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Subject[PATCH] arm64/prefetch: fix a -Wtype-limits warning
Date
The commit d5370f754875 ("arm64: prefetch: add alternative pattern for
CPUs without a prefetcher") introduced MIDR_IS_CPU_MODEL_RANGE() to be
used in has_no_hw_prefetch() with rv_min=0 which generates a compilation
warning from GCC,

In file included from ./arch/arm64/include/asm/cache.h:8,
from ./include/linux/cache.h:6,
from ./include/linux/printk.h:9,
from ./include/linux/kernel.h:15,
from ./include/linux/cpumask.h:10,
from arch/arm64/kernel/cpufeature.c:11:
arch/arm64/kernel/cpufeature.c: In function 'has_no_hw_prefetch':
./arch/arm64/include/asm/cputype.h:59:26: warning: comparison of
unsigned expression >= 0 is always true [-Wtype-limits]
_model == (model) && rv >= (rv_min) && rv <= (rv_max); \
^~
arch/arm64/kernel/cpufeature.c:889:9: note: in expansion of macro
'MIDR_IS_CPU_MODEL_RANGE'
return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX,
^~~~~~~~~~~~~~~~~~~~~~~

Fix it by making rv_min=1.

Signed-off-by: Qian Cai <cai@lca.pw>
---
arch/arm64/kernel/cpufeature.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index f29f36a65175..7d15cf6d62c1 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -883,7 +883,7 @@ static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int _

/* Cavium ThunderX pass 1.x and 2.x */
return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX,
- MIDR_CPU_VAR_REV(0, 0),
+ MIDR_CPU_VAR_REV(0, 1),
MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK));
}

--
1.8.3.1
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