1#include <linux/errno.h> 2#include <linux/linkage.h> 3#include <asm/asm-offsets.h> 4#include <asm/assembler.h> 5 6 .text 7/* 8 * Implementation of MPIDR_EL1 hash algorithm through shifting 9 * and OR'ing. 10 * 11 * @dst: register containing hash result 12 * @rs0: register containing affinity level 0 bit shift 13 * @rs1: register containing affinity level 1 bit shift 14 * @rs2: register containing affinity level 2 bit shift 15 * @rs3: register containing affinity level 3 bit shift 16 * @mpidr: register containing MPIDR_EL1 value 17 * @mask: register containing MPIDR mask 18 * 19 * Pseudo C-code: 20 * 21 *u32 dst; 22 * 23 *compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 rs3, u64 mpidr, u64 mask) { 24 * u32 aff0, aff1, aff2, aff3; 25 * u64 mpidr_masked = mpidr & mask; 26 * aff0 = mpidr_masked & 0xff; 27 * aff1 = mpidr_masked & 0xff00; 28 * aff2 = mpidr_masked & 0xff0000; 29 * aff2 = mpidr_masked & 0xff00000000; 30 * dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2 | aff3 >> rs3); 31 *} 32 * Input registers: rs0, rs1, rs2, rs3, mpidr, mask 33 * Output register: dst 34 * Note: input and output registers must be disjoint register sets 35 (eg: a macro instance with mpidr = x1 and dst = x1 is invalid) 36 */ 37 .macro compute_mpidr_hash dst, rs0, rs1, rs2, rs3, mpidr, mask 38 and \mpidr, \mpidr, \mask // mask out MPIDR bits 39 and \dst, \mpidr, #0xff // mask=aff0 40 lsr \dst ,\dst, \rs0 // dst=aff0>>rs0 41 and \mask, \mpidr, #0xff00 // mask = aff1 42 lsr \mask ,\mask, \rs1 43 orr \dst, \dst, \mask // dst|=(aff1>>rs1) 44 and \mask, \mpidr, #0xff0000 // mask = aff2 45 lsr \mask ,\mask, \rs2 46 orr \dst, \dst, \mask // dst|=(aff2>>rs2) 47 and \mask, \mpidr, #0xff00000000 // mask = aff3 48 lsr \mask ,\mask, \rs3 49 orr \dst, \dst, \mask // dst|=(aff3>>rs3) 50 .endm 51/* 52 * Save CPU state for a suspend and execute the suspend finisher. 53 * On success it will return 0 through cpu_resume - ie through a CPU 54 * soft/hard reboot from the reset vector. 55 * On failure it returns the suspend finisher return value or force 56 * -EOPNOTSUPP if the finisher erroneously returns 0 (the suspend finisher 57 * is not allowed to return, if it does this must be considered failure). 58 * It saves callee registers, and allocates space on the kernel stack 59 * to save the CPU specific registers + some other data for resume. 60 * 61 * x0 = suspend finisher argument 62 * x1 = suspend finisher function pointer 63 */ 64ENTRY(__cpu_suspend_enter) 65 stp x29, lr, [sp, #-96]! 66 stp x19, x20, [sp,#16] 67 stp x21, x22, [sp,#32] 68 stp x23, x24, [sp,#48] 69 stp x25, x26, [sp,#64] 70 stp x27, x28, [sp,#80] 71 /* 72 * Stash suspend finisher and its argument in x20 and x19 73 */ 74 mov x19, x0 75 mov x20, x1 76 mov x2, sp 77 sub sp, sp, #CPU_SUSPEND_SZ // allocate cpu_suspend_ctx 78 mov x0, sp 79 /* 80 * x0 now points to struct cpu_suspend_ctx allocated on the stack 81 */ 82 str x2, [x0, #CPU_CTX_SP] 83 ldr x1, =sleep_save_sp 84 ldr x1, [x1, #SLEEP_SAVE_SP_VIRT] 85#ifdef CONFIG_SMP 86 mrs x7, mpidr_el1 87 ldr x9, =mpidr_hash 88 ldr x10, [x9, #MPIDR_HASH_MASK] 89 /* 90 * Following code relies on the struct mpidr_hash 91 * members size. 92 */ 93 ldp w3, w4, [x9, #MPIDR_HASH_SHIFTS] 94 ldp w5, w6, [x9, #(MPIDR_HASH_SHIFTS + 8)] 95 compute_mpidr_hash x8, x3, x4, x5, x6, x7, x10 96 add x1, x1, x8, lsl #3 97#endif 98 bl __cpu_suspend_save 99 /* 100 * Grab suspend finisher in x20 and its argument in x19 101 */ 102 mov x0, x19 103 mov x1, x20 104 /* 105 * We are ready for power down, fire off the suspend finisher 106 * in x1, with argument in x0 107 */ 108 blr x1 109 /* 110 * Never gets here, unless suspend finisher fails. 111 * Successful cpu_suspend should return from cpu_resume, returning 112 * through this code path is considered an error 113 * If the return value is set to 0 force x0 = -EOPNOTSUPP 114 * to make sure a proper error condition is propagated 115 */ 116 cmp x0, #0 117 mov x3, #-EOPNOTSUPP 118 csel x0, x3, x0, eq 119 add sp, sp, #CPU_SUSPEND_SZ // rewind stack pointer 120 ldp x19, x20, [sp, #16] 121 ldp x21, x22, [sp, #32] 122 ldp x23, x24, [sp, #48] 123 ldp x25, x26, [sp, #64] 124 ldp x27, x28, [sp, #80] 125 ldp x29, lr, [sp], #96 126 ret 127ENDPROC(__cpu_suspend_enter) 128 .ltorg 129 130/* 131 * x0 must contain the sctlr value retrieved from restored context 132 */ 133 .pushsection ".idmap.text", "ax" 134ENTRY(cpu_resume_mmu) 135 ldr x3, =cpu_resume_after_mmu 136 msr sctlr_el1, x0 // restore sctlr_el1 137 isb 138 br x3 // global jump to virtual address 139ENDPROC(cpu_resume_mmu) 140 .popsection 141cpu_resume_after_mmu: 142 mov x0, #0 // return zero on success 143 ldp x19, x20, [sp, #16] 144 ldp x21, x22, [sp, #32] 145 ldp x23, x24, [sp, #48] 146 ldp x25, x26, [sp, #64] 147 ldp x27, x28, [sp, #80] 148 ldp x29, lr, [sp], #96 149 ret 150ENDPROC(cpu_resume_after_mmu) 151 152ENTRY(cpu_resume) 153 bl el2_setup // if in EL2 drop to EL1 cleanly 154#ifdef CONFIG_SMP 155 mrs x1, mpidr_el1 156 adrp x8, mpidr_hash 157 add x8, x8, #:lo12:mpidr_hash // x8 = struct mpidr_hash phys address 158 /* retrieve mpidr_hash members to compute the hash */ 159 ldr x2, [x8, #MPIDR_HASH_MASK] 160 ldp w3, w4, [x8, #MPIDR_HASH_SHIFTS] 161 ldp w5, w6, [x8, #(MPIDR_HASH_SHIFTS + 8)] 162 compute_mpidr_hash x7, x3, x4, x5, x6, x1, x2 163 /* x7 contains hash index, let's use it to grab context pointer */ 164#else 165 mov x7, xzr 166#endif 167 ldr_l x0, sleep_save_sp + SLEEP_SAVE_SP_PHYS 168 ldr x0, [x0, x7, lsl #3] 169 /* load sp from context */ 170 ldr x2, [x0, #CPU_CTX_SP] 171 /* load physical address of identity map page table in x1 */ 172 adrp x1, idmap_pg_dir 173 mov sp, x2 174 /* 175 * cpu_do_resume expects x0 to contain context physical address 176 * pointer and x1 to contain physical address of 1:1 page tables 177 */ 178 bl cpu_do_resume // PC relative jump, MMU off 179 b cpu_resume_mmu // Resume MMU, never returns 180ENDPROC(cpu_resume) 181