1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * linux/arch/arm/mm/proc-v6.S 4 * 5 * Copyright (C) 2001 Deep Blue Solutions Ltd. 6 * Modified by Catalin Marinas for noMMU support 7 * 8 * This is the "shell" of the ARMv6 processor support. 9 */ 10#include <linux/init.h> 11#include <linux/linkage.h> 12#include <asm/assembler.h> 13#include <asm/asm-offsets.h> 14#include <asm/hwcap.h> 15#include <asm/pgtable-hwdef.h> 16#include <asm/pgtable.h> 17 18#include "proc-macros.S" 19 20#define D_CACHE_LINE_SIZE 32 21 22#define TTB_C (1 << 0) 23#define TTB_S (1 << 1) 24#define TTB_IMP (1 << 2) 25#define TTB_RGN_NC (0 << 3) 26#define TTB_RGN_WBWA (1 << 3) 27#define TTB_RGN_WT (2 << 3) 28#define TTB_RGN_WB (3 << 3) 29 30#define TTB_FLAGS_UP TTB_RGN_WBWA 31#define PMD_FLAGS_UP PMD_SECT_WB 32#define TTB_FLAGS_SMP TTB_RGN_WBWA|TTB_S 33#define PMD_FLAGS_SMP PMD_SECT_WBWA|PMD_SECT_S 34 35ENTRY(cpu_v6_proc_init) 36 ret lr 37 38ENTRY(cpu_v6_proc_fin) 39 mrc p15, 0, r0, c1, c0, 0 @ ctrl register 40 bic r0, r0, #0x1000 @ ...i............ 41 bic r0, r0, #0x0006 @ .............ca. 42 mcr p15, 0, r0, c1, c0, 0 @ disable caches 43 ret lr 44 45/* 46 * cpu_v6_reset(loc) 47 * 48 * Perform a soft reset of the system. Put the CPU into the 49 * same state as it would be if it had been reset, and branch 50 * to what would be the reset vector. 51 * 52 * - loc - location to jump to for soft reset 53 */ 54 .align 5 55 .pushsection .idmap.text, "ax" 56ENTRY(cpu_v6_reset) 57 mrc p15, 0, r1, c1, c0, 0 @ ctrl register 58 bic r1, r1, #0x1 @ ...............m 59 mcr p15, 0, r1, c1, c0, 0 @ disable MMU 60 mov r1, #0 61 mcr p15, 0, r1, c7, c5, 4 @ ISB 62 ret r0 63ENDPROC(cpu_v6_reset) 64 .popsection 65 66/* 67 * cpu_v6_do_idle() 68 * 69 * Idle the processor (eg, wait for interrupt). 70 * 71 * IRQs are already disabled. 72 */ 73ENTRY(cpu_v6_do_idle) 74 mov r1, #0 75 mcr p15, 0, r1, c7, c10, 4 @ DWB - WFI may enter a low-power mode 76 mcr p15, 0, r1, c7, c0, 4 @ wait for interrupt 77 ret lr 78 79ENTRY(cpu_v6_dcache_clean_area) 801: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 81 add r0, r0, #D_CACHE_LINE_SIZE 82 subs r1, r1, #D_CACHE_LINE_SIZE 83 bhi 1b 84 ret lr 85 86/* 87 * cpu_v6_switch_mm(pgd_phys, tsk) 88 * 89 * Set the translation table base pointer to be pgd_phys 90 * 91 * - pgd_phys - physical address of new TTB 92 * 93 * It is assumed that: 94 * - we are not using split page tables 95 */ 96ENTRY(cpu_v6_switch_mm) 97#ifdef CONFIG_MMU 98 mov r2, #0 99 mmid r1, r1 @ get mm->context.id 100 ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP) 101 ALT_UP(orr r0, r0, #TTB_FLAGS_UP) 102 mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB 103 mcr p15, 0, r2, c7, c10, 4 @ drain write buffer 104 mcr p15, 0, r0, c2, c0, 0 @ set TTB 0 105#ifdef CONFIG_PID_IN_CONTEXTIDR 106 mrc p15, 0, r2, c13, c0, 1 @ read current context ID 107 bic r2, r2, #0xff @ extract the PID 108 and r1, r1, #0xff 109 orr r1, r1, r2 @ insert into new context ID 110#endif 111 mcr p15, 0, r1, c13, c0, 1 @ set context ID 112#endif 113 ret lr 114 115/* 116 * cpu_v6_set_pte_ext(ptep, pte, ext) 117 * 118 * Set a level 2 translation table entry. 119 * 120 * - ptep - pointer to level 2 translation table entry 121 * (hardware version is stored at -1024 bytes) 122 * - pte - PTE value to store 123 * - ext - value for extended PTE bits 124 */ 125 armv6_mt_table cpu_v6 126 127ENTRY(cpu_v6_set_pte_ext) 128#ifdef CONFIG_MMU 129 armv6_set_pte_ext cpu_v6 130#endif 131 ret lr 132 133/* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */ 134.globl cpu_v6_suspend_size 135.equ cpu_v6_suspend_size, 4 * 6 136#ifdef CONFIG_ARM_CPU_SUSPEND 137ENTRY(cpu_v6_do_suspend) 138 stmfd sp!, {r4 - r9, lr} 139 mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID 140#ifdef CONFIG_MMU 141 mrc p15, 0, r5, c3, c0, 0 @ Domain ID 142 mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1 143#endif 144 mrc p15, 0, r7, c1, c0, 1 @ auxiliary control register 145 mrc p15, 0, r8, c1, c0, 2 @ co-processor access control 146 mrc p15, 0, r9, c1, c0, 0 @ control register 147 stmia r0, {r4 - r9} 148 ldmfd sp!, {r4- r9, pc} 149ENDPROC(cpu_v6_do_suspend) 150 151ENTRY(cpu_v6_do_resume) 152 mov ip, #0 153 mcr p15, 0, ip, c7, c14, 0 @ clean+invalidate D cache 154 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache 155 mcr p15, 0, ip, c7, c15, 0 @ clean+invalidate cache 156 mcr p15, 0, ip, c7, c10, 4 @ drain write buffer 157 mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID 158 ldmia r0, {r4 - r9} 159 mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID 160#ifdef CONFIG_MMU 161 mcr p15, 0, r5, c3, c0, 0 @ Domain ID 162 ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP) 163 ALT_UP(orr r1, r1, #TTB_FLAGS_UP) 164 mcr p15, 0, r1, c2, c0, 0 @ Translation table base 0 165 mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1 166 mcr p15, 0, ip, c2, c0, 2 @ TTB control register 167#endif 168 mcr p15, 0, r7, c1, c0, 1 @ auxiliary control register 169 mcr p15, 0, r8, c1, c0, 2 @ co-processor access control 170 mcr p15, 0, ip, c7, c5, 4 @ ISB 171 mov r0, r9 @ control register 172 b cpu_resume_mmu 173ENDPROC(cpu_v6_do_resume) 174#endif 175 176 string cpu_v6_name, "ARMv6-compatible processor" 177 178 .align 179 180/* 181 * __v6_setup 182 * 183 * Initialise TLB, Caches, and MMU state ready to switch the MMU 184 * on. Return in r0 the new CP15 C1 control register setting. 185 * 186 * We automatically detect if we have a Harvard cache, and use the 187 * Harvard cache control instructions insead of the unified cache 188 * control instructions. 189 * 190 * This should be able to cover all ARMv6 cores. 191 * 192 * It is assumed that: 193 * - cache type register is implemented 194 */ 195__v6_setup: 196#ifdef CONFIG_SMP 197 ALT_SMP(mrc p15, 0, r0, c1, c0, 1) @ Enable SMP/nAMP mode 198 ALT_UP(nop) 199 orr r0, r0, #0x20 200 ALT_SMP(mcr p15, 0, r0, c1, c0, 1) 201 ALT_UP(nop) 202#endif 203 204 mov r0, #0 205 mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache 206 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 207 mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache 208#ifdef CONFIG_MMU 209 mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs 210 mcr p15, 0, r0, c2, c0, 2 @ TTB control register 211 ALT_SMP(orr r4, r4, #TTB_FLAGS_SMP) 212 ALT_UP(orr r4, r4, #TTB_FLAGS_UP) 213 ALT_SMP(orr r8, r8, #TTB_FLAGS_SMP) 214 ALT_UP(orr r8, r8, #TTB_FLAGS_UP) 215 mcr p15, 0, r8, c2, c0, 1 @ load TTB1 216#endif /* CONFIG_MMU */ 217 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer and 218 @ complete invalidations 219 adr r5, v6_crval 220 ldmia r5, {r5, r6} 221 ARM_BE8(orr r6, r6, #1 << 25) @ big-endian page tables 222 mrc p15, 0, r0, c1, c0, 0 @ read control register 223 bic r0, r0, r5 @ clear bits them 224 orr r0, r0, r6 @ set them 225#ifdef CONFIG_ARM_ERRATA_364296 226 /* 227 * Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data 228 * corruption with hit-under-miss enabled). The conditional code below 229 * (setting the undocumented bit 31 in the auxiliary control register 230 * and the FI bit in the control register) disables hit-under-miss 231 * without putting the processor into full low interrupt latency mode. 232 */ 233 ldr r6, =0x4107b362 @ id for ARM1136 r0p2 234 mrc p15, 0, r5, c0, c0, 0 @ get processor id 235 teq r5, r6 @ check for the faulty core 236 mrceq p15, 0, r5, c1, c0, 1 @ load aux control reg 237 orreq r5, r5, #(1 << 31) @ set the undocumented bit 31 238 mcreq p15, 0, r5, c1, c0, 1 @ write aux control reg 239 orreq r0, r0, #(1 << 21) @ low interrupt latency configuration 240#endif 241 ret lr @ return to head.S:__ret 242 243 /* 244 * V X F I D LR 245 * .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM 246 * rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced 247 * 0 110 0011 1.00 .111 1101 < we want 248 */ 249 .type v6_crval, #object 250v6_crval: 251 crval clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c 252 253 __INITDATA 254 255 @ define struct processor (see <asm/proc-fns.h> and proc-macros.S) 256 define_processor_functions v6, dabort=v6_early_abort, pabort=v6_pabort, suspend=1 257 258 .section ".rodata" 259 260 string cpu_arch_name, "armv6" 261 string cpu_elf_name, "v6" 262 .align 263 264 .section ".proc.info.init", #alloc 265 266 /* 267 * Match any ARMv6 processor core. 268 */ 269 .type __v6_proc_info, #object 270__v6_proc_info: 271 .long 0x0007b000 272 .long 0x0007f000 273 ALT_SMP(.long \ 274 PMD_TYPE_SECT | \ 275 PMD_SECT_AP_WRITE | \ 276 PMD_SECT_AP_READ | \ 277 PMD_FLAGS_SMP) 278 ALT_UP(.long \ 279 PMD_TYPE_SECT | \ 280 PMD_SECT_AP_WRITE | \ 281 PMD_SECT_AP_READ | \ 282 PMD_FLAGS_UP) 283 .long PMD_TYPE_SECT | \ 284 PMD_SECT_XN | \ 285 PMD_SECT_AP_WRITE | \ 286 PMD_SECT_AP_READ 287 initfn __v6_setup, __v6_proc_info 288 .long cpu_arch_name 289 .long cpu_elf_name 290 /* See also feat_v6_fixup() for HWCAP_TLS */ 291 .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA|HWCAP_TLS 292 .long cpu_v6_name 293 .long v6_processor_functions 294 .long v6wbi_tlb_fns 295 .long v6_user_fns 296 .long v6_cache_fns 297 .size __v6_proc_info, . - __v6_proc_info 298