diff options
Diffstat (limited to 'drivers/pci/msi/msi.c')
| -rw-r--r-- | drivers/pci/msi/msi.c | 1147 |
1 files changed, 1147 insertions, 0 deletions
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c new file mode 100644 index 000000000000..c19c7ca58186 --- /dev/null +++ b/drivers/pci/msi/msi.c @@ -0,0 +1,1147 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Message Signaled Interrupt (MSI) + * + * Copyright (C) 2003-2004 Intel + * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com) + * Copyright (C) 2016 Christoph Hellwig. + */ +#include <linux/err.h> +#include <linux/export.h> +#include <linux/irq.h> + +#include "../pci.h" +#include "msi.h" + +static int pci_msi_enable = 1; +int pci_msi_ignore_mask; + +static noinline void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set) +{ + raw_spinlock_t *lock = &to_pci_dev(desc->dev)->msi_lock; + unsigned long flags; + + if (!desc->pci.msi_attrib.can_mask) + return; + + raw_spin_lock_irqsave(lock, flags); + desc->pci.msi_mask &= ~clear; + desc->pci.msi_mask |= set; + pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->pci.mask_pos, + desc->pci.msi_mask); + raw_spin_unlock_irqrestore(lock, flags); +} + +static inline void pci_msi_mask(struct msi_desc *desc, u32 mask) +{ + pci_msi_update_mask(desc, 0, mask); +} + +static inline void pci_msi_unmask(struct msi_desc *desc, u32 mask) +{ + pci_msi_update_mask(desc, mask, 0); +} + +static inline void __iomem *pci_msix_desc_addr(struct msi_desc *desc) +{ + return desc->pci.mask_base + desc->msi_index * PCI_MSIX_ENTRY_SIZE; +} + +/* + * This internal function does not flush PCI writes to the device. All + * users must ensure that they read from the device before either assuming + * that the device state is up to date, or returning out of this file. + * It does not affect the msi_desc::msix_ctrl cache either. Use with care! + */ +static void pci_msix_write_vector_ctrl(struct msi_desc *desc, u32 ctrl) +{ + void __iomem *desc_addr = pci_msix_desc_addr(desc); + + if (desc->pci.msi_attrib.can_mask) + writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL); +} + +static inline void pci_msix_mask(struct msi_desc *desc) +{ + desc->pci.msix_ctrl |= PCI_MSIX_ENTRY_CTRL_MASKBIT; + pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl); + /* Flush write to device */ + readl(desc->pci.mask_base); +} + +static inline void pci_msix_unmask(struct msi_desc *desc) +{ + desc->pci.msix_ctrl &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT; + pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl); +} + +static void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask) +{ + if (desc->pci.msi_attrib.is_msix) + pci_msix_mask(desc); + else + pci_msi_mask(desc, mask); +} + +static void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask) +{ + if (desc->pci.msi_attrib.is_msix) + pci_msix_unmask(desc); + else + pci_msi_unmask(desc, mask); +} + +/** + * pci_msi_mask_irq - Generic IRQ chip callback to mask PCI/MSI interrupts + * @data: pointer to irqdata associated to that interrupt + */ +void pci_msi_mask_irq(struct irq_data *data) +{ + struct msi_desc *desc = irq_data_get_msi_desc(data); + + __pci_msi_mask_desc(desc, BIT(data->irq - desc->irq)); +} +EXPORT_SYMBOL_GPL(pci_msi_mask_irq); + +/** + * pci_msi_unmask_irq - Generic IRQ chip callback to unmask PCI/MSI interrupts + * @data: pointer to irqdata associated to that interrupt + */ +void pci_msi_unmask_irq(struct irq_data *data) +{ + struct msi_desc *desc = irq_data_get_msi_desc(data); + + __pci_msi_unmask_desc(desc, BIT(data->irq - desc->irq)); +} +EXPORT_SYMBOL_GPL(pci_msi_unmask_irq); + +void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg) +{ + struct pci_dev *dev = msi_desc_to_pci_dev(entry); + + BUG_ON(dev->current_state != PCI_D0); + + if (entry->pci.msi_attrib.is_msix) { + void __iomem *base = pci_msix_desc_addr(entry); + + if (WARN_ON_ONCE(entry->pci.msi_attrib.is_virtual)) + return; + + msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR); + msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR); + msg->data = readl(base + PCI_MSIX_ENTRY_DATA); + } else { + int pos = dev->msi_cap; + u16 data; + + pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, + &msg->address_lo); + if (entry->pci.msi_attrib.is_64) { + pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, + &msg->address_hi); + pci_read_config_word(dev, pos + PCI_MSI_DATA_64, &data); + } else { + msg->address_hi = 0; + pci_read_config_word(dev, pos + PCI_MSI_DATA_32, &data); + } + msg->data = data; + } +} + +void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) +{ + struct pci_dev *dev = msi_desc_to_pci_dev(entry); + + if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) { + /* Don't touch the hardware now */ + } else if (entry->pci.msi_attrib.is_msix) { + void __iomem *base = pci_msix_desc_addr(entry); + u32 ctrl = entry->pci.msix_ctrl; + bool unmasked = !(ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT); + + if (entry->pci.msi_attrib.is_virtual) + goto skip; + + /* + * The specification mandates that the entry is masked + * when the message is modified: + * + * "If software changes the Address or Data value of an + * entry while the entry is unmasked, the result is + * undefined." + */ + if (unmasked) + pci_msix_write_vector_ctrl(entry, ctrl | PCI_MSIX_ENTRY_CTRL_MASKBIT); + + writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR); + writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR); + writel(msg->data, base + PCI_MSIX_ENTRY_DATA); + + if (unmasked) + pci_msix_write_vector_ctrl(entry, ctrl); + + /* Ensure that the writes are visible in the device */ + readl(base + PCI_MSIX_ENTRY_DATA); + } else { + int pos = dev->msi_cap; + u16 msgctl; + + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl); + msgctl &= ~PCI_MSI_FLAGS_QSIZE; + msgctl |= entry->pci.msi_attrib.multiple << 4; + pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl); + + pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, + msg->address_lo); + if (entry->pci.msi_attrib.is_64) { + pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, + msg->address_hi); + pci_write_config_word(dev, pos + PCI_MSI_DATA_64, + msg->data); + } else { + pci_write_config_word(dev, pos + PCI_MSI_DATA_32, + msg->data); + } + /* Ensure that the writes are visible in the device */ + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl); + } + +skip: + entry->msg = *msg; + + if (entry->write_msi_msg) + entry->write_msi_msg(entry, entry->write_msi_msg_data); + +} + +void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg) +{ + struct msi_desc *entry = irq_get_msi_desc(irq); + + __pci_write_msi_msg(entry, msg); +} +EXPORT_SYMBOL_GPL(pci_write_msi_msg); + +static void free_msi_irqs(struct pci_dev *dev) +{ + pci_msi_teardown_msi_irqs(dev); + + if (dev->msix_base) { + iounmap(dev->msix_base); + dev->msix_base = NULL; + } +} + +static void pci_intx_for_msi(struct pci_dev *dev, int enable) +{ + if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG)) + pci_intx(dev, enable); +} + +static void pci_msi_set_enable(struct pci_dev *dev, int enable) +{ + u16 control; + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + control &= ~PCI_MSI_FLAGS_ENABLE; + if (enable) + control |= PCI_MSI_FLAGS_ENABLE; + pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control); +} + +/* + * Architecture override returns true when the PCI MSI message should be + * written by the generic restore function. + */ +bool __weak arch_restore_msi_irqs(struct pci_dev *dev) +{ + return true; +} + +static void __pci_restore_msi_state(struct pci_dev *dev) +{ + struct msi_desc *entry; + u16 control; + + if (!dev->msi_enabled) + return; + + entry = irq_get_msi_desc(dev->irq); + + pci_intx_for_msi(dev, 0); + pci_msi_set_enable(dev, 0); + if (arch_restore_msi_irqs(dev)) + __pci_write_msi_msg(entry, &entry->msg); + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + pci_msi_update_mask(entry, 0, 0); + control &= ~PCI_MSI_FLAGS_QSIZE; + control |= (entry->pci.msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE; + pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control); +} + +static void pci_msix_clear_and_set_ctrl(struct pci_dev *dev, u16 clear, u16 set) +{ + u16 ctrl; + + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl); + ctrl &= ~clear; + ctrl |= set; + pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, ctrl); +} + +static void __pci_restore_msix_state(struct pci_dev *dev) +{ + struct msi_desc *entry; + bool write_msg; + + if (!dev->msix_enabled) + return; + + /* route the table */ + pci_intx_for_msi(dev, 0); + pci_msix_clear_and_set_ctrl(dev, 0, + PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL); + + write_msg = arch_restore_msi_irqs(dev); + + msi_lock_descs(&dev->dev); + msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) { + if (write_msg) + __pci_write_msi_msg(entry, &entry->msg); + pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl); + } + msi_unlock_descs(&dev->dev); + + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0); +} + +void pci_restore_msi_state(struct pci_dev *dev) +{ + __pci_restore_msi_state(dev); + __pci_restore_msix_state(dev); +} +EXPORT_SYMBOL_GPL(pci_restore_msi_state); + +static void pcim_msi_release(void *pcidev) +{ + struct pci_dev *dev = pcidev; + + dev->is_msi_managed = false; + pci_free_irq_vectors(dev); +} + +/* + * Needs to be separate from pcim_release to prevent an ordering problem + * vs. msi_device_data_release() in the MSI core code. + */ +static int pcim_setup_msi_release(struct pci_dev *dev) +{ + int ret; + + if (!pci_is_managed(dev) || dev->is_msi_managed) + return 0; + + ret = devm_add_action(&dev->dev, pcim_msi_release, dev); + if (!ret) + dev->is_msi_managed = true; + return ret; +} + +/* + * Ordering vs. devres: msi device data has to be installed first so that + * pcim_msi_release() is invoked before it on device release. + */ +static int pci_setup_msi_context(struct pci_dev *dev) +{ + int ret = msi_setup_device_data(&dev->dev); + + if (!ret) + ret = pcim_setup_msi_release(dev); + return ret; +} + +static int msi_setup_msi_desc(struct pci_dev *dev, int nvec, + struct irq_affinity_desc *masks) +{ + struct msi_desc desc; + u16 control; + + /* MSI Entry Initialization */ + memset(&desc, 0, sizeof(desc)); + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + /* Lies, damned lies, and MSIs */ + if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING) + control |= PCI_MSI_FLAGS_MASKBIT; + /* Respect XEN's mask disabling */ + if (pci_msi_ignore_mask) + control &= ~PCI_MSI_FLAGS_MASKBIT; + + desc.nvec_used = nvec; + desc.pci.msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT); + desc.pci.msi_attrib.can_mask = !!(control & PCI_MSI_FLAGS_MASKBIT); + desc.pci.msi_attrib.default_irq = dev->irq; + desc.pci.msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1; + desc.pci.msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec)); + desc.affinity = masks; + + if (control & PCI_MSI_FLAGS_64BIT) + desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_64; + else + desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_32; + + /* Save the initial mask status */ + if (desc.pci.msi_attrib.can_mask) + pci_read_config_dword(dev, desc.pci.mask_pos, &desc.pci.msi_mask); + + return msi_add_msi_desc(&dev->dev, &desc); +} + +static int msi_verify_entries(struct pci_dev *dev) +{ + struct msi_desc *entry; + + if (!dev->no_64bit_msi) + return 0; + + msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) { + if (entry->msg.address_hi) { + pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n", + entry->msg.address_hi, entry->msg.address_lo); + break; + } + } + return !entry ? 0 : -EIO; +} + +/** + * msi_capability_init - configure device's MSI capability structure + * @dev: pointer to the pci_dev data structure of MSI device function + * @nvec: number of interrupts to allocate + * @affd: description of automatic IRQ affinity assignments (may be %NULL) + * + * Setup the MSI capability structure of the device with the requested + * number of interrupts. A return value of zero indicates the successful + * setup of an entry with the new MSI IRQ. A negative return value indicates + * an error, and a positive return value indicates the number of interrupts + * which could have been allocated. + */ +static int msi_capability_init(struct pci_dev *dev, int nvec, + struct irq_affinity *affd) +{ + struct irq_affinity_desc *masks = NULL; + struct msi_desc *entry; + int ret; + + /* + * Disable MSI during setup in the hardware, but mark it enabled + * so that setup code can evaluate it. + */ + pci_msi_set_enable(dev, 0); + dev->msi_enabled = 1; + + if (affd) + masks = irq_create_affinity_masks(nvec, affd); + + msi_lock_descs(&dev->dev); + ret = msi_setup_msi_desc(dev, nvec, masks); + if (ret) + goto fail; + + /* All MSIs are unmasked by default; mask them all */ + entry = msi_first_desc(&dev->dev, MSI_DESC_ALL); + pci_msi_mask(entry, msi_multi_mask(entry)); + + /* Configure MSI capability structure */ + ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI); + if (ret) + goto err; + + ret = msi_verify_entries(dev); + if (ret) + goto err; + + /* Set MSI enabled bits */ + pci_intx_for_msi(dev, 0); + pci_msi_set_enable(dev, 1); + + pcibios_free_irq(dev); + dev->irq = entry->irq; + goto unlock; + +err: + pci_msi_unmask(entry, msi_multi_mask(entry)); + free_msi_irqs(dev); +fail: + dev->msi_enabled = 0; +unlock: + msi_unlock_descs(&dev->dev); + kfree(masks); + return ret; +} + +static void __iomem *msix_map_region(struct pci_dev *dev, + unsigned int nr_entries) +{ + resource_size_t phys_addr; + u32 table_offset; + unsigned long flags; + u8 bir; + + pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE, + &table_offset); + bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR); + flags = pci_resource_flags(dev, bir); + if (!flags || (flags & IORESOURCE_UNSET)) + return NULL; + + table_offset &= PCI_MSIX_TABLE_OFFSET; + phys_addr = pci_resource_start(dev, bir) + table_offset; + + return ioremap(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE); +} + +static int msix_setup_msi_descs(struct pci_dev *dev, void __iomem *base, + struct msix_entry *entries, int nvec, + struct irq_affinity_desc *masks) +{ + int ret = 0, i, vec_count = pci_msix_vec_count(dev); + struct irq_affinity_desc *curmsk; + struct msi_desc desc; + void __iomem *addr; + + memset(&desc, 0, sizeof(desc)); + + desc.nvec_used = 1; + desc.pci.msi_attrib.is_msix = 1; + desc.pci.msi_attrib.is_64 = 1; + desc.pci.msi_attrib.default_irq = dev->irq; + desc.pci.mask_base = base; + + for (i = 0, curmsk = masks; i < nvec; i++, curmsk++) { + desc.msi_index = entries ? entries[i].entry : i; + desc.affinity = masks ? curmsk : NULL; + desc.pci.msi_attrib.is_virtual = desc.msi_index >= vec_count; + desc.pci.msi_attrib.can_mask = !pci_msi_ignore_mask && + !desc.pci.msi_attrib.is_virtual; + + if (!desc.pci.msi_attrib.can_mask) { + addr = pci_msix_desc_addr(&desc); + desc.pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); + } + + ret = msi_add_msi_desc(&dev->dev, &desc); + if (ret) + break; + } + return ret; +} + +static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries) +{ + struct msi_desc *desc; + + if (entries) { + msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL) { + entries->vector = desc->irq; + entries++; + } + } +} + +static void msix_mask_all(void __iomem *base, int tsize) +{ + u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT; + int i; + + if (pci_msi_ignore_mask) + return; + + for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE) + writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL); +} + +static int msix_setup_interrupts(struct pci_dev *dev, void __iomem *base, + struct msix_entry *entries, int nvec, + struct irq_affinity *affd) +{ + struct irq_affinity_desc *masks = NULL; + int ret; + + if (affd) + masks = irq_create_affinity_masks(nvec, affd); + + msi_lock_descs(&dev->dev); + ret = msix_setup_msi_descs(dev, base, entries, nvec, masks); + if (ret) + goto out_free; + + ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX); + if (ret) + goto out_free; + + /* Check if all MSI entries honor device restrictions */ + ret = msi_verify_entries(dev); + if (ret) + goto out_free; + + msix_update_entries(dev, entries); + goto out_unlock; + +out_free: + free_msi_irqs(dev); +out_unlock: + msi_unlock_descs(&dev->dev); + kfree(masks); + return ret; +} + +/** + * 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 + * @affd: Optional pointer to enable automatic affinity assignment + * + * 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 irq_affinity *affd) +{ + void __iomem *base; + int ret, tsize; + u16 control; + + /* + * Some devices require MSI-X to be enabled before the MSI-X + * registers can be accessed. Mask all the vectors to prevent + * interrupts coming in before they're fully set up. + */ + pci_msix_clear_and_set_ctrl(dev, 0, PCI_MSIX_FLAGS_MASKALL | + PCI_MSIX_FLAGS_ENABLE); + + /* Mark it enabled so setup functions can query it */ + dev->msix_enabled = 1; + + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); + /* Request & Map MSI-X table region */ + tsize = msix_table_size(control); + base = msix_map_region(dev, tsize); + if (!base) { + ret = -ENOMEM; + goto out_disable; + } + + dev->msix_base = base; + + ret = msix_setup_interrupts(dev, base, entries, nvec, affd); + if (ret) + goto out_disable; + + /* Disable INTX */ + pci_intx_for_msi(dev, 0); + + /* + * Ensure that all table entries are masked to prevent + * stale entries from firing in a crash kernel. + * + * Done late to deal with a broken Marvell NVME device + * which takes the MSI-X mask bits into account even + * when MSI-X is disabled, which prevents MSI delivery. + */ + msix_mask_all(base, tsize); + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0); + + pcibios_free_irq(dev); + return 0; + +out_disable: + dev->msix_enabled = 0; + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0); + + return ret; +} + +/** + * pci_msi_supported - 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? + * + * Look at global flags, the device itself, and its parent buses + * to determine if MSI/-X are supported for the device. If MSI/-X is + * supported return 1, else return 0. + **/ +static int pci_msi_supported(struct pci_dev *dev, int nvec) +{ + struct pci_bus *bus; + + /* MSI must be globally enabled and supported by the device */ + if (!pci_msi_enable) + return 0; + + if (!dev || dev->no_msi) + return 0; + + /* + * 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 0; + + /* + * Any bridge which does NOT route MSI transactions from its + * secondary bus to its primary bus must set NO_MSI flag on + * the secondary pci_bus. + * + * The NO_MSI flag can either be set directly by: + * - arch-specific PCI host bus controller drivers (deprecated) + * - quirks for specific PCI bridges + * + * or indirectly by platform-specific PCI host bridge drivers by + * advertising the 'msi_domain' property, which results in + * the NO_MSI flag when no MSI domain is found for this bridge + * at probe time. + */ + for (bus = dev->bus; bus; bus = bus->parent) + if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI) + return 0; + + return 1; +} + +/** + * pci_msi_vec_count - Return the number of MSI vectors a device can send + * @dev: device to report about + * + * This function returns the number of MSI vectors a device requested via + * Multiple Message Capable register. It returns a negative errno if the + * device is not capable sending MSI interrupts. Otherwise, the call succeeds + * and returns a power of two, up to a maximum of 2^5 (32), according to the + * MSI specification. + **/ +int pci_msi_vec_count(struct pci_dev *dev) +{ + int ret; + u16 msgctl; + + if (!dev->msi_cap) + return -EINVAL; + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl); + ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1); + + return ret; +} +EXPORT_SYMBOL(pci_msi_vec_count); + +static void pci_msi_shutdown(struct pci_dev *dev) +{ + struct msi_desc *desc; + + if (!pci_msi_enable || !dev || !dev->msi_enabled) + return; + + pci_msi_set_enable(dev, 0); + pci_intx_for_msi(dev, 1); + dev->msi_enabled = 0; + + /* Return the device with MSI unmasked as initial states */ + desc = msi_first_desc(&dev->dev, MSI_DESC_ALL); + if (!WARN_ON_ONCE(!desc)) + pci_msi_unmask(desc, msi_multi_mask(desc)); + + /* Restore dev->irq to its default pin-assertion IRQ */ + dev->irq = desc->pci.msi_attrib.default_irq; + pcibios_alloc_irq(dev); +} + +void pci_disable_msi(struct pci_dev *dev) +{ + if (!pci_msi_enable || !dev || !dev->msi_enabled) + return; + + msi_lock_descs(&dev->dev); + pci_msi_shutdown(dev); + free_msi_irqs(dev); + msi_unlock_descs(&dev->dev); +} +EXPORT_SYMBOL(pci_disable_msi); + +/** + * pci_msix_vec_count - return the number of device's MSI-X table entries + * @dev: pointer to the pci_dev data structure of MSI-X device function + * This function returns the number of device's MSI-X table entries and + * therefore the number of MSI-X vectors device is capable of sending. + * It returns a negative errno if the device is not capable of sending MSI-X + * interrupts. + **/ +int pci_msix_vec_count(struct pci_dev *dev) +{ + u16 control; + + if (!dev->msix_cap) + return -EINVAL; + + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); + return msix_table_size(control); +} +EXPORT_SYMBOL(pci_msix_vec_count); + +static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, + int nvec, struct irq_affinity *affd, int flags) +{ + int nr_entries; + int i, j; + + if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0) + return -EINVAL; + + nr_entries = pci_msix_vec_count(dev); + if (nr_entries < 0) + return nr_entries; + if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL)) + return nr_entries; + + if (entries) { + /* 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 */ + } + } + } + + /* Check whether driver already requested for MSI IRQ */ + if (dev->msi_enabled) { + pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n"); + return -EINVAL; + } + return msix_capability_init(dev, entries, nvec, affd); +} + +static void pci_msix_shutdown(struct pci_dev *dev) +{ + struct msi_desc *desc; + + if (!pci_msi_enable || !dev || !dev->msix_enabled) + return; + + if (pci_dev_is_disconnected(dev)) { + dev->msix_enabled = 0; + return; + } + + /* Return the device with MSI-X masked as initial states */ + msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL) + pci_msix_mask(desc); + + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); + pci_intx_for_msi(dev, 1); + dev->msix_enabled = 0; + pcibios_alloc_irq(dev); +} + +void pci_disable_msix(struct pci_dev *dev) +{ + if (!pci_msi_enable || !dev || !dev->msix_enabled) + return; + + msi_lock_descs(&dev->dev); + pci_msix_shutdown(dev); + free_msi_irqs(dev); + msi_unlock_descs(&dev->dev); +} +EXPORT_SYMBOL(pci_disable_msix); + +static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec, + struct irq_affinity *affd) +{ + int nvec; + int rc; + + if (!pci_msi_supported(dev, minvec) || dev->current_state != PCI_D0) + return -EINVAL; + + /* Check whether driver already requested MSI-X IRQs */ + if (dev->msix_enabled) { + pci_info(dev, "can't enable MSI (MSI-X already enabled)\n"); + return -EINVAL; + } + + if (maxvec < minvec) + return -ERANGE; + + if (WARN_ON_ONCE(dev->msi_enabled)) + return -EINVAL; + + nvec = pci_msi_vec_count(dev); + if (nvec < 0) + return nvec; + if (nvec < minvec) + return -ENOSPC; + + if (nvec > maxvec) + nvec = maxvec; + + rc = pci_setup_msi_context(dev); + if (rc) + return rc; + + for (;;) { + if (affd) { + nvec = irq_calc_affinity_vectors(minvec, nvec, affd); + if (nvec < minvec) + return -ENOSPC; + } + + rc = msi_capability_init(dev, nvec, affd); + if (rc == 0) + return nvec; + + if (rc < 0) + return rc; + if (rc < minvec) + return -ENOSPC; + + nvec = rc; + } +} + +/* deprecated, don't use */ +int pci_enable_msi(struct pci_dev *dev) +{ + int rc = __pci_enable_msi_range(dev, 1, 1, NULL); + if (rc < 0) + return rc; + return 0; +} +EXPORT_SYMBOL(pci_enable_msi); + +static int __pci_enable_msix_range(struct pci_dev *dev, + struct msix_entry *entries, int minvec, + int maxvec, struct irq_affinity *affd, + int flags) +{ + int rc, nvec = maxvec; + + if (maxvec < minvec) + return -ERANGE; + + if (WARN_ON_ONCE(dev->msix_enabled)) + return -EINVAL; + + rc = pci_setup_msi_context(dev); + if (rc) + return rc; + + for (;;) { + if (affd) { + nvec = irq_calc_affinity_vectors(minvec, nvec, affd); + if (nvec < minvec) + return -ENOSPC; + } + + rc = __pci_enable_msix(dev, entries, nvec, affd, flags); + if (rc == 0) + return nvec; + + if (rc < 0) + return rc; + if (rc < minvec) + return -ENOSPC; + + nvec = rc; + } +} + +/** + * pci_enable_msix_range - 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 + * @minvec: minimum number of MSI-X IRQs requested + * @maxvec: maximum number of MSI-X IRQs requested + * + * Setup the MSI-X capability structure of device function with a maximum + * possible number of interrupts in the range between @minvec and @maxvec + * upon its software driver call to request for MSI-X mode enabled on its + * hardware device function. It returns a negative errno if an error occurs. + * If it succeeds, it returns the actual number of interrupts allocated and + * indicates the successful configuration of MSI-X capability structure + * with new allocated MSI-X interrupts. + **/ +int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries, + int minvec, int maxvec) +{ + return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0); +} +EXPORT_SYMBOL(pci_enable_msix_range); + +/** + * pci_alloc_irq_vectors_affinity - allocate multiple IRQs for a device + * @dev: PCI device to operate on + * @min_vecs: minimum number of vectors required (must be >= 1) + * @max_vecs: maximum (desired) number of vectors + * @flags: flags or quirks for the allocation + * @affd: optional description of the affinity requirements + * + * Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI + * vectors if available, and fall back to a single legacy vector + * if neither is available. Return the number of vectors allocated, + * (which might be smaller than @max_vecs) if successful, or a negative + * error code on error. If less than @min_vecs interrupt vectors are + * available for @dev the function will fail with -ENOSPC. + * + * To get the Linux IRQ number used for a vector that can be passed to + * request_irq() use the pci_irq_vector() helper. + */ +int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, + unsigned int max_vecs, unsigned int flags, + struct irq_affinity *affd) +{ + struct irq_affinity msi_default_affd = {0}; + int nvecs = -ENOSPC; + + if (flags & PCI_IRQ_AFFINITY) { + if (!affd) + affd = &msi_default_affd; + } else { + if (WARN_ON(affd)) + affd = NULL; + } + + if (flags & PCI_IRQ_MSIX) { + nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs, + affd, flags); + if (nvecs > 0) + return nvecs; + } + + if (flags & PCI_IRQ_MSI) { + nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd); + if (nvecs > 0) + return nvecs; + } + + /* use legacy IRQ if allowed */ + if (flags & PCI_IRQ_LEGACY) { + if (min_vecs == 1 && dev->irq) { + /* + * Invoke the affinity spreading logic to ensure that + * the device driver can adjust queue configuration + * for the single interrupt case. + */ + if (affd) + irq_create_affinity_masks(1, affd); + pci_intx(dev, 1); + return 1; + } + } + + return nvecs; +} +EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity); + +/** + * pci_free_irq_vectors - free previously allocated IRQs for a device + * @dev: PCI device to operate on + * + * Undoes the allocations and enabling in pci_alloc_irq_vectors(). + */ +void pci_free_irq_vectors(struct pci_dev *dev) +{ + pci_disable_msix(dev); + pci_disable_msi(dev); +} +EXPORT_SYMBOL(pci_free_irq_vectors); + +/** + * pci_irq_vector - return Linux IRQ number of a device vector + * @dev: PCI device to operate on + * @nr: Interrupt vector index (0-based) + * + * @nr has the following meanings depending on the interrupt mode: + * MSI-X: The index in the MSI-X vector table + * MSI: The index of the enabled MSI vectors + * INTx: Must be 0 + * + * Return: The Linux interrupt number or -EINVAl if @nr is out of range. + */ +int pci_irq_vector(struct pci_dev *dev, unsigned int nr) +{ + unsigned int irq; + + if (!dev->msi_enabled && !dev->msix_enabled) + return !nr ? dev->irq : -EINVAL; + + irq = msi_get_virq(&dev->dev, nr); + return irq ? irq : -EINVAL; +} +EXPORT_SYMBOL(pci_irq_vector); + +/** + * pci_irq_get_affinity - return the affinity of a particular MSI vector + * @dev: PCI device to operate on + * @nr: device-relative interrupt vector index (0-based). + * + * @nr has the following meanings depending on the interrupt mode: + * MSI-X: The index in the MSI-X vector table + * MSI: The index of the enabled MSI vectors + * INTx: Must be 0 + * + * Return: A cpumask pointer or NULL if @nr is out of range + */ +const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr) +{ + int idx, irq = pci_irq_vector(dev, nr); + struct msi_desc *desc; + + if (WARN_ON_ONCE(irq <= 0)) + return NULL; + + desc = irq_get_msi_desc(irq); + /* Non-MSI does not have the information handy */ + if (!desc) + return cpu_possible_mask; + + if (WARN_ON_ONCE(!desc->affinity)) + return NULL; + + /* + * MSI has a mask array in the descriptor. + * MSI-X has a single mask. + */ + idx = dev->msi_enabled ? nr : 0; + return &desc->affinity[idx].mask; +} +EXPORT_SYMBOL(pci_irq_get_affinity); + +struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc) +{ + return to_pci_dev(desc->dev); +} +EXPORT_SYMBOL(msi_desc_to_pci_dev); + +void pci_no_msi(void) +{ + pci_msi_enable = 0; +} + +/** + * pci_msi_enabled - is MSI enabled? + * + * Returns true if MSI has not been disabled by the command-line option + * pci=nomsi. + **/ +int pci_msi_enabled(void) +{ + return pci_msi_enable; +} +EXPORT_SYMBOL(pci_msi_enabled); |