Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the display.
Signed-off-by: Simon Glass sjg@chromium.org ---
arch/x86/include/asm/string.h | 2 +- arch/x86/lib/Makefile | 1 + arch/x86/lib/memmove.c | 193 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 195 insertions(+), 1 deletion(-) create mode 100644 arch/x86/lib/memmove.c
diff --git a/arch/x86/include/asm/string.h b/arch/x86/include/asm/string.h index 0ad612f..38afd23 100644 --- a/arch/x86/include/asm/string.h +++ b/arch/x86/include/asm/string.h @@ -17,7 +17,7 @@ extern char * strchr(const char * s, int c); #define __HAVE_ARCH_MEMCPY extern void * memcpy(void *, const void *, __kernel_size_t);
-#undef __HAVE_ARCH_MEMMOVE +#define __HAVE_ARCH_MEMMOVE extern void * memmove(void *, const void *, __kernel_size_t);
#undef __HAVE_ARCH_MEMCHR diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index e17f0bb..b380d62 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -17,6 +17,7 @@ obj-y += gcc.o obj-y += init_helpers.o obj-y += interrupts.o obj-y += lpc-uclass.o +obj-y += memmove.o obj-y += mpspec.o obj-$(CONFIG_ENABLE_MRC_CACHE) += mrccache.o obj-y += cmd_mtrr.o diff --git a/arch/x86/lib/memmove.c b/arch/x86/lib/memmove.c new file mode 100644 index 0000000..504a184 --- /dev/null +++ b/arch/x86/lib/memmove.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2016 Google, Inc + * Taken from Linux v4.7. There is no copyright notice on the original file. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> + +void *memmove(void *dest, const void *src, size_t n) +{ + int d0, d1, d2, d3, d4, d5; + char *ret = dest; + + __asm__ __volatile__( + /* Handle more 16 bytes in loop */ + "cmp $0x10, %0\n\t" + "jb 1f\n\t" + + /* Decide forward/backward copy mode */ + "cmp %2, %1\n\t" + "jb 2f\n\t" + + /* + * movs instruction have many startup latency + * so we handle small size by general register. + */ + "cmp $680, %0\n\t" + "jb 3f\n\t" + /* + * movs instruction is only good for aligned case. + */ + "mov %1, %3\n\t" + "xor %2, %3\n\t" + "and $0xff, %3\n\t" + "jz 4f\n\t" + "3:\n\t" + "sub $0x10, %0\n\t" + + /* + * We gobble 16 bytes forward in each loop. + */ + "3:\n\t" + "sub $0x10, %0\n\t" + "mov 0*4(%1), %3\n\t" + "mov 1*4(%1), %4\n\t" + "mov %3, 0*4(%2)\n\t" + "mov %4, 1*4(%2)\n\t" + "mov 2*4(%1), %3\n\t" + "mov 3*4(%1), %4\n\t" + "mov %3, 2*4(%2)\n\t" + "mov %4, 3*4(%2)\n\t" + "lea 0x10(%1), %1\n\t" + "lea 0x10(%2), %2\n\t" + "jae 3b\n\t" + "add $0x10, %0\n\t" + "jmp 1f\n\t" + + /* + * Handle data forward by movs. + */ + ".p2align 4\n\t" + "4:\n\t" + "mov -4(%1, %0), %3\n\t" + "lea -4(%2, %0), %4\n\t" + "shr $2, %0\n\t" + "rep movsl\n\t" + "mov %3, (%4)\n\t" + "jmp 11f\n\t" + /* + * Handle data backward by movs. + */ + ".p2align 4\n\t" + "6:\n\t" + "mov (%1), %3\n\t" + "mov %2, %4\n\t" + "lea -4(%1, %0), %1\n\t" + "lea -4(%2, %0), %2\n\t" + "shr $2, %0\n\t" + "std\n\t" + "rep movsl\n\t" + "mov %3,(%4)\n\t" + "cld\n\t" + "jmp 11f\n\t" + + /* + * Start to prepare for backward copy. + */ + ".p2align 4\n\t" + "2:\n\t" + "cmp $680, %0\n\t" + "jb 5f\n\t" + "mov %1, %3\n\t" + "xor %2, %3\n\t" + "and $0xff, %3\n\t" + "jz 6b\n\t" + + /* + * Calculate copy position to tail. + */ + "5:\n\t" + "add %0, %1\n\t" + "add %0, %2\n\t" + "sub $0x10, %0\n\t" + + /* + * We gobble 16 bytes backward in each loop. + */ + "7:\n\t" + "sub $0x10, %0\n\t" + + "mov -1*4(%1), %3\n\t" + "mov -2*4(%1), %4\n\t" + "mov %3, -1*4(%2)\n\t" + "mov %4, -2*4(%2)\n\t" + "mov -3*4(%1), %3\n\t" + "mov -4*4(%1), %4\n\t" + "mov %3, -3*4(%2)\n\t" + "mov %4, -4*4(%2)\n\t" + "lea -0x10(%1), %1\n\t" + "lea -0x10(%2), %2\n\t" + "jae 7b\n\t" + /* + * Calculate copy position to head. + */ + "add $0x10, %0\n\t" + "sub %0, %1\n\t" + "sub %0, %2\n\t" + + /* + * Move data from 8 bytes to 15 bytes. + */ + ".p2align 4\n\t" + "1:\n\t" + "cmp $8, %0\n\t" + "jb 8f\n\t" + "mov 0*4(%1), %3\n\t" + "mov 1*4(%1), %4\n\t" + "mov -2*4(%1, %0), %5\n\t" + "mov -1*4(%1, %0), %1\n\t" + + "mov %3, 0*4(%2)\n\t" + "mov %4, 1*4(%2)\n\t" + "mov %5, -2*4(%2, %0)\n\t" + "mov %1, -1*4(%2, %0)\n\t" + "jmp 11f\n\t" + + /* + * Move data from 4 bytes to 7 bytes. + */ + ".p2align 4\n\t" + "8:\n\t" + "cmp $4, %0\n\t" + "jb 9f\n\t" + "mov 0*4(%1), %3\n\t" + "mov -1*4(%1, %0), %4\n\t" + "mov %3, 0*4(%2)\n\t" + "mov %4, -1*4(%2, %0)\n\t" + "jmp 11f\n\t" + + /* + * Move data from 2 bytes to 3 bytes. + */ + ".p2align 4\n\t" + "9:\n\t" + "cmp $2, %0\n\t" + "jb 10f\n\t" + "movw 0*2(%1), %%dx\n\t" + "movw -1*2(%1, %0), %%bx\n\t" + "movw %%dx, 0*2(%2)\n\t" + "movw %%bx, -1*2(%2, %0)\n\t" + "jmp 11f\n\t" + + /* + * Move data for 1 byte. + */ + ".p2align 4\n\t" + "10:\n\t" + "cmp $1, %0\n\t" + "jb 11f\n\t" + "movb (%1), %%cl\n\t" + "movb %%cl, (%2)\n\t" + ".p2align 4\n\t" + "11:" + : "=&c" (d0), "=&S" (d1), "=&D" (d2), + "=r" (d3), "=r" (d4), "=r"(d5) + : "0" (n), + "1" (src), + "2" (dest) + : "memory"); + + return ret; +}