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/sys.h> 12#include <asm/unistd.h> 13#include <asm/errno.h> 14#include <asm/reg.h> 15#include <asm/page.h> 16#include <asm/cache.h> 17#include <asm/cputable.h> 18#include <asm/mmu.h> 19#include <asm/ppc_asm.h> 20#include <asm/thread_info.h> 21#include <asm/asm-offsets.h> 22#include <asm/processor.h> 23#include <asm/bug.h> 24#include <asm/ptrace.h> 25#include <asm/export.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#ifdef CONFIG_40x 180 181/* 182 * Do an IO access in real mode 183 */ 184_GLOBAL(real_readb) 185 mfmsr r7 186 rlwinm r0,r7,0,~MSR_DR 187 sync 188 mtmsr r0 189 sync 190 isync 191 lbz r3,0(r3) 192 sync 193 mtmsr r7 194 sync 195 isync 196 blr 197_ASM_NOKPROBE_SYMBOL(real_readb) 198 199 /* 200 * Do an IO access in real mode 201 */ 202_GLOBAL(real_writeb) 203 mfmsr r7 204 rlwinm r0,r7,0,~MSR_DR 205 sync 206 mtmsr r0 207 sync 208 isync 209 stb r3,0(r4) 210 sync 211 mtmsr r7 212 sync 213 isync 214 blr 215_ASM_NOKPROBE_SYMBOL(real_writeb) 216 217#endif /* CONFIG_40x */ 218 219/* 220 * Copy a whole page. We use the dcbz instruction on the destination 221 * to reduce memory traffic (it eliminates the unnecessary reads of 222 * the destination into cache). This requires that the destination 223 * is cacheable. 224 */ 225#define COPY_16_BYTES \ 226 lwz r6,4(r4); \ 227 lwz r7,8(r4); \ 228 lwz r8,12(r4); \ 229 lwzu r9,16(r4); \ 230 stw r6,4(r3); \ 231 stw r7,8(r3); \ 232 stw r8,12(r3); \ 233 stwu r9,16(r3) 234 235_GLOBAL(copy_page) 236 rlwinm r5, r3, 0, L1_CACHE_BYTES - 1 237 addi r3,r3,-4 238 2390: twnei r5, 0 /* WARN if r3 is not cache aligned */ 240 EMIT_WARN_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING 241 242 addi r4,r4,-4 243 244 li r5,4 245 246#if MAX_COPY_PREFETCH > 1 247 li r0,MAX_COPY_PREFETCH 248 li r11,4 249 mtctr r0 25011: dcbt r11,r4 251 addi r11,r11,L1_CACHE_BYTES 252 bdnz 11b 253#else /* MAX_COPY_PREFETCH == 1 */ 254 dcbt r5,r4 255 li r11,L1_CACHE_BYTES+4 256#endif /* MAX_COPY_PREFETCH */ 257 li r0,PAGE_SIZE/L1_CACHE_BYTES - MAX_COPY_PREFETCH 258 crclr 4*cr0+eq 2592: 260 mtctr r0 2611: 262 dcbt r11,r4 263 dcbz r5,r3 264 COPY_16_BYTES 265#if L1_CACHE_BYTES >= 32 266 COPY_16_BYTES 267#if L1_CACHE_BYTES >= 64 268 COPY_16_BYTES 269 COPY_16_BYTES 270#if L1_CACHE_BYTES >= 128 271 COPY_16_BYTES 272 COPY_16_BYTES 273 COPY_16_BYTES 274 COPY_16_BYTES 275#endif 276#endif 277#endif 278 bdnz 1b 279 beqlr 280 crnot 4*cr0+eq,4*cr0+eq 281 li r0,MAX_COPY_PREFETCH 282 li r11,4 283 b 2b 284EXPORT_SYMBOL(copy_page) 285 286/* 287 * Extended precision shifts. 288 * 289 * Updated to be valid for shift counts from 0 to 63 inclusive. 290 * -- Gabriel 291 * 292 * R3/R4 has 64 bit value 293 * R5 has shift count 294 * result in R3/R4 295 * 296 * ashrdi3: arithmetic right shift (sign propagation) 297 * lshrdi3: logical right shift 298 * ashldi3: left shift 299 */ 300_GLOBAL(__ashrdi3) 301 subfic r6,r5,32 302 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count 303 addi r7,r5,32 # could be xori, or addi with -32 304 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) 305 rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0 306 sraw r7,r3,r7 # t2 = MSW >> (count-32) 307 or r4,r4,r6 # LSW |= t1 308 slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2 309 sraw r3,r3,r5 # MSW = MSW >> count 310 or r4,r4,r7 # LSW |= t2 311 blr 312EXPORT_SYMBOL(__ashrdi3) 313 314_GLOBAL(__ashldi3) 315 subfic r6,r5,32 316 slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count 317 addi r7,r5,32 # could be xori, or addi with -32 318 srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count) 319 slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32) 320 or r3,r3,r6 # MSW |= t1 321 slw r4,r4,r5 # LSW = LSW << count 322 or r3,r3,r7 # MSW |= t2 323 blr 324EXPORT_SYMBOL(__ashldi3) 325 326_GLOBAL(__lshrdi3) 327 subfic r6,r5,32 328 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count 329 addi r7,r5,32 # could be xori, or addi with -32 330 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) 331 srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32) 332 or r4,r4,r6 # LSW |= t1 333 srw r3,r3,r5 # MSW = MSW >> count 334 or r4,r4,r7 # LSW |= t2 335 blr 336EXPORT_SYMBOL(__lshrdi3) 337 338/* 339 * 64-bit comparison: __cmpdi2(s64 a, s64 b) 340 * Returns 0 if a < b, 1 if a == b, 2 if a > b. 341 */ 342_GLOBAL(__cmpdi2) 343 cmpw r3,r5 344 li r3,1 345 bne 1f 346 cmplw r4,r6 347 beqlr 3481: li r3,0 349 bltlr 350 li r3,2 351 blr 352EXPORT_SYMBOL(__cmpdi2) 353/* 354 * 64-bit comparison: __ucmpdi2(u64 a, u64 b) 355 * Returns 0 if a < b, 1 if a == b, 2 if a > b. 356 */ 357_GLOBAL(__ucmpdi2) 358 cmplw r3,r5 359 li r3,1 360 bne 1f 361 cmplw r4,r6 362 beqlr 3631: li r3,0 364 bltlr 365 li r3,2 366 blr 367EXPORT_SYMBOL(__ucmpdi2) 368 369_GLOBAL(__bswapdi2) 370 rotlwi r9,r4,8 371 rotlwi r10,r3,8 372 rlwimi r9,r4,24,0,7 373 rlwimi r10,r3,24,0,7 374 rlwimi r9,r4,24,16,23 375 rlwimi r10,r3,24,16,23 376 mr r3,r9 377 mr r4,r10 378 blr 379EXPORT_SYMBOL(__bswapdi2) 380 381#ifdef CONFIG_SMP 382_GLOBAL(start_secondary_resume) 383 /* Reset stack */ 384 rlwinm r1, r1, 0, 0, 31 - THREAD_SHIFT 385 addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD 386 li r3,0 387 stw r3,0(r1) /* Zero the stack frame pointer */ 388 bl start_secondary 389 b . 390#endif /* CONFIG_SMP */ 391