/* * 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/pci.h> #include <linux/proc_fs.h> #include <linux/msi.h> #include <linux/smp.h> #include <asm/errno.h> #include <asm/io.h> #include "pci.h" #include "msi.h" static int pci_msi_enable = 1; static void msi_set_enable(struct pci_dev *dev, int enable) { int pos; u16 control; pos = pci_find_capability(dev, PCI_CAP_ID_MSI); if (pos) { pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); control &= ~PCI_MSI_FLAGS_ENABLE; if (enable) control |= PCI_MSI_FLAGS_ENABLE; pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); } } static void msix_set_enable(struct pci_dev *dev, int enable) { int pos; u16 control; pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (pos) { pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control); control &= ~PCI_MSIX_FLAGS_ENABLE; if (enable) control |= PCI_MSIX_FLAGS_ENABLE; pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control); } } static void msix_flush_writes(unsigned int irq) { struct msi_desc *entry; entry = get_irq_msi(irq); BUG_ON(!entry || !entry->dev); switch (entry->msi_attrib.type) { case PCI_CAP_ID_MSI: /* nothing to do */ break; case PCI_CAP_ID_MSIX: { int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET; readl(entry->mask_base + offset); break; } default: BUG(); break; } } 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); } else { msi_set_enable(entry->dev, !flag); } 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); readl(entry->mask_base + offset); break; } default: BUG(); break; } entry->msi_attrib.masked = !!flag; } 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(); } entry->msg = *msg; } void mask_msi_irq(unsigned int irq) { msi_set_mask_bit(irq, 1); msix_flush_writes(irq); } void unmask_msi_irq(unsigned int irq) { msi_set_mask_bit(irq, 0); msix_flush_writes(irq); } static int msi_free_irqs(struct pci_dev* dev); static struct msi_desc* alloc_msi_entry(void) { struct msi_desc *entry; entry = kzalloc(sizeof(struct msi_desc), GFP_KERNEL); if (!entry) return NULL; INIT_LIST_HEAD(&entry->list); entry->irq = 0; entry->dev = NULL; return entry; } #ifdef CONFIG_PM static void __pci_restore_msi_state(struct pci_dev *dev) { int pos; u16 control; struct msi_desc *entry; if (!dev->msi_enabled) return; entry = get_irq_msi(dev->irq); pos = entry->msi_attrib.pos; pci_intx(dev, 0); /* disable intx */ msi_set_enable(dev, 0); write_msi_msg(dev->irq, &entry->msg); if (entry->msi_attrib.maskbit) msi_set_mask_bit(dev->irq, entry->msi_attrib.masked); pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); control &= ~(PCI_MSI_FLAGS_QSIZE | PCI_MSI_FLAGS_ENABLE); if (entry->msi_attrib.maskbit || !entry->msi_attrib.masked) control |= PCI_MSI_FLAGS_ENABLE; pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); } static void __pci_restore_msix_state(struct pci_dev *dev) { int pos; struct msi_desc *entry; u16 control; if (!dev->msix_enabled) return; /* route the table */ pci_intx(dev, 0); /* disable intx */ msix_set_enable(dev, 0); list_for_each_entry(entry, &dev->msi_list, list) { write_msi_msg(entry->irq, &entry->msg); msi_set_mask_bit(entry->irq, entry->msi_attrib.masked); } BUG_ON(list_empty(&dev->msi_list)); entry = list_entry(dev->msi_list.next, struct msi_desc, list); pos = entry->msi_attrib.pos; pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control); control &= ~PCI_MSIX_FLAGS_MASKALL; control |= PCI_MSIX_FLAGS_ENABLE; pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control); } 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, ret; u16 control; msi_set_enable(dev, 0); /* Ensure msi is disabled as I set it up */ 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.masked = 1; 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); } list_add_tail(&entry->list, &dev->msi_list); /* Configure MSI capability structure */ ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI); if (ret) { msi_free_irqs(dev); return ret; } /* Set MSI enabled bits */ pci_intx(dev, 0); /* disable intx */ msi_set_enable(dev, 1); dev->msi_enabled = 1; dev->irq = entry->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 *entry; int pos, i, j, nr_entries, ret; unsigned long phys_addr; u32 table_offset; u16 control; u8 bir; void __iomem *base; msix_set_enable(dev, 0);/* Ensure msix is disabled as I set it up */ 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.masked = 1; entry->msi_attrib.default_irq = dev->irq; entry->msi_attrib.pos = pos; entry->dev = dev; entry->mask_base = base; list_add_tail(&entry->list, &dev->msi_list); } ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX); if (ret) { int avail = 0; list_for_each_entry(entry, &dev->msi_list, list) { if (entry->irq != 0) { avail++; } } msi_free_irqs(dev); /* If we had some success report the number of irqs * we succeeded in setting up. */ if (avail == 0) avail = ret; return avail; } i = 0; list_for_each_entry(entry, &dev->msi_list, list) { entries[i].vector = entry->irq; set_irq_msi(entry->irq, entry); i++; } /* Set MSI-X enabled bits */ pci_intx(dev, 0); /* disable intx */ msix_set_enable(dev, 1); dev->msix_enabled = 1; return 0; } /** * pci_msi_check_device - check whether MSI may be enabled on a device * @dev: pointer to the pci_dev data structure of MSI device function * @nvec: how many MSIs have been requested ? * @type: are we checking for MSI or MSI-X ? * * Look at global flags, the device itself, and its parent busses * to determine if MSI/-X are supported for the device. If MSI/-X is * supported return 0, else return an error code. **/ static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type) { struct pci_bus *bus; int ret; /* MSI must be globally enabled and supported by the device */ if (!pci_msi_enable || !dev || dev->no_msi) return -EINVAL; /* * You can't ask to have 0 or less MSIs configured. * a) it's stupid .. * b) the list manipulation code assumes nvec >= 1. */ if (nvec < 1) return -ERANGE; /* 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; ret = arch_msi_check_device(dev, nvec, type); if (ret) return ret; if (!pci_find_capability(dev, type)) 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 status; status = pci_msi_check_device(dev, 1, PCI_CAP_ID_MSI); if (status) return status; WARN_ON(!!dev->msi_enabled); /* Check whether driver already requested for MSI-X irqs */ if (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; } EXPORT_SYMBOL(pci_enable_msi); void pci_disable_msi(struct pci_dev* dev) { struct msi_desc *entry; int default_irq; if (!pci_msi_enable || !dev || !dev->msi_enabled) return; msi_set_enable(dev, 0); pci_intx(dev, 1); /* enable intx */ dev->msi_enabled = 0; BUG_ON(list_empty(&dev->msi_list)); entry = list_entry(dev->msi_list.next, struct msi_desc, list); if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) { return; } default_irq = entry->msi_attrib.default_irq; msi_free_irqs(dev); /* Restore dev->irq to its default pin-assertion irq */ dev->irq = default_irq; } EXPORT_SYMBOL(pci_disable_msi); static int msi_free_irqs(struct pci_dev* dev) { struct msi_desc *entry, *tmp; list_for_each_entry(entry, &dev->msi_list, list) { if (entry->irq) BUG_ON(irq_has_action(entry->irq)); } arch_teardown_msi_irqs(dev); list_for_each_entry_safe(entry, tmp, &dev->msi_list, list) { if (entry->msi_attrib.type == PCI_CAP_ID_MSIX) { writel(1, entry->mask_base + entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET); if (list_is_last(&entry->list, &dev->msi_list)) iounmap(entry->mask_base); } list_del(&entry->list); kfree(entry); } 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) return -EINVAL; status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX); if (status) return status; pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); 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 (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; } EXPORT_SYMBOL(pci_enable_msix); static void msix_free_all_irqs(struct pci_dev *dev) { msi_free_irqs(dev); } void pci_disable_msix(struct pci_dev* dev) { if (!pci_msi_enable || !dev || !dev->msix_enabled) return; msix_set_enable(dev, 0); pci_intx(dev, 1); /* enable intx */ dev->msix_enabled = 0; msix_free_all_irqs(dev); } EXPORT_SYMBOL(pci_disable_msix); /** * 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) msi_free_irqs(dev); if (dev->msix_enabled) msix_free_all_irqs(dev); } void pci_no_msi(void) { pci_msi_enable = 0; } void pci_msi_init_pci_dev(struct pci_dev *dev) { INIT_LIST_HEAD(&dev->msi_list); } /* Arch hooks */ int __attribute__ ((weak)) arch_msi_check_device(struct pci_dev* dev, int nvec, int type) { return 0; } int __attribute__ ((weak)) arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *entry) { return 0; } int __attribute__ ((weak)) arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) { struct msi_desc *entry; int ret; list_for_each_entry(entry, &dev->msi_list, list) { ret = arch_setup_msi_irq(dev, entry); if (ret) return ret; } return 0; } void __attribute__ ((weak)) arch_teardown_msi_irq(unsigned int irq) { return; } void __attribute__ ((weak)) arch_teardown_msi_irqs(struct pci_dev *dev) { struct msi_desc *entry; list_for_each_entry(entry, &dev->msi_list, list) { if (entry->irq != 0) arch_teardown_msi_irq(entry->irq); } }