diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/lib/memset-arm64.S | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/lib/memset-arm64.S b/arch/arm/lib/memset-arm64.S index 710f6f582c..ee9f9a96cf 100644 --- a/arch/arm/lib/memset-arm64.S +++ b/arch/arm/lib/memset-arm64.S @@ -11,6 +11,7 @@ * */ +#include <asm/macro.h> #include "asmdefs.h" #define dstin x0 @@ -25,6 +26,37 @@ ENTRY (memset) PTR_ARG (0) SIZE_ARG (2) + /* + * The optimized memset uses the dc opcode, which causes problems + * when the cache is disabled. Let's check if the cache is disabled + * and use a very simple memset implementation in this case. Otherwise + * jump to the optimized version. + */ + switch_el x6, 3f, 2f, 1f +3: mrs x6, sctlr_el3 + b 0f +2: mrs x6, sctlr_el2 + b 0f +1: mrs x6, sctlr_el1 +0: + tst x6, #CR_C + bne 9f + + /* + * A very "simple" memset implementation without the use of the + * dc opcode. Can be run with caches disabled. + */ + mov x3, #0x0 + cmp count, x3 /* check for zero length */ + beq 8f +4: strb valw, [dstin, x3] + add x3, x3, #0x1 + cmp count, x3 + bne 4b +8: ret +9: + + /* Here the optimized memset version starts */ dup v0.16B, valw add dstend, dstin, count |