[POWERPC] spufs: add support for nonschedulable contexts

This adds two new flags to spu_create:

SPU_CREATE_NONSCHED: create a context that is never moved
away from an SPE once it has started running. This flag
can only be used by tasks with the CAP_SYS_NICE capability.

SPU_CREATE_ISOLATED: create a nonschedulable context that
enters isolation mode upon first run. This requires the
SPU_CREATE_NONSCHED flag.

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, 16 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 427d00a4f6a0..787ae71a6859 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -258,7 +258,12 @@ spufs_mkdir(struct inode *dir, struct dentry *dentry, unsigned int flags,
 
         inode->i_op = &spufs_dir_inode_operations;
         inode->i_fop = &simple_dir_operations;
-        ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
+        if (flags & SPU_CREATE_NOSCHED)
+                ret = spufs_fill_dir(dentry, spufs_dir_nosched_contents,
+                                         mode, ctx);
+        else
+                ret = spufs_fill_dir(dentry, spufs_dir_contents, mode, ctx);
+
         if (ret)
                 goto out_free_ctx;
 
@@ -307,6 +312,16 @@ static int spufs_create_context(struct inode *inode,
 {
         int ret;
 
+        ret = -EPERM;
+        if ((flags & SPU_CREATE_NOSCHED) &&
+            !capable(CAP_SYS_NICE))
+                goto out_unlock;
+
+        ret = -EINVAL;
+        if ((flags & (SPU_CREATE_NOSCHED | SPU_CREATE_ISOLATE))
+            == SPU_CREATE_ISOLATE)
+                goto out_unlock;
+
         ret = spufs_mkdir(inode, dentry, flags, mode & S_IRWXUGO);
         if (ret)
                 goto out_unlock;