MIPS: Add HARDWARE_WATCHPOINTS definitions and support code.

This is the main support code for the patch.  Here we just add the
code, the following patches hook it up.

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

 create mode 100644 arch/mips/include/asm/watch.h
 create mode 100644 arch/mips/kernel/watch.c

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h
index a1e4453469f9..18ee58e39445 100644
--- a/arch/mips/include/asm/processor.h
+++ b/arch/mips/include/asm/processor.h
@@ -105,6 +105,19 @@ struct mips_dsp_state {
         {0,} \
 }
 
+struct mips3264_watch_reg_state {
+        /* The width of watchlo is 32 in a 32 bit kernel and 64 in a
+           64 bit kernel.  We use unsigned long as it has the same
+           property. */
+        unsigned long watchlo[NUM_WATCH_REGS];
+        /* Only the mask and IRW bits from watchhi. */
+        u16 watchhi[NUM_WATCH_REGS];
+};
+
+union mips_watch_reg_state {
+        struct mips3264_watch_reg_state mips3264;
+};
+
 typedef struct {
         unsigned long seg;
 } mm_segment_t;
@@ -137,6 +150,9 @@ struct thread_struct {
         /* Saved state of the DSP ASE, if available. */
         struct mips_dsp_state dsp;
 
+        /* Saved watch register state, if available. */
+        union mips_watch_reg_state watch;
+
         /* Other stuff associated with the thread. */
         unsigned long cp0_badvaddr;     /* Last user fault */
         unsigned long cp0_baduaddr;     /* Last kernel fault accessing USEG */
@@ -193,6 +209,10 @@ struct thread_struct {
                 .dspcontrol     = 0,                            \
         },                                                      \
         /*                                                      \
+         * saved watch register stuff                           \
+         */                                                     \
+        .watch = {{{0,},},},                                    \
+        /*                                                      \
          * Other stuff associated with the process              \
          */                                                     \
         .cp0_badvaddr           = 0,                            \