diff options
Diffstat (limited to 'arch/powerpc/lib/string_32.S')
| -rw-r--r-- | arch/powerpc/lib/string_32.S | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/powerpc/lib/string_32.S b/arch/powerpc/lib/string_32.S new file mode 100644 index 000000000000..f69a6aab7bfb --- /dev/null +++ b/arch/powerpc/lib/string_32.S @@ -0,0 +1,90 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * String handling functions for PowerPC32 + * + * Copyright (C) 1996 Paul Mackerras. + * + */ + +#include <asm/ppc_asm.h> +#include <asm/export.h> +#include <asm/cache.h> + + .text + +CACHELINE_BYTES = L1_CACHE_BYTES +LG_CACHELINE_BYTES = L1_CACHE_SHIFT +CACHELINE_MASK = (L1_CACHE_BYTES-1) + +_GLOBAL(__clear_user) +/* + * Use dcbz on the complete cache lines in the destination + * to set them to zero. This requires that the destination + * area is cacheable. + */ + cmplwi cr0, r4, 4 + mr r10, r3 + li r3, 0 + blt 7f + +11: stw r3, 0(r10) + beqlr + andi. r0, r10, 3 + add r11, r0, r4 + subf r6, r0, r10 + + clrlwi r7, r6, 32 - LG_CACHELINE_BYTES + add r8, r7, r11 + srwi r9, r8, LG_CACHELINE_BYTES + addic. r9, r9, -1 /* total number of complete cachelines */ + ble 2f + xori r0, r7, CACHELINE_MASK & ~3 + srwi. r0, r0, 2 + beq 3f + mtctr r0 +4: stwu r3, 4(r6) + bdnz 4b +3: mtctr r9 + li r7, 4 +10: dcbz r7, r6 + addi r6, r6, CACHELINE_BYTES + bdnz 10b + clrlwi r11, r8, 32 - LG_CACHELINE_BYTES + addi r11, r11, 4 + +2: srwi r0 ,r11 ,2 + mtctr r0 + bdz 6f +1: stwu r3, 4(r6) + bdnz 1b +6: andi. r11, r11, 3 + beqlr + mtctr r11 + addi r6, r6, 3 +8: stbu r3, 1(r6) + bdnz 8b + blr + +7: cmpwi cr0, r4, 0 + beqlr + mtctr r4 + addi r6, r10, -1 +9: stbu r3, 1(r6) + bdnz 9b + blr + +90: mr r3, r4 + blr +91: add r3, r10, r4 + subf r3, r6, r3 + blr + + EX_TABLE(11b, 90b) + EX_TABLE(4b, 91b) + EX_TABLE(10b, 91b) + EX_TABLE(1b, 91b) + EX_TABLE(8b, 91b) + EX_TABLE(9b, 91b) + +EXPORT_SYMBOL(__clear_user) |