1/* SPDX-License-Identifier: GPL-2.0 */ 2#include <linux/errno.h> 3#include <linux/linkage.h> 4#include <asm/asm-offsets.h> 5#include <asm/assembler.h> 6 7 .text 8/* 9 * Implementation of MPIDR_EL1 hash algorithm through shifting 10 * and OR'ing. 11 * 12 * @dst: register containing hash result 13 * @rs0: register containing affinity level 0 bit shift 14 * @rs1: register containing affinity level 1 bit shift 15 * @rs2: register containing affinity level 2 bit shift 16 * @rs3: register containing affinity level 3 bit shift 17 * @mpidr: register containing MPIDR_EL1 value 18 * @mask: register containing MPIDR mask 19 * 20 * Pseudo C-code: 21 * 22 *u32 dst; 23 * 24 *compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 rs3, u64 mpidr, u64 mask) { 25 * u32 aff0, aff1, aff2, aff3; 26 * u64 mpidr_masked = mpidr & mask; 27 * aff0 = mpidr_masked & 0xff; 28 * aff1 = mpidr_masked & 0xff00; 29 * aff2 = mpidr_masked & 0xff0000; 30 * aff2 = mpidr_masked & 0xff00000000; 31 * dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2 | aff3 >> rs3); 32 *} 33 * Input registers: rs0, rs1, rs2, rs3, mpidr, mask 34 * Output register: dst 35 * Note: input and output registers must be disjoint register sets 36 (eg: a macro instance with mpidr = x1 and dst = x1 is invalid) 37 */ 38 .macro compute_mpidr_hash dst, rs0, rs1, rs2, rs3, mpidr, mask 39 and \mpidr, \mpidr, \mask // mask out MPIDR bits 40 and \dst, \mpidr, #0xff // mask=aff0 41 lsr \dst ,\dst, \rs0 // dst=aff0>>rs0 42 and \mask, \mpidr, #0xff00 // mask = aff1 43 lsr \mask ,\mask, \rs1 44 orr \dst, \dst, \mask // dst|=(aff1>>rs1) 45 and \mask, \mpidr, #0xff0000 // mask = aff2 46 lsr \mask ,\mask, \rs2 47 orr \dst, \dst, \mask // dst|=(aff2>>rs2) 48 and \mask, \mpidr, #0xff00000000 // mask = aff3 49 lsr \mask ,\mask, \rs3 50 orr \dst, \dst, \mask // dst|=(aff3>>rs3) 51 .endm 52/* 53 * Save CPU state in the provided sleep_stack_data area, and publish its 54 * location for cpu_resume()'s use in sleep_save_stash. 55 * 56 * cpu_resume() will restore this saved state, and return. Because the 57 * link-register is saved and restored, it will appear to return from this 58 * function. So that the caller can tell the suspend/resume paths apart, 59 * __cpu_suspend_enter() will always return a non-zero value, whereas the 60 * path through cpu_resume() will return 0. 61 * 62 * x0 = struct sleep_stack_data area 63 */ 64ENTRY(__cpu_suspend_enter) 65 stp x29, lr, [x0, #SLEEP_STACK_DATA_CALLEE_REGS] 66 stp x19, x20, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+16] 67 stp x21, x22, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+32] 68 stp x23, x24, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+48] 69 stp x25, x26, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+64] 70 stp x27, x28, [x0,#SLEEP_STACK_DATA_CALLEE_REGS+80] 71 72 /* save the sp in cpu_suspend_ctx */ 73 mov x2, sp 74 str x2, [x0, #SLEEP_STACK_DATA_SYSTEM_REGS + CPU_CTX_SP] 75 76 /* find the mpidr_hash */ 77 ldr_l x1, sleep_save_stash 78 mrs x7, mpidr_el1 79 adr_l x9, mpidr_hash 80 ldr x10, [x9, #MPIDR_HASH_MASK] 81 /* 82 * Following code relies on the struct mpidr_hash 83 * members size. 84 */ 85 ldp w3, w4, [x9, #MPIDR_HASH_SHIFTS] 86 ldp w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)] 87 compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10 88 add x1, x1, x8, lsl #3 89 90 str x0, [x1] 91 add x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS 92 stp x29, lr, [sp, #-16]! 93 bl cpu_do_suspend 94 ldp x29, lr, [sp], #16 95 mov x0, #1 96 ret 97ENDPROC(__cpu_suspend_enter) 98 99 .pushsection ".idmap.text", "awx" 100ENTRY(cpu_resume) 101 bl el2_setup // if in EL2 drop to EL1 cleanly 102 bl __cpu_setup 103 /* enable the MMU early - so we can access sleep_save_stash by va */ 104 adrp x1, swapper_pg_dir 105 bl __enable_mmu 106 ldr x8, =_cpu_resume 107 br x8 108ENDPROC(cpu_resume) 109 .ltorg 110 .popsection 111 112ENTRY(_cpu_resume) 113 mrs x1, mpidr_el1 114 adr_l x8, mpidr_hash // x8 = struct mpidr_hash virt address 115 116 /* retrieve mpidr_hash members to compute the hash */ 117 ldr x2, [x8, #MPIDR_HASH_MASK] 118 ldp w3, w4, [x8, #MPIDR_HASH_SHIFTS] 119 ldp w5, w6, [x8, #(MPIDR_HASH_SHIFTS + 8)] 120 compute_mpidr_hash x7, x3, x4, x5, x6, x1, x2 121 122 /* x7 contains hash index, let's use it to grab context pointer */ 123 ldr_l x0, sleep_save_stash 124 ldr x0, [x0, x7, lsl #3] 125 add x29, x0, #SLEEP_STACK_DATA_CALLEE_REGS 126 add x0, x0, #SLEEP_STACK_DATA_SYSTEM_REGS 127 /* load sp from context */ 128 ldr x2, [x0, #CPU_CTX_SP] 129 mov sp, x2 130 /* 131 * cpu_do_resume expects x0 to contain context address pointer 132 */ 133 bl cpu_do_resume 134 135#ifdef CONFIG_KASAN 136 mov x0, sp 137 bl kasan_unpoison_task_stack_below 138#endif 139 140 ldp x19, x20, [x29, #16] 141 ldp x21, x22, [x29, #32] 142 ldp x23, x24, [x29, #48] 143 ldp x25, x26, [x29, #64] 144 ldp x27, x28, [x29, #80] 145 ldp x29, lr, [x29] 146 mov x0, #0 147 ret 148ENDPROC(_cpu_resume) 149