ARM: 5746/1: Handle possible translation errors in ARMv6/v7 coherent_user_range
This is needed because applications using the sys_cacheflush system call
can pass a memory range which isn't mapped yet even though the
corresponding vma is valid. The patch also adds unwinding annotations
for correct backtraces from the coherent_user_range() functions.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index 8f5c13f..295e25d 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -12,6 +12,7 @@
#include <linux/linkage.h>
#include <linux/init.h>
#include <asm/assembler.h>
+#include <asm/unwind.h>
#include "proc-macros.S"
@@ -121,11 +122,13 @@
* - the Icache does not read data from the write buffer
*/
ENTRY(v6_coherent_user_range)
-
+ UNWIND(.fnstart )
#ifdef HARVARD_CACHE
bic r0, r0, #CACHE_LINE_SIZE - 1
-1: mcr p15, 0, r0, c7, c10, 1 @ clean D line
+1:
+ USER( mcr p15, 0, r0, c7, c10, 1 ) @ clean D line
add r0, r0, #CACHE_LINE_SIZE
+2:
cmp r0, r1
blo 1b
#endif
@@ -143,6 +146,19 @@
mov pc, lr
/*
+ * Fault handling for the cache operation above. If the virtual address in r0
+ * isn't mapped, just try the next page.
+ */
+9001:
+ mov r0, r0, lsr #12
+ mov r0, r0, lsl #12
+ add r0, r0, #4096
+ b 2b
+ UNWIND(.fnend )
+ENDPROC(v6_coherent_user_range)
+ENDPROC(v6_coherent_kern_range)
+
+/*
* v6_flush_kern_dcache_page(kaddr)
*
* Ensure that the data held in the page kaddr is written back