[POWERPC] spufs: Add isolated-mode SPE recycling support

When in isolated mode, SPEs have access to an area of persistent
storage, which is per-SPE. In order for isolated-mode apps to
communicate arbitrary data through this storage, we need to ensure that
isolated physical SPEs can be reused for subsequent applications.

Add a file ("recycle") in a spethread dir to enable isolated-mode
recycling. By writing to this file, the kernel will reload the
isolated-mode loader kernel, allowing a new app to be run on the same
physical SPE.

This requires the spu_acquire_exclusive function to enforce exclusive
access to the SPE while the loader is initialised.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 8ca330671ad1..5b8ba6c3aa3c 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -1343,6 +1343,37 @@ static struct file_operations spufs_mfc_fops = {
 	.mmap	 = spufs_mfc_mmap,
 };
 
+
+static int spufs_recycle_open(struct inode *inode, struct file *file)
+{
+	file->private_data = SPUFS_I(inode)->i_ctx;
+	return nonseekable_open(inode, file);
+}
+
+static ssize_t spufs_recycle_write(struct file *file,
+		const char __user *buffer, size_t size, loff_t *pos)
+{
+	struct spu_context *ctx = file->private_data;
+	int ret;
+
+	if (!(ctx->flags & SPU_CREATE_ISOLATE))
+		return -EINVAL;
+
+	if (size < 1)
+		return -EINVAL;
+
+	ret = spu_recycle_isolated(ctx);
+
+	if (ret)
+		return ret;
+	return size;
+}
+
+static struct file_operations spufs_recycle_fops = {
+	.open	 = spufs_recycle_open,
+	.write	 = spufs_recycle_write,
+};
+
 static void spufs_npc_set(void *data, u64 val)
 {
 	struct spu_context *ctx = data;
@@ -1551,5 +1582,6 @@ struct tree_descr spufs_dir_nosched_contents[] = {
 	{ "psmap", &spufs_psmap_fops, 0666, },
 	{ "phys-id", &spufs_id_ops, 0666, },
 	{ "object-id", &spufs_object_id_ops, 0666, },
+	{ "recycle", &spufs_recycle_fops, 0222, },
 	{},
 };