arm64: Update memcpy_{from, to}io() helpers

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@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Cc: mark.kettenis@xs4all.nl
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>

diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index 15cecb5e0b34ad3b92dd3ef246e683426974af19..3de18c7675b9eb9a6e496b0cd849a10f1909fd66 100644 (file)
--- 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 df264a170b29fa15dad6b1b36b5288bceaa0809c..36b840378a9e834887e608271242772e28135a32 100644 (file)
--- 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 c3a66f04059dce2dc752add72af8786b07d58ad6..23cd5eca39805136bd0899305cf03a5605d669de 100644 (file)
--- 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);