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 72IMPORTANT: 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 */ 90BEGIN_FTR_SECTION 91 li r3,-1 92 blr 93END_FTR_SECTION_IFCLR(CPU_FTR_L2CR) 94 95 mflr r9 96 97 /* Stop DST streams */ 98BEGIN_FTR_SECTION 99 DSSALL 100 sync 101END_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 147BEGIN_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 165END_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 1721: 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 1831: 184 dcbf 0,r4 185 addi r4,r4,32 /* Go to start of next cache line */ 186 bdnz 1b 187 1882: 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 19522: 196 sync 197 mtspr SPRN_L2CR,r3 198 sync 199 b 23f 20020: 201 b 21f 20221: sync 203 isync 204 b 22b 205 20623: 207 /* Perform a global invalidation */ 208 oris r3,r3,0x0020 209 sync 210 mtspr SPRN_L2CR,r3 211 sync 212 isync /* For errata */ 213 214BEGIN_FTR_SECTION 215 /* On the 7450, we wait for the L2I bit to clear...... 216 */ 21710: mfspr r3,SPRN_L2CR 218 andis. r4,r3,0x0020 219 bne 10b 220 b 11f 221END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450) 222 223 /* Wait for the invalidation to complete */ 2243: mfspr r3,SPRN_L2CR 225 rlwinm. r4,r3,0,31,31 226 bne 3b 227 22811: 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 */ 243BEGIN_FTR_SECTION 244 mfspr r3,SPRN_MSSCR0 245 ori r3,r3,3 246 sync 247 mtspr SPRN_MSSCR0,r3 248 sync 249 isync 250END_FTR_SECTION_IFSET(CPU_FTR_SPEC7450) 2514: 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 mtmsr r7 260 isync 261 262 mtlr r9 263 blr 264 265_GLOBAL(_get_L2CR) 266 /* Return the L2CR contents */ 267 li r3,0 268BEGIN_FTR_SECTION 269 mfspr r3,SPRN_L2CR 270END_FTR_SECTION_IFSET(CPU_FTR_L2CR) 271 blr 272 273 274/* 275 * Here is a similar routine for dealing with the L3 cache 276 * on the 745x family of chips 277 */ 278 279_GLOBAL(_set_L3CR) 280 /* Make sure this is a 745x chip */ 281BEGIN_FTR_SECTION 282 li r3,-1 283 blr 284END_FTR_SECTION_IFCLR(CPU_FTR_L3CR) 285 286 /* Turn off interrupts and data relocation. */ 287 mfmsr r7 /* Save MSR in r7 */ 288 rlwinm r4,r7,0,17,15 289 rlwinm r4,r4,0,28,26 /* Turn off DR bit */ 290 sync 291 mtmsr r4 292 isync 293 294 /* Stop DST streams */ 295 DSSALL 296 sync 297 298 /* Get the current enable bit of the L3CR into r4 */ 299 mfspr r4,SPRN_L3CR 300 301 /* Tweak some bits */ 302 rlwinm r5,r3,0,0,0 /* r5 contains the new enable bit */ 303 rlwinm r3,r3,0,22,20 /* Turn off the invalidate bit */ 304 rlwinm r3,r3,0,2,31 /* Turn off the enable & PE bits */ 305 rlwinm r3,r3,0,5,3 /* Turn off the clken bit */ 306 /* Check to see if we need to flush */ 307 rlwinm. r4,r4,0,0,0 308 beq 2f 309 310 /* Flush the cache. 311 */ 312 313 /* TODO: use HW flush assist */ 314 315 lis r4,0x0008 316 mtctr r4 317 li r4,0 3181: 319 lwzx r0,0,r4 320 dcbf 0,r4 321 addi r4,r4,32 /* Go to start of next cache line */ 322 bdnz 1b 323 3242: 325 /* Set up the L3CR configuration bits (and switch L3 off) */ 326 sync 327 mtspr SPRN_L3CR,r3 328 sync 329 330 oris r3,r3,L3CR_L3RES@h /* Set reserved bit 5 */ 331 mtspr SPRN_L3CR,r3 332 sync 333 oris r3,r3,L3CR_L3CLKEN@h /* Set clken */ 334 mtspr SPRN_L3CR,r3 335 sync 336 337 /* Wait for stabilize */ 338 li r0,256 339 mtctr r0 3401: bdnz 1b 341 342 /* Perform a global invalidation */ 343 ori r3,r3,0x0400 344 sync 345 mtspr SPRN_L3CR,r3 346 sync 347 isync 348 349 /* We wait for the L3I bit to clear...... */ 35010: mfspr r3,SPRN_L3CR 351 andi. r4,r3,0x0400 352 bne 10b 353 354 /* Clear CLKEN */ 355 rlwinm r3,r3,0,5,3 /* Turn off the clken bit */ 356 mtspr SPRN_L3CR,r3 357 sync 358 359 /* Wait for stabilize */ 360 li r0,256 361 mtctr r0 3621: bdnz 1b 363 364 /* See if we need to enable the cache */ 365 cmplwi r5,0 366 beq 4f 367 368 /* Enable the cache */ 369 oris r3,r3,(L3CR_L3E | L3CR_L3CLKEN)@h 370 mtspr SPRN_L3CR,r3 371 sync 372 373 /* Wait for stabilize */ 374 li r0,256 375 mtctr r0 3761: bdnz 1b 377 378 /* Restore MSR (restores EE and DR bits to original state) */ 3794: 380 mtmsr r7 381 isync 382 blr 383 384_GLOBAL(_get_L3CR) 385 /* Return the L3CR contents */ 386 li r3,0 387BEGIN_FTR_SECTION 388 mfspr r3,SPRN_L3CR 389END_FTR_SECTION_IFSET(CPU_FTR_L3CR) 390 blr 391 392/* --- End of PowerLogix code --- 393 */ 394 395 396/* flush_disable_L1() - Flush and disable L1 cache 397 * 398 * clobbers r0, r3, ctr, cr0 399 * Must be called with interrupts disabled and MMU enabled. 400 */ 401_GLOBAL(__flush_disable_L1) 402 /* Stop pending alitvec streams and memory accesses */ 403BEGIN_FTR_SECTION 404 DSSALL 405END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) 406 sync 407 408 /* Load counter to 0x4000 cache lines (512k) and 409 * load cache with datas 410 */ 411 li r3,0x4000 /* 512kB / 32B */ 412 mtctr r3 413 lis r3,KERNELBASE@h 4141: 415 lwz r0,0(r3) 416 addi r3,r3,0x0020 /* Go to start of next cache line */ 417 bdnz 1b 418 isync 419 sync 420 421 /* Now flush those cache lines */ 422 li r3,0x4000 /* 512kB / 32B */ 423 mtctr r3 424 lis r3,KERNELBASE@h 4251: 426 dcbf 0,r3 427 addi r3,r3,0x0020 /* Go to start of next cache line */ 428 bdnz 1b 429 sync 430 431 /* We can now disable the L1 cache (HID0:DCE, HID0:ICE) */ 432 mfspr r3,SPRN_HID0 433 rlwinm r3,r3,0,18,15 434 mtspr SPRN_HID0,r3 435 sync 436 isync 437 blr 438 439/* inval_enable_L1 - Invalidate and enable L1 cache 440 * 441 * Assumes L1 is already disabled and MSR:EE is off 442 * 443 * clobbers r3 444 */ 445_GLOBAL(__inval_enable_L1) 446 /* Enable and then Flash inval the instruction & data cache */ 447 mfspr r3,SPRN_HID0 448 ori r3,r3, HID0_ICE|HID0_ICFI|HID0_DCE|HID0_DCI 449 sync 450 isync 451 mtspr SPRN_HID0,r3 452 xori r3,r3, HID0_ICFI|HID0_DCI 453 mtspr SPRN_HID0,r3 454 sync 455 456 blr 457_ASM_NOKPROBE_SYMBOL(__inval_enable_L1) 458 459 460