diff options
Diffstat (limited to 'drivers/pci/msi.c')
| -rw-r--r-- | drivers/pci/msi.c | 1365 |
1 files changed, 1365 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c new file mode 100644 index 000000000..c3e7dfcf9 --- /dev/null +++ b/drivers/pci/msi.c @@ -0,0 +1,1365 @@ +/* + * 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/export.h> +#include <linux/ioport.h> +#include <linux/pci.h> +#include <linux/proc_fs.h> +#include <linux/msi.h> +#include <linux/smp.h> +#include <linux/errno.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/irqdomain.h> + +#include "pci.h" + +static int pci_msi_enable = 1; +int pci_msi_ignore_mask; + +#define msix_table_size(flags) ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) + +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN +static struct irq_domain *pci_msi_default_domain; +static DEFINE_MUTEX(pci_msi_domain_lock); + +struct irq_domain * __weak arch_get_pci_msi_domain(struct pci_dev *dev) +{ + return pci_msi_default_domain; +} + +static struct irq_domain *pci_msi_get_domain(struct pci_dev *dev) +{ + struct irq_domain *domain = NULL; + + if (dev->bus->msi) + domain = dev->bus->msi->domain; + if (!domain) + domain = arch_get_pci_msi_domain(dev); + + return domain; +} + +static int pci_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) +{ + struct irq_domain *domain; + + domain = pci_msi_get_domain(dev); + if (domain) + return pci_msi_domain_alloc_irqs(domain, dev, nvec, type); + + return arch_setup_msi_irqs(dev, nvec, type); +} + +static void pci_msi_teardown_msi_irqs(struct pci_dev *dev) +{ + struct irq_domain *domain; + + domain = pci_msi_get_domain(dev); + if (domain) + pci_msi_domain_free_irqs(domain, dev); + else + arch_teardown_msi_irqs(dev); +} +#else +#define pci_msi_setup_msi_irqs arch_setup_msi_irqs +#define pci_msi_teardown_msi_irqs arch_teardown_msi_irqs +#endif + +/* Arch hooks */ + +struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev) +{ + return NULL; +} + +static struct msi_controller *pci_msi_controller(struct pci_dev *dev) +{ + struct msi_controller *msi_ctrl = dev->bus->msi; + + if (msi_ctrl) + return msi_ctrl; + + return pcibios_msi_controller(dev); +} + +int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc) +{ + struct msi_controller *chip = pci_msi_controller(dev); + int err; + + if (!chip || !chip->setup_irq) + return -EINVAL; + + err = chip->setup_irq(chip, dev, desc); + if (err < 0) + return err; + + irq_set_chip_data(desc->irq, chip); + + return 0; +} + +void __weak arch_teardown_msi_irq(unsigned int irq) +{ + struct msi_controller *chip = irq_get_chip_data(irq); + + if (!chip || !chip->teardown_irq) + return; + + chip->teardown_irq(chip, irq); +} + +int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) +{ + struct msi_desc *entry; + int ret; + + /* + * If an architecture wants to support multiple MSI, it needs to + * override arch_setup_msi_irqs() + */ + if (type == PCI_CAP_ID_MSI && nvec > 1) + return 1; + + list_for_each_entry(entry, &dev->msi_list, list) { + ret = arch_setup_msi_irq(dev, entry); + if (ret < 0) + return ret; + if (ret > 0) + return -ENOSPC; + } + + return 0; +} + +/* + * We have a default implementation available as a separate non-weak + * function, as it is used by the Xen x86 PCI code + */ +void default_teardown_msi_irqs(struct pci_dev *dev) +{ + int i; + struct msi_desc *entry; + + list_for_each_entry(entry, &dev->msi_list, list) + if (entry->irq) + for (i = 0; i < entry->nvec_used; i++) + arch_teardown_msi_irq(entry->irq + i); +} + +void __weak arch_teardown_msi_irqs(struct pci_dev *dev) +{ + return default_teardown_msi_irqs(dev); +} + +static void default_restore_msi_irq(struct pci_dev *dev, int irq) +{ + struct msi_desc *entry; + + entry = NULL; + if (dev->msix_enabled) { + list_for_each_entry(entry, &dev->msi_list, list) { + if (irq == entry->irq) + break; + } + } else if (dev->msi_enabled) { + entry = irq_get_msi_desc(irq); + } + + if (entry) + __pci_write_msi_msg(entry, &entry->msg); +} + +void __weak arch_restore_msi_irqs(struct pci_dev *dev) +{ + return default_restore_msi_irqs(dev); +} + +static void 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); +} + +static void 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 inline __attribute_const__ u32 msi_mask(unsigned x) +{ + /* Don't shift by >= width of type */ + if (x >= 5) + return 0xffffffff; + return (1 << (1 << x)) - 1; +} + +/* + * PCI 2.3 does not specify mask bits for each MSI interrupt. Attempting to + * mask all MSI interrupts by clearing the MSI enable bit does not work + * reliably as devices without an INTx disable bit will then generate a + * level IRQ which will never be cleared. + */ +u32 __pci_msi_desc_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) +{ + u32 mask_bits = desc->masked; + + if (pci_msi_ignore_mask || !desc->msi_attrib.maskbit) + return 0; + + mask_bits &= ~mask; + mask_bits |= flag; + pci_write_config_dword(desc->dev, desc->mask_pos, mask_bits); + + return mask_bits; +} + +static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) +{ + desc->masked = __pci_msi_desc_mask_irq(desc, mask, flag); +} + +/* + * 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. This saves a few milliseconds when initialising devices with lots + * of MSI-X interrupts. + */ +u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag) +{ + u32 mask_bits = desc->masked; + unsigned offset = desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + + PCI_MSIX_ENTRY_VECTOR_CTRL; + + if (pci_msi_ignore_mask) + return 0; + + mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT; + if (flag) + mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT; + writel(mask_bits, desc->mask_base + offset); + + return mask_bits; +} + +static void msix_mask_irq(struct msi_desc *desc, u32 flag) +{ + desc->masked = __pci_msix_desc_mask_irq(desc, flag); +} + +static void msi_set_mask_bit(struct irq_data *data, u32 flag) +{ + struct msi_desc *desc = irq_data_get_msi(data); + + if (desc->msi_attrib.is_msix) { + msix_mask_irq(desc, flag); + readl(desc->mask_base); /* Flush write to device */ + } else { + unsigned offset = data->irq - desc->irq; + msi_mask_irq(desc, 1 << offset, flag << offset); + } +} + +/** + * 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) +{ + msi_set_mask_bit(data, 1); +} + +/** + * 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) +{ + msi_set_mask_bit(data, 0); +} + +void default_restore_msi_irqs(struct pci_dev *dev) +{ + struct msi_desc *entry; + + list_for_each_entry(entry, &dev->msi_list, list) + default_restore_msi_irq(dev, entry->irq); +} + +void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg) +{ + BUG_ON(entry->dev->current_state != PCI_D0); + + if (entry->msi_attrib.is_msix) { + void __iomem *base = entry->mask_base + + entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; + + 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 { + struct pci_dev *dev = entry->dev; + int pos = dev->msi_cap; + u16 data; + + pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, + &msg->address_lo); + if (entry->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) +{ + if (entry->dev->current_state != PCI_D0) { + /* Don't touch the hardware now */ + } else if (entry->msi_attrib.is_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); + writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR); + writel(msg->data, base + PCI_MSIX_ENTRY_DATA); + } else { + struct pci_dev *dev = entry->dev; + int pos = dev->msi_cap; + u16 msgctl; + + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl); + msgctl &= ~PCI_MSI_FLAGS_QSIZE; + msgctl |= entry->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->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); + } + } + entry->msg = *msg; +} + +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) +{ + struct msi_desc *entry, *tmp; + struct attribute **msi_attrs; + struct device_attribute *dev_attr; + int i, count = 0; + + list_for_each_entry(entry, &dev->msi_list, list) + if (entry->irq) + for (i = 0; i < entry->nvec_used; i++) + BUG_ON(irq_has_action(entry->irq + i)); + + pci_msi_teardown_msi_irqs(dev); + + list_for_each_entry_safe(entry, tmp, &dev->msi_list, list) { + if (entry->msi_attrib.is_msix) { + if (list_is_last(&entry->list, &dev->msi_list)) + iounmap(entry->mask_base); + } + + list_del(&entry->list); + kfree(entry); + } + + if (dev->msi_irq_groups) { + sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups); + msi_attrs = dev->msi_irq_groups[0]->attrs; + while (msi_attrs[count]) { + dev_attr = container_of(msi_attrs[count], + struct device_attribute, attr); + kfree(dev_attr->attr.name); + kfree(dev_attr); + ++count; + } + kfree(msi_attrs); + kfree(dev->msi_irq_groups[0]); + kfree(dev->msi_irq_groups); + dev->msi_irq_groups = NULL; + } +} + +static struct msi_desc *alloc_msi_entry(struct pci_dev *dev) +{ + struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + return NULL; + + INIT_LIST_HEAD(&desc->list); + desc->dev = dev; + + return desc; +} + +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_restore_msi_state(struct pci_dev *dev) +{ + u16 control; + struct msi_desc *entry; + + if (!dev->msi_enabled) + return; + + entry = irq_get_msi_desc(dev->irq); + + pci_intx_for_msi(dev, 0); + msi_set_enable(dev, 0); + arch_restore_msi_irqs(dev); + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + msi_mask_irq(entry, msi_mask(entry->msi_attrib.multi_cap), + entry->masked); + control &= ~PCI_MSI_FLAGS_QSIZE; + control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE; + pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control); +} + +static void __pci_restore_msix_state(struct pci_dev *dev) +{ + struct msi_desc *entry; + + if (!dev->msix_enabled) + return; + BUG_ON(list_empty(&dev->msi_list)); + + /* route the table */ + pci_intx_for_msi(dev, 0); + msix_clear_and_set_ctrl(dev, 0, + PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL); + + arch_restore_msi_irqs(dev); + list_for_each_entry(entry, &dev->msi_list, list) + msix_mask_irq(entry, entry->masked); + + 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 ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct msi_desc *entry; + unsigned long irq; + int retval; + + retval = kstrtoul(attr->attr.name, 10, &irq); + if (retval) + return retval; + + entry = irq_get_msi_desc(irq); + if (entry) + return sprintf(buf, "%s\n", + entry->msi_attrib.is_msix ? "msix" : "msi"); + + return -ENODEV; +} + +static int populate_msi_sysfs(struct pci_dev *pdev) +{ + struct attribute **msi_attrs; + struct attribute *msi_attr; + struct device_attribute *msi_dev_attr; + struct attribute_group *msi_irq_group; + const struct attribute_group **msi_irq_groups; + struct msi_desc *entry; + int ret = -ENOMEM; + int num_msi = 0; + int count = 0; + + /* Determine how many msi entries we have */ + list_for_each_entry(entry, &pdev->msi_list, list) + ++num_msi; + if (!num_msi) + return 0; + + /* Dynamically create the MSI attributes for the PCI device */ + msi_attrs = kzalloc(sizeof(void *) * (num_msi + 1), GFP_KERNEL); + if (!msi_attrs) + return -ENOMEM; + list_for_each_entry(entry, &pdev->msi_list, list) { + msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL); + if (!msi_dev_attr) + goto error_attrs; + msi_attrs[count] = &msi_dev_attr->attr; + + sysfs_attr_init(&msi_dev_attr->attr); + msi_dev_attr->attr.name = kasprintf(GFP_KERNEL, "%d", + entry->irq); + if (!msi_dev_attr->attr.name) + goto error_attrs; + msi_dev_attr->attr.mode = S_IRUGO; + msi_dev_attr->show = msi_mode_show; + ++count; + } + + msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL); + if (!msi_irq_group) + goto error_attrs; + msi_irq_group->name = "msi_irqs"; + msi_irq_group->attrs = msi_attrs; + + msi_irq_groups = kzalloc(sizeof(void *) * 2, GFP_KERNEL); + if (!msi_irq_groups) + goto error_irq_group; + msi_irq_groups[0] = msi_irq_group; + + ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups); + if (ret) + goto error_irq_groups; + pdev->msi_irq_groups = msi_irq_groups; + + return 0; + +error_irq_groups: + kfree(msi_irq_groups); +error_irq_group: + kfree(msi_irq_group); +error_attrs: + count = 0; + msi_attr = msi_attrs[count]; + while (msi_attr) { + msi_dev_attr = container_of(msi_attr, struct device_attribute, attr); + kfree(msi_attr->name); + kfree(msi_dev_attr); + ++count; + msi_attr = msi_attrs[count]; + } + kfree(msi_attrs); + return ret; +} + +static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec) +{ + u16 control; + struct msi_desc *entry; + + /* MSI Entry Initialization */ + entry = alloc_msi_entry(dev); + if (!entry) + return NULL; + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + + entry->msi_attrib.is_msix = 0; + entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT); + entry->msi_attrib.entry_nr = 0; + entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT); + entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */ + entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1; + entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec)); + entry->nvec_used = nvec; + + if (control & PCI_MSI_FLAGS_64BIT) + entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64; + else + entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32; + + /* Save the initial mask status */ + if (entry->msi_attrib.maskbit) + pci_read_config_dword(dev, entry->mask_pos, &entry->masked); + + return entry; +} + +static int msi_verify_entries(struct pci_dev *dev) +{ + struct msi_desc *entry; + + list_for_each_entry(entry, &dev->msi_list, list) { + if (!dev->no_64bit_msi || !entry->msg.address_hi) + continue; + dev_err(&dev->dev, "Device has broken 64-bit MSI but arch" + " tried to assign one above 4G\n"); + return -EIO; + } + return 0; +} + +/** + * 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 + * + * 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 msi_desc *entry; + int ret; + unsigned mask; + + msi_set_enable(dev, 0); /* Disable MSI during set up */ + + entry = msi_setup_entry(dev, nvec); + if (!entry) + return -ENOMEM; + + /* All MSIs are unmasked by default, Mask them all */ + mask = msi_mask(entry->msi_attrib.multi_cap); + msi_mask_irq(entry, mask, mask); + + list_add_tail(&entry->list, &dev->msi_list); + + /* Configure MSI capability structure */ + ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI); + if (ret) { + msi_mask_irq(entry, mask, ~mask); + free_msi_irqs(dev); + return ret; + } + + ret = msi_verify_entries(dev); + if (ret) { + msi_mask_irq(entry, mask, ~mask); + free_msi_irqs(dev); + return ret; + } + + ret = populate_msi_sysfs(dev); + if (ret) { + msi_mask_irq(entry, mask, ~mask); + free_msi_irqs(dev); + return ret; + } + + /* Set MSI enabled bits */ + pci_intx_for_msi(dev, 0); + msi_set_enable(dev, 1); + dev->msi_enabled = 1; + + dev->irq = entry->irq; + return 0; +} + +static void __iomem *msix_map_region(struct pci_dev *dev, unsigned 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_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE); +} + +static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, + struct msix_entry *entries, int nvec) +{ + struct msi_desc *entry; + int i; + + for (i = 0; i < nvec; i++) { + entry = alloc_msi_entry(dev); + if (!entry) { + if (!i) + iounmap(base); + else + free_msi_irqs(dev); + /* No enough memory. Don't try again */ + return -ENOMEM; + } + + entry->msi_attrib.is_msix = 1; + entry->msi_attrib.is_64 = 1; + entry->msi_attrib.entry_nr = entries[i].entry; + entry->msi_attrib.default_irq = dev->irq; + entry->mask_base = base; + entry->nvec_used = 1; + + list_add_tail(&entry->list, &dev->msi_list); + } + + return 0; +} + +static void msix_program_entries(struct pci_dev *dev, + struct msix_entry *entries) +{ + struct msi_desc *entry; + int i = 0; + + list_for_each_entry(entry, &dev->msi_list, list) { + int offset = entries[i].entry * PCI_MSIX_ENTRY_SIZE + + PCI_MSIX_ENTRY_VECTOR_CTRL; + + entries[i].vector = entry->irq; + entry->masked = readl(entry->mask_base + offset); + msix_mask_irq(entry, 1); + i++; + } +} + +/** + * 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) +{ + int ret; + u16 control; + void __iomem *base; + + /* Ensure MSI-X is disabled while it is set up */ + msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); + + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); + /* Request & Map MSI-X table region */ + base = msix_map_region(dev, msix_table_size(control)); + if (!base) + return -ENOMEM; + + ret = msix_setup_entries(dev, base, entries, nvec); + if (ret) + return ret; + + ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX); + if (ret) + goto out_avail; + + /* Check if all MSI entries honor device restrictions */ + ret = msi_verify_entries(dev); + if (ret) + goto out_free; + + /* + * Some devices require MSI-X to be enabled before we can touch the + * MSI-X registers. We need to mask all the vectors to prevent + * interrupts coming in before they're fully set up. + */ + msix_clear_and_set_ctrl(dev, 0, + PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE); + + msix_program_entries(dev, entries); + + ret = populate_msi_sysfs(dev); + if (ret) + goto out_free; + + /* Set MSI-X enabled bits and unmask the function */ + pci_intx_for_msi(dev, 0); + dev->msix_enabled = 1; + + msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0); + + return 0; + +out_avail: + if (ret < 0) { + /* + * If we had some success, report the number of irqs + * we succeeded in setting up. + */ + struct msi_desc *entry; + int avail = 0; + + list_for_each_entry(entry, &dev->msi_list, list) { + if (entry->irq != 0) + avail++; + } + if (avail != 0) + ret = avail; + } + +out_free: + free_msi_irqs(dev); + + 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 || dev->current_state != PCI_D0) + 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. + * 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 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); + +void pci_msi_shutdown(struct pci_dev *dev) +{ + struct msi_desc *desc; + u32 mask; + + if (!pci_msi_enable || !dev || !dev->msi_enabled) + return; + + BUG_ON(list_empty(&dev->msi_list)); + desc = list_first_entry(&dev->msi_list, struct msi_desc, list); + + msi_set_enable(dev, 0); + pci_intx_for_msi(dev, 1); + dev->msi_enabled = 0; + + /* Return the device with MSI unmasked as initial states */ + mask = msi_mask(desc->msi_attrib.multi_cap); + /* Keep cached state to be restored */ + __pci_msi_desc_mask_irq(desc, mask, ~mask); + + /* Restore dev->irq to its default pin-assertion irq */ + dev->irq = desc->msi_attrib.default_irq; +} + +void pci_disable_msi(struct pci_dev *dev) +{ + if (!pci_msi_enable || !dev || !dev->msi_enabled) + return; + + pci_msi_shutdown(dev); + free_msi_irqs(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); + +/** + * 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 or MSI-X vectors 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 nr_entries; + int i, j; + + if (!pci_msi_supported(dev, nvec)) + return -EINVAL; + + if (!entries) + return -EINVAL; + + nr_entries = pci_msix_vec_count(dev); + if (nr_entries < 0) + return nr_entries; + if (nvec > nr_entries) + return nr_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 */ + } + } + WARN_ON(!!dev->msix_enabled); + + /* Check whether driver already requested for MSI irq */ + if (dev->msi_enabled) { + dev_info(&dev->dev, "can't enable MSI-X (MSI IRQ already assigned)\n"); + return -EINVAL; + } + return msix_capability_init(dev, entries, nvec); +} +EXPORT_SYMBOL(pci_enable_msix); + +void pci_msix_shutdown(struct pci_dev *dev) +{ + struct msi_desc *entry; + + if (!pci_msi_enable || !dev || !dev->msix_enabled) + return; + + /* Return the device with MSI-X masked as initial states */ + list_for_each_entry(entry, &dev->msi_list, list) { + /* Keep cached states to be restored */ + __pci_msix_desc_mask_irq(entry, 1); + } + + msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); + pci_intx_for_msi(dev, 1); + dev->msix_enabled = 0; +} + +void pci_disable_msix(struct pci_dev *dev) +{ + if (!pci_msi_enable || !dev || !dev->msix_enabled) + return; + + pci_msix_shutdown(dev); + free_msi_irqs(dev); +} +EXPORT_SYMBOL(pci_disable_msix); + +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); + +void pci_msi_init_pci_dev(struct pci_dev *dev) +{ + INIT_LIST_HEAD(&dev->msi_list); + + /* Disable the msi hardware to avoid screaming interrupts + * during boot. This is the power on reset default so + * usually this should be a noop. + */ + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (dev->msi_cap) + msi_set_enable(dev, 0); + + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); + if (dev->msix_cap) + msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); +} + +/** + * pci_enable_msi_range - configure device's MSI capability structure + * @dev: device to configure + * @minvec: minimal number of interrupts to configure + * @maxvec: maximum number of interrupts to configure + * + * This function tries to allocate a maximum possible number of interrupts in a + * range between @minvec and @maxvec. It returns a negative errno if an error + * occurs. If it succeeds, it returns the actual number of interrupts allocated + * and updates the @dev's irq member to the lowest new interrupt number; + * the other interrupt numbers allocated to this device are consecutive. + **/ +int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec) +{ + int nvec; + int rc; + + if (!pci_msi_supported(dev, minvec)) + return -EINVAL; + + WARN_ON(!!dev->msi_enabled); + + /* Check whether driver already requested MSI-X irqs */ + if (dev->msix_enabled) { + dev_info(&dev->dev, + "can't enable MSI (MSI-X already enabled)\n"); + return -EINVAL; + } + + if (maxvec < minvec) + return -ERANGE; + + nvec = pci_msi_vec_count(dev); + if (nvec < 0) + return nvec; + else if (nvec < minvec) + return -EINVAL; + else if (nvec > maxvec) + nvec = maxvec; + + do { + rc = msi_capability_init(dev, nvec); + if (rc < 0) { + return rc; + } else if (rc > 0) { + if (rc < minvec) + return -ENOSPC; + nvec = rc; + } + } while (rc); + + return nvec; +} +EXPORT_SYMBOL(pci_enable_msi_range); + +/** + * 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) +{ + int nvec = maxvec; + int rc; + + if (maxvec < minvec) + return -ERANGE; + + do { + rc = pci_enable_msix(dev, entries, nvec); + if (rc < 0) { + return rc; + } else if (rc > 0) { + if (rc < minvec) + return -ENOSPC; + nvec = rc; + } + } while (rc); + + return nvec; +} +EXPORT_SYMBOL(pci_enable_msix_range); + +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN +/** + * pci_msi_domain_write_msg - Helper to write MSI message to PCI config space + * @irq_data: Pointer to interrupt data of the MSI interrupt + * @msg: Pointer to the message + */ +void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *msg) +{ + struct msi_desc *desc = irq_data->msi_desc; + + /* + * For MSI-X desc->irq is always equal to irq_data->irq. For + * MSI only the first interrupt of MULTI MSI passes the test. + */ + if (desc->irq == irq_data->irq) + __pci_write_msi_msg(desc, msg); +} + +/** + * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source + * @dev: Pointer to the PCI device + * @desc: Pointer to the msi descriptor + * + * The ID number is only used within the irqdomain. + */ +irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev, + struct msi_desc *desc) +{ + return (irq_hw_number_t)desc->msi_attrib.entry_nr | + PCI_DEVID(dev->bus->number, dev->devfn) << 11 | + (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27; +} + +static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc) +{ + return !desc->msi_attrib.is_msix && desc->nvec_used > 1; +} + +/** + * pci_msi_domain_check_cap - Verify that @domain supports the capabilities for @dev + * @domain: The interrupt domain to check + * @info: The domain info for verification + * @dev: The device to check + * + * Returns: + * 0 if the functionality is supported + * 1 if Multi MSI is requested, but the domain does not support it + * -ENOTSUPP otherwise + */ +int pci_msi_domain_check_cap(struct irq_domain *domain, + struct msi_domain_info *info, struct device *dev) +{ + struct msi_desc *desc = first_pci_msi_entry(to_pci_dev(dev)); + + /* Special handling to support pci_enable_msi_range() */ + if (pci_msi_desc_is_multi_msi(desc) && + !(info->flags & MSI_FLAG_MULTI_PCI_MSI)) + return 1; + else if (desc->msi_attrib.is_msix && !(info->flags & MSI_FLAG_PCI_MSIX)) + return -ENOTSUPP; + + return 0; +} + +static int pci_msi_domain_handle_error(struct irq_domain *domain, + struct msi_desc *desc, int error) +{ + /* Special handling to support pci_enable_msi_range() */ + if (pci_msi_desc_is_multi_msi(desc) && error == -ENOSPC) + return 1; + + return error; +} + +#ifdef GENERIC_MSI_DOMAIN_OPS +static void pci_msi_domain_set_desc(msi_alloc_info_t *arg, + struct msi_desc *desc) +{ + arg->desc = desc; + arg->hwirq = pci_msi_domain_calc_hwirq(msi_desc_to_pci_dev(desc), + desc); +} +#else +#define pci_msi_domain_set_desc NULL +#endif + +static struct msi_domain_ops pci_msi_domain_ops_default = { + .set_desc = pci_msi_domain_set_desc, + .msi_check = pci_msi_domain_check_cap, + .handle_error = pci_msi_domain_handle_error, +}; + +static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info) +{ + struct msi_domain_ops *ops = info->ops; + + if (ops == NULL) { + info->ops = &pci_msi_domain_ops_default; + } else { + if (ops->set_desc == NULL) + ops->set_desc = pci_msi_domain_set_desc; + if (ops->msi_check == NULL) + ops->msi_check = pci_msi_domain_check_cap; + if (ops->handle_error == NULL) + ops->handle_error = pci_msi_domain_handle_error; + } +} + +static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info) +{ + struct irq_chip *chip = info->chip; + + BUG_ON(!chip); + if (!chip->irq_write_msi_msg) + chip->irq_write_msi_msg = pci_msi_domain_write_msg; +} + +/** + * pci_msi_create_irq_domain - Creat a MSI interrupt domain + * @node: Optional device-tree node of the interrupt controller + * @info: MSI domain info + * @parent: Parent irq domain + * + * Updates the domain and chip ops and creates a MSI interrupt domain. + * + * Returns: + * A domain pointer or NULL in case of failure. + */ +struct irq_domain *pci_msi_create_irq_domain(struct device_node *node, + struct msi_domain_info *info, + struct irq_domain *parent) +{ + if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) + pci_msi_domain_update_dom_ops(info); + if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) + pci_msi_domain_update_chip_ops(info); + + return msi_create_irq_domain(node, info, parent); +} + +/** + * pci_msi_domain_alloc_irqs - Allocate interrupts for @dev in @domain + * @domain: The interrupt domain to allocate from + * @dev: The device for which to allocate + * @nvec: The number of interrupts to allocate + * @type: Unused to allow simpler migration from the arch_XXX interfaces + * + * Returns: + * A virtual interrupt number or an error code in case of failure + */ +int pci_msi_domain_alloc_irqs(struct irq_domain *domain, struct pci_dev *dev, + int nvec, int type) +{ + return msi_domain_alloc_irqs(domain, &dev->dev, nvec); +} + +/** + * pci_msi_domain_free_irqs - Free interrupts for @dev in @domain + * @domain: The interrupt domain + * @dev: The device for which to free interrupts + */ +void pci_msi_domain_free_irqs(struct irq_domain *domain, struct pci_dev *dev) +{ + msi_domain_free_irqs(domain, &dev->dev); +} + +/** + * pci_msi_create_default_irq_domain - Create a default MSI interrupt domain + * @node: Optional device-tree node of the interrupt controller + * @info: MSI domain info + * @parent: Parent irq domain + * + * Returns: A domain pointer or NULL in case of failure. If successful + * the default PCI/MSI irqdomain pointer is updated. + */ +struct irq_domain *pci_msi_create_default_irq_domain(struct device_node *node, + struct msi_domain_info *info, struct irq_domain *parent) +{ + struct irq_domain *domain; + + mutex_lock(&pci_msi_domain_lock); + if (pci_msi_default_domain) { + pr_err("PCI: default irq domain for PCI MSI has already been created.\n"); + domain = NULL; + } else { + domain = pci_msi_create_irq_domain(node, info, parent); + pci_msi_default_domain = domain; + } + mutex_unlock(&pci_msi_domain_lock); + + return domain; +} +#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */ |