Fix do_IRQ high bit masking.

Instead of setting the highest bit (which isn't easily done on native x86_64),
negate the interrupt vector stored in orig_{e,r}ax.
Also add patch for native build.

Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>

6 files changed, 115 insertions, 8 deletions

diff --git a/linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S b/linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S
index c1784979e3..072172cda7 100644
--- a/linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/entry-xen.S
@@ -461,7 +461,7 @@ vector=0
 ENTRY(irq_entries_start)
 .rept NR_IRQS
 	ALIGN
-1:	pushl 0x80000000+$vector
+1:	pushl $~(vector)
 	jmp common_interrupt
 .data
 	.long 1b
@@ -478,7 +478,7 @@ common_interrupt:
 
 #define BUILD_INTERRUPT(name, nr)	\
 ENTRY(name)				\
-	pushl 0x80000000+$nr;		\
+	pushl $~(nr);			\
 	SAVE_ALL			\
 	movl %esp,%eax;			\
 	call smp_/**/name;		\
diff --git a/linux-2.6-xen-sparse/arch/i386/kernel/irq-xen.c b/linux-2.6-xen-sparse/arch/i386/kernel/irq-xen.c
index b1d8634bd6..b4a38e4d92 100644
--- a/linux-2.6-xen-sparse/arch/i386/kernel/irq-xen.c
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/irq-xen.c
@@ -54,7 +54,7 @@ static union irq_ctx *softirq_ctx[NR_CPUS];
 fastcall unsigned int do_IRQ(struct pt_regs *regs)
 {	
 	/* high bit used in ret_from_ code */
-	int irq = regs->orig_eax & __IRQ_MASK(BITS_PER_LONG - 1);
+	int irq = ~regs->orig_eax;
 #ifdef CONFIG_4KSTACKS
 	union irq_ctx *curctx, *irqctx;
 	u32 *isp;
diff --git a/linux-2.6-xen-sparse/arch/x86_64/kernel/entry-xen.S b/linux-2.6-xen-sparse/arch/x86_64/kernel/entry-xen.S
index 604365dec3..2930d58da2 100644
--- a/linux-2.6-xen-sparse/arch/x86_64/kernel/entry-xen.S
+++ b/linux-2.6-xen-sparse/arch/x86_64/kernel/entry-xen.S
@@ -584,7 +584,7 @@ retint_kernel:
  */		
 	.macro apicinterrupt num,func
 	INTR_FRAME
-	pushq 0x8000000000000000+$\num
+	pushq $~(\num)
 	CFI_ADJUST_CFA_OFFSET 8
 	interrupt \func
 	jmp error_entry
diff --git a/linux-2.6-xen-sparse/arch/x86_64/kernel/irq-xen.c b/linux-2.6-xen-sparse/arch/x86_64/kernel/irq-xen.c
index 663e890c94..268f8cd6dc 100644
--- a/linux-2.6-xen-sparse/arch/x86_64/kernel/irq-xen.c
+++ b/linux-2.6-xen-sparse/arch/x86_64/kernel/irq-xen.c
@@ -97,7 +97,7 @@ skip:
 asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 {	
 	/* high bit used in ret_from_ code  */
-        int irq = regs->orig_rax & __IRQ_MASK(BITS_PER_LONG - 1);
+	unsigned irq = ~regs->orig_rax;
 
 	exit_idle();
 	irq_enter();
diff --git a/linux-2.6-xen-sparse/drivers/xen/core/evtchn.c b/linux-2.6-xen-sparse/drivers/xen/core/evtchn.c
index 6dee25cab7..820ce89069 100644
--- a/linux-2.6-xen-sparse/drivers/xen/core/evtchn.c
+++ b/linux-2.6-xen-sparse/drivers/xen/core/evtchn.c
@@ -170,9 +170,9 @@ static inline void exit_idle(void) {}
 #include <asm/idle.h>
 #define IRQ_REG orig_rax
 #endif
-#define do_IRQ(irq, regs) do {					\
-	(regs)->IRQ_REG = (irq) | (1UL << (BITS_PER_LONG - 1));	\
-	do_IRQ((regs));						\
+#define do_IRQ(irq, regs) do {		\
+	(regs)->IRQ_REG = ~(irq);	\
+	do_IRQ((regs));			\
 } while (0)
 #endif
 
diff --git a/patches/linux-2.6.16/x86-increase-interrupt-vector-range.patch b/patches/linux-2.6.16/x86-increase-interrupt-vector-range.patch
new file mode 100644
index 0000000000..c79abfc274
--- /dev/null
+++ b/patches/linux-2.6.16/x86-increase-interrupt-vector-range.patch
@@ -0,0 +1,107 @@
+Subject: Increase x86 interrupt vector range
+
+Remove the limit of 256 interrupt vectors by changing the value
+stored in orig_{e,r}ax to be the negated 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.
+
+Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
+---
+ 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 -r 7d239c83edea arch/i386/kernel/entry.S
+--- a/arch/i386/kernel/entry.S	Mon Mar 20 06:00:20 2006 +0000
++++ b/arch/i386/kernel/entry.S	Fri Mar 31 17:01:35 2006 +0100
+@@ -406,7 +406,7 @@ ENTRY(irq_entries_start)
+ ENTRY(irq_entries_start)
+ .rept NR_IRQS
+ 	ALIGN
+-1:	pushl $vector-256
++1:	pushl $~(vector)
+ 	jmp common_interrupt
+ .data
+ 	.long 1b
+@@ -423,7 +423,7 @@ common_interrupt:
+ 
+ #define BUILD_INTERRUPT(name, nr)	\
+ ENTRY(name)				\
+-	pushl $nr-256;			\
++	pushl $~(nr);			\
+ 	SAVE_ALL			\
+ 	movl %esp,%eax;			\
+ 	call smp_/**/name;		\
+diff -r 7d239c83edea arch/i386/kernel/irq.c
+--- a/arch/i386/kernel/irq.c	Mon Mar 20 06:00:20 2006 +0000
++++ b/arch/i386/kernel/irq.c	Fri Mar 31 17:01:35 2006 +0100
+@@ -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 -r 7d239c83edea arch/x86_64/kernel/entry.S
+--- a/arch/x86_64/kernel/entry.S	Mon Mar 20 06:00:20 2006 +0000
++++ b/arch/x86_64/kernel/entry.S	Fri Mar 31 17:01:35 2006 +0100
+@@ -609,7 +609,7 @@ retint_kernel:
+  */		
+ 	.macro apicinterrupt num,func
+ 	INTR_FRAME
+-	pushq $\num-256
++	pushq $~(\num)
+ 	CFI_ADJUST_CFA_OFFSET 8
+ 	interrupt \func
+ 	jmp ret_from_intr
+diff -r 7d239c83edea arch/x86_64/kernel/irq.c
+--- a/arch/x86_64/kernel/irq.c	Mon Mar 20 06:00:20 2006 +0000
++++ b/arch/x86_64/kernel/irq.c	Fri Mar 31 17:01:35 2006 +0100
+@@ -96,8 +96,8 @@ 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 -r 7d239c83edea arch/x86_64/kernel/smp.c
+--- a/arch/x86_64/kernel/smp.c	Mon Mar 20 06:00:20 2006 +0000
++++ b/arch/x86_64/kernel/smp.c	Fri Mar 31 17:01:35 2006 +0100
+@@ -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 -r 7d239c83edea include/asm-x86_64/hw_irq.h
+--- a/include/asm-x86_64/hw_irq.h	Mon Mar 20 06:00:20 2006 +0000
++++ b/include/asm-x86_64/hw_irq.h	Fri Mar 31 17:01:35 2006 +0100
+@@ -127,7 +127,7 @@ __asm__( \
+ __asm__( \
+ "\n.p2align\n" \
+ "IRQ" #nr "_interrupt:\n\t" \
+-	"push $" #nr "-256 ; " \
++	"push $~(" #nr ") ; " \
+ 	"jmp common_interrupt");
+ 
+ #if defined(CONFIG_X86_IO_APIC)