[PATCH 21/25] x86_64 irq: Make the external irq handlers report their vector, not the irq number.

From: Eric W. Biederman
Date: Tue Jun 20 2006 - 18:32:17 EST


This is a small pessimization but it paves the way for making this information
per cpu. Which allows the the maximum number of IRQS to become NR_CPUS*224.

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
arch/x86_64/kernel/i8259.c | 62 +++++++++++++++++-------------------------
arch/x86_64/kernel/io_apic.c | 4 +--
arch/x86_64/kernel/irq.c | 7 +++--
include/asm-x86_64/hw_irq.h | 1 +
4 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/arch/x86_64/kernel/i8259.c b/arch/x86_64/kernel/i8259.c
index 4749954..c3e737a 100644
--- a/arch/x86_64/kernel/i8259.c
+++ b/arch/x86_64/kernel/i8259.c
@@ -44,19 +44,11 @@ #define BUILD_16_IRQS(x) \
BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
BI(x,c) BI(x,d) BI(x,e) BI(x,f)

-#define BUILD_15_IRQS(x) \
- BI(x,0) BI(x,1) BI(x,2) BI(x,3) \
- BI(x,4) BI(x,5) BI(x,6) BI(x,7) \
- BI(x,8) BI(x,9) BI(x,a) BI(x,b) \
- BI(x,c) BI(x,d) BI(x,e)
-
/*
* ISA PIC or low IO-APIC triggered (INTA-cycle or APIC) interrupts:
* (these are usually mapped to vectors 0x20-0x2f)
*/
-BUILD_16_IRQS(0x0)

-#ifdef CONFIG_X86_LOCAL_APIC
/*
* The IO-APIC gives us many more interrupt sources. Most of these
* are unused but an SMP system is supposed to have enough memory ...
@@ -67,19 +59,13 @@ #ifdef CONFIG_X86_LOCAL_APIC
*
* (these are usually mapped into the 0x30-0xff vector range)
*/
- BUILD_16_IRQS(0x1) BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
+ BUILD_16_IRQS(0x2) BUILD_16_IRQS(0x3)
BUILD_16_IRQS(0x4) BUILD_16_IRQS(0x5) BUILD_16_IRQS(0x6) BUILD_16_IRQS(0x7)
BUILD_16_IRQS(0x8) BUILD_16_IRQS(0x9) BUILD_16_IRQS(0xa) BUILD_16_IRQS(0xb)
-BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd)
+BUILD_16_IRQS(0xc) BUILD_16_IRQS(0xd) BUILD_16_IRQS(0xe) BUILD_16_IRQS(0xf)

-#ifdef CONFIG_PCI_MSI
- BUILD_15_IRQS(0xe)
-#endif
-
-#endif

#undef BUILD_16_IRQS
-#undef BUILD_15_IRQS
#undef BI


@@ -92,31 +78,15 @@ #define IRQLIST_16(x) \
IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
IRQ(x,c), IRQ(x,d), IRQ(x,e), IRQ(x,f)

-#define IRQLIST_15(x) \
- IRQ(x,0), IRQ(x,1), IRQ(x,2), IRQ(x,3), \
- IRQ(x,4), IRQ(x,5), IRQ(x,6), IRQ(x,7), \
- IRQ(x,8), IRQ(x,9), IRQ(x,a), IRQ(x,b), \
- IRQ(x,c), IRQ(x,d), IRQ(x,e)
-
void (*interrupt[NR_IRQS])(void) = {
- IRQLIST_16(0x0),
-
-#ifdef CONFIG_X86_IO_APIC
- IRQLIST_16(0x1), IRQLIST_16(0x2), IRQLIST_16(0x3),
+ IRQLIST_16(0x2), IRQLIST_16(0x3),
IRQLIST_16(0x4), IRQLIST_16(0x5), IRQLIST_16(0x6), IRQLIST_16(0x7),
IRQLIST_16(0x8), IRQLIST_16(0x9), IRQLIST_16(0xa), IRQLIST_16(0xb),
- IRQLIST_16(0xc), IRQLIST_16(0xd)
-
-#ifdef CONFIG_PCI_MSI
- , IRQLIST_15(0xe)
-#endif
-
-#endif
+ IRQLIST_16(0xc), IRQLIST_16(0xd), IRQLIST_16(0xe), IRQLIST_16(0xf)
};

#undef IRQ
#undef IRQLIST_16
-#undef IRQLIST_14

/*
* This is the 'legacy' 8259A Programmable Interrupt Controller,
@@ -424,6 +394,26 @@ device_initcall(i8259A_init_sysfs);
*/

static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL};
+int vector_irq[NR_VECTORS] __read_mostly = {
+ [0 ... FIRST_EXTERNAL_VECTOR - 1] = -1,
+ [FIRST_EXTERNAL_VECTOR + 0] = 0,
+ [FIRST_EXTERNAL_VECTOR + 1] = 1,
+ [FIRST_EXTERNAL_VECTOR + 2] = 2,
+ [FIRST_EXTERNAL_VECTOR + 3] = 3,
+ [FIRST_EXTERNAL_VECTOR + 4] = 4,
+ [FIRST_EXTERNAL_VECTOR + 5] = 5,
+ [FIRST_EXTERNAL_VECTOR + 6] = 6,
+ [FIRST_EXTERNAL_VECTOR + 7] = 7,
+ [FIRST_EXTERNAL_VECTOR + 8] = 8,
+ [FIRST_EXTERNAL_VECTOR + 9] = 9,
+ [FIRST_EXTERNAL_VECTOR + 10] = 10,
+ [FIRST_EXTERNAL_VECTOR + 11] = 11,
+ [FIRST_EXTERNAL_VECTOR + 12] = 12,
+ [FIRST_EXTERNAL_VECTOR + 13] = 13,
+ [FIRST_EXTERNAL_VECTOR + 14] = 14,
+ [FIRST_EXTERNAL_VECTOR + 15] = 15,
+ [FIRST_EXTERNAL_VECTOR + 16 ... NR_VECTORS - 1] = -1
+};

void __init init_ISA_irqs (void)
{
@@ -523,8 +513,6 @@ void __init init_IRQ(void)
*/
for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
int vector = FIRST_EXTERNAL_VECTOR + i;
- if (i >= NR_IRQS)
- break;
if (vector != IA32_SYSCALL_VECTOR)
set_intr_gate(vector, interrupt[i]);
}
@@ -534,7 +522,7 @@ #ifdef CONFIG_SMP
* IRQ0 must be given a fixed assignment and initialized,
* because it's used before the IO-APIC is set up.
*/
- set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
+ vector_irq[FIRST_DEVICE_VECTOR] = 0;

/*
* The reschedule interrupt is a CPU-to-CPU reschedule-helper
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c
index 1a63a0e..3ff5606 100644
--- a/arch/x86_64/kernel/io_apic.c
+++ b/arch/x86_64/kernel/io_apic.c
@@ -850,6 +850,7 @@ next:
}

vector = current_vector;
+ vector_irq[vector] = irq;
IO_APIC_VECTOR(irq) = vector;

return vector;
@@ -884,7 +885,6 @@ static void ioapic_register_intr(int irq
else
set_irq_chip_and_handler(irq, &ioapic_chip,
handle_edge_irq);
- set_intr_gate(vector, interrupt[irq]);
}

static void __init setup_IO_APIC_irqs(void)
@@ -1727,7 +1727,6 @@ static inline void check_timer(void)
*/
disable_8259A_irq(0);
vector = assign_irq_vector(0);
- set_intr_gate(vector, interrupt[0]);

/*
* Subtle, code in do_timer_interrupt() expects an AEOI
@@ -1988,7 +1987,6 @@ int create_irq(void)
spin_unlock_irqrestore(&vector_lock, flags);

if (irq >= 0) {
- set_intr_gate(vector, interrupt[irq]);
dynamic_irq_init(irq);
}
return irq;
diff --git a/arch/x86_64/kernel/irq.c b/arch/x86_64/kernel/irq.c
index c2d27d3..dd8d79a 100644
--- a/arch/x86_64/kernel/irq.c
+++ b/arch/x86_64/kernel/irq.c
@@ -93,12 +93,15 @@ #endif
asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
{
/* high bit used in ret_from_ code */
- unsigned irq = ~regs->orig_rax;
+ unsigned vector = ~regs->orig_rax;
+ unsigned irq;

exit_idle();
irq_enter();

- generic_handle_irq(irq, regs);
+ irq = vector_irq[vector];
+ if (likely(irq < NR_IRQS))
+ generic_handle_irq(irq, regs);

irq_exit();

diff --git a/include/asm-x86_64/hw_irq.h b/include/asm-x86_64/hw_irq.h
index 1a8dc18..9f6a0bf 100644
--- a/include/asm-x86_64/hw_irq.h
+++ b/include/asm-x86_64/hw_irq.h
@@ -74,6 +74,7 @@ #define FIRST_SYSTEM_VECTOR 0xef /* du

#ifndef __ASSEMBLY__
extern u8 irq_vector[NR_IRQ_VECTORS];
+extern int vector_irq[NR_VECTORS];
#define IO_APIC_VECTOR(irq) (irq_vector[irq])

/*
--
1.4.0.gc07e

-
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