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Diffstat (limited to 'arch/x86_64/kernel/io_apic.c')
-rw-r--r--arch/x86_64/kernel/io_apic.c80
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 c8eee20cd51..97154ab058b 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
*/