Subject: spufs: synchronize pte invalidation vs ps close

From: Christoph Hellwig <hch@lst.de>
Make sure the mapping_lock also protects access to the various address_space
pointers used for tearing down the ptes on a spu context switch.

Because unmap_mapping_range can sleep we need to turn mapping_lock from
a spinlock into a sleeping mutex.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

Index: linux-2.6/arch/powerpc/platforms/cell/spufs/context.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/context.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/context.c
@@ -44,7 +44,7 @@ struct spu_context *alloc_spu_context(st
 	if (spu_init_csa(&ctx->csa))
 		goto out_free;
 	spin_lock_init(&ctx->mmio_lock);
-	spin_lock_init(&ctx->mapping_lock);
+	mutex_init(&ctx->mapping_lock);
 	kref_init(&ctx->kref);
 	mutex_init(&ctx->state_mutex);
 	mutex_init(&ctx->run_mutex);
@@ -112,6 +112,7 @@ void spu_forget(struct spu_context *ctx)
 
 void spu_unmap_mappings(struct spu_context *ctx)
 {
+	mutex_lock(&ctx->mapping_lock);
 	if (ctx->local_store)
 		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);
 	if (ctx->mfc)
@@ -126,6 +127,7 @@ void spu_unmap_mappings(struct spu_conte
 		unmap_mapping_range(ctx->mss, 0, 0x1000, 1);
 	if (ctx->psmap)
 		unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);
+	mutex_unlock(&ctx->mapping_lock);
 }
 
 /**
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/file.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
@@ -47,11 +47,11 @@ spufs_mem_open(struct inode *inode, stru
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	file->private_data = ctx;
 	if (!i->i_openers++)
 		ctx->local_store = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -61,10 +61,10 @@ spufs_mem_release(struct inode *inode, s
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->local_store = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -312,11 +312,11 @@ static int spufs_cntl_open(struct inode 
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	file->private_data = ctx;
 	if (!i->i_openers++)
 		ctx->cntl = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return simple_attr_open(inode, file, spufs_cntl_get,
 					spufs_cntl_set, "0x%08lx");
 }
@@ -329,10 +329,10 @@ spufs_cntl_release(struct inode *inode, 
 
 	simple_attr_close(inode, file);
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->cntl = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -815,11 +815,11 @@ static int spufs_signal1_open(struct ino
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	file->private_data = ctx;
 	if (!i->i_openers++)
 		ctx->signal1 = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return nonseekable_open(inode, file);
 }
 
@@ -829,10 +829,10 @@ spufs_signal1_release(struct inode *inod
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->signal1 = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -939,11 +939,11 @@ static int spufs_signal2_open(struct ino
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	file->private_data = ctx;
 	if (!i->i_openers++)
 		ctx->signal2 = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return nonseekable_open(inode, file);
 }
 
@@ -953,10 +953,10 @@ spufs_signal2_release(struct inode *inod
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->signal2 = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -1157,10 +1157,10 @@ static int spufs_mss_open(struct inode *
 
 	file->private_data = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!i->i_openers++)
 		ctx->mss = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return nonseekable_open(inode, file);
 }
 
@@ -1170,10 +1170,10 @@ spufs_mss_release(struct inode *inode, s
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->mss = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -1214,11 +1214,11 @@ static int spufs_psmap_open(struct inode
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	file->private_data = i->i_ctx;
 	if (!i->i_openers++)
 		ctx->psmap = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return nonseekable_open(inode, file);
 }
 
@@ -1228,10 +1228,10 @@ spufs_psmap_release(struct inode *inode,
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->psmap = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
@@ -1284,11 +1284,11 @@ static int spufs_mfc_open(struct inode *
 	if (atomic_read(&inode->i_count) != 1)
 		return -EBUSY;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	file->private_data = ctx;
 	if (!i->i_openers++)
 		ctx->mfc = inode->i_mapping;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return nonseekable_open(inode, file);
 }
 
@@ -1298,10 +1298,10 @@ spufs_mfc_release(struct inode *inode, s
 	struct spufs_inode_info *i = SPUFS_I(inode);
 	struct spu_context *ctx = i->i_ctx;
 
-	spin_lock(&ctx->mapping_lock);
+	mutex_lock(&ctx->mapping_lock);
 	if (!--i->i_openers)
 		ctx->mfc = NULL;
-	spin_unlock(&ctx->mapping_lock);
+	mutex_unlock(&ctx->mapping_lock);
 	return 0;
 }
 
Index: linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/spufs.h
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/spufs.h
@@ -56,7 +56,7 @@ struct spu_context {
 	struct address_space *signal2;	   /* 'signal2' area mappings. */
 	struct address_space *mss;	   /* 'mss' area mappings. */
 	struct address_space *psmap;	   /* 'psmap' area mappings. */
-	spinlock_t mapping_lock;
+	struct mutex mapping_lock;
 	u64 object_id;		   /* user space pointer for oprofile */
 
 	enum { SPU_STATE_RUNNABLE, SPU_STATE_SAVED } state;