diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
---|---|---|
committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/blackfin/lib/strncpy.S |
Initial import
Diffstat (limited to 'arch/blackfin/lib/strncpy.S')
-rw-r--r-- | arch/blackfin/lib/strncpy.S | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/blackfin/lib/strncpy.S b/arch/blackfin/lib/strncpy.S new file mode 100644 index 000000000..92fd1823b --- /dev/null +++ b/arch/blackfin/lib/strncpy.S @@ -0,0 +1,85 @@ +/* + * Copyright 2005-2010 Analog Devices Inc. + * + * Licensed under the Clear BSD license or the GPL-2 (or later) + */ + +#include <linux/linkage.h> +#include <asm/context.S> + +/* void *strncpy(char *dest, const char *src, size_t n); + * R0 = address (dest) + * R1 = address (src) + * R2 = size + * Returns a pointer (R0) to the destination string dest + * we do this by not changing R0 + */ + +#ifdef CONFIG_STRNCPY_L1 +.section .l1.text +#else +.text +#endif + +.align 2 + +ENTRY(_strncpy) + CC = R2 == 0; + if CC JUMP 6f; + + P2 = R2 ; /* size */ + P0 = R0 ; /* dst*/ + P1 = R1 ; /* src*/ + + LSETUP (1f, 2f) LC0 = P2; +1: + R1 = B [P1++] (Z); + B [P0++] = R1; + CC = R1 == 0; +2: + if CC jump 3f; + + RTS; + + /* if src is shorter than n, we need to null pad bytes in dest + * but, we can get here when the last byte is zero, and we don't + * want to copy an extra byte at the end, so we need to check + */ +3: + R2 = LC0; + CC = R2 + if ! CC jump 6f; + + /* if the required null padded portion is small, do it here, rather than + * handling the overhead of memset (which is OK when things are big). + */ + R3 = 0x20; + CC = R2 < R3; + IF CC jump 4f; + + R2 += -1; + + /* Set things up for memset + * R0 = address + * R1 = filler byte (this case it's zero, set above) + * R2 = count (set above) + */ + + I1 = R0; + R0 = RETS; + I0 = R0; + R0 = P0; + pseudo_long_call _memset, p0; + R0 = I0; + RETS = R0; + R0 = I1; + RTS; + +4: + LSETUP(5f, 5f) LC0; +5: + B [P0++] = R1; +6: + RTS; + +ENDPROC(_strncpy) |