diff options
86 files changed, 1439 insertions, 2603 deletions
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt new file mode 100644 index 00000000000..27dcaabfb4d --- /dev/null +++ b/Documentation/IRQ-domain.txt @@ -0,0 +1,117 @@ +irq_domain interrupt number mapping library + +The current design of the Linux kernel uses a single large number +space where each separate IRQ source is assigned a different number. +This is simple when there is only one interrupt controller, but in +systems with multiple interrupt controllers the kernel must ensure +that each one gets assigned non-overlapping allocations of Linux +IRQ numbers. + +The irq_alloc_desc*() and irq_free_desc*() APIs provide allocation of +irq numbers, but they don't provide any support for reverse mapping of +the controller-local IRQ (hwirq) number into the Linux IRQ number +space. + +The irq_domain library adds mapping between hwirq and IRQ numbers on +top of the irq_alloc_desc*() API. An irq_domain to manage mapping is +preferred over interrupt controller drivers open coding their own +reverse mapping scheme. + +irq_domain also implements translation from Device Tree interrupt +specifiers to hwirq numbers, and can be easily extended to support +other IRQ topology data sources. + +=== irq_domain usage === +An interrupt controller driver creates and registers an irq_domain by +calling one of the irq_domain_add_*() functions (each mapping method +has a different allocator function, more on that later). The function +will return a pointer to the irq_domain on success. The caller must +provide the allocator function with an irq_domain_ops structure with +the .map callback populated as a minimum. + +In most cases, the irq_domain will begin empty without any mappings +between hwirq and IRQ numbers. Mappings are added to the irq_domain +by calling irq_create_mapping() which accepts the irq_domain and a +hwirq number as arguments. If a mapping for the hwirq doesn't already +exist then it will allocate a new Linux irq_desc, associate it with +the hwirq, and call the .map() callback so the driver can perform any +required hardware setup. + +When an interrupt is received, irq_find_mapping() function should +be used to find the Linux IRQ number from the hwirq number. + +If the driver has the Linux IRQ number or the irq_data pointer, and +needs to know the associated hwirq number (such as in the irq_chip +callbacks) then it can be directly obtained from irq_data->hwirq. + +=== Types of irq_domain mappings === +There are several mechanisms available for reverse mapping from hwirq +to Linux irq, and each mechanism uses a different allocation function. +Which reverse map type should be used depends on the use case. Each +of the reverse map types are described below: + +==== Linear ==== +irq_domain_add_linear() + +The linear reverse map maintains a fixed size table indexed by the +hwirq number. When a hwirq is mapped, an irq_desc is allocated for +the hwirq, and the IRQ number is stored in the table. + +The Linear map is a good choice when the maximum number of hwirqs is +fixed and a relatively small number (~ < 256). The advantages of this +map are fixed time lookup for IRQ numbers, and irq_descs are only +allocated for in-use IRQs. The disadvantage is that the table must be +as large as the largest possible hwirq number. + +The majority of drivers should use the linear map. + +==== Tree ==== +irq_domain_add_tree() + +The irq_domain maintains a radix tree map from hwirq numbers to Linux +IRQs. When an hwirq is mapped, an irq_desc is allocated and the +hwirq is used as the lookup key for the radix tree. + +The tree map is a good choice if the hwirq number can be very large +since it doesn't need to allocate a table as large as the largest +hwirq number. The disadvantage is that hwirq to IRQ number lookup is +dependent on how many entries are in the table. + +Very few drivers should need this mapping. At the moment, powerpc +iseries is the only user. + +==== No Map ===- +irq_domain_add_nomap() + +The No Map mapping is to be used when the hwirq number is +programmable in the hardware. In this case it is best to program the +Linux IRQ number into the hardware itself so that no mapping is +required. Calling irq_create_direct_mapping() will allocate a Linux +IRQ number and call the .map() callback so that driver can program the +Linux IRQ number into the hardware. + +Most drivers cannot use this mapping. + +==== Legacy ==== +irq_domain_add_legacy() +irq_domain_add_legacy_isa() + +The Legacy mapping is a special case for drivers that already have a +range of irq_descs allocated for the hwirqs. It is used when the +driver cannot be immediately converted to use the linear mapping. For +example, many embedded system board support files use a set of #defines +for IRQ numbers that are passed to struct device registrations. In that +case the Linux IRQ numbers cannot be dynamically assigned and the legacy +mapping should be used. + +The legacy map assumes a contiguous range of IRQ numbers has already +been allocated for the controller and that the IRQ number can be +calculated by adding a fixed offset to the hwirq number, and +visa-versa. The disadvantage is that it requires the interrupt +controller to manage IRQ allocations and it requires an irq_desc to be +allocated for every hwirq, even if it is unused. + +The legacy map should only be used if fixed IRQ mappings must be +supported. For example, ISA controllers would use the legacy map for +mapping Linux IRQs 0-15 so that existing ISA drivers get the correct IRQ +numbers. diff --git a/MAINTAINERS b/MAINTAINERS index 8f254e7b6c7..92f9924c433 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3666,6 +3666,15 @@ S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core F: kernel/irq/ +IRQ DOMAINS (IRQ NUMBER MAPPING LIBRARY) +M: Benjamin Herrenschmidt <benh@kernel.crashing.org> +M: Grant Likely <grant.likely@secretlab.ca> +T: git git://git.secretlab.ca/git/linux-2.6.git irqdomain/next +S: Maintained +F: Documentation/IRQ-domain.txt +F: include/linux/irqdomain.h +F: kernel/irq/irqdomain.c + ISAPNP M: Jaroslav Kysela <perex@perex.cz> S: Maintained diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c index c47d6199b78..f0783be1735 100644 --- a/arch/arm/common/gic.c +++ b/arch/arm/common/gic.c @@ -51,7 +51,6 @@ union gic_base { }; struct gic_chip_data { - unsigned int irq_offset; union gic_base dist_base; union gic_base cpu_base; #ifdef CONFIG_CPU_PM @@ -61,9 +60,7 @@ struct gic_chip_data { u32 __percpu *saved_ppi_enable; u32 __percpu *saved_ppi_conf; #endif -#ifdef CONFIG_IRQ_DOMAIN - struct irq_domain domain; -#endif + struct irq_domain *domain; unsigned int gic_irqs; #ifdef CONFIG_GIC_NON_BANKED void __iomem *(*get_base)(union gic_base *); @@ -282,7 +279,7 @@ asmlinkage void __exception_irq_entry gic_handle_irq(struct pt_regs *regs) irqnr = irqstat & ~0x1c00; if (likely(irqnr > 15 && irqnr < 1021)) { - irqnr = irq_domain_to_irq(&gic->domain, irqnr); + irqnr = irq_find_mapping(gic->domain, irqnr); handle_IRQ(irqnr, regs); continue; } @@ -314,8 +311,8 @@ static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc) if (gic_irq == 1023) goto out; - cascade_irq = irq_domain_to_irq(&chip_data->domain, gic_irq); - if (unlikely(gic_irq < 32 || gic_irq > 1020 || cascade_irq >= NR_IRQS)) + cascade_irq = irq_find_mapping(chip_data->domain, gic_irq); + if (unlikely(gic_irq < 32 || gic_irq > 1020)) do_bad_IRQ(cascade_irq, desc); else generic_handle_irq(cascade_irq); @@ -348,10 +345,9 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq) static void __init gic_dist_init(struct gic_chip_data *gic) { - unsigned int i, irq; + unsigned int i; u32 cpumask; unsigned int gic_irqs = gic->gic_irqs; - struct irq_domain *domain = &gic->domain; void __iomem *base = gic_data_dist_base(gic); u32 cpu = cpu_logical_map(smp_processor_id()); @@ -386,23 +382,6 @@ static void __init gic_dist_init(struct gic_chip_data *gic) for (i = 32; i < gic_irqs; i += 32) writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32); - /* - * Setup the Linux IRQ subsystem. - */ - irq_domain_for_each_irq(domain, i, irq) { - if (i < 32) { - irq_set_percpu_devid(irq); - irq_set_chip_and_handler(irq, &gic_chip, - handle_percpu_devid_irq); - set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN); - } else { - irq_set_chip_and_handler(irq, &gic_chip, - handle_fasteoi_irq); - set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); - } - irq_set_chip_data(irq, gic); - } - writel_relaxed(1, base + GIC_DIST_CTRL); } @@ -618,11 +597,27 @@ static void __init gic_pm_init(struct gic_chip_data *gic) } #endif -#ifdef CONFIG_OF -static int gic_irq_domain_dt_translate(struct irq_domain *d, - struct device_node *controller, - const u32 *intspec, unsigned int intsize, - unsigned long *out_hwirq, unsigned int *out_type) +static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ + if (hw < 32) { + irq_set_percpu_devid(irq); + irq_set_chip_and_handler(irq, &gic_chip, + handle_percpu_devid_irq); + set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN); + } else { + irq_set_chip_and_handler(irq, &gic_chip, + handle_fasteoi_irq); + set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); + } + irq_set_chip_data(irq, d->host_data); + return 0; +} + +static int gic_irq_domain_xlate(struct irq_domain *d, + struct device_node *controller, + const u32 *intspec, unsigned int intsize, + unsigned long *out_hwirq, unsigned int *out_type) { if (d->of_node != controller) return -EINVAL; @@ -639,26 +634,23 @@ static int gic_irq_domain_dt_translate(struct irq_domain *d, *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK; return 0; } -#endif const struct irq_domain_ops gic_irq_domain_ops = { -#ifdef CONFIG_OF - .dt_translate = gic_irq_domain_dt_translate, -#endif + .map = gic_irq_domain_map, + .xlate = gic_irq_domain_xlate, }; void __init gic_init_bases(unsigned int gic_nr, int irq_start, void __iomem *dist_base, void __iomem *cpu_base, - u32 percpu_offset) + u32 percpu_offset, struct device_node *node) { + irq_hw_number_t hwirq_base; struct gic_chip_data *gic; - struct irq_domain *domain; - int gic_irqs; + int gic_irqs, irq_base; BUG_ON(gic_nr >= MAX_GIC_NR); gic = &gic_data[gic_nr]; - domain = &gic->domain; #ifdef CONFIG_GIC_NON_BANKED if (percpu_offset) { /* Frankein-GIC without banked registers... */ unsigned int cpu; @@ -694,10 +686,10 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, * For primary GICs, skip over SGIs. * For secondary GICs, skip over PPIs, too. */ - domain->hwirq_base = 32; + hwirq_base = 32; if (gic_nr == 0) { if ((irq_start & 31) > 0) { - domain->hwirq_base = 16; + hwirq_base = 16; if (irq_start != -1) irq_start = (irq_start & ~31) + 16; } @@ -713,17 +705,17 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, gic_irqs = 1020; gic->gic_irqs = gic_irqs; - domain->nr_irq = gic_irqs - domain->hwirq_base; - domain->irq_base = irq_alloc_descs(irq_start, 16, domain->nr_irq, - numa_node_id()); - if (IS_ERR_VALUE(domain->irq_base)) { + gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */ + irq_base = irq_alloc_descs(irq_start, 16, gic_irqs, numa_node_id()); + if (IS_ERR_VALUE(irq_base)) { WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n", irq_start); - domain->irq_base = irq_start; + irq_base = irq_start; } - domain->priv = gic; - domain->ops = &gic_irq_domain_ops; - irq_domain_add(domain); + gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base, + hwirq_base, &gic_irq_domain_ops, gic); + if (WARN_ON(!gic->domain)) + return; gic_chip.flags |= gic_arch_extn.flags; gic_dist_init(gic); @@ -768,7 +760,6 @@ int __init gic_of_init(struct device_node *node, struct device_node *parent) void __iomem *dist_base; u32 percpu_offset; int irq; - struct irq_domain *domain = &gic_data[gic_cnt].domain; if (WARN_ON(!node)) return -ENODEV; @@ -782,9 +773,7 @@ int __init gic_of_init(struct device_node *node, struct device_node *parent) if (of_property_read_u32(node, "cpu-offset", &percpu_offset)) percpu_offset = 0; - domain->of_node = of_node_get(node); - - gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset); + gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node); if (parent) { irq = irq_of_parse_and_map(node, 0); diff --git a/arch/arm/common/vic.c b/arch/arm/common/vic.c index dcb004a804c..7a66311f306 100644 --- a/arch/arm/common/vic.c +++ b/arch/arm/common/vic.c @@ -56,7 +56,7 @@ struct vic_device { u32 int_enable; u32 soft_int; u32 protect; - struct irq_domain domain; + struct irq_domain *domain; }; /* we cannot allocate memory when VICs are initially registered */ @@ -192,14 +192,8 @@ static void __init vic_register(void __iomem *base, unsigned int irq, v->resume_sources = resume_sources; v->irq = irq; vic_id++; - - v->domain.irq_base = irq; - v->domain.nr_irq = 32; -#ifdef CONFIG_OF_IRQ - v->domain.of_node = of_node_get(node); -#endif /* CONFIG_OF */ - v->domain.ops = &irq_domain_simple_ops; - irq_domain_add(&v->domain); + v->domain = irq_domain_add_legacy(node, 32, irq, 0, + &irq_domain_simple_ops, v); } static void vic_ack_irq(struct irq_data *d) @@ -348,7 +342,7 @@ static void __init vic_init_st(void __iomem *base, unsigned int irq_start, vic_register(base, irq_start, 0, node); } -static void __init __vic_init(void __iomem *base, unsigned int irq_start, +void __init __vic_init(void __iomem *base, unsigned int irq_start, u32 vic_sources, u32 resume_sources, struct device_node *node) { @@ -444,7 +438,7 @@ static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs) stat = readl_relaxed(vic->base + VIC_IRQ_STATUS); while (stat) { irq = ffs(stat) - 1; - handle_IRQ(irq_domain_to_irq(&vic->domain, irq), regs); + handle_IRQ(irq_find_mapping(vic->domain, irq), regs); stat &= ~(1 << irq); handled = 1; } diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h index 4bdfe001869..4b1ce6cd477 100644 --- a/arch/arm/include/asm/hardware/gic.h +++ b/arch/arm/include/asm/hardware/gic.h @@ -39,7 +39,7 @@ struct device_node; extern struct irq_chip gic_arch_e |