From 0b8f1efad30bd58f89961b82dfe68b9edf8fd2ac Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 5 Dec 2008 18:58:31 -0800 Subject: sparse irq_desc[] array: core kernel and x86 changes Impact: new feature Problem on distro kernels: irq_desc[NR_IRQS] takes megabytes of RAM with NR_CPUS set to large values. The goal is to be able to scale up to much larger NR_IRQS value without impacting the (important) common case. To solve this, we generalize irq_desc[NR_IRQS] to an (optional) array of irq_desc pointers. When CONFIG_SPARSE_IRQ=y is used, we use kzalloc_node to get irq_desc, this also makes the IRQ descriptors NUMA-local (to the site that calls request_irq()). This gets rid of the irq_cfg[] static array on x86 as well: irq_cfg now uses desc->chip_data for x86 to store irq_cfg. Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- drivers/pci/intr_remapping.c | 76 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 74 insertions(+), 2 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c index 2de5a3238c9..c9958ec5e25 100644 --- a/drivers/pci/intr_remapping.c +++ b/drivers/pci/intr_remapping.c @@ -19,17 +19,75 @@ struct irq_2_iommu { u8 irte_mask; }; -static struct irq_2_iommu irq_2_iommuX[NR_IRQS]; +#ifdef CONFIG_SPARSE_IRQ +static struct irq_2_iommu *get_one_free_irq_2_iommu(int cpu) +{ + struct irq_2_iommu *iommu; + int node; + + node = cpu_to_node(cpu); + + iommu = kzalloc_node(sizeof(*iommu), GFP_ATOMIC, node); + printk(KERN_DEBUG "alloc irq_2_iommu on cpu %d node %d\n", cpu, node); + + return iommu; +} static struct irq_2_iommu *irq_2_iommu(unsigned int irq) { - return (irq < nr_irqs) ? irq_2_iommuX + irq : NULL; + struct irq_desc *desc; + + desc = irq_to_desc(irq); + + if (WARN_ON_ONCE(!desc)) + return NULL; + + return desc->irq_2_iommu; +} + +static struct irq_2_iommu *irq_2_iommu_alloc_cpu(unsigned int irq, int cpu) +{ + struct irq_desc *desc; + struct irq_2_iommu *irq_iommu; + + /* + * alloc irq desc if not allocated already. + */ + desc = irq_to_desc_alloc_cpu(irq, cpu); + if (!desc) { + printk(KERN_INFO "can not get irq_desc for %d\n", irq); + return NULL; + } + + irq_iommu = desc->irq_2_iommu; + + if (!irq_iommu) + desc->irq_2_iommu = get_one_free_irq_2_iommu(cpu); + + return desc->irq_2_iommu; } +static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq) +{ + return irq_2_iommu_alloc_cpu(irq, boot_cpu_id); +} + +#else /* !CONFIG_SPARSE_IRQ */ + +static struct irq_2_iommu irq_2_iommuX[NR_IRQS]; + +static struct irq_2_iommu *irq_2_iommu(unsigned int irq) +{ + if (irq < nr_irqs) + return &irq_2_iommuX[irq]; + + return NULL; +} static struct irq_2_iommu *irq_2_iommu_alloc(unsigned int irq) { return irq_2_iommu(irq); } +#endif static DEFINE_SPINLOCK(irq_2_ir_lock); @@ -86,9 +144,11 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count) if (!count) return -1; +#ifndef CONFIG_SPARSE_IRQ /* protect irq_2_iommu_alloc later */ if (irq >= nr_irqs) return -1; +#endif /* * start the IRTE search from index 0. @@ -130,6 +190,12 @@ int alloc_irte(struct intel_iommu *iommu, int irq, u16 count) table->base[i].present = 1; irq_iommu = irq_2_iommu_alloc(irq); + if (!irq_iommu) { + spin_unlock(&irq_2_ir_lock); + printk(KERN_ERR "can't allocate irq_2_iommu\n"); + return -1; + } + irq_iommu->iommu = iommu; irq_iommu->irte_index = index; irq_iommu->sub_handle = 0; @@ -177,6 +243,12 @@ int set_irte_irq(int irq, struct intel_iommu *iommu, u16 index, u16 subhandle) irq_iommu = irq_2_iommu_alloc(irq); + if (!irq_iommu) { + spin_unlock(&irq_2_ir_lock); + printk(KERN_ERR "can't allocate irq_2_iommu\n"); + return -1; + } + irq_iommu->iommu = iommu; irq_iommu->irte_index = index; irq_iommu->sub_handle = subhandle; -- cgit v1.2.3 From 3145e941fcfe2548fa2270afb1a05bab3a6bc418 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 5 Dec 2008 18:58:34 -0800 Subject: x86, MSI: pass irq_cfg and irq_desc Impact: simplify code Pass irq_desc and cfg around, instead of raw IRQ numbers - this way we dont have to look it up again and again. Signed-off-by: Yinghai Lu Signed-off-by: Ingo Molnar --- drivers/pci/msi.c | 55 ++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 17 deletions(-) (limited to 'drivers/pci') diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 74801f7df9c..11a51f8ed3b 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -103,11 +103,11 @@ static void msix_set_enable(struct pci_dev *dev, int enable) } } -static void msix_flush_writes(unsigned int irq) +static void msix_flush_writes(struct irq_desc *desc) { struct msi_desc *entry; - entry = get_irq_msi(irq); + entry = get_irq_desc_msi(desc); BUG_ON(!entry || !entry->dev); switch (entry->msi_attrib.type) { case PCI_CAP_ID_MSI: @@ -135,11 +135,11 @@ static void msix_flush_writes(unsigned int irq) * 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(unsigned int irq, u32 mask, u32 flag) +static int msi_set_mask_bits(struct irq_desc *desc, u32 mask, u32 flag) { struct msi_desc *entry; - entry = get_irq_msi(irq); + entry = get_irq_desc_msi(desc); BUG_ON(!entry || !entry->dev); switch (entry->msi_attrib.type) { case PCI_CAP_ID_MSI: @@ -172,9 +172,9 @@ static int msi_set_mask_bits(unsigned int irq, u32 mask, u32 flag) return 1; } -void read_msi_msg(unsigned int irq, struct msi_msg *msg) +void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) { - struct msi_desc *entry = get_irq_msi(irq); + struct msi_desc *entry = get_irq_desc_msi(desc); switch(entry->msi_attrib.type) { case PCI_CAP_ID_MSI: { @@ -211,9 +211,16 @@ void read_msi_msg(unsigned int irq, struct msi_msg *msg) } } -void write_msi_msg(unsigned int irq, struct msi_msg *msg) +void read_msi_msg(unsigned int irq, struct msi_msg *msg) { - struct msi_desc *entry = get_irq_msi(irq); + struct irq_desc *desc = irq_to_desc(irq); + + read_msi_msg_desc(desc, msg); +} + +void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) +{ + struct msi_desc *entry = get_irq_desc_msi(desc); switch (entry->msi_attrib.type) { case PCI_CAP_ID_MSI: { @@ -252,21 +259,31 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg) entry->msg = *msg; } +void write_msi_msg(unsigned int irq, struct msi_msg *msg) +{ + struct irq_desc *desc = irq_to_desc(irq); + + write_msi_msg_desc(desc, msg); +} + void mask_msi_irq(unsigned int irq) { - msi_set_mask_bits(irq, 1, 1); - msix_flush_writes(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) { - msi_set_mask_bits(irq, 1, 0); - msix_flush_writes(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(void) { struct msi_desc *entry; @@ -303,9 +320,11 @@ 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) - msi_set_mask_bits(dev->irq, entry->msi_attrib.maskbits_mask, + 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); control &= ~PCI_MSI_FLAGS_QSIZE; @@ -327,8 +346,9 @@ 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(entry->irq, 1, entry->msi_attrib.masked); + msi_set_mask_bits(desc, 1, entry->msi_attrib.masked); } BUG_ON(list_empty(&dev->msi_list)); @@ -596,7 +616,8 @@ void pci_msi_shutdown(struct pci_dev* dev) /* Return the the pci reset with msi irqs unmasked */ if (entry->msi_attrib.maskbit) { u32 mask = entry->msi_attrib.maskbits_mask; - msi_set_mask_bits(dev->irq, mask, ~mask); + struct irq_desc *desc = irq_to_desc(dev->irq); + msi_set_mask_bits(desc, mask, ~mask); } if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) return; -- cgit v1.2.3