[PATCH] drm/nouveau/clk/gk20a: fix undefined behaviour in signed left shift

MASK(w) expands as ((1 << (w)) - 1), and GPC2CLK_OUT_SDIV14_INDIV4_MODE
is defined as plain 1. Both are used, via GPC2CLK_OUT_INIT_MASK and
GPC2CLK_OUT_INIT_VAL in gk20a_clk_prog() (and reused by gm20b, which
includes gk20a.h), to compute:

	1 << 31

Left-shifting a signed int into its sign bit is undefined behaviour
per the C standard (ISO C11 6.5.7p4), and is flagged by UBSan and
static analysis tools such as cppcheck (shiftTooManyBitsSigned). Make
the shifted operand unsigned to fix it, matching the pattern used
elsewhere in the kernel for register bitfield masks.

No functional change intended.

Found via static analysis (cppcheck --enable=portability) while
auditing nvkm/subdev/clk for correctness issues.

Signed-off-by: Muhammed Sariyildiz <[email protected]>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.h b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.h
index ea5b0ba..7a93f9f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.h
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/gk20a.h
@@ -27,7 +27,7 @@
 #define KHZ (1000)
 #define MHZ (KHZ * 1000)
 
-#define MASK(w)	((1 << (w)) - 1)
+#define MASK(w)	((1U << (w)) - 1)
 
 #define GK20A_CLK_GPC_MDIV 1000
 
@@ -79,7 +79,7 @@
 #define GPC2CLK_OUT			(SYS_GPCPLL_CFG_BASE + 0x250)
 #define GPC2CLK_OUT_SDIV14_INDIV4_WIDTH	1
 #define GPC2CLK_OUT_SDIV14_INDIV4_SHIFT	31
-#define GPC2CLK_OUT_SDIV14_INDIV4_MODE	1
+#define GPC2CLK_OUT_SDIV14_INDIV4_MODE	1U
 #define GPC2CLK_OUT_VCODIV_WIDTH	6
 #define GPC2CLK_OUT_VCODIV_SHIFT	8
 #define GPC2CLK_OUT_VCODIV1		0
-- 
2.43.0