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authorRusty Russell <rusty@rustcorp.com.au>2006-06-27 02:53:44 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-27 17:32:37 -0700
commit19eadf98c8167eac843580683317b99572e2abf0 (patch)
treea5625f7834f0f06fc28a605c3cdb8debe2218498 /arch/i386
parentbd9e0b74f52dbac6241643fadca2393808b14c7a (diff)
[PATCH] x86: increase interrupt vector range
Remove the limit of 256 interrupt vectors by changing the value stored in orig_{e,r}ax to be the complemented interrupt vector. The orig_{e,r}ax needs to be < 0 to allow the signal code to distinguish between return from interrupt and return from syscall. With this change applied, NR_IRQS can be > 256. Xen extends the IRQ numbering space to include room for dynamically allocated virtual interrupts (in the range 256-511), which requires a more permissive interface to do_IRQ. Signed-off-by: Ian Pratt <ian.pratt@xensource.com> Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386')
-rw-r--r--arch/i386/kernel/entry.S4
-rw-r--r--arch/i386/kernel/irq.c4
2 files changed, 4 insertions, 4 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index e6e4506e749..8713e0248a0 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -515,7 +515,7 @@ ENTRY(irq_entries_start)
.if vector
CFI_ADJUST_CFA_OFFSET -4
.endif
-1: pushl $vector-256
+1: pushl $~(vector)
CFI_ADJUST_CFA_OFFSET 4
jmp common_interrupt
.data
@@ -535,7 +535,7 @@ common_interrupt:
#define BUILD_INTERRUPT(name, nr) \
ENTRY(name) \
RING0_INT_FRAME; \
- pushl $nr-256; \
+ pushl $~(nr); \
CFI_ADJUST_CFA_OFFSET 4; \
SAVE_ALL; \
movl %esp,%eax; \
diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
index 061533e0cb5..586b15f6741 100644
--- a/arch/i386/kernel/irq.c
+++ b/arch/i386/kernel/irq.c
@@ -53,8 +53,8 @@ static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
*/
fastcall unsigned int do_IRQ(struct pt_regs *regs)
{
- /* high bits used in ret_from_ code */
- int irq = regs->orig_eax & 0xff;
+ /* high bit used in ret_from_ code */
+ int irq = ~regs->orig_eax;
#ifdef CONFIG_4KSTACKS
union irq_ctx *curctx, *irqctx;
u32 *isp;