1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 L2CR functions 4 Copyright © 1997-1998 by PowerLogix R & D, Inc. 5 6 */ 7 /* 8 Thur, Dec. 12, 1998. 9 - First public release, contributed by PowerLogix. 10 *********** 11 Sat, Aug. 7, 1999. 12 - Terry: Made sure code disabled interrupts before running. (Previously 13 it was assumed interrupts were already disabled). 14 - Terry: Updated for tentative G4 support. 4MB of memory is now flushed 15 instead of 2MB. (Prob. only 3 is necessary). 16 - Terry: Updated for workaround to HID0[DPM] processor bug 17 during global invalidates. 18 *********** 19 Thu, July 13, 2000. 20 - Terry: Added isync to correct for an errata. 21 22 22 August 2001. 23 - DanM: Finally added the 7450 patch I've had for the past 24 several months. The L2CR is similar, but I'm going 25 to assume the user of this functions knows what they 26 are doing. 27 28 Author: Terry Greeniaus (tgree@phys.ualberta.ca) 29 Please e-mail updates to this file to me, thanks! 30 */ 31 #include <asm/processor.h> 32 #include <asm/cputable.h> 33 #include <asm/ppc_asm.h> 34 #include <asm/cache.h> 35 #include <asm/page.h> 36 #include <asm/feature-fixups.h> 37 38 /* Usage: 39 40 When setting the L2CR register, you must do a few special 41 things. If you are enabling the cache, you must perform a 42 global invalidate. If you are disabling the cache, you must 43 flush the cache contents first. This routine takes care of 44 doing these things. When first enabling the cache, make sure 45 you pass in the L2CR you want, as well as passing in the 46 global invalidate bit set. A global invalidate will only be 47 performed if the L2I bit is set in applyThis. When enabling 48 the cache, you should also set the L2E bit in applyThis. If 49 you want to modify the L2CR contents after the cache has been 50 enabled, the recommended procedure is to first call 51 __setL2CR(0) to disable the cache and then call it again with 52 the new values for L2CR. Examples: 53 54 _setL2CR(0) - disables the cache 55 _setL2CR(0xB3A04000) - enables my G3 upgrade card: 56 - L2E set to turn on the cache 57 - L2SIZ set to 1MB 58 - L2CLK set to 1:1 59 - L2RAM set to pipelined synchronous late-write 60 - L2I set to perform a global invalidation 61 - L2OH set to 0.5 nS 62 - L2DF set because this upgrade card 63 requires it 64 65 A similar call should work for your card. You need to know 66 the correct setting for your card and then place them in the 67 fields I have outlined above. Other fields support optional 68 features, such as L2DO which caches only data, or L2TS which 69 causes cache pushes from the L1 cache to go to the L2 cache 70 instead of to main memory. 71 72 IMPORTANT: 73 Starting with the 7450, the bits in this register have moved 74 or behave differently. The Enable, Parity Enable, Size, 75 and L2 Invalidate are the only bits that have not moved. 76 The size is read-only for these processors with internal L2 77 cache, and the invalidate is a control as well as status. 78 -- Dan 79 80 */ 81 /* 82 * Summary: this procedure ignores the L2I bit in the value passed in, 83 * flushes the cache if it was already enabled, always invalidates the 84 * cache, then enables the cache if the L2E bit is set in the value 85 * passed in. 86 * -- paulus. 87 */ 88 _GLOBAL(_set_L2CR) 89 /* Make sure this is a 750 or 7400 chip */ 90 BEGIN_FTR_SECTION 91 li r3,-1 92 blr 93 END_FTR_SECTION_IFCLR(CPU_FTR_L2CR) 94 95 mflr r9 96 97 /* Stop DST streams */ 98 BEGIN_FTR_SECTION 99 DSSALL 100 sync 101 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) 102 103 /* Turn off interrupts and data relocation. */ 104 mfmsr r7 /* Save MSR in r7 */ 105 rlwinm r4,r7,0,17,15 106 rlwinm r4,r4,0,28,26 /* Turn off DR bit */ 107 sync 108 mtmsr r4 109 isync 110 111 /* Before we perform the global invalidation, we must disable dynamic 112 * power management via HID0[DPM] to work around a processor bug where 113 * DPM can possibly interfere with the state machine in the processor 114 * that invalidates the L2 cache tags. 115 */ 116 mfspr r8,SPRN_HID0 /* Save HID0 in r8 */ 117 rlwinm r4,r8,0,12,10 /* Turn off HID0[DPM] */ 118 sync 119 mtspr SPRN_HID0,r4 /* Disable DPM */ 120 sync 121 122 /* Get the current enable bit of the L2CR into r4 */ 123 mfspr r4,SPRN_L2CR 124 125 /* Tweak some bits */ 126 rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */ 127 rlwinm r3,r3,0,11,9 /* Turn off the invalidate bit */ 128 rlwinm r3,r3,0,1,31 /* Turn off the enable bit */ 129 130 /* Check to see if we need to flush */ 131 rlwinm. r4,r4,0,0,0 132 beq 2f 133 134 /* Flush the cache. First, read the first 4MB of memory (physical) to 135 * put new data in the cache. (Actually we only need 136 * the size of the L2 cache plus the size of the L1 cache, but 4MB will 137 * cover everything just to be safe). 138 */ 139 140 /**** Might be a good idea to set L2DO here - to prevent instructions 141 from getting into the cache. But since we invalidate 142 the next time we enable the cache it doesn't really matter. 143 Don't do this unless you accommodate all processor variations. 144 The bit moved on the 7450..... 145 ****/ 146 147 BEGIN_FTR_SECTION 148 /* Disable L2 prefetch on some 745x and try to ensure 149 * L2 prefetch engines are idle. As explained by errata 150 * text, we can't be sure they are, we just hope very hard 151 * that well be enough (sic !). At least I noticed Apple 152 * doesn't even bother doing the dcbf's here... 153 */ 154 mfspr r4,SPRN_MSSCR0 155 rlwinm r4,r4,0,0,29 156 sync 157 mtspr SPRN_MSSCR0,r4 158 sync 159 isync 160 lis r4,KERNELBASE@h 161 dcbf 0,r4 162 dcbf 0,r4 163 dcbf 0,r4 164 dcbf 0,r4 165 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450) 166 167 /* TODO: use HW flush assist when available */ 168 169 lis r4,0x0002 170 mtctr r4 171 li r4,0 172 1: 173 lwzx r0,0,r4 174 addi r4,r4,32 /* Go to start of next cache line */ 175 bdnz 1b 176 isync 177 178 /* Now, flush the first 4MB of memory */ 179 lis r4,0x0002 180 mtctr r4 181 li r4,0 182 sync 183 1: 184 dcbf 0,r4 185 addi r4,r4,32 /* Go to start of next cache line */ 186 bdnz 1b 187 188 2: 189 /* Set up the L2CR configuration bits (and switch L2 off) */ 190 /* CPU errata: Make sure the mtspr below is already in the 191 * L1 icache 192 */ 193 b 20f 194 .balign L1_CACHE_BYTES 195 22: 196 sync 197 mtspr SPRN_L2CR,r3 198 sync 199 b 23f 200 20: 201 b 21f 202 21: sync 203 isync 204 b 22b 205 206 23: 207 /* Perform a global invalidation */ 208 oris r3,r3,0x0020 209 sync 210 mtspr SPRN_L2CR,r3 211 sync 212 isync /* For errata */ 213 214 BEGIN_FTR_SECTION 215 /* On the 7450, we wait for the L2I bit to clear...... 216 */ 217 10: mfspr r3,SPRN_L2CR 218 andis. r4,r3,0x0020 219 bne 10b 220 b 11f 221 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450) 222 223 /* Wait for the invalidation to complete */ 224 3: mfspr r3,SPRN_L2CR 225 rlwinm. r4,r3,0,31,31 226 bne 3b 227 228 11: rlwinm r3,r3,0,11,9 /* Turn off the L2I bit */ 229 sync 230 mtspr SPRN_L2CR,r3 231 sync 232 233 /* See if we need to enable the cache */ 234 cmplwi r5,0 235 beq 4f 236 237 /* Enable the cache */ 238 oris r3,r3,0x8000 239 mtspr SPRN_L2CR,r3 240 sync 241 242 /* Enable L2 HW prefetch on 744x/745x */ 243 BEGIN_FTR_SECTION 244 mfspr r3,SPRN_MSSCR0 245 ori r3,r3,3 246 sync 247 mtspr SPRN_MSSCR0,r3 248 sync 249 isync 250 END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450) 251 4: 252 253 /* Restore HID0[DPM] to whatever it was before */ 254 sync 255 mtspr 1008,r8 256 sync 257 258 /* Restore MSR (restores EE and DR bits to original state) */ 259 SYNC 260 mtmsr r7 261 isync 262 263 mtlr r9 264 blr 265 266 _GLOBAL(_get_L2CR) 267 /* Return the L2CR contents */ 268 li r3,0 269 BEGIN_FTR_SECTION 270 mfspr r3,SPRN_L2CR 271 END_FTR_SECTION_IFSET(CPU_FTR_L2CR) 272 blr 273 274 275 /* 276 * Here is a similar routine for dealing with the L3 cache 277 * on the 745x family of chips 278 */ 279 280 _GLOBAL(_set_L3CR) 281 /* Make sure this is a 745x chip */ 282 BEGIN_FTR_SECTION 283 li r3,-1 284 blr 285 END_FTR_SECTION_IFCLR(CPU_FTR_L3CR) 286 287 /* Turn off interrupts and data relocation. */ 288 mfmsr r7 /* Save MSR in r7 */ 289 rlwinm r4,r7,0,17,15 290 rlwinm r4,r4,0,28,26 /* Turn off DR bit */ 291 sync 292 mtmsr r4 293 isync 294 295 /* Stop DST streams */ 296 DSSALL 297 sync 298 299 /* Get the current enable bit of the L3CR into r4 */ 300 mfspr r4,SPRN_L3CR 301 302 /* Tweak some bits */ 303 rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */ 304 rlwinm r3,r3,0,22,20 /* Turn off the invalidate bit */ 305 rlwinm r3,r3,0,2,31 /* Turn off the enable & PE bits */ 306 rlwinm r3,r3,0,5,3 /* Turn off the clken bit */ 307 /* Check to see if we need to flush */ 308 rlwinm. r4,r4,0,0,0 309 beq 2f 310 311 /* Flush the cache. 312 */ 313 314 /* TODO: use HW flush assist */ 315 316 lis r4,0x0008 317 mtctr r4 318 li r4,0 319 1: 320 lwzx r0,0,r4 321 dcbf 0,r4 322 addi r4,r4,32 /* Go to start of next cache line */ 323 bdnz 1b 324 325 2: 326 /* Set up the L3CR configuration bits (and switch L3 off) */ 327 sync 328 mtspr SPRN_L3CR,r3 329 sync 330 331 oris r3,r3,L3CR_L3RES@h /* Set reserved bit 5 */ 332 mtspr SPRN_L3CR,r3 333 sync 334 oris r3,r3,L3CR_L3CLKEN@h /* Set clken */ 335 mtspr SPRN_L3CR,r3 336 sync 337 338 /* Wait for stabilize */ 339 li r0,256 340 mtctr r0 341 1: bdnz 1b 342 343 /* Perform a global invalidation */ 344 ori r3,r3,0x0400 345 sync 346 mtspr SPRN_L3CR,r3 347 sync 348 isync 349 350 /* We wait for the L3I bit to clear...... */ 351 10: mfspr r3,SPRN_L3CR 352 andi. r4,r3,0x0400 353 bne 10b 354 355 /* Clear CLKEN */ 356 rlwinm r3,r3,0,5,3 /* Turn off the clken bit */ 357 mtspr SPRN_L3CR,r3 358 sync 359 360 /* Wait for stabilize */ 361 li r0,256 362 mtctr r0 363 1: bdnz 1b 364 365 /* See if we need to enable the cache */ 366 cmplwi r5,0 367 beq 4f 368 369 /* Enable the cache */ 370 oris r3,r3,(L3CR_L3E | L3CR_L3CLKEN)@h 371 mtspr SPRN_L3CR,r3 372 sync 373 374 /* Wait for stabilize */ 375 li r0,256 376 mtctr r0 377 1: bdnz 1b 378 379 /* Restore MSR (restores EE and DR bits to original state) */ 380 4: SYNC 381 mtmsr r7 382 isync 383 blr 384 385 _GLOBAL(_get_L3CR) 386 /* Return the L3CR contents */ 387 li r3,0 388 BEGIN_FTR_SECTION 389 mfspr r3,SPRN_L3CR 390 END_FTR_SECTION_IFSET(CPU_FTR_L3CR) 391 blr 392 393 /* --- End of PowerLogix code --- 394 */ 395 396 397 /* flush_disable_L1() - Flush and disable L1 cache 398 * 399 * clobbers r0, r3, ctr, cr0 400 * Must be called with interrupts disabled and MMU enabled. 401 */ 402 _GLOBAL(__flush_disable_L1) 403 /* Stop pending alitvec streams and memory accesses */ 404 BEGIN_FTR_SECTION 405 DSSALL 406 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) 407 sync 408 409 /* Load counter to 0x4000 cache lines (512k) and 410 * load cache with datas 411 */ 412 li r3,0x4000 /* 512kB / 32B */ 413 mtctr r3 414 lis r3,KERNELBASE@h 415 1: 416 lwz r0,0(r3) 417 addi r3,r3,0x0020 /* Go to start of next cache line */ 418 bdnz 1b 419 isync 420 sync 421 422 /* Now flush those cache lines */ 423 li r3,0x4000 /* 512kB / 32B */ 424 mtctr r3 425 lis r3,KERNELBASE@h 426 1: 427 dcbf 0,r3 428 addi r3,r3,0x0020 /* Go to start of next cache line */ 429 bdnz 1b 430 sync 431 432 /* We can now disable the L1 cache (HID0:DCE, HID0:ICE) */ 433 mfspr r3,SPRN_HID0 434 rlwinm r3,r3,0,18,15 435 mtspr SPRN_HID0,r3 436 sync 437 isync 438 blr 439 440 /* inval_enable_L1 - Invalidate and enable L1 cache 441 * 442 * Assumes L1 is already disabled and MSR:EE is off 443 * 444 * clobbers r3 445 */ 446 _GLOBAL(__inval_enable_L1) 447 /* Enable and then Flash inval the instruction & data cache */ 448 mfspr r3,SPRN_HID0 449 ori r3,r3, HID0_ICE|HID0_ICFI|HID0_DCE|HID0_DCI 450 sync 451 isync 452 mtspr SPRN_HID0,r3 453 xori r3,r3, HID0_ICFI|HID0_DCI 454 mtspr SPRN_HID0,r3 455 sync 456 457 blr 458 459