From 650f8b0291ecd0abdeadbd0ff3d70c3538e55405 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 13 Feb 2007 21:36:50 +0100 Subject: [PATCH] [POWERPC] spufs: simplify state_mutex The r/w semaphore to lock the spus was overkill and can be replaced with a mutex to make it faster, simpler and easier to debug. It also helps to allow making most spufs interruptible in future patches. Signed-off-by: Christoph Hellwig Signed-off-by: Arnd Bergmann --- arch/powerpc/platforms/cell/spufs/context.c | 33 +++++++++-------------------- arch/powerpc/platforms/cell/spufs/sched.c | 8 +++---- arch/powerpc/platforms/cell/spufs/spufs.h | 6 +++--- 3 files changed, 17 insertions(+), 30 deletions(-) diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c index ccffc44..c9aab9b 100644 --- a/arch/powerpc/platforms/cell/spufs/context.c +++ b/arch/powerpc/platforms/cell/spufs/context.c @@ -42,7 +42,7 @@ struct spu_context *alloc_spu_context(struct spu_gang *gang) } spin_lock_init(&ctx->mmio_lock); kref_init(&ctx->kref); - init_rwsem(&ctx->state_sema); + mutex_init(&ctx->state_mutex); init_MUTEX(&ctx->run_sema); init_waitqueue_head(&ctx->ibox_wq); init_waitqueue_head(&ctx->wbox_wq); @@ -65,9 +65,9 @@ void destroy_spu_context(struct kref *kref) { struct spu_context *ctx; ctx = container_of(kref, struct spu_context, kref); - down_write(&ctx->state_sema); + mutex_lock(&ctx->state_mutex); spu_deactivate(ctx); - up_write(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); spu_fini_csa(&ctx->csa); if (ctx->gang) spu_gang_remove_ctx(ctx->gang, ctx); @@ -98,12 +98,12 @@ void spu_forget(struct spu_context *ctx) void spu_acquire(struct spu_context *ctx) { - down_read(&ctx->state_sema); + mutex_lock(&ctx->state_mutex); } void spu_release(struct spu_context *ctx) { - up_read(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); } void spu_unmap_mappings(struct spu_context *ctx) @@ -128,7 +128,7 @@ int spu_acquire_exclusive(struct spu_context *ctx) { int ret = 0; - down_write(&ctx->state_sema); + mutex_lock(&ctx->state_mutex); /* ctx is about to be freed, can't acquire any more */ if (!ctx->owner) { ret = -EINVAL; @@ -146,7 +146,7 @@ int spu_acquire_exclusive(struct spu_context *ctx) out: if (ret) - up_write(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); return ret; } @@ -154,14 +154,12 @@ int spu_acquire_runnable(struct spu_context *ctx) { int ret = 0; - down_read(&ctx->state_sema); + mutex_lock(&ctx->state_mutex); if (ctx->state == SPU_STATE_RUNNABLE) { ctx->spu->prio = current->prio; return 0; } - up_read(&ctx->state_sema); - down_write(&ctx->state_sema); /* ctx is about to be freed, can't acquire any more */ if (!ctx->owner) { ret = -EINVAL; @@ -174,29 +172,18 @@ int spu_acquire_runnable(struct spu_context *ctx) goto out; } - downgrade_write(&ctx->state_sema); /* On success, we return holding the lock */ - return ret; out: /* Release here, to simplify calling code. */ - up_write(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); return ret; } void spu_acquire_saved(struct spu_context *ctx) { - down_read(&ctx->state_sema); - - if (ctx->state == SPU_STATE_SAVED) - return; - - up_read(&ctx->state_sema); - down_write(&ctx->state_sema); - + mutex_lock(&ctx->state_mutex); if (ctx->state == SPU_STATE_RUNNABLE) spu_deactivate(ctx); - - downgrade_write(&ctx->state_sema); } diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 1d330f6..c61a34b 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -233,11 +233,11 @@ static void spu_prio_wait(struct spu_context *ctx, u64 flags) spu_add_wq(wq, &wait, prio); if (!signal_pending(current)) { - up_write(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); pr_debug("%s: pid=%d prio=%d\n", __FUNCTION__, current->pid, current->prio); schedule(); - down_write(&ctx->state_sema); + mutex_lock(&ctx->state_mutex); } spu_del_wq(wq, &wait, prio); @@ -334,7 +334,7 @@ void spu_yield(struct spu_context *ctx) struct spu *spu; int need_yield = 0; - if (down_write_trylock(&ctx->state_sema)) { + if (mutex_trylock(&ctx->state_mutex)) { if ((spu = ctx->spu) != NULL) { int best = sched_find_first_bit(spu_prio->bitmap); if (best < MAX_PRIO) { @@ -346,7 +346,7 @@ void spu_yield(struct spu_context *ctx) spu->prio = MAX_PRIO; } } - up_write(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); } if (unlikely(need_yield)) yield(); diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h index 9b44abe..de2401a 100644 --- a/arch/powerpc/platforms/cell/spufs/spufs.h +++ b/arch/powerpc/platforms/cell/spufs/spufs.h @@ -23,7 +23,7 @@ #define SPUFS_H #include -#include +#include #include #include @@ -53,7 +53,7 @@ struct spu_context { u64 object_id; /* user space pointer for oprofile */ enum { SPU_STATE_RUNNABLE, SPU_STATE_SAVED } state; - struct rw_semaphore state_sema; + struct mutex state_mutex; struct semaphore run_sema; struct mm_struct *owner; @@ -173,7 +173,7 @@ int spu_acquire_exclusive(struct spu_context *ctx); static inline void spu_release_exclusive(struct spu_context *ctx) { - up_write(&ctx->state_sema); + mutex_unlock(&ctx->state_mutex); } int spu_activate(struct spu_context *ctx, u64 flags); -- 2.7.4