[PATCH v2 2/2] arm64: Update memcpy_{from, to}io() helpers
Patrick Delaunay
patrick.delaunay at foss.st.com
Mon Jul 19 11:21:51 CEST 2021
From: Patrice Chotard <patrice.chotard at foss.st.com>
At early U-Boot stage, before relocation, MMU is not yet configured
and disabled. DDR may not be configured with the correct memory
attributes (can be configured in MT_DEVICE instead of MT_MEMORY).
In this case, usage of memcpy_{from, to}io() may leads to synchronous
abort in AARCH64 in case the normal memory address is not 64Bits aligned.
To avoid such situation, forbid usage of normal memory cast to (u64 *) in
case MMU is not enabled.
Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
Cc: mark.kettenis at xs4all.nl
Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
---
(no changes since v1)
arch/arm/cpu/armv8/cache_v8.c | 10 ++++++++++
arch/arm/include/asm/io.h | 25 +++++++++++++++----------
include/cpu_func.h | 1 +
3 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index 15cecb5e0b..3de18c7675 100644
--- a/arch/arm/cpu/armv8/cache_v8.c
+++ b/arch/arm/cpu/armv8/cache_v8.c
@@ -719,6 +719,11 @@ int icache_status(void)
return (get_sctlr() & CR_I) != 0;
}
+int mmu_status(void)
+{
+ return (get_sctlr() & CR_M) != 0;
+}
+
void invalidate_icache_all(void)
{
__asm_invalidate_icache_all();
@@ -740,6 +745,11 @@ int icache_status(void)
return 0;
}
+int mmu_status(void)
+{
+ return 0;
+}
+
void invalidate_icache_all(void)
{
}
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index df264a170b..36b840378a 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -338,6 +338,7 @@ extern void __readwrite_bug(const char *fn);
/* Optimized copy functions to read from/write to IO sapce */
#ifdef CONFIG_ARM64
+#include <cpu_func.h>
/*
* Copy data from IO memory space to "real" memory space.
*/
@@ -351,11 +352,13 @@ void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
count--;
}
- while (count >= 8) {
- *(u64 *)to = __raw_readq(from);
- from += 8;
- to += 8;
- count -= 8;
+ if (mmu_status()) {
+ while (count >= 8) {
+ *(u64 *)to = __raw_readq(from);
+ from += 8;
+ to += 8;
+ count -= 8;
+ }
}
while (count) {
@@ -379,11 +382,13 @@ void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
count--;
}
- while (count >= 8) {
- __raw_writeq(*(u64 *)from, to);
- from += 8;
- to += 8;
- count -= 8;
+ if (mmu_status()) {
+ while (count >= 8) {
+ __raw_writeq(*(u64 *)from, to);
+ from += 8;
+ to += 8;
+ count -= 8;
+ }
}
while (count) {
diff --git a/include/cpu_func.h b/include/cpu_func.h
index c3a66f0405..23cd5eca39 100644
--- a/include/cpu_func.h
+++ b/include/cpu_func.h
@@ -59,6 +59,7 @@ int dcache_status(void);
void dcache_enable(void);
void dcache_disable(void);
void mmu_disable(void);
+int mmu_status(void);
/* arch/$(ARCH)/lib/cache.c */
void enable_caches(void);
--
2.25.1
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