powerpc/spufs: Use simple_write_to_buffer

Simplify several write fileoperations for spufs by using
simple_write_to_buffer().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 7 insertions, 20 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 02f7b113a31b..3c7c3f82d842 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -219,24 +219,17 @@ spufs_mem_write(struct file *file, const char __user *buffer,
         loff_t pos = *ppos;
         int ret;
 
-        if (pos < 0)
-                return -EINVAL;
         if (pos > LS_SIZE)
                 return -EFBIG;
-        if (size > LS_SIZE - pos)
-                size = LS_SIZE - pos;
 
         ret = spu_acquire(ctx);
         if (ret)
                 return ret;
 
         local_store = ctx->ops->get_ls(ctx);
-        ret = copy_from_user(local_store + pos, buffer, size);
+        size = simple_write_to_buffer(local_store, LS_SIZE, ppos, buffer, size);
         spu_release(ctx);
 
-        if (ret)
-                return -EFAULT;
-        *ppos = pos + size;
         return size;
 }
 
@@ -574,18 +567,15 @@ spufs_regs_write(struct file *file, const char __user *buffer,
         if (*pos >= sizeof(lscsa->gprs))
                 return -EFBIG;
 
-        size = min_t(ssize_t, sizeof(lscsa->gprs) - *pos, size);
-        *pos += size;
-
         ret = spu_acquire_saved(ctx);
         if (ret)
                 return ret;
 
-        ret = copy_from_user((char *)lscsa->gprs + *pos - size,
-                             buffer, size) ? -EFAULT : size;
+        size = simple_write_to_buffer(lscsa->gprs, sizeof(lscsa->gprs), pos,
+                                        buffer, size);
 
         spu_release_saved(ctx);
-        return ret;
+        return size;
 }
 
 static const struct file_operations spufs_regs_fops = {
@@ -630,18 +620,15 @@ spufs_fpcr_write(struct file *file, const char __user * buffer,
         if (*pos >= sizeof(lscsa->fpcr))
                 return -EFBIG;
 
-        size = min_t(ssize_t, sizeof(lscsa->fpcr) - *pos, size);
-
         ret = spu_acquire_saved(ctx);
         if (ret)
                 return ret;
 
-        *pos += size;
-        ret = copy_from_user((char *)&lscsa->fpcr + *pos - size,
-                             buffer, size) ? -EFAULT : size;
+        size = simple_write_to_buffer(&lscsa->fpcr, sizeof(lscsa->fpcr), pos,
+                                        buffer, size);
 
         spu_release_saved(ctx);
-        return ret;
+        return size;
 }
 
 static const struct file_operations spufs_fpcr_fops = {