/* SPDX-License-Identifier: GPL-2.0-only */ /* * This file is derived from memcpy_32.c in the Linux kernel. */ #include <string.h> #include <stdbool.h> #include <asan.h> void *memmove(void *dest, const void *src, size_t n) { int d0, d1, d2, d3, d4, d5; char *ret = dest; #if (ENV_SEPARATE_ROMSTAGE && CONFIG(ASAN_IN_ROMSTAGE)) || \ (ENV_RAMSTAGE && CONFIG(ASAN_IN_RAMSTAGE)) check_memory_region((unsigned long)src, n, false, _RET_IP_); check_memory_region((unsigned long)dest, n, true, _RET_IP_); #endif __asm__ __volatile__( /* Handle more 16bytes 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 16byts 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 16byts 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; }