From 73970c47beb42f3e1ab0b86c537b1c79539f05f4 Mon Sep 17 00:00:00 2001
From: Ilia Mirkin <imirkin@alum.mit.edu>
Date: Sun, 9 Feb 2014 15:51:24 -0500
Subject: [PATCH] drm/nouveau: replace ffsll with __ffs64
The ffsll function is a lot slower than the __ffs64 built-in which
compiles to a single instruction on 64-bit. It's also nice to avoid
custom versions of standard functions. Note that __ffs == ffs - 1.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---
drivers/gpu/drm/nouveau/core/core/parent.c | 2 +-
drivers/gpu/drm/nouveau/nouveau_abi16.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/core/core/parent.c b/drivers/gpu/drm/nouveau/core/core/parent.c
index 313380ce632d..dee5d1235e9b 100644
--- a/drivers/gpu/drm/nouveau/core/core/parent.c
+++ b/drivers/gpu/drm/nouveau/core/core/parent.c
@@ -49,7 +49,7 @@ nouveau_parent_sclass(struct nouveau_object *parent, u16 handle,
mask = nv_parent(parent)->engine;
while (mask) {
- int i = ffsll(mask) - 1;
+ int i = __ffs64(mask);
if (nv_iclass(parent, NV_CLIENT_CLASS))
engine = nv_engine(nv_client(parent)->device);
diff --git a/drivers/gpu/drm/nouveau/nouveau_abi16.c b/drivers/gpu/drm/nouveau/nouveau_abi16.c
index 900fae01793e..b70111711be3 100644
--- a/drivers/gpu/drm/nouveau/nouveau_abi16.c
+++ b/drivers/gpu/drm/nouveau/nouveau_abi16.c
@@ -270,8 +270,8 @@ nouveau_abi16_ioctl_channel_alloc(ABI16_IOCTL_ARGS)
return nouveau_abi16_put(abi16, -EINVAL);
/* allocate "abi16 channel" data and make up a handle for it */
- init->channel = ffsll(~abi16->handles);
- if (!init->channel--)
+ init->channel = __ffs64(~abi16->handles);
+ if (~abi16->handles == 0)
return nouveau_abi16_put(abi16, -ENOSPC);
chan = kzalloc(sizeof(*chan), GFP_KERNEL);
--
2.20.1