MIPS: Ptrace support for HARDWARE_WATCHPOINTS

This is the final part of the watch register patch.  Here we hook up
ptrace so that the user space debugger (gdb), can set and read the
registers.

Signed-off-by: David Daney <ddaney@avtrex.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/arch/mips/include/asm/ptrace.h b/arch/mips/include/asm/ptrace.h
index c00cca24dae0..cd5e8a47812b 100644
--- a/arch/mips/include/asm/ptrace.h
+++ b/arch/mips/include/asm/ptrace.h
@@ -74,11 +74,57 @@ struct pt_regs {
 #define PTRACE_POKEDATA_3264    0xc3
 #define PTRACE_GET_THREAD_AREA_3264     0xc4
 
+/* Read and write watchpoint registers.  */
+enum pt_watch_style {
+        pt_watch_style_mips32,
+        pt_watch_style_mips64
+};
+struct mips32_watch_regs {
+        uint32_t watchlo[8];
+        /* Lower 16 bits of watchhi. */
+        uint16_t watchhi[8];
+        /* Valid mask and I R W bits.
+         * bit 0 -- 1 if W bit is usable.
+         * bit 1 -- 1 if R bit is usable.
+         * bit 2 -- 1 if I bit is usable.
+         * bits 3 - 11 -- Valid watchhi mask bits.
+         */
+        uint16_t watch_masks[8];
+        /* The number of valid watch register pairs.  */
+        uint32_t num_valid;
+} __attribute__((aligned(8)));
+
+struct mips64_watch_regs {
+        uint64_t watchlo[8];
+        uint16_t watchhi[8];
+        uint16_t watch_masks[8];
+        uint32_t num_valid;
+} __attribute__((aligned(8)));
+
+struct pt_watch_regs {
+        enum pt_watch_style style;
+        union {
+                struct mips32_watch_regs mips32;
+                struct mips32_watch_regs mips64;
+        };
+};
+
+#define PTRACE_GET_WATCH_REGS   0xd0
+#define PTRACE_SET_WATCH_REGS   0xd1
+
 #ifdef __KERNEL__
 
+#include <linux/compiler.h>
 #include <linux/linkage.h>
 #include <asm/isadep.h>
 
+struct task_struct;
+
+extern int ptrace_get_watch_regs(struct task_struct *child,
+        struct pt_watch_regs __user *addr);
+extern int ptrace_set_watch_regs(struct task_struct *child,
+        struct pt_watch_regs __user *addr);
+
 /*
  * Does the process account for user or for system time?
  */