From: Rusty Russell 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 Signed-off-by: Christian Limpach Signed-off-by: Chris Wright Signed-off-by: Rusty Russell Cc: "Protasevich, Natalie" Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/i386/kernel/entry.S | 4 ++-- arch/i386/kernel/irq.c | 4 ++-- arch/x86_64/kernel/entry.S | 2 +- arch/x86_64/kernel/irq.c | 4 ++-- arch/x86_64/kernel/smp.c | 4 ++-- include/asm-x86_64/hw_irq.h | 2 +- 6 files changed, 10 insertions(+), 10 deletions(-) diff -puN arch/i386/kernel/entry.S~x86-increase-interrupt-vector-range arch/i386/kernel/entry.S --- devel/arch/i386/kernel/entry.S~x86-increase-interrupt-vector-range 2006-05-26 09:30:22.000000000 -0700 +++ devel-akpm/arch/i386/kernel/entry.S 2006-05-26 09:31:03.000000000 -0700 @@ -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 -puN arch/i386/kernel/irq.c~x86-increase-interrupt-vector-range arch/i386/kernel/irq.c --- devel/arch/i386/kernel/irq.c~x86-increase-interrupt-vector-range 2006-05-26 09:30:22.000000000 -0700 +++ devel-akpm/arch/i386/kernel/irq.c 2006-05-26 09:30:22.000000000 -0700 @@ -53,8 +53,8 @@ static union irq_ctx *softirq_ctx[NR_CPU */ 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; diff -puN arch/x86_64/kernel/entry.S~x86-increase-interrupt-vector-range arch/x86_64/kernel/entry.S --- devel/arch/x86_64/kernel/entry.S~x86-increase-interrupt-vector-range 2006-05-26 09:30:22.000000000 -0700 +++ devel-akpm/arch/x86_64/kernel/entry.S 2006-05-26 09:30:22.000000000 -0700 @@ -593,7 +593,7 @@ END(common_interrupt) */ .macro apicinterrupt num,func INTR_FRAME - pushq $\num-256 + pushq $~(\num) CFI_ADJUST_CFA_OFFSET 8 interrupt \func jmp ret_from_intr diff -puN arch/x86_64/kernel/irq.c~x86-increase-interrupt-vector-range arch/x86_64/kernel/irq.c --- devel/arch/x86_64/kernel/irq.c~x86-increase-interrupt-vector-range 2006-05-26 09:30:22.000000000 -0700 +++ devel-akpm/arch/x86_64/kernel/irq.c 2006-05-26 09:30:22.000000000 -0700 @@ -91,8 +91,8 @@ skip: */ asmlinkage unsigned int do_IRQ(struct pt_regs *regs) { - /* high bits used in ret_from_ code */ - unsigned irq = regs->orig_rax & 0xff; + /* high bit used in ret_from_ code */ + unsigned irq = ~regs->orig_rax; exit_idle(); irq_enter(); diff -puN arch/x86_64/kernel/smp.c~x86-increase-interrupt-vector-range arch/x86_64/kernel/smp.c --- devel/arch/x86_64/kernel/smp.c~x86-increase-interrupt-vector-range 2006-05-26 09:30:22.000000000 -0700 +++ devel-akpm/arch/x86_64/kernel/smp.c 2006-05-26 09:30:22.000000000 -0700 @@ -135,10 +135,10 @@ asmlinkage void smp_invalidate_interrupt cpu = smp_processor_id(); /* - * orig_rax contains the interrupt vector - 256. + * orig_rax contains the negated interrupt vector. * Use that to determine where the sender put the data. */ - sender = regs->orig_rax + 256 - INVALIDATE_TLB_VECTOR_START; + sender = ~regs->orig_rax - INVALIDATE_TLB_VECTOR_START; f = &per_cpu(flush_state, sender); if (!cpu_isset(cpu, f->flush_cpumask)) diff -puN include/asm-x86_64/hw_irq.h~x86-increase-interrupt-vector-range include/asm-x86_64/hw_irq.h --- devel/include/asm-x86_64/hw_irq.h~x86-increase-interrupt-vector-range 2006-05-26 09:30:22.000000000 -0700 +++ devel-akpm/include/asm-x86_64/hw_irq.h 2006-05-26 09:30:22.000000000 -0700 @@ -124,7 +124,7 @@ asmlinkage void IRQ_NAME(nr); \ __asm__( \ "\n.p2align\n" \ "IRQ" #nr "_interrupt:\n\t" \ - "push $" #nr "-256 ; " \ + "push $~(" #nr ") ; " \ "jmp common_interrupt"); #if defined(CONFIG_X86_IO_APIC) _