162306a36Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 262306a36Sopenharmony_ci#include <linux/linkage.h> 362306a36Sopenharmony_ci 462306a36Sopenharmony_ci#define R0 0x00 562306a36Sopenharmony_ci#define R1 0x08 662306a36Sopenharmony_ci#define R2 0x10 762306a36Sopenharmony_ci#define R3 0x18 862306a36Sopenharmony_ci#define R4 0x20 962306a36Sopenharmony_ci#define R5 0x28 1062306a36Sopenharmony_ci#define R6 0x30 1162306a36Sopenharmony_ci#define R7 0x38 1262306a36Sopenharmony_ci#define R8 0x40 1362306a36Sopenharmony_ci#define R9 0x48 1462306a36Sopenharmony_ci#define SL 0x50 1562306a36Sopenharmony_ci#define FP 0x58 1662306a36Sopenharmony_ci#define IP 0x60 1762306a36Sopenharmony_ci#define SP 0x68 1862306a36Sopenharmony_ci#define LR 0x70 1962306a36Sopenharmony_ci#define PC 0x78 2062306a36Sopenharmony_ci 2162306a36Sopenharmony_ci/* 2262306a36Sopenharmony_ci * Implementation of void perf_regs_load(u64 *regs); 2362306a36Sopenharmony_ci * 2462306a36Sopenharmony_ci * This functions fills in the 'regs' buffer from the actual registers values, 2562306a36Sopenharmony_ci * in the way the perf built-in unwinding test expects them: 2662306a36Sopenharmony_ci * - the PC at the time at the call to this function. Since this function 2762306a36Sopenharmony_ci * is called using a bl instruction, the PC value is taken from LR. 2862306a36Sopenharmony_ci * The built-in unwinding test then unwinds the call stack from the dwarf 2962306a36Sopenharmony_ci * information in unwind__get_entries. 3062306a36Sopenharmony_ci * 3162306a36Sopenharmony_ci * Notes: 3262306a36Sopenharmony_ci * - the 8 bytes stride in the registers offsets comes from the fact 3362306a36Sopenharmony_ci * that the registers are stored in an u64 array (u64 *regs), 3462306a36Sopenharmony_ci * - the regs buffer needs to be zeroed before the call to this function, 3562306a36Sopenharmony_ci * in this case using a calloc in dwarf-unwind.c. 3662306a36Sopenharmony_ci */ 3762306a36Sopenharmony_ci 3862306a36Sopenharmony_ci.text 3962306a36Sopenharmony_ci.type perf_regs_load,%function 4062306a36Sopenharmony_ciSYM_FUNC_START(perf_regs_load) 4162306a36Sopenharmony_ci str r0, [r0, #R0] 4262306a36Sopenharmony_ci str r1, [r0, #R1] 4362306a36Sopenharmony_ci str r2, [r0, #R2] 4462306a36Sopenharmony_ci str r3, [r0, #R3] 4562306a36Sopenharmony_ci str r4, [r0, #R4] 4662306a36Sopenharmony_ci str r5, [r0, #R5] 4762306a36Sopenharmony_ci str r6, [r0, #R6] 4862306a36Sopenharmony_ci str r7, [r0, #R7] 4962306a36Sopenharmony_ci str r8, [r0, #R8] 5062306a36Sopenharmony_ci str r9, [r0, #R9] 5162306a36Sopenharmony_ci str sl, [r0, #SL] 5262306a36Sopenharmony_ci str fp, [r0, #FP] 5362306a36Sopenharmony_ci str ip, [r0, #IP] 5462306a36Sopenharmony_ci str sp, [r0, #SP] 5562306a36Sopenharmony_ci str lr, [r0, #LR] 5662306a36Sopenharmony_ci str lr, [r0, #PC] // store pc as lr in order to skip the call 5762306a36Sopenharmony_ci // to this function 5862306a36Sopenharmony_ci mov pc, lr 5962306a36Sopenharmony_ciSYM_FUNC_END(perf_regs_load) 60