev *dev = entry->dev; int pos = entry->msi_attrib.pos; pci_write_config_dword(dev, msi_lower_address_reg(pos), msg->address_lo); if (entry->msi_attrib.is_64) { pci_write_config_dword(dev, msi_upper_address_reg(pos), msg->address_hi); pci_write_config_word(dev, msi_data_reg(pos, 1), msg->data); } else { pci_write_config_word(dev, msi_data_reg(pos, 0), msg->data); } break; } case PCI_CAP_ID_MSIX: { void __iomem *base; base = entry->mask_base + entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET); writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET); writel(msg->data, base + PCI_MSIX_ENTRY_DATA_OFFSET); break; } default: BUG(); } } void mask_msi_irq(unsigned int irq) { msi_set_mask_bit(irq, 1); } void unmask_msi_irq(unsigned int irq) { msi_set_mask_bit(irq, 0); } static int msi_free_irq(struct pci_dev* dev, int irq); static int msi_init(void) { static int status = -ENOMEM; if (!status) return status; status = msi_cache_init(); if (status < 0) { pci_msi_enable = 0; printk(KERN_WARNING "PCI: MSI cache init failed\n"); return status; } return status; } static struct msi_desc* alloc_msi_entry(void) { struct msi_desc *entry; entry = kmem_cache_zalloc(msi_cachep, GFP_KERNEL); if (!entry) return NULL; entry->link.tail = entry->link.head = 0; /* single message */ entry->dev = NULL; return entry; } static void enable_msi_mode(struct pci_dev *dev, int pos, int type) { u16 control; pci_read_config_word(dev, msi_control_reg(pos), &control); if (type == PCI_CAP_ID_MSI) { /* Set enabled bits to single MSI & enable MSI_enable bit */ msi_enable(control, 1); pci_write_config_word(dev, msi_control_reg(pos), control); dev->msi_enabled = 1; } else { msix_enable(control); pci_write_config_word(dev, msi_control_reg(pos), control); dev->msix_enabled = 1; } pci_intx(dev, 0); /* disable intx */ } void disable_msi_mode(struct pci_dev *dev, int pos, int type) { u16 control; pci_read_config_word(dev, msi_control_reg(pos), &control); if (type == PCI_CAP_ID_MSI) { /* Set enabled bits to single MSI & enable MSI_enable bit */ msi_disable(control); pci_write_config_word(dev, msi_control_reg(pos), control); dev->msi_enabled = 0; } else { msix_disable(control); pci_write_config_word(dev, msi_control_reg(pos), control); dev->msix_enabled = 0; } pci_intx(dev, 1); /* enable intx */ } #ifdef CONFIG_PM static int __pci_save_msi_state(struct pci_dev *dev) { int pos, i = 0; u16 control; struct pci_cap_saved_state *save_state; u32 *cap; pos = pci_find_capability(dev, PCI_CAP_ID_MSI); if (pos <= 0 || dev->no_msi) return 0; pci_read_config_word(dev, msi_control_reg(pos), &control); if (!(control & PCI_MSI_FLAGS_ENABLE)) return 0; save_state = kzalloc(sizeof(struct pci_cap_saved_state) + sizeof(u32) * 5, GFP_KERNEL); if (!save_state) { printk(KERN_ERR "Out of memory in pci_save_msi_state\n"); return -ENOMEM; } cap = &save_state->data[0]; pci_read_config_dword(dev, pos, &cap[i++]); control = cap[0] >> 16; pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, &cap[i++]); if (control & PCI_MSI_FLAGS_64BIT) { pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, &cap[i++]); pci_read_config_dword(dev, pos + PCI_MSI_DATA_64, &cap[i++]); } else pci_read_config_dword(dev, pos + PCI_MSI_DATA_32, &cap[i++]); if (control & PCI_MSI_FLAGS_MASKBIT) pci_read_config_dword(dev, pos + PCI_MSI_MASK_BIT, &cap[i++]); save_state->cap_nr = PCI_CAP_ID_MSI; pci_add_saved_cap(dev, save_state); return 0; } static void __pci_restore_msi_state(struct pci_dev *dev) { int i = 0, pos; u16 control; struct pci_cap_saved_state *save_state; u32 *cap; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSI); pos = pci_find_capability(dev, PCI_CAP_ID_MSI); if (!save_state || pos <= 0) return; cap = &save_state->data[0]; control = cap[i++] >> 16; pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, cap[i++]); if (control & PCI_MSI_FLAGS_64BIT) { pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, cap[i++]); pci_write_config_dword(dev, pos + PCI_MSI_DATA_64, cap[i++]); } else pci_write_config_dword(dev, pos + PCI_MSI_DATA_32, cap[i++]); if (control & PCI_MSI_FLAGS_MASKBIT) pci_write_config_dword(dev, pos + PCI_MSI_MASK_BIT, cap[i++]); pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); enable_msi_mode(dev, pos, PCI_CAP_ID_MSI); pci_remove_saved_cap(save_state); kfree(save_state); } static int __pci_save_msix_state(struct pci_dev *dev) { int pos; int irq, head, tail = 0; u16 control; struct pci_cap_saved_state *save_state; if (!dev->msix_enabled) return 0; pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (pos <= 0 || dev->no_msi) return 0; /* save the capability */ pci_read_config_word(dev, msi_control_reg(pos), &control); if (!(control & PCI_MSIX_FLAGS_ENABLE)) return 0; save_state = kzalloc(sizeof(struct pci_cap_saved_state) + sizeof(u16), GFP_KERNEL); if (!save_state) { printk(KERN_ERR "Out of memory in pci_save_msix_state\n"); return -ENOMEM; } *((u16 *)&save_state->data[0]) = control; /* save the table */ irq = head = dev->first_msi_irq; while (head != tail) { struct msi_desc *entry; entry = get_irq_msi(irq); read_msi_msg(irq, &entry->msg_save); tail = entry->link.tail; irq = tail; } save_state->cap_nr = PCI_CAP_ID_MSIX; pci_add_saved_cap(dev, save_state); return 0; } int pci_save_msi_state(struct pci_dev *dev) { int rc; rc = __pci_save_msi_state(dev); if (rc) return rc; rc = __pci_save_msix_state(dev); return rc; } static void __pci_restore_msix_state(struct pci_dev *dev) { u16 save; int pos; int irq, head, tail = 0; struct msi_desc *entry; struct pci_cap_saved_state *save_state; if (!dev->msix_enabled) return; save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSIX); if (!save_state) return; save = *((u16 *)&save_state->data[0]); pci_remove_saved_cap(save_state); kfree(save_state); pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (pos <= 0) return; /* route the table */ irq = head = dev->first_msi_irq; while (head != tail) { entry = get_irq_msi(irq); write_msi_msg(irq, &entry->msg_save); tail = entry->link.tail; irq = tail; } pci_write_config_word(dev, msi_control_reg(pos), save); enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX); } void pci_restore_msi_state(struct pci_dev *dev) { __pci_restore_msi_state(dev); __pci_restore_msix_state(dev); } #endif /* CONFIG_PM */ /** * msi_capability_init - configure device's MSI capability structure * @dev: pointer to the pci_dev data structure of MSI device function * * Setup the MSI capability structure of device function with a single * MSI irq, regardless of device function is capable of handling * multiple messages. A return of zero indicates the successful setup * of an entry zero with the new MSI irq or non-zero for otherwise. **/ static int msi_capability_init(struct pci_dev *dev) { struct msi_desc *entry; int pos, irq; u16 control; pos = pci_find_capability(dev, PCI_CAP_ID_MSI); pci_read_config_word(dev, msi_control_reg(pos), &control); /* MSI Entry Initialization */ entry = alloc_msi_entry(); if (!entry) return -ENOMEM; entry->msi_attrib.type = PCI_CAP_ID_MSI; entry->msi_attrib.is_64 = is_64bit_address(control); entry->msi_attrib.entry_nr = 0; entry->msi_attrib.maskbit = is_mask_bit_support(control); entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */ entry->msi_attrib.pos = pos; if (is_mask_bit_support(control)) { entry->mask_base = (void __iomem *)(long)msi_mask_bits_reg(pos, is_64bit_address(control)); } entry->dev = dev; if (entry->msi_attrib.maskbit) { unsigned int maskbits, temp; /* All MSIs are unmasked by default, Mask them all */ pci_read_config_dword(dev, msi_mask_bits_reg(pos, is_64bit_address(control)), &maskbits); temp = (1 << multi_msi_capable(control)); temp = ((temp - 1) & ~temp); maskbits |= temp; pci_write_config_dword(dev, msi_mask_bits_reg(pos, is_64bit_address(control)), maskbits); } /* Configure MSI capability structure */ irq = arch_setup_msi_irq(dev, entry); if (irq < 0) { kmem_cache_free(msi_cachep, entry); return irq; } entry->link.head = irq; entry->link.tail = irq; dev->first_msi_irq = irq; set_irq_msi(irq, entry); /* Set MSI enabled bits */ enable_msi_mode(dev, pos, PCI_CAP_ID_MSI); dev->irq = irq; return 0; } /** * msix_capability_init - configure device's MSI-X capability * @dev: pointer to the pci_dev data structure of MSI-X device function * @entries: pointer to an array of struct msix_entry entries * @nvec: number of @entries * * Setup the MSI-X capability structure of device function with a * single MSI-X irq. A return of zero indicates the successful setup of * requested MSI-X entries with allocated irqs or non-zero for otherwise. **/ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, int nvec) { struct msi_desc *head = NULL, *tail = NULL, *entry = NULL; int irq, pos, i, j, nr_entries, temp = 0; unsigned long phys_addr; u32 table_offset; u16 control; u8 bir; void __iomem *base; pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); /* Request & Map MSI-X table region */ pci_read_config_word(dev, msi_control_reg(pos), &control); nr_entries = multi_msix_capable(control); pci_read_config_dword(dev, msix_table_offset_reg(pos), &table_offset); bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK); table_offset &= ~PCI_MSIX_FLAGS_BIRMASK; phys_addr = pci_resource_start (dev, bir) + table_offset; base = ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE); if (base == NULL) return -ENOMEM; /* MSI-X Table Initialization */ for (i = 0; i < nvec; i++) { entry = alloc_msi_entry(); if (!entry) break; j = entries[i].entry; entry->msi_attrib.type = PCI_CAP_ID_MSIX; entry->msi_attrib.is_64 = 1; entry->msi_attrib.entry_nr = j; entry->msi_attrib.maskbit = 1; entry->msi_attrib.default_irq = dev->irq; entry->msi_attrib.pos = pos; entry->dev = dev; entry->mask_base = base; /* Configure MSI-X capability structure */ irq = arch_setup_msi_irq(dev, entry); if (irq < 0) { kmem_cache_free(msi_cachep, entry); break; } entries[i].vector = irq; if (!head) { entry->link.head = irq; entry->link.tail = irq; head = entry; } else { entry->link.head = temp; entry->link.tail = tail->link.tail; tail->link.tail = irq; head->link.head = irq; } temp = irq; tail = entry; set_irq_msi(irq, entry); } if (i != nvec) { int avail = i - 1; i--; for (; i >= 0; i--) { irq = (entries + i)->vector; msi_free_irq(dev, irq); (entries + i)->vector = 0; } /* If we had some success report the number of irqs * we succeeded in setting up. */ if (avail <= 0) avail = -EBUSY; return avail; } dev->first_msi_irq = entries[0].vector; /* Set MSI-X enabled bits */ enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX); return 0; } /** * pci_msi_supported - check whether MSI may be enabled on device * @dev: pointer to the pci_dev data structure of MSI device function * * Look at global flags, the device itself, and its parent busses * to return 0 if MSI are supported for the device. **/ static int pci_msi_supported(struct pci_dev * dev) { struct pci_bus *bus; /* MSI must be globally enabled and supported by the device */ if (!pci_msi_enable || !dev || dev->no_msi) return -EINVAL; /* Any bridge which does NOT route MSI transactions from it's * secondary bus to it's primary bus must set NO_MSI flag on * the secondary pci_bus. * We expect only arch-specific PCI host bus controller driver * or quirks for specific PCI bridges to be setting NO_MSI. */ for (bus = dev->bus; bus; bus = bus->parent) if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI) return -EINVAL; return 0; } /** * pci_enable_msi - configure device's MSI capability structure * @dev: pointer to the pci_dev data structure of MSI device function * * Setup the MSI capability structure of device function with * a single MSI irq upon its software driver call to request for * MSI mode enabled on its hardware device function. A return of zero * indicates the successful setup of an entry zero with the new MSI * irq or non-zero for otherwise. **/ int pci_enable_msi(struct pci_dev* dev) { int pos, status; if (pci_msi_supported(dev) < 0) return -EINVAL; status = msi_init(); if (status < 0) return status; pos = pci_find_capability(dev, PCI_CAP_ID_MSI); if (!pos) return -EINVAL; WARN_ON(!!dev->msi_enabled); /* Check whether driver already requested for MSI-X irqs */ pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (pos > 0 && dev->msix_enabled) { printk(KERN_INFO "PCI: %s: Can't enable MSI. " "Device already has MSI-X enabled\n", pci_name(dev)); return -EINVAL; } status = msi_capability_init(dev); return status; } void pci_disable_msi(struct pci_dev* dev) { struct msi_desc *entry; int pos, default_irq; u16 control; if (!pci_msi_enable) return; if (!dev) return; if (!dev->msi_enabled) return; pos = pci_find_capability(dev, PCI_CAP_ID_MSI); if (!pos) return; pci_read_config_word(dev, msi_control_reg(pos), &control); if (!(control & PCI_MSI_FLAGS_ENABLE)) return; disable_msi_mode(dev, pos, PCI_CAP_ID_MSI); entry = get_irq_msi(dev->first_msi_irq); if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) { return; } if (irq_has_action(dev->first_msi_irq)) { printk(KERN_WARNING "PCI: %s: pci_disable_msi() called without " "free_irq() on MSI irq %d\n", pci_name(dev), dev->first_msi_irq); BUG_ON(irq_has_action(dev->first_msi_irq)); } else { default_irq = entry->msi_attrib.default_irq; msi_free_irq(dev, dev->first_msi_irq); /* Restore dev->irq to its default pin-assertion irq */ dev->irq = default_irq; } dev->first_msi_irq = 0; } static int msi_free_irq(struct pci_dev* dev, int irq) { struct msi_desc *entry; int head, entry_nr, type; void __iomem *base; entry = get_irq_msi(irq); if (!entry || entry->dev != dev) { return -EINVAL; } type = entry->msi_attrib.type; entry_nr = entry->msi_attrib.entry_nr; head = entry->link.head; base = entry->mask_base; get_irq_msi(entry->link.head)->link.tail = entry->link.tail; get_irq_msi(entry->link.tail)->link.head = entry->link.head; arch_teardown_msi_irq(irq); kmem_cache_free(msi_cachep, entry); if (type == PCI_CAP_ID_MSIX) { writel(1, base + entry_nr * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET); if (head == irq) iounmap(base); } return 0; } /** * pci_enable_msix - configure device's MSI-X capability structure * @dev: pointer to the pci_dev data structure of MSI-X device function * @entries: pointer to an array of MSI-X entries * @nvec: number of MSI-X irqs requested for allocation by device driver * * Setup the MSI-X capability structure of device function with the number * of requested irqs upon its software driver call to request for * MSI-X mode enabled on its hardware device function. A return of zero * indicates the successful configuration of MSI-X capability structure * with new allocated MSI-X irqs. A return of < 0 indicates a failure. * Or a return of > 0 indicates that driver request is exceeding the number * of irqs available. Driver should use the returned value to re-send * its request. **/ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) { int status, pos, nr_entries; int i, j; u16 control; if (!entries || pci_msi_supported(dev) < 0) return -EINVAL; status = msi_init(); if (status < 0) return status; pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (!pos) return -EINVAL; pci_read_config_word(dev, msi_control_reg(pos), &control); nr_entries = multi_msix_capable(control); if (nvec > nr_entries) return -EINVAL; /* Check for any invalid entries */ for (i = 0; i < nvec; i++) { if (entries[i].entry >= nr_entries) return -EINVAL; /* invalid entry */ for (j = i + 1; j < nvec; j++) { if (entries[i].entry == entries[j].entry) return -EINVAL; /* duplicate entry */ } } WARN_ON(!!dev->msix_enabled); /* Check whether driver already requested for MSI irq */ if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 && dev->msi_enabled) { printk(KERN_INFO "PCI: %s: Can't enable MSI-X. " "Device already has an MSI irq assigned\n", pci_name(dev)); return -EINVAL; } status = msix_capability_init(dev, entries, nvec); return status; } void pci_disable_msix(struct pci_dev* dev) { int irq, head, tail = 0, warning = 0; int pos; u16 control; if (!pci_msi_enable) return; if (!dev) return; if (!dev->msix_enabled) return; pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (!pos) return; pci_read_config_word(dev, msi_control_reg(pos), &control); if (!(control & PCI_MSIX_FLAGS_ENABLE)) return; disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX); irq = head = dev->first_msi_irq; while (head != tail) { tail = get_irq_msi(irq)->link.tail; if (irq_has_action(irq)) warning = 1; else if (irq != head) /* Release MSI-X irq */ msi_free_irq(dev, irq); irq = tail; } msi_free_irq(dev, irq); if (warning) { printk(KERN_WARNING "PCI: %s: pci_disable_msix() called without " "free_irq() on all MSI-X irqs\n", pci_name(dev)); BUG_ON(warning > 0); } dev->first_msi_irq = 0; } /** * msi_remove_pci_irq_vectors - reclaim MSI(X) irqs to unused state * @dev: pointer to the pci_dev data structure of MSI(X) device function * * Being called during hotplug remove, from which the device function * is hot-removed. All previous assigned MSI/MSI-X irqs, if * allocated for this device function, are reclaimed to unused state, * which may be used later on. **/ void msi_remove_pci_irq_vectors(struct pci_dev* dev) { if (!pci_msi_enable || !dev) return; if (dev->msi_enabled) { if (irq_has_action(dev->first_msi_irq)) { printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() " "called without free_irq() on MSI irq %d\n", pci_name(dev), dev->first_msi_irq); BUG_ON(irq_has_action(dev->first_msi_irq)); } else /* Release MSI irq assigned to this device */ msi_free_irq(dev, dev->first_msi_irq); } if (dev->msix_enabled) { int irq, head, tail = 0, warning = 0; void __iomem *base = NULL; irq = head = dev->first_msi_irq; while (head != tail) { tail = get_irq_msi(irq)->link.tail; base = get_irq_msi(irq)->mask_base; if (irq_has_action(irq)) warning = 1; else if (irq != head) /* Release MSI-X irq */ msi_free_irq(dev, irq); irq = tail; } msi_free_irq(dev, irq); if (warning) { iounmap(base); printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() " "called without free_irq() on all MSI-X irqs\n", pci_name(dev)); BUG_ON(warning > 0); } } } void pci_no_msi(void) { pci_msi_enable = 0; } EXPORT_SYMBOL(pci_enable_msi); EXPORT_SYMBOL(pci_disable_msi); EXPORT_SYMBOL(pci_enable_msix); EXPORT_SYMBOL(pci_disable_msix);