[U-Boot] [PATCH 08/19] x86: Fix %ss and %esp in register structure for interrupts

[Graeme Russ]

Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
---
 arch/i386/cpu/interrupts.c        |   23 +++++++++++++++++++----
 arch/i386/include/asm/interrupt.h |    2 ++
 arch/i386/include/asm/ptrace.h    |   24 ++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/arch/i386/cpu/interrupts.c b/arch/i386/cpu/interrupts.c
index 47a7a29..e4d0868 100644
--- a/arch/i386/cpu/interrupts.c
+++ b/arch/i386/cpu/interrupts.c
@@ -104,7 +104,7 @@ static inline unsigned long get_debugreg(int regno)
 	return val;
 }
 
-void dump_regs(struct pt_regs *regs)
+void dump_regs(struct irq_regs *regs)
 {
 	unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
 	unsigned long d0, d1, d2, d3, d6, d7;
@@ -225,7 +225,7 @@ int disable_interrupts(void)
 }
 
 /* IRQ Low-Level Service Routine */
-void irq_llsr(struct pt_regs *regs)
+void irq_llsr(struct irq_regs *regs)
 {
 	/*
 	 * For detailed description of each exception, refer to:
@@ -234,7 +234,7 @@ void irq_llsr(struct pt_regs *regs)
 	 * Order Number: 253665-029US, November 2008
 	 * Table 6-1. Exceptions and Interrupts
 	 */
-	switch (regs->orig_eax) {
+	switch (regs->irq_id) {
 	case 0x00:
 		printf("Divide Error (Division by zero)\n");
 		dump_regs(regs);
@@ -340,7 +340,7 @@ void irq_llsr(struct pt_regs *regs)
 
 	default:
 		/* Hardware or User IRQ */
-		do_irq(regs->orig_eax);
+		do_irq(regs->irq_id);
 	}
 }
 
@@ -352,17 +352,30 @@ void irq_llsr(struct pt_regs *regs)
  *  Interrupt entries are now very small (a push and a jump) but they are
  *  now slower (all registers pushed on stack which provides complete
  *  crash dumps in the low level handlers
+ *
+ * Interrupt Entry Point:
+ *  - Interrupt has caused eflags, CS and EIP to be pushed
+ *  - Interrupt Vector Handler has pushed orig_eax
+ *  - pt_regs.esp needs to be adjusted by 40 bytes:
+ *      12 bytes pushed by CPU (EFLAGSF, CS, EIP)
+ *      4 bytes pushed by vector handler (irq_id)
+ *      24 bytes pushed before SP (SS, GS, FS, ES, DS, EAX)
+ *      NOTE: Only longs are pushed on/popped off the stack!
  */
 asm(".globl irq_common_entry\n" \
 	".hidden irq_common_entry\n" \
 	".type irq_common_entry, @function\n" \
 	"irq_common_entry:\n" \
 	"cld\n" \
+	"pushl %ss\n" \
 	"pushl %gs\n" \
 	"pushl %fs\n" \
 	"pushl %es\n" \
 	"pushl %ds\n" \
 	"pushl %eax\n" \
+	"movl  %esp, %eax\n" \
+	"addl  $40, %eax\n" \
+	"pushl %eax\n" \
 	"pushl %ebp\n" \
 	"pushl %edi\n" \
 	"pushl %esi\n" \
@@ -378,10 +391,12 @@ asm(".globl irq_common_entry\n" \
 	"popl %edi\n" \
 	"popl %ebp\n" \
 	"popl %eax\n" \
+	"popl %eax\n" \
 	"popl %ds\n" \
 	"popl %es\n" \
 	"popl %fs\n" \
 	"popl %gs\n" \
+	"popl %ss\n" \
 	"add  $4, %esp\n" \
 	"iret\n" \
 	DECLARE_INTERRUPT(0) \
diff --git a/arch/i386/include/asm/interrupt.h b/arch/i386/include/asm/interrupt.h
index 99ae843..d32ef8b 100644
--- a/arch/i386/include/asm/interrupt.h
+++ b/arch/i386/include/asm/interrupt.h
@@ -27,6 +27,8 @@
 #ifndef __ASM_INTERRUPT_H_
 #define __ASM_INTERRUPT_H_ 1
 
+#include <asm/types.h>
+
 /* arch/i386/cpu/interrupts.c */
 void set_vector(u8 intnum, void *routine);
 
diff --git a/arch/i386/include/asm/ptrace.h b/arch/i386/include/asm/ptrace.h
index 750e40d..a727dbf 100644
--- a/arch/i386/include/asm/ptrace.h
+++ b/arch/i386/include/asm/ptrace.h
@@ -1,6 +1,8 @@
 #ifndef _I386_PTRACE_H
 #define _I386_PTRACE_H
 
+#include <asm/types.h>
+
 #define EBX 0
 #define ECX 1
 #define EDX 2
@@ -43,6 +45,28 @@ struct pt_regs {
 	int  xss;
 }  __attribute__ ((packed));
 
+struct irq_regs {
+	/* Pushed by irq_common_entry */
+	long ebx;
+	long ecx;
+	long edx;
+	long esi;
+	long edi;
+	long ebp;
+	long esp;
+	long eax;
+	long xds;
+	long xes;
+	long xfs;
+	long xgs;
+	long xss;
+	/* Pushed by vector handler (irq_<num>) */
+	long irq_id;
+	/* Pushed by cpu in response to interrupt */
+	long eip;
+	long xcs;
+	long eflags;
+}  __attribute__ ((packed));
 
 /* Arbitrarily choose the same ptrace numbers as used by the Sparc code. */
 #define PTRACE_GETREGS            12
-- 
1.7.1.422.g049e9