[CELL] spufs: add spu stats in sysfs and ctx stat file in spufs

This patch exports per-context statistics in spufs as long as spu
statistics in sysfs.

It was formed by merging:
"spufs: add spu stats in sysfs"   From: Christoph Hellwig
"spufs: add stat file to spufs"   From: Christoph Hellwig
"spufs: fix libassist accounting" From: Jeremy Kerr
"spusched: fix spu utilization statistics" From: Luke Browning
And some adjustments by myself, after suggestions on cbe-oss-dev.

Having separate patches was making the review process harder
than it should, as we end up integrating spus and ctx statistics
accounting much more than it was on the first implementation.

Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

1 files changed, 27 insertions, 36 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h
index 34d5f9f8b4a..fdace928437 100644
--- a/arch/powerpc/platforms/cell/spufs/spufs.h
+++ b/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -40,19 +40,6 @@ enum {
 struct spu_context_ops;
 struct spu_gang;
 
-/*
- * This is the state for spu utilization reporting to userspace.
- * Because this state is visible to userspace it must never change and needs
- * to be kept strictly separate from any internal state kept by the kernel.
- */
-enum spuctx_execution_state {
-        SPUCTX_UTIL_USER = 0,
-        SPUCTX_UTIL_SYSTEM,
-        SPUCTX_UTIL_IOWAIT,
-        SPUCTX_UTIL_LOADED,
-        SPUCTX_UTIL_MAX
-};
-
 struct spu_context {
         struct spu *spu;                  /* pointer to a physical SPU */
         struct spu_state csa;             /* SPU context save area. */
@@ -104,9 +91,9 @@ struct spu_context {
         /* statistics */
         struct {
                 /* updates protected by ctx->state_mutex */
-                enum spuctx_execution_state execution_state;
-                unsigned long tstamp;           /* time of last ctx switch */
-                unsigned long times[SPUCTX_UTIL_MAX];
+                enum spu_utilization_state util_state;
+                unsigned long long tstamp;      /* time of last state switch */
+                unsigned long long times[SPU_UTIL_MAX];
                 unsigned long long vol_ctx_switch;
                 unsigned long long invol_ctx_switch;
                 unsigned long long min_flt;
@@ -293,30 +280,34 @@ extern int spufs_coredump_num_notes;
  * line.
  */
 static inline void spuctx_switch_state(struct spu_context *ctx,
-                enum spuctx_execution_state new_state)
+                enum spu_utilization_state new_state)
 {
-        WARN_ON(!mutex_is_locked(&ctx->state_mutex));
+        unsigned long long curtime;
+        signed long long delta;
+        struct timespec ts;
+        struct spu *spu;
+        enum spu_utilization_state old_state;
 
-        if (ctx->stats.execution_state != new_state) {
-                unsigned long curtime = jiffies;
+        ktime_get_ts(&ts);
+        curtime = timespec_to_ns(&ts);
+        delta = curtime - ctx->stats.tstamp;
 
-                ctx->stats.times[ctx->stats.execution_state] +=
-                                 curtime - ctx->stats.tstamp;
-                ctx->stats.tstamp = curtime;
-                ctx->stats.execution_state = new_state;
-        }
-}
-
-static inline void spu_switch_state(struct spu *spu,
-                enum spuctx_execution_state new_state)
-{
-        if (spu->stats.utilization_state != new_state) {
-                unsigned long curtime = jiffies;
-
-                spu->stats.times[spu->stats.utilization_state] +=
-                                 curtime - spu->stats.tstamp;
+        WARN_ON(!mutex_is_locked(&ctx->state_mutex));
+        WARN_ON(delta < 0);
+
+        spu = ctx->spu;
+        old_state = ctx->stats.util_state;
+        ctx->stats.util_state = new_state;
+        ctx->stats.tstamp = curtime;
+
+        /*
+         * Update the physical SPU utilization statistics.
+         */
+        if (spu) {
+                ctx->stats.times[old_state] += delta;
+                spu->stats.times[old_state] += delta;
+                spu->stats.util_state = new_state;
                 spu->stats.tstamp = curtime;
-                spu->stats.utilization_state = new_state;
         }
 }