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1/* SPDX-License-Identifier: GPL-2.0 */2#include <linux/linkage.h>3 4#define R0 0x005#define R1 0x086#define R2 0x107#define R3 0x188#define R4 0x209#define R5 0x2810#define R6 0x3011#define R7 0x3812#define R8 0x4013#define R9 0x4814#define SL 0x5015#define FP 0x5816#define IP 0x6017#define SP 0x6818#define LR 0x7019#define PC 0x7820 21/*22 * Implementation of void perf_regs_load(u64 *regs);23 *24 * This functions fills in the 'regs' buffer from the actual registers values,25 * in the way the perf built-in unwinding test expects them:26 * - the PC at the time at the call to this function. Since this function27 * is called using a bl instruction, the PC value is taken from LR.28 * The built-in unwinding test then unwinds the call stack from the dwarf29 * information in unwind__get_entries.30 *31 * Notes:32 * - the 8 bytes stride in the registers offsets comes from the fact33 * that the registers are stored in an u64 array (u64 *regs),34 * - the regs buffer needs to be zeroed before the call to this function,35 * in this case using a calloc in dwarf-unwind.c.36 */37 38.text39.type perf_regs_load,%function40SYM_FUNC_START(perf_regs_load)41 str r0, [r0, #R0]42 str r1, [r0, #R1]43 str r2, [r0, #R2]44 str r3, [r0, #R3]45 str r4, [r0, #R4]46 str r5, [r0, #R5]47 str r6, [r0, #R6]48 str r7, [r0, #R7]49 str r8, [r0, #R8]50 str r9, [r0, #R9]51 str sl, [r0, #SL]52 str fp, [r0, #FP]53 str ip, [r0, #IP]54 str sp, [r0, #SP]55 str lr, [r0, #LR]56 str lr, [r0, #PC] // store pc as lr in order to skip the call57 // to this function58 mov pc, lr59SYM_FUNC_END(perf_regs_load)60