From d9dd421fd6ed17af55d27c8d93a9f561be0ff50f Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Wed, 13 Aug 2008 11:29:31 +1000 Subject: [PATCH 1/3] powerpc/spufs: fix npc setting for NOSCHED contexts Currently, spu_run ignores the npc argument for contexts created with SPU_CREATE_NOSCHED. While this is correct for isolated contexts, there's no need to enforce the npc restriction on non-isolated NOSCHED contexts. This means that NOSCHED contexts can only ever run with an entry point of 0x0. This change to spu_run_init allows setting of the npc (and, while we're at it, the privcntl) for non-isolated NOSCHED contexts. This allows us to run NOSCHED contexts from any entry point. Signed-off-by: Jeremy Kerr --- arch/powerpc/platforms/cell/spufs/run.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c index f7edba6cb795..c9bb7cfd3dca 100644 --- a/arch/powerpc/platforms/cell/spufs/run.c +++ b/arch/powerpc/platforms/cell/spufs/run.c @@ -206,11 +206,6 @@ static int spu_run_init(struct spu_context *ctx, u32 *npc) (SPU_RUNCNTL_RUNNABLE | SPU_RUNCNTL_ISOLATE); if (runcntl == 0) runcntl = SPU_RUNCNTL_RUNNABLE; - } - - if (ctx->flags & SPU_CREATE_NOSCHED) { - spuctx_switch_state(ctx, SPU_UTIL_USER); - ctx->ops->runcntl_write(ctx, runcntl); } else { unsigned long privcntl; @@ -219,9 +214,15 @@ static int spu_run_init(struct spu_context *ctx, u32 *npc) else privcntl = SPU_PRIVCNTL_MODE_NORMAL; - ctx->ops->npc_write(ctx, *npc); ctx->ops->privcntl_write(ctx, privcntl); - ctx->ops->runcntl_write(ctx, runcntl); + ctx->ops->npc_write(ctx, *npc); + } + + ctx->ops->runcntl_write(ctx, runcntl); + + if (ctx->flags & SPU_CREATE_NOSCHED) { + spuctx_switch_state(ctx, SPU_UTIL_USER); + } else { if (ctx->state == SPU_STATE_SAVED) { ret = spu_activate(ctx, 0); From 8d5636fbca202f61fdb808fc9e20c0142291d802 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Thu, 14 Aug 2008 14:59:12 +1000 Subject: [PATCH 2/3] powerpc/spufs: reference context while dropping state mutex in scheduler Based on an original patch from Christoph Hellwig . Currently, there is a possible reference-after-free in the spusched code - contexts may be freed after we have released their state_mutex in spusched_tick and find_victim. This change takes a reference to the context before releasing the mutex, so that the context doesn't get destroyed. Signed-off-by: Jeremy Kerr --- arch/powerpc/platforms/cell/spufs/sched.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 2deeeba7eccf..4b6b0c3a8c95 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -641,8 +641,10 @@ static struct spu *find_victim(struct spu_context *ctx) if (tmp && tmp->prio > ctx->prio && !(tmp->flags & SPU_CREATE_NOSCHED) && - (!victim || tmp->prio > victim->prio)) + (!victim || tmp->prio > victim->prio)) { victim = spu->ctx; + get_spu_context(victim); + } } mutex_unlock(&cbe_spu_info[node].list_mutex); @@ -658,6 +660,7 @@ static struct spu *find_victim(struct spu_context *ctx) * look at another context or give up after X retries. */ if (!mutex_trylock(&victim->state_mutex)) { + put_spu_context(victim); victim = NULL; goto restart; } @@ -670,6 +673,7 @@ static struct spu *find_victim(struct spu_context *ctx) * restart the search. */ mutex_unlock(&victim->state_mutex); + put_spu_context(victim); victim = NULL; goto restart; } @@ -687,6 +691,7 @@ static struct spu *find_victim(struct spu_context *ctx) spu_add_to_rq(victim); mutex_unlock(&victim->state_mutex); + put_spu_context(victim); return spu; } @@ -985,9 +990,11 @@ static int spusched_thread(void *unused) struct spu_context *ctx = spu->ctx; if (ctx) { + get_spu_context(ctx); mutex_unlock(mtx); spusched_tick(ctx); mutex_lock(mtx); + put_spu_context(ctx); } } mutex_unlock(mtx); From cb9808d3d0cb0ed97197decadcf0431140b9e231 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Tue, 19 Aug 2008 08:48:57 +0300 Subject: [PATCH 3/3] powerpc/spufs: Remove invalid semicolon after if statement MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Ilpo Järvinen Signed-off-by: Jeremy Kerr --- arch/powerpc/platforms/cell/spufs/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 4b6b0c3a8c95..1c1b627ee843 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -1037,7 +1037,7 @@ void spuctx_switch_state(struct spu_context *ctx, node = spu->node; if (old_state == SPU_UTIL_USER) atomic_dec(&cbe_spu_info[node].busy_spus); - if (new_state == SPU_UTIL_USER); + if (new_state == SPU_UTIL_USER) atomic_inc(&cbe_spu_info[node].busy_spus); } }