From b99286b088ea843b935dcfb29f187697359fe5cd Mon Sep 17 00:00:00 2001 From: Qian Cai Date: Mon, 5 Aug 2019 23:05:03 -0400 Subject: [PATCH] arm64/prefetch: fix a -Wtype-limits warning 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 converting MIDR_IS_CPU_MODEL_RANGE to a static inline function. Signed-off-by: Qian Cai Signed-off-by: Will Deacon --- arch/arm64/include/asm/cputype.h | 21 +++++++++++---------- arch/arm64/kernel/cpufeature.c | 2 +- 2 files changed, 12 insertions(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index e7d4663..b1454d1 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -51,14 +51,6 @@ #define MIDR_CPU_MODEL_MASK (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | \ MIDR_ARCHITECTURE_MASK) -#define MIDR_IS_CPU_MODEL_RANGE(midr, model, rv_min, rv_max) \ -({ \ - u32 _model = (midr) & MIDR_CPU_MODEL_MASK; \ - u32 rv = (midr) & (MIDR_REVISION_MASK | MIDR_VARIANT_MASK); \ - \ - _model == (model) && rv >= (rv_min) && rv <= (rv_max); \ - }) - #define ARM_CPU_IMP_ARM 0x41 #define ARM_CPU_IMP_APM 0x50 #define ARM_CPU_IMP_CAVIUM 0x43 @@ -159,10 +151,19 @@ struct midr_range { #define MIDR_REV(m, v, r) MIDR_RANGE(m, v, r, v, r) #define MIDR_ALL_VERSIONS(m) MIDR_RANGE(m, 0, 0, 0xf, 0xf) +static inline bool midr_is_cpu_model_range(u32 midr, u32 model, u32 rv_min, + u32 rv_max) +{ + u32 _model = midr & MIDR_CPU_MODEL_MASK; + u32 rv = midr & (MIDR_REVISION_MASK | MIDR_VARIANT_MASK); + + return _model == model && rv >= rv_min && rv <= rv_max; +} + static inline bool is_midr_in_range(u32 midr, struct midr_range const *range) { - return MIDR_IS_CPU_MODEL_RANGE(midr, range->model, - range->rv_min, range->rv_max); + return midr_is_cpu_model_range(midr, range->model, + range->rv_min, range->rv_max); } static inline bool diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index d19d14b..95201e5 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -886,7 +886,7 @@ static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int _ u32 midr = read_cpuid_id(); /* Cavium ThunderX pass 1.x and 2.x */ - return MIDR_IS_CPU_MODEL_RANGE(midr, MIDR_THUNDERX, + return midr_is_cpu_model_range(midr, MIDR_THUNDERX, MIDR_CPU_VAR_REV(0, 0), MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK)); } -- 2.7.4