diff options
Diffstat (limited to 'arch/x86_64/kernel/io_apic.c')
| -rw-r--r-- | arch/x86_64/kernel/io_apic.c | 80 |
1 files changed, 73 insertions, 7 deletions
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index c8eee20cd519..97154ab058b4 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -57,7 +57,7 @@ int nr_ioapic_registers[MAX_IO_APICS]; * Rough estimation of how many shared IRQs there are, can * be changed anytime. */ -#define MAX_PLUS_SHARED_IRQS NR_IRQS +#define MAX_PLUS_SHARED_IRQS NR_IRQ_VECTORS #define PIN_MAP_SIZE (MAX_PLUS_SHARED_IRQS + NR_IRQS) /* @@ -85,6 +85,7 @@ int vector_irq[NR_VECTORS] __read_mostly = { [0 ... NR_VECTORS - 1] = -1}; int pin; \ struct irq_pin_list *entry = irq_2_pin + irq; \ \ + BUG_ON(irq >= NR_IRQS); \ for (;;) { \ unsigned int reg; \ pin = entry->pin; \ @@ -127,6 +128,8 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t mask) } #endif +static u8 gsi_2_irq[NR_IRQ_VECTORS] = { [0 ... NR_IRQ_VECTORS-1] = 0xFF }; + /* * The common case is 1:1 IRQ<->pin mappings. Sometimes there are * shared ISA-space IRQs, so we have to support them. We are super @@ -137,6 +140,7 @@ static void add_pin_to_irq(unsigned int irq, int apic, int pin) static int first_free_entry = NR_IRQS; struct irq_pin_list *entry = irq_2_pin + irq; + BUG_ON(irq >= NR_IRQS); while (entry->next) entry = irq_2_pin + entry->next; @@ -144,7 +148,7 @@ static void add_pin_to_irq(unsigned int irq, int apic, int pin) entry->next = first_free_entry; entry = irq_2_pin + entry->next; if (++first_free_entry >= PIN_MAP_SIZE) - panic("io_apic.c: whoops"); + panic("io_apic.c: ran out of irq_2_pin entries!"); } entry->apic = apic; entry->pin = pin; @@ -420,6 +424,7 @@ int IO_APIC_get_PCI_irq_vector(int bus, int slot, int pin) best_guess = irq; } } + BUG_ON(best_guess >= NR_IRQS); return best_guess; } @@ -610,6 +615,64 @@ static inline int irq_trigger(int idx) return MPBIOS_trigger(idx); } +static int next_irq = 16; + +/* + * gsi_irq_sharing -- Name overload! "irq" can be either a legacy IRQ + * in the range 0-15, a linux IRQ in the range 0-223, or a GSI number + * from ACPI, which can reach 800 in large boxen. + * + * Compact the sparse GSI space into a sequential IRQ series and reuse + * vectors if possible. + */ +int gsi_irq_sharing(int gsi) +{ + int i, tries, vector; + + BUG_ON(gsi >= NR_IRQ_VECTORS); + + if (platform_legacy_irq(gsi)) + return gsi; + + if (gsi_2_irq[gsi] != 0xFF) + return (int)gsi_2_irq[gsi]; + + tries = NR_IRQS; + try_again: + vector = assign_irq_vector(gsi); + + /* + * Sharing vectors means sharing IRQs, so scan irq_vectors for previous + * use of vector and if found, return that IRQ. However, we never want + * to share legacy IRQs, which usually have a different trigger mode + * than PCI. + */ + for (i = 0; i < NR_IRQS; i++) + if (IO_APIC_VECTOR(i) == vector) + break; + if (platform_legacy_irq(i)) { + if (--tries >= 0) { + IO_APIC_VECTOR(i) = 0; + goto try_again; + } + panic("gsi_irq_sharing: didn't find an IRQ using vector 0x%02X for GSI %d", vector, gsi); + } + if (i < NR_IRQS) { + gsi_2_irq[gsi] = i; + printk(KERN_INFO "GSI %d sharing vector 0x%02X and IRQ %d\n", + gsi, vector, i); + return i; + } + + i = next_irq++; + BUG_ON(i >= NR_IRQS); + gsi_2_irq[gsi] = i; + IO_APIC_VECTOR(i) = vector; + printk(KERN_INFO "GSI %d assigned vector 0x%02X and IRQ %d\n", + gsi, vector, i); + return i; +} + static int pin_2_irq(int idx, int apic, int pin) { int irq, i; @@ -639,6 +702,7 @@ static int pin_2_irq(int idx, int apic, int pin) while (i < apic) irq += nr_ioapic_registers[i++]; irq += pin; + irq = gsi_irq_sharing(irq); break; } default: @@ -648,6 +712,7 @@ static int pin_2_irq(int idx, int apic, int pin) break; } } + BUG_ON(irq >= NR_IRQS); /* * PCI IRQ command line redirection. Yes, limits are hardcoded. @@ -663,6 +728,7 @@ static int pin_2_irq(int idx, int apic, int pin) } } } + BUG_ON(irq >= NR_IRQS); return irq; } @@ -690,8 +756,8 @@ int assign_irq_vector(int irq) { static int current_vector = FIRST_DEVICE_VECTOR, offset = 0; - BUG_ON(irq >= NR_IRQ_VECTORS); - if (IO_APIC_VECTOR(irq) > 0) + BUG_ON(irq != AUTO_ASSIGN && (unsigned)irq >= NR_IRQ_VECTORS); + if (irq != AUTO_ASSIGN && IO_APIC_VECTOR(irq) > 0) return IO_APIC_VECTOR(irq); next: current_vector += 8; @@ -699,9 +765,8 @@ next: goto next; if (current_vector >= FIRST_SYSTEM_VECTOR) { - offset++; - if (!(offset%8)) - return -ENOSPC; + /* If we run out of vectors on large boxen, must share them. */ + offset = (offset + 1) % 8; current_vector = FIRST_DEVICE_VECTOR + offset; } @@ -1917,6 +1982,7 @@ int io_apic_set_pci_routing (int ioapic, int pin, int irq, int edge_level, int a entry.polarity = active_high_low; entry.mask = 1; /* Disabled (masked) */ + irq = gsi_irq_sharing(irq); /* * IRQs < 16 are already in the irq_2_pin[] map */ |