x86: kgdb support

simplified and streamlined kgdb support on x86, both 32-bit and 64-bit,
based on patch from:

  Subject: kgdb: core-lite
  From: Jason Wessel <jason.wessel@windriver.com>

[ and countless other authors - see the patch for details. ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 81 insertions, 0 deletions

diff --git a/include/asm-x86/kgdb.h b/include/asm-x86/kgdb.h
new file mode 100644
index 000000000000..484c47554f3b
--- /dev/null
+++ b/include/asm-x86/kgdb.h
@@ -0,0 +1,81 @@
+#ifndef _ASM_KGDB_H_
+#define _ASM_KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ * Copyright (C) 2008 Wind River Systems, Inc.
+ */
+
+/*
+ * BUFMAX defines the maximum number of characters in inbound/outbound
+ * buffers at least NUMREGBYTES*2 are needed for register packets
+ * Longer buffer is needed to list all threads
+ */
+#define BUFMAX                  1024
+
+/*
+ *  Note that this register image is in a different order than
+ *  the register image that Linux produces at interrupt time.
+ *
+ *  Linux's register image is defined by struct pt_regs in ptrace.h.
+ *  Just why GDB uses a different order is a historical mystery.
+ */
+#ifdef CONFIG_X86_32
+enum regnames {
+        GDB_AX,                 /* 0 */
+        GDB_CX,                 /* 1 */
+        GDB_DX,                 /* 2 */
+        GDB_BX,                 /* 3 */
+        GDB_SP,                 /* 4 */
+        GDB_BP,                 /* 5 */
+        GDB_SI,                 /* 6 */
+        GDB_DI,                 /* 7 */
+        GDB_PC,                 /* 8 also known as eip */
+        GDB_PS,                 /* 9 also known as eflags */
+        GDB_CS,                 /* 10 */
+        GDB_SS,                 /* 11 */
+        GDB_DS,                 /* 12 */
+        GDB_ES,                 /* 13 */
+        GDB_FS,                 /* 14 */
+        GDB_GS,                 /* 15 */
+};
+#else /* ! CONFIG_X86_32 */
+enum regnames {
+        GDB_AX,                 /* 0 */
+        GDB_DX,                 /* 1 */
+        GDB_CX,                 /* 2 */
+        GDB_BX,                 /* 3 */
+        GDB_SI,                 /* 4 */
+        GDB_DI,                 /* 5 */
+        GDB_BP,                 /* 6 */
+        GDB_SP,                 /* 7 */
+        GDB_R8,                 /* 8 */
+        GDB_R9,                 /* 9 */
+        GDB_R10,                /* 10 */
+        GDB_R11,                /* 11 */
+        GDB_R12,                /* 12 */
+        GDB_R13,                /* 13 */
+        GDB_R14,                /* 14 */
+        GDB_R15,                /* 15 */
+        GDB_PC,                 /* 16 */
+        GDB_PS,                 /* 17 */
+};
+#endif /* CONFIG_X86_32 */
+
+/*
+ * Number of bytes of registers:
+ */
+#ifdef CONFIG_X86_32
+# define NUMREGBYTES            64
+#else
+# define NUMREGBYTES            ((GDB_PS+1)*8)
+#endif
+
+static inline void arch_kgdb_breakpoint(void)
+{
+        asm("   int $3");
+}
+#define BREAK_INSTR_SIZE        1
+#define CACHE_FLUSH_IS_SAFE     1
+
+#endif                          /* _ASM_KGDB_H_ */