[POWERPC] spufs: state_mutex cleanup

[firefly-linux-kernel-4.4.55.git] / arch / powerpc / platforms / cell / spufs / context.c

diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index c9aab9b1cd8a89f9d2cf94a99f42f5d314b94fb2..f2630dc0db8919f8e28b6e021f2206f78618c1dc 100644 (file)
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -96,16 +96,6 @@ void spu_forget(struct spu_context *ctx)
        spu_release(ctx);
 }
 
-void spu_acquire(struct spu_context *ctx)
-{
-       mutex_lock(&ctx->state_mutex);
-}
-
-void spu_release(struct spu_context *ctx)
-{
-       mutex_unlock(&ctx->state_mutex);
-}
-
 void spu_unmap_mappings(struct spu_context *ctx)
 {
        if (ctx->local_store)
@@ -124,66 +114,85 @@ void spu_unmap_mappings(struct spu_context *ctx)
                unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
 }
 
+/**
+ * spu_acquire_exclusive - lock spu contex and protect against userspace access
+ * @ctx:       spu contex to lock
+ *
+ * Note:
+ *     Returns 0 and with the context locked on success
+ *     Returns negative error and with the context _unlocked_ on failure.
+ */
 int spu_acquire_exclusive(struct spu_context *ctx)
 {
-       int ret = 0;
+       int ret = -EINVAL;
 
-       mutex_lock(&ctx->state_mutex);
-       /* ctx is about to be freed, can't acquire any more */
-       if (!ctx->owner) {
-               ret = -EINVAL;
-               goto out;
-       }
+       spu_acquire(ctx);
+       /*
+        * Context is about to be freed, so we can't acquire it anymore.
+        */
+       if (!ctx->owner)
+               goto out_unlock;
 
        if (ctx->state == SPU_STATE_SAVED) {
                ret = spu_activate(ctx, 0);
                if (ret)
-                       goto out;
+                       goto out_unlock;
        } else {
-               /* We need to exclude userspace access to the context. */
+               /*
+                * We need to exclude userspace access to the context.
+                *
+                * To protect against memory access we invalidate all ptes
+                * and make sure the pagefault handlers block on the mutex.
+                */
                spu_unmap_mappings(ctx);
        }
 
-out:
-       if (ret)
-               mutex_unlock(&ctx->state_mutex);
+       return 0;
+
+ out_unlock:
+       spu_release(ctx);
        return ret;
 }
 
+/**
+ * spu_acquire_runnable - lock spu contex and make sure it is in runnable state
+ * @ctx:       spu contex to lock
+ *
+ * Note:
+ *     Returns 0 and with the context locked on success
+ *     Returns negative error and with the context _unlocked_ on failure.
+ */
 int spu_acquire_runnable(struct spu_context *ctx)
 {
-       int ret = 0;
-
-       mutex_lock(&ctx->state_mutex);
-       if (ctx->state == SPU_STATE_RUNNABLE) {
-               ctx->spu->prio = current->prio;
-               return 0;
-       }
-
-       /* ctx is about to be freed, can't acquire any more */
-       if (!ctx->owner) {
-               ret = -EINVAL;
-               goto out;
-       }
+       int ret = -EINVAL;
 
+       spu_acquire(ctx);
        if (ctx->state == SPU_STATE_SAVED) {
+               /*
+                * Context is about to be freed, so we can't acquire it anymore.
+                */
+               if (!ctx->owner)
+                       goto out_unlock;
                ret = spu_activate(ctx, 0);
                if (ret)
-                       goto out;
-       }
+                       goto out_unlock;
+       } else
+               ctx->spu->prio = current->prio;
 
-       /* On success, we return holding the lock */
-       return ret;
-out:
-       /* Release here, to simplify calling code. */
-       mutex_unlock(&ctx->state_mutex);
+       return 0;
 
+ out_unlock:
+       spu_release(ctx);
        return ret;
 }
 
+/**
+ * spu_acquire_saved - lock spu contex and make sure it is in saved state
+ * @ctx:       spu contex to lock
+ */
 void spu_acquire_saved(struct spu_context *ctx)
 {
-       mutex_lock(&ctx->state_mutex);
-       if (ctx->state == SPU_STATE_RUNNABLE)
+       spu_acquire(ctx);
+       if (ctx->state != SPU_STATE_SAVED)
                spu_deactivate(ctx);
 }