[U-Boot] [PATCH v3 06/10] arm: minor fixes for cache and mmu handling

Aneesh V
2011-05-12T12:11:12Z

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 fd97c45..b1ccc3c 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")));
--
1.7.0.4