On 5/31/23 00:08, Emanuele Ghidoli wrote:
From: Emanuele Ghidoli
On Cortex-R5 flushing and disabling cache is not enough to avoid
cache and memory incoherence.
In particular, when the cache is enabled after a disable, and if there
are entry in the cache the value from the cache is used instead of the
value from the memory. This, in particular, lead to stack corruption if
the stack is in a cached area.
The commit 44df5e8d30a2 ("arm: move flush_dcache_all() to just before disable
cache")
already states that following a cache disable an invalidate is expected
to be done but without coping with cache enable. So just add it explicitly.
Signed-off-by: Emanuele Ghidoli
---
arch/arm/lib/cache-cp15.c | 8
1 file changed, 8 insertions(+)
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
index 0893915b3004..2921277d69e0 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/arch/arm/lib/cache-cp15.c
@@ -254,7 +254,15 @@ static void cache_disable(uint32_t cache_bit)
if (cache_bit == CR_C)
#endif
flush_dcache_all();
+
set_cr(reg & ~cache_bit);
+
+#ifdef CONFIG_SYS_ARM_MMU
+ if (cache_bit == (CR_C | CR_M))
+#elif defined(CONFIG_SYS_ARM_MPU)
+ if (cache_bit == CR_C)
+#endif
We prefer 'if' over '#ifdef'. So you should use something like:
if (IS_ENABLED(CONFIG_SYS_ARM_MMU) && (cache_bit == (CR_C | CR_M) ||
IS_ENABLED(CONFIG_SYS_ARM_MPU) && (cache_bit == CR_C)) {
flush_dcache_all();
invalidate_dcache_all();
}
set_cr(reg & ~cache_bit);
(Assuming set_cr() can be called after invalidate_dcache_all.)
Best regards
Heinrich
+ invalidate_dcache_all();
}
#endif
