[Adeos-main] [PATCH 2/3] i386: Rework root IRQ handler invocation

[Adeos-main] [PATCH 2/3] i386: Rework root IRQ handler invocation

[Jan Kiszka]

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i386 port of the earlier posted x86_64 patch.

Jan


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Re: [Adeos-main] [PATCH 2/3] i386: Rework root IRQ handler invocation

[Jan Kiszka]

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Jan Kiszka wrote:
> i386 port of the earlier posted x86_64 patch.
> 

The usual mistake...

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---
 arch/i386/kernel/ipipe.c |   22 ++++++++-------
 include/asm-i386/ipipe.h |   65 +++++++++++++++++++++++++++--------------------
 2 files changed, 50 insertions(+), 37 deletions(-)

Index: linux-2.6.23.12-xeno/arch/i386/kernel/ipipe.c
===================================================================
--- linux-2.6.23.12-xeno.orig/arch/i386/kernel/ipipe.c
+++ linux-2.6.23.12-xeno/arch/i386/kernel/ipipe.c
@@ -764,17 +764,19 @@ int __ipipe_handle_irq(struct pt_regs re
 
 finalize:
 
-	/* Given our deferred dispatching model for regular IRQs, we
-	 * only record CPU regs for the last timer interrupt, so that
-	 * the timer handler charges CPU times properly. It is assumed
-	 * that other interrupt handlers don't actually care for such
-	 * information. */
-
+	/*
+	 * Given our deferred dispatching model for regular IRQs, we only
+	 * record relevant registers for the last timer interrupt, so that the
+	 * timer handler charges CPU times properly. It is assumed that other
+	 * interrupt handlers don't actually care for such information.
+	 */
 	if (irq == __ipipe_tick_irq) {
-		__raw_get_cpu_var(__ipipe_tick_regs).eflags = regs.eflags;
-		__raw_get_cpu_var(__ipipe_tick_regs).eip = regs.eip;
-		__raw_get_cpu_var(__ipipe_tick_regs).xcs = regs.xcs;
-		__raw_get_cpu_var(__ipipe_tick_regs).ebp = regs.ebp;
+		struct pt_regs *tick_regs =
+			&__raw_get_cpu_var(__ipipe_tick_regs);
+		tick_regs->eflags = regs.eflags;
+		tick_regs->xcs = regs.xcs;
+		tick_regs->eip = regs.eip;
+		tick_regs->ebp = regs.ebp;
 	}
 
 	/*
Index: linux-2.6.23.12-xeno/include/asm-i386/ipipe.h
===================================================================
--- linux-2.6.23.12-xeno.orig/include/asm-i386/ipipe.h
+++ linux-2.6.23.12-xeno/include/asm-i386/ipipe.h
@@ -123,27 +123,40 @@ extern int __ipipe_tick_irq;
 
 DECLARE_PER_CPU(struct pt_regs, __ipipe_tick_regs);
 
-#define __ipipe_call_root_xirq_handler(ipd,irq) \
-   __asm__ __volatile__ ("pushfl\n\t" \
-                         "pushl %%cs\n\t" \
-                         "pushl $1f\n\t" \
-	                 "pushl %%eax\n\t" \
-                         "pushl %%fs\n\t" \
-	                 "pushl %%es\n\t" \
-	                 "pushl %%ds\n\t" \
-	                 "pushl %%eax\n\t" \
-	                 "pushl %%ebp\n\t" \
-	                 "pushl %%edi\n\t" \
-	                 "pushl %%esi\n\t" \
-	                 "pushl %%edx\n\t" \
-	                 "pushl %%ecx\n\t" \
-	                 "pushl %%ebx\n\t" \
-                         "movl  %%esp,%%eax\n\t" \
-                         "call *%1\n\t" \
-	                 "jmp ret_from_intr\n\t" \
-	                 "1: cli\n" \
-			 : /* no output */ \
-			 : "a" (~irq), "m" ((ipd)->irqs[irq].handler))
+static inline void
+__ipipe_call_root_xirq_handler(unsigned irq,
+			       void (*handler)(unsigned irq, void *cookie))
+{
+	struct pt_regs *regs = &__raw_get_cpu_var(__ipipe_tick_regs);
+
+	regs->orig_eax = ~irq;
+
+	__asm__ __volatile__ (
+		"pushfl\n\t"
+		"pushl %%cs\n\t"
+		"pushl $xirq_end\n\t"
+		"pushl %%eax		# dummy value\n\t"
+		"pushl %%fs\n\t"
+		"pushl %%es\n\t"
+		"pushl %%ds\n\t"
+		"pushl %%eax\n\t"
+		"pushl %%ebp\n\t"
+		"pushl %%edi\n\t"
+		"pushl %%esi\n\t"
+		"pushl %%edx\n\t"
+		"pushl %%ecx\n\t"
+		"pushl %%ebx\n\t"
+
+		"movl  %[regs],%%eax	# always pass tick regs\n\t"
+		"call *%[handler]\n\t"
+
+		"jmp ret_from_intr	# Linux IRQ epilogue\n\t"
+
+		"xirq_end: cli\n\t"
+		 : /* no output */ \
+		 : [handler] "rm" (handler), [regs] "rm" (regs)
+		 : "eax");
+}
 
 #define __ipipe_call_root_virq_handler(ipd,irq) \
    __asm__ __volatile__ ("pushfl\n\t" \
@@ -189,12 +202,10 @@ static inline unsigned long __ipipe_ffnz
 	do {								\
 		local_irq_enable_nohead(ipd);				\
 		if (ipd == ipipe_root_domain) {				\
-			if (likely(!ipipe_virtual_irq_p(irq))) {	\
-				struct pt_regs *old_regs;		\
-				old_regs = set_irq_regs(&__raw_get_cpu_var(__ipipe_tick_regs)); \
-				__ipipe_call_root_xirq_handler(ipd,irq); \
-				set_irq_regs(old_regs);			\
-			} else {					\
+			if (likely(!ipipe_virtual_irq_p(irq)))		\
+				__ipipe_call_root_xirq_handler(		\
+					irq, (ipd)->irqs[irq].handler); \
+			else {						\
 				irq_enter();				\
 				__ipipe_call_root_virq_handler(ipd,irq); \
 				irq_exit();				\

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