powerpc/spufs: add atomic busy_spus counter to struct cbe_spu_info

As nr_active counter includes also spus waiting for syscalls to return
we need a seperate counter that only counts spus that are currently running
on spu side. This counter shall be used by a cpufreq governor that targets
a frequency dependent from the number of running spus.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 7 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index afb92d4fbcf5..34654743363d 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -994,6 +994,7 @@ void spuctx_switch_state(struct spu_context *ctx,
         struct timespec ts;
         struct spu *spu;
         enum spu_utilization_state old_state;
+        int node;
 
         ktime_get_ts(&ts);
         curtime = timespec_to_ns(&ts);
@@ -1015,6 +1016,11 @@ void spuctx_switch_state(struct spu_context *ctx,
                 spu->stats.times[old_state] += delta;
                 spu->stats.util_state = new_state;
                 spu->stats.tstamp = curtime;
+                node = spu->node;
+                if (old_state == SPU_UTIL_USER)
+                        atomic_dec(&cbe_spu_info[node].busy_spus);
+                if (new_state == SPU_UTIL_USER);
+                        atomic_inc(&cbe_spu_info[node].busy_spus);
         }
 }
 
diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h
index 99348c1f4cab..8b2eb044270a 100644
--- a/include/asm-powerpc/spu.h
+++ b/include/asm-powerpc/spu.h
@@ -191,6 +191,7 @@ struct cbe_spu_info {
         struct list_head spus;
         int n_spus;
         int nr_active;
+        atomic_t busy_spus;
         atomic_t reserved_spus;
 };