1. make sure that page table setup is not done multiple times 2. flush_dcache_all() is more appropriate while disabling cache than a range flush on the entire memory(flush_cache())
Provide a default implementation for flush_dcache_all() for backward compatibility and to avoid build issues.
Signed-off-by: Aneesh V aneesh@ti.com --- V2: * Fixed signature of flush_cache in cache.c --- arch/arm/lib/cache-cp15.c | 9 +++++++-- arch/arm/lib/cache.c | 11 +++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c index 51831a9..e6c3eae 100644 --- a/arch/arm/lib/cache-cp15.c +++ b/arch/arm/lib/cache-cp15.c @@ -92,13 +92,18 @@ static inline void mmu_setup(void) set_cr(reg | CR_M); }
+static int mmu_enabled(void) +{ + return get_cr() & CR_M; +} + /* cache_bit must be either CR_I or CR_C */ static void cache_enable(uint32_t cache_bit) { uint32_t reg;
/* The data cache is not active unless the mmu is enabled too */ - if (cache_bit == CR_C) + if ((cache_bit == CR_C) && !mmu_enabled()) mmu_setup(); reg = get_cr(); /* get control reg. */ cp_delay(); @@ -117,7 +122,7 @@ static void cache_disable(uint32_t cache_bit) return; /* if disabling data cache, disable mmu too */ cache_bit |= CR_M; - flush_cache(0, ~0); + flush_dcache_all(); } reg = get_cr(); cp_delay(); diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c index dc3242c..92b61a2 100644 --- a/arch/arm/lib/cache.c +++ b/arch/arm/lib/cache.c @@ -42,3 +42,14 @@ void __flush_cache(unsigned long start, unsigned long size) } void flush_cache(unsigned long start, unsigned long size) __attribute__((weak, alias("__flush_cache"))); + +/* + * Default implementation: + * do a range flush for the entire range + */ +void __flush_dcache_all(void) +{ + flush_cache(0, ~0); +} +void flush_dcache_all(void) + __attribute__((weak, alias("__flush_dcache_all")));