1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * This file contains miscellaneous low-level functions. 4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 5 * 6 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu) 7 * and Paul Mackerras. 8 * 9 */ 10 11#include <linux/export.h> 12#include <linux/sys.h> 13#include <asm/unistd.h> 14#include <asm/errno.h> 15#include <asm/reg.h> 16#include <asm/page.h> 17#include <asm/cache.h> 18#include <asm/cputable.h> 19#include <asm/mmu.h> 20#include <asm/ppc_asm.h> 21#include <asm/thread_info.h> 22#include <asm/asm-offsets.h> 23#include <asm/processor.h> 24#include <asm/bug.h> 25#include <asm/ptrace.h> 26#include <asm/feature-fixups.h> 27 28 .text 29 30/* 31 * This returns the high 64 bits of the product of two 64-bit numbers. 32 */ 33_GLOBAL(mulhdu) 34 cmpwi r6,0 35 cmpwi cr1,r3,0 36 mr r10,r4 37 mulhwu r4,r4,r5 38 beq 1f 39 mulhwu r0,r10,r6 40 mullw r7,r10,r5 41 addc r7,r0,r7 42 addze r4,r4 431: beqlr cr1 /* all done if high part of A is 0 */ 44 mullw r9,r3,r5 45 mulhwu r10,r3,r5 46 beq 2f 47 mullw r0,r3,r6 48 mulhwu r8,r3,r6 49 addc r7,r0,r7 50 adde r4,r4,r8 51 addze r10,r10 522: addc r4,r4,r9 53 addze r3,r10 54 blr 55 56/* 57 * reloc_got2 runs through the .got2 section adding an offset 58 * to each entry. 59 */ 60_GLOBAL(reloc_got2) 61 mflr r11 62 lis r7,__got2_start@ha 63 addi r7,r7,__got2_start@l 64 lis r8,__got2_end@ha 65 addi r8,r8,__got2_end@l 66 subf r8,r7,r8 67 srwi. r8,r8,2 68 beqlr 69 mtctr r8 70 bcl 20,31,$+4 711: mflr r0 72 lis r4,1b@ha 73 addi r4,r4,1b@l 74 subf r0,r4,r0 75 add r7,r0,r7 762: lwz r0,0(r7) 77 add r0,r0,r3 78 stw r0,0(r7) 79 addi r7,r7,4 80 bdnz 2b 81 mtlr r11 82 blr 83 84/* 85 * call_setup_cpu - call the setup_cpu function for this cpu 86 * r3 = data offset, r24 = cpu number 87 * 88 * Setup function is called with: 89 * r3 = data offset 90 * r4 = ptr to CPU spec (relocated) 91 */ 92_GLOBAL(call_setup_cpu) 93 addis r4,r3,cur_cpu_spec@ha 94 addi r4,r4,cur_cpu_spec@l 95 lwz r4,0(r4) 96 add r4,r4,r3 97 lwz r5,CPU_SPEC_SETUP(r4) 98 cmpwi 0,r5,0 99 add r5,r5,r3 100 beqlr 101 mtctr r5 102 bctr 103 104#if defined(CONFIG_CPU_FREQ_PMAC) && defined(CONFIG_PPC_BOOK3S_32) 105 106/* This gets called by via-pmu.c to switch the PLL selection 107 * on 750fx CPU. This function should really be moved to some 108 * other place (as most of the cpufreq code in via-pmu 109 */ 110_GLOBAL(low_choose_750fx_pll) 111 /* Clear MSR:EE */ 112 mfmsr r7 113 rlwinm r0,r7,0,17,15 114 mtmsr r0 115 116 /* If switching to PLL1, disable HID0:BTIC */ 117 cmplwi cr0,r3,0 118 beq 1f 119 mfspr r5,SPRN_HID0 120 rlwinm r5,r5,0,27,25 121 sync 122 mtspr SPRN_HID0,r5 123 isync 124 sync 125 1261: 127 /* Calc new HID1 value */ 128 mfspr r4,SPRN_HID1 /* Build a HID1:PS bit from parameter */ 129 rlwinm r5,r3,16,15,15 /* Clear out HID1:PS from value read */ 130 rlwinm r4,r4,0,16,14 /* Could have I used rlwimi here ? */ 131 or r4,r4,r5 132 mtspr SPRN_HID1,r4 133 134#ifdef CONFIG_SMP 135 /* Store new HID1 image */ 136 lwz r6,TASK_CPU(r2) 137 slwi r6,r6,2 138#else 139 li r6, 0 140#endif 141 addis r6,r6,nap_save_hid1@ha 142 stw r4,nap_save_hid1@l(r6) 143 144 /* If switching to PLL0, enable HID0:BTIC */ 145 cmplwi cr0,r3,0 146 bne 1f 147 mfspr r5,SPRN_HID0 148 ori r5,r5,HID0_BTIC 149 sync 150 mtspr SPRN_HID0,r5 151 isync 152 sync 153 1541: 155 /* Return */ 156 mtmsr r7 157 blr 158 159_GLOBAL(low_choose_7447a_dfs) 160 /* Clear MSR:EE */ 161 mfmsr r7 162 rlwinm r0,r7,0,17,15 163 mtmsr r0 164 165 /* Calc new HID1 value */ 166 mfspr r4,SPRN_HID1 167 insrwi r4,r3,1,9 /* insert parameter into bit 9 */ 168 sync 169 mtspr SPRN_HID1,r4 170 sync 171 isync 172 173 /* Return */ 174 mtmsr r7 175 blr 176 177#endif /* CONFIG_CPU_FREQ_PMAC && CONFIG_PPC_BOOK3S_32 */ 178 179/* 180 * Copy a whole page. We use the dcbz instruction on the destination 181 * to reduce memory traffic (it eliminates the unnecessary reads of 182 * the destination into cache). This requires that the destination 183 * is cacheable. 184 */ 185#define COPY_16_BYTES \ 186 lwz r6,4(r4); \ 187 lwz r7,8(r4); \ 188 lwz r8,12(r4); \ 189 lwzu r9,16(r4); \ 190 stw r6,4(r3); \ 191 stw r7,8(r3); \ 192 stw r8,12(r3); \ 193 stwu r9,16(r3) 194 195_GLOBAL(copy_page) 196 rlwinm r5, r3, 0, L1_CACHE_BYTES - 1 197 addi r3,r3,-4 198 1990: twnei r5, 0 /* WARN if r3 is not cache aligned */ 200 EMIT_WARN_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING 201 202 addi r4,r4,-4 203 204 li r5,4 205 206#if MAX_COPY_PREFETCH > 1 207 li r0,MAX_COPY_PREFETCH 208 li r11,4 209 mtctr r0 21011: dcbt r11,r4 211 addi r11,r11,L1_CACHE_BYTES 212 bdnz 11b 213#else /* MAX_COPY_PREFETCH == 1 */ 214 dcbt r5,r4 215 li r11,L1_CACHE_BYTES+4 216#endif /* MAX_COPY_PREFETCH */ 217 li r0,PAGE_SIZE/L1_CACHE_BYTES - MAX_COPY_PREFETCH 218 crclr 4*cr0+eq 2192: 220 mtctr r0 2211: 222 dcbt r11,r4 223 dcbz r5,r3 224 COPY_16_BYTES 225#if L1_CACHE_BYTES >= 32 226 COPY_16_BYTES 227#if L1_CACHE_BYTES >= 64 228 COPY_16_BYTES 229 COPY_16_BYTES 230#if L1_CACHE_BYTES >= 128 231 COPY_16_BYTES 232 COPY_16_BYTES 233 COPY_16_BYTES 234 COPY_16_BYTES 235#endif 236#endif 237#endif 238 bdnz 1b 239 beqlr 240 crnot 4*cr0+eq,4*cr0+eq 241 li r0,MAX_COPY_PREFETCH 242 li r11,4 243 b 2b 244EXPORT_SYMBOL(copy_page) 245 246/* 247 * Extended precision shifts. 248 * 249 * Updated to be valid for shift counts from 0 to 63 inclusive. 250 * -- Gabriel 251 * 252 * R3/R4 has 64 bit value 253 * R5 has shift count 254 * result in R3/R4 255 * 256 * ashrdi3: arithmetic right shift (sign propagation) 257 * lshrdi3: logical right shift 258 * ashldi3: left shift 259 */ 260_GLOBAL(__ashrdi3) 261 subfic r6,r5,32 262 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count 263 addi r7,r5,32 # could be xori, or addi with -32 264 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) 265 rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0 266 sraw r7,r3,r7 # t2 = MSW >> (count-32) 267 or r4,r4,r6 # LSW |= t1 268 slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2 269 sraw r3,r3,r5 # MSW = MSW >> count 270 or r4,r4,r7 # LSW |= t2 271 blr 272EXPORT_SYMBOL(__ashrdi3) 273 274_GLOBAL(__ashldi3) 275 subfic r6,r5,32 276 slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count 277 addi r7,r5,32 # could be xori, or addi with -32 278 srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count) 279 slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32) 280 or r3,r3,r6 # MSW |= t1 281 slw r4,r4,r5 # LSW = LSW << count 282 or r3,r3,r7 # MSW |= t2 283 blr 284EXPORT_SYMBOL(__ashldi3) 285 286_GLOBAL(__lshrdi3) 287 subfic r6,r5,32 288 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count 289 addi r7,r5,32 # could be xori, or addi with -32 290 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) 291 srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32) 292 or r4,r4,r6 # LSW |= t1 293 srw r3,r3,r5 # MSW = MSW >> count 294 or r4,r4,r7 # LSW |= t2 295 blr 296EXPORT_SYMBOL(__lshrdi3) 297 298/* 299 * 64-bit comparison: __cmpdi2(s64 a, s64 b) 300 * Returns 0 if a < b, 1 if a == b, 2 if a > b. 301 */ 302_GLOBAL(__cmpdi2) 303 cmpw r3,r5 304 li r3,1 305 bne 1f 306 cmplw r4,r6 307 beqlr 3081: li r3,0 309 bltlr 310 li r3,2 311 blr 312EXPORT_SYMBOL(__cmpdi2) 313/* 314 * 64-bit comparison: __ucmpdi2(u64 a, u64 b) 315 * Returns 0 if a < b, 1 if a == b, 2 if a > b. 316 */ 317_GLOBAL(__ucmpdi2) 318 cmplw r3,r5 319 li r3,1 320 bne 1f 321 cmplw r4,r6 322 beqlr 3231: li r3,0 324 bltlr 325 li r3,2 326 blr 327EXPORT_SYMBOL(__ucmpdi2) 328 329_GLOBAL(__bswapdi2) 330 rotlwi r9,r4,8 331 rotlwi r10,r3,8 332 rlwimi r9,r4,24,0,7 333 rlwimi r10,r3,24,0,7 334 rlwimi r9,r4,24,16,23 335 rlwimi r10,r3,24,16,23 336 mr r3,r9 337 mr r4,r10 338 blr 339EXPORT_SYMBOL(__bswapdi2) 340 341#ifdef CONFIG_SMP 342_GLOBAL(start_secondary_resume) 343 /* Reset stack */ 344 rlwinm r1, r1, 0, 0, 31 - THREAD_SHIFT 345 addi r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE 346 li r3,0 347 stw r3,0(r1) /* Zero the stack frame pointer */ 348 bl start_secondary 349 b . 350#endif /* CONFIG_SMP */ 351