From f2440d9acbe866b917b16cc0f927366341ce9215 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 17 Mar 2009 08:54:09 -0400 Subject: [PATCH] PCI MSI: Refactor interrupt masking code Since most of the callers already know whether they have an MSI or an MSI-X capability, split msi_set_mask_bits() into msi_mask_irq() and msix_mask_irq(). The only callers which don't (mask_msi_irq() and unmask_msi_irq()) can share code in msi_set_mask_bit(). This then becomes the only caller of msix_flush_writes(), so we can inline it. The flushing read can be to any address that belongs to the device, so we can eliminate the calculation too. We can also get rid of maskbits_mask from struct msi_desc and simply recalculate it on the rare occasion that we need it. The single-bit 'masked' element is replaced by a copy of the 32-bit 'masked' register, so this patch does not affect the size of msi_desc. Signed-off-by: Matthew Wilcox Signed-off-by: Jesse Barnes --- drivers/pci/msi.c | 155 +++++++++++++++++++++----------------------- include/linux/msi.h | 5 +- 2 files changed, 77 insertions(+), 83 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index fcde04df6dfe..adcc78242571 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -105,17 +105,14 @@ static inline __attribute_const__ u32 msi_mask(unsigned x) return (1 << (1 << x)) - 1; } -static void msix_flush_writes(struct irq_desc *desc) +static inline __attribute_const__ u32 msi_capable_mask(u16 control) { - struct msi_desc *entry; + return msi_mask((control >> 1) & 7); +} - entry = get_irq_desc_msi(desc); - BUG_ON(!entry); - if (entry->msi_attrib.is_msix) { - int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET; - readl(entry->mask_base + offset); - } +static inline __attribute_const__ u32 msi_enabled_mask(u16 control) +{ + return msi_mask((control >> 4) & 7); } /* @@ -127,32 +124,57 @@ static void msix_flush_writes(struct irq_desc *desc) * Returns 1 if it succeeded in masking the interrupt and 0 if the device * doesn't support MSI masking. */ -static int msi_set_mask_bits(struct irq_desc *desc, u32 mask, u32 flag) +static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) { - struct msi_desc *entry; + u32 mask_bits = desc->masked; - entry = get_irq_desc_msi(desc); - BUG_ON(!entry); - if (entry->msi_attrib.is_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); + if (!desc->msi_attrib.maskbit) + return; + + mask_bits &= ~mask; + mask_bits |= flag; + pci_write_config_dword(desc->dev, desc->mask_pos, mask_bits); + desc->masked = mask_bits; +} + +/* + * 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. + */ +static void msix_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_OFFSET; + mask_bits &= ~1; + mask_bits |= flag; + writel(mask_bits, desc->mask_base + offset); + desc->masked = mask_bits; +} + +static void msi_set_mask_bit(unsigned irq, u32 flag) +{ + struct msi_desc *desc = get_irq_msi(irq); + + if (desc->msi_attrib.is_msix) { + msix_mask_irq(desc, flag); + readl(desc->mask_base); /* Flush write to device */ } else { - int pos; - u32 mask_bits; - - if (!entry->msi_attrib.maskbit) - return 0; - - pos = entry->mask_pos; - pci_read_config_dword(entry->dev, pos, &mask_bits); - mask_bits &= ~mask; - mask_bits |= flag & mask; - pci_write_config_dword(entry->dev, pos, mask_bits); + msi_mask_irq(desc, 1, flag); } - entry->msi_attrib.masked = !!flag; - return 1; +} + +void mask_msi_irq(unsigned int irq) +{ + msi_set_mask_bit(irq, 1); +} + +void unmask_msi_irq(unsigned int irq) +{ + msi_set_mask_bit(irq, 0); } void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) @@ -230,22 +252,6 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg) write_msi_msg_desc(desc, msg); } -void mask_msi_irq(unsigned int irq) -{ - struct irq_desc *desc = irq_to_desc(irq); - - msi_set_mask_bits(desc, 1, 1); - msix_flush_writes(desc); -} - -void unmask_msi_irq(unsigned int irq) -{ - struct irq_desc *desc = irq_to_desc(irq); - - msi_set_mask_bits(desc, 1, 0); - msix_flush_writes(desc); -} - static int msi_free_irqs(struct pci_dev* dev); static struct msi_desc *alloc_msi_entry(struct pci_dev *dev) @@ -281,13 +287,9 @@ static void __pci_restore_msi_state(struct pci_dev *dev) pci_intx_for_msi(dev, 0); msi_set_enable(dev, 0); write_msi_msg(dev->irq, &entry->msg); - if (entry->msi_attrib.maskbit) { - struct irq_desc *desc = irq_to_desc(dev->irq); - msi_set_mask_bits(desc, entry->msi_attrib.maskbits_mask, - entry->msi_attrib.masked); - } 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; pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control); @@ -307,9 +309,8 @@ static void __pci_restore_msix_state(struct pci_dev *dev) msix_set_enable(dev, 0); list_for_each_entry(entry, &dev->msi_list, list) { - struct irq_desc *desc = irq_to_desc(entry->irq); write_msi_msg(entry->irq, &entry->msg); - msi_set_mask_bits(desc, 1, entry->msi_attrib.masked); + msix_mask_irq(entry, entry->masked); } BUG_ON(list_empty(&dev->msi_list)); @@ -342,6 +343,7 @@ static int msi_capability_init(struct pci_dev *dev) struct msi_desc *entry; int pos, ret; u16 control; + unsigned mask; msi_set_enable(dev, 0); /* Ensure msi is disabled as I set it up */ @@ -356,21 +358,16 @@ static int msi_capability_init(struct pci_dev *dev) 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 (entry->msi_attrib.maskbit) { - unsigned int base, maskbits, temp; - base = msi_mask_bits_reg(pos, entry->msi_attrib.is_64); - entry->mask_pos = base; - /* All MSIs are unmasked by default, Mask them all */ - pci_read_config_dword(dev, base, &maskbits); - temp = msi_mask((control & PCI_MSI_FLAGS_QMASK) >> 1); - maskbits |= temp; - pci_write_config_dword(dev, base, maskbits); - entry->msi_attrib.maskbits_mask = temp; - } + entry->mask_pos = msi_mask_bits_reg(pos, entry->msi_attrib.is_64); + /* All MSIs are unmasked by default, Mask them all */ + if (entry->msi_attrib.maskbit) + pci_read_config_dword(dev, entry->mask_pos, &entry->masked); + mask = msi_capable_mask(control); + msi_mask_irq(entry, mask, mask); + list_add_tail(&entry->list, &dev->msi_list); /* Configure MSI capability structure */ @@ -435,11 +432,12 @@ static int msix_capability_init(struct pci_dev *dev, entry->msi_attrib.is_msix = 1; 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->mask_base = base; + entry->masked = readl(base + j * PCI_MSIX_ENTRY_SIZE + + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET); + msix_mask_irq(entry, 1); list_add_tail(&entry->list, &dev->msi_list); } @@ -556,9 +554,11 @@ int pci_enable_msi(struct pci_dev* dev) } EXPORT_SYMBOL(pci_enable_msi); -void pci_msi_shutdown(struct pci_dev* dev) +void pci_msi_shutdown(struct pci_dev *dev) { - struct msi_desc *entry; + struct msi_desc *desc; + u32 mask; + u16 ctrl; if (!pci_msi_enable || !dev || !dev->msi_enabled) return; @@ -568,18 +568,13 @@ void pci_msi_shutdown(struct pci_dev* dev) dev->msi_enabled = 0; BUG_ON(list_empty(&dev->msi_list)); - entry = list_entry(dev->msi_list.next, struct msi_desc, list); - /* Return the the pci reset with msi irqs unmasked */ - if (entry->msi_attrib.maskbit) { - u32 mask = entry->msi_attrib.maskbits_mask; - struct irq_desc *desc = irq_to_desc(dev->irq); - msi_set_mask_bits(desc, mask, ~mask); - } - if (entry->msi_attrib.is_msix) - return; + desc = list_first_entry(&dev->msi_list, struct msi_desc, list); + pci_read_config_word(dev, desc->msi_attrib.pos + PCI_MSI_FLAGS, &ctrl); + mask = msi_capable_mask(ctrl); + msi_mask_irq(desc, mask, ~mask); /* Restore dev->irq to its default pin-assertion irq */ - dev->irq = entry->msi_attrib.default_irq; + dev->irq = desc->msi_attrib.default_irq; } void pci_disable_msi(struct pci_dev* dev) diff --git a/include/linux/msi.h b/include/linux/msi.h index 5025ca4d91e4..37c1bbe546e5 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -22,14 +22,13 @@ struct msi_desc { struct { __u8 is_msix : 1; __u8 maskbit : 1; /* mask-pending bit supported ? */ - __u8 masked : 1; __u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */ __u8 pos; /* Location of the msi capability */ __u16 entry_nr; /* specific enabled entry */ - __u32 maskbits_mask; /* mask bits mask */ unsigned default_irq; /* default pre-assigned irq */ - }msi_attrib; + } msi_attrib; + u32 masked; /* mask bits */ unsigned int irq; struct list_head list;