diff options
| -rw-r--r-- | Documentation/PCI/MSI-HOWTO.txt | 45 | ||||
| -rw-r--r-- | arch/powerpc/kernel/msi.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/io_apic.c | 4 | ||||
| -rw-r--r-- | drivers/pci/msi.c | 91 | ||||
| -rw-r--r-- | drivers/pci/msi.h | 6 | ||||
| -rw-r--r-- | include/linux/msi.h | 1 | ||||
| -rw-r--r-- | include/linux/pci.h | 6 |
7 files changed, 116 insertions, 41 deletions
diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 1c02431..9494f6d 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -94,15 +94,48 @@ This function should be called before the driver calls request_irq() since enabling MSIs disables the pin-based IRQ and the driver will not receive interrupts on the old interrupt. -4.2.2 pci_disable_msi +4.2.2 pci_enable_msi_block + +int pci_enable_msi_block(struct pci_dev *dev, int count) + +This variation on the above call allows a device driver to request multiple +MSIs. The MSI specification only allows interrupts to be allocated in +powers of two, up to a maximum of 2^5 (32). + +If this function returns 0, it has succeeded in allocating at least as many +interrupts as the driver requested (it may have allocated more in order +to satisfy the power-of-two requirement). In this case, the function +enables MSI on this device and updates dev->irq to be the lowest of +the new interrupts assigned to it. The other interrupts assigned to +the device are in the range dev->irq to dev->irq + count - 1. + +If this function returns a negative number, it indicates an error and +the driver should not attempt to request any more MSI interrupts for +this device. If this function returns a positive number, it will be +less than 'count' and indicate the number of interrupts that could have +been allocated. In neither case will the irq value have been +updated, nor will the device have been switched into MSI mode. + +The device driver must decide what action to take if +pci_enable_msi_block() returns a value less than the number asked for. +Some devices can make use of fewer interrupts than the maximum they +request; in this case the driver should call pci_enable_msi_block() +again. Note that it is not guaranteed to succeed, even when the +'count' has been reduced to the value returned from a previous call to +pci_enable_msi_block(). This is because there are multiple constraints +on the number of vectors that can be allocated; pci_enable_msi_block() +will return as soon as it finds any constraint that doesn't allow the +call to succeed. + +4.2.3 pci_disable_msi void pci_disable_msi(struct pci_dev *dev) -This function should be used to undo the effect of pci_enable_msi(). -Calling it restores dev->irq to the pin-based interrupt number and frees -the previously allocated message signaled interrupt(s). The interrupt -may subsequently be assigned to another device, so drivers should not -cache the value of dev->irq. +This function should be used to undo the effect of pci_enable_msi() or +pci_enable_msi_block(). Calling it restores dev->irq to the pin-based +interrupt number and frees the previously allocated message signaled +interrupt(s). The interrupt may subsequently be assigned to another +device, so drivers should not cache the value of dev->irq. A device driver must always call free_irq() on the interrupt(s) for which it has called request_irq() before calling this function. diff --git a/arch/powerpc/kernel/msi.c b/arch/powerpc/kernel/msi.c index 3bb7d3d..0c16e2a 100644 --- a/arch/powerpc/kernel/msi.c +++ b/arch/powerpc/kernel/msi.c @@ -19,6 +19,10 @@ int arch_msi_check_device(struct pci_dev* dev, int nvec, int type) return -ENOSYS; } + /* PowerPC doesn't support multiple MSI yet */ + if (type == PCI_CAP_ID_MSI && nvec > 1) + return 1; + if (ppc_md.msi_check_device) { pr_debug("msi: Using platform check routine.\n"); return ppc_md.msi_check_device(dev, nvec, type); diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c index bc7ac4d..a09549a 100644 --- a/arch/x86/kernel/io_apic.c +++ b/arch/x86/kernel/io_apic.c @@ -3510,6 +3510,10 @@ int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) int index = 0; #endif + /* x86 doesn't support multiple MSI yet */ + if (type == PCI_CAP_ID_MSI && nvec > 1) + return 1; + irq_want = nr_irqs_gsi; sub_handle = 0; list_for_each_entry(msidesc, &dev->msi_list, list) { diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index adcc782..6f2e629 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -40,6 +40,13 @@ int 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) @@ -58,8 +65,12 @@ void 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); + int i, nvec; + if (entry->irq == 0) + continue; + nvec = 1 << entry->msi_attrib.multiple; + for (i = 0; i < nvec; i++) + arch_teardown_msi_irq(entry->irq + i); } } #endif @@ -163,7 +174,8 @@ static void msi_set_mask_bit(unsigned irq, u32 flag) msix_mask_irq(desc, flag); readl(desc->mask_base); /* Flush write to device */ } else { - msi_mask_irq(desc, 1, flag); + unsigned offset = irq - desc->dev->irq; + msi_mask_irq(desc, 1 << offset, flag << offset); } } @@ -229,6 +241,12 @@ void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) } else { struct pci_dev *dev = entry->dev; int pos = entry->msi_attrib.pos; + u16 msgctl; + + pci_read_config_word(dev, msi_control_reg(pos), &msgctl); + msgctl &= ~PCI_MSI_FLAGS_QSIZE; + msgctl |= entry->msi_attrib.multiple << 4; + pci_write_config_word(dev, msi_control_reg(pos), msgctl); pci_write_config_dword(dev, msi_lower_address_reg(pos), msg->address_lo); @@ -291,7 +309,7 @@ static void __pci_restore_msi_state(struct pci_dev *dev) pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control); msi_mask_irq(entry, msi_capable_mask(control), entry->masked); control &= ~PCI_MSI_FLAGS_QSIZE; - control |= PCI_MSI_FLAGS_ENABLE; + control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE; pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); } @@ -332,13 +350,15 @@ EXPORT_SYMBOL_GPL(pci_restore_msi_state); /** * 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 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) + * 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 pos, ret; @@ -371,7 +391,7 @@ static int msi_capability_init(struct pci_dev *dev) list_add_tail(&entry->list, &dev->msi_list); /* Configure MSI capability structure */ - ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI); + ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI); if (ret) { msi_free_irqs(dev); return ret; @@ -524,35 +544,48 @@ static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type) } /** - * pci_enable_msi - configure device's MSI capability structure - * @dev: pointer to the pci_dev data structure of MSI device function + * pci_enable_msi_block - configure device's MSI capability structure + * @dev: device to configure + * @nvec: number of interrupts to configure * - * 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) + * Allocate IRQs for a device with the MSI capability. + * This function returns a negative errno if an error occurs. If it + * is unable to allocate the number of interrupts requested, it returns + * the number of interrupts it might be able to allocate. If it successfully + * allocates at least the number of interrupts requested, it returns 0 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_block(struct pci_dev *dev, unsigned int nvec) { - int status; + int status, pos, maxvec; + u16 msgctl; + + pos = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (!pos) + return -EINVAL; + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl); + maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1); + if (nvec > maxvec) + return maxvec; - status = pci_msi_check_device(dev, 1, PCI_CAP_ID_MSI); + status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI); if (status) return status; WARN_ON(!!dev->msi_enabled); - /* Check whether driver already requested for MSI-X irqs */ + /* 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; } - status = msi_capability_init(dev); + + status = msi_capability_init(dev, nvec); return status; } -EXPORT_SYMBOL(pci_enable_msi); +EXPORT_SYMBOL(pci_enable_msi_block); void pci_msi_shutdown(struct pci_dev *dev) { @@ -599,8 +632,12 @@ 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)); + int i, nvec; + if (!entry->irq) + continue; + nvec = 1 << entry->msi_attrib.multiple; + for (i = 0; i < nvec; i++) + BUG_ON(irq_has_action(entry->irq + i)); } arch_teardown_msi_irqs(dev); diff --git a/drivers/pci/msi.h b/drivers/pci/msi.h index 3898f52..71f4df2 100644 --- a/drivers/pci/msi.h +++ b/drivers/pci/msi.h @@ -20,14 +20,8 @@ #define msi_mask_bits_reg(base, is64bit) \ ( (is64bit == 1) ? base+PCI_MSI_MASK_BIT : base+PCI_MSI_MASK_BIT-4) #define msi_disable(control) control &= ~PCI_MSI_FLAGS_ENABLE -#define multi_msi_capable(control) \ - (1 << ((control & PCI_MSI_FLAGS_QMASK) >> 1)) -#define multi_msi_enable(control, num) \ - control |= (((num >> 1) << 4) & PCI_MSI_FLAGS_QSIZE); #define is_64bit_address(control) (!!(control & PCI_MSI_FLAGS_64BIT)) #define is_mask_bit_support(control) (!!(control & PCI_MSI_FLAGS_MASKBIT)) -#define msi_enable(control, num) multi_msi_enable(control, num); \ - control |= PCI_MSI_FLAGS_ENABLE #define msix_table_offset_reg(base) (base + 0x04) #define msix_pba_offset_reg(base) (base + 0x08) diff --git a/include/linux/msi.h b/include/linux/msi.h index 37c1bbe..6991ab5 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -21,6 +21,7 @@ extern void write_msi_msg(unsigned int irq, struct msi_msg *msg); struct msi_desc { struct { __u8 is_msix : 1; + __u8 multiple: 3; /* log2 number of messages */ __u8 maskbit : 1; /* mask-pending bit supported ? */ __u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */ __u8 pos; /* Location of the msi capability */ diff --git a/include/linux/pci.h b/include/linux/pci.h index 7baf2a5..1f6c5dd 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -789,7 +789,7 @@ struct msix_entry { #ifndef CONFIG_PCI_MSI -static inline int pci_enable_msi(struct pci_dev *dev) +static inline int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec) { return -1; } @@ -824,7 +824,7 @@ static inline int pci_msi_enabled(void) return 0; } #else -extern int pci_enable_msi(struct pci_dev *dev); +extern int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec); extern void pci_msi_shutdown(struct pci_dev *dev); extern void pci_disable_msi(struct pci_dev *dev); extern int pci_msix_table_size(struct pci_dev *dev); @@ -846,6 +846,8 @@ static inline int pcie_aspm_enabled(void) extern int pcie_aspm_enabled(void); #endif +#define pci_enable_msi(pdev) pci_enable_msi_block(pdev, 1) + #ifdef CONFIG_HT_IRQ /* The functions a driver should call */ int ht_create_irq(struct pci_dev *dev, int idx); |
