arch/mips/mm/page.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org)
   7  * Copyright (C) 2007  Maciej W. Rozycki
   8  * Copyright (C) 2008  Thiemo Seufer
   9  */
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/mm.h>
  14 #include <linux/module.h>
  15 #include <linux/proc_fs.h>
  16
  17 #include <asm/bugs.h>
  18 #include <asm/cacheops.h>
  19 #include <asm/inst.h>
  20 #include <asm/io.h>
  21 #include <asm/page.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/prefetch.h>
  24 #include <asm/system.h>
  25 #include <asm/bootinfo.h>
  26 #include <asm/mipsregs.h>
  27 #include <asm/mmu_context.h>
  28 #include <asm/cpu.h>
  29 #include <asm/war.h>
  30
  31 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
  32 #include <asm/sibyte/sb1250.h>
  33 #include <asm/sibyte/sb1250_regs.h>
  34 #include <asm/sibyte/sb1250_dma.h>
  35 #endif
  36
  37 #include "uasm.h"
  38
  39 /* Registers used in the assembled routines. */
  40 #define ZERO 0
  41 #define AT 2
  42 #define A0 4
  43 #define A1 5
  44 #define A2 6
  45 #define T0 8
  46 #define T1 9
  47 #define T2 10
  48 #define T3 11
  49 #define T9 25
  50 #define RA 31
  51
  52 /* Handle labels (which must be positive integers). */
  53 enum label_id {
  54         label_clear_nopref = 1,
  55         label_clear_pref,
  56         label_copy_nopref,
  57         label_copy_pref_both,
  58         label_copy_pref_store,
  59 };
  60
  61 UASM_L_LA(_clear_nopref)
  62 UASM_L_LA(_clear_pref)
  63 UASM_L_LA(_copy_nopref)
  64 UASM_L_LA(_copy_pref_both)
  65 UASM_L_LA(_copy_pref_store)
  66
  67 /* We need one branch and therefore one relocation per target label. */
  68 static struct uasm_label __cpuinitdata labels[5];
  69 static struct uasm_reloc __cpuinitdata relocs[5];
  70
  71 #define cpu_is_r4600_v1_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002010)
  72 #define cpu_is_r4600_v2_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002020)
  73
  74 /*
  75  * Maximum sizes:
  76  *
  77  * R4000 128 bytes S-cache:             0x058 bytes
  78  * R4600 v1.7:                          0x05c bytes
  79  * R4600 v2.0:                          0x060 bytes
  80  * With prefetching, 16 word strides    0x120 bytes
  81  */
  82
  83 static u32 clear_page_array[0x120 / 4];
  84
  85 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
  86 void clear_page_cpu(void *page) __attribute__((alias("clear_page_array")));
  87 #else
  88 void clear_page(void *page) __attribute__((alias("clear_page_array")));
  89 #endif
  90
  91 EXPORT_SYMBOL(clear_page);
  92
  93 /*
  94  * Maximum sizes:
  95  *
  96  * R4000 128 bytes S-cache:             0x11c bytes
  97  * R4600 v1.7:                          0x080 bytes
  98  * R4600 v2.0:                          0x07c bytes
  99  * With prefetching, 16 word strides    0x540 bytes
 100  */
 101 static u32 copy_page_array[0x540 / 4];
 102
 103 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 104 void
 105 copy_page_cpu(void *to, void *from) __attribute__((alias("copy_page_array")));
 106 #else
 107 void copy_page(void *to, void *from) __attribute__((alias("copy_page_array")));
 108 #endif
 109
 110 EXPORT_SYMBOL(copy_page);
 111
 112
 113 static int pref_bias_clear_store __cpuinitdata;
 114 static int pref_bias_copy_load __cpuinitdata;
 115 static int pref_bias_copy_store __cpuinitdata;
 116
 117 static u32 pref_src_mode __cpuinitdata;
 118 static u32 pref_dst_mode __cpuinitdata;
 119
 120 static int clear_word_size __cpuinitdata;
 121 static int copy_word_size __cpuinitdata;
 122
 123 static int half_clear_loop_size __cpuinitdata;
 124 static int half_copy_loop_size __cpuinitdata;
 125
 126 static int cache_line_size __cpuinitdata;
 127 #define cache_line_mask() (cache_line_size - 1)
 128
 129 static inline void __cpuinit
 130 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
 131 {
 132         if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
 133                 if (off > 0x7fff) {
 134                         uasm_i_lui(buf, T9, uasm_rel_hi(off));
 135                         uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 136                 } else
 137                         uasm_i_addiu(buf, T9, ZERO, off);
 138                 uasm_i_daddu(buf, reg1, reg2, T9);
 139         } else {
 140                 if (off > 0x7fff) {
 141                         uasm_i_lui(buf, T9, uasm_rel_hi(off));
 142                         uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 143                         UASM_i_ADDU(buf, reg1, reg2, T9);
 144                 } else
 145                         UASM_i_ADDIU(buf, reg1, reg2, off);
 146         }
 147 }
 148
 149 static void __cpuinit set_prefetch_parameters(void)
 150 {
 151         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
 152                 clear_word_size = 8;
 153         else
 154                 clear_word_size = 4;
 155
 156         if (cpu_has_64bit_gp_regs)
 157                 copy_word_size = 8;
 158         else
 159                 copy_word_size = 4;
 160
 161         /*
 162          * The pref's used here are using "streaming" hints, which cause the
 163          * copied data to be kicked out of the cache sooner.  A page copy often
 164          * ends up copying a lot more data than is commonly used, so this seems
 165          * to make sense in terms of reducing cache pollution, but I've no real
 166          * performance data to back this up.
 167          */
 168         if (cpu_has_prefetch) {
 169                 /*
 170                  * XXX: Most prefetch bias values in here are based on
 171                  * guesswork.
 172                  */
 173                 cache_line_size = cpu_dcache_line_size();
 174                 switch (current_cpu_type()) {
 175                 case CPU_TX49XX:
 176                         /* TX49 supports only Pref_Load */
 177                         pref_bias_copy_load = 256;
 178                         break;
 179
 180                 case CPU_RM9000:
 181                         /*
 182                          * As a workaround for erratum G105 which make the
 183                          * PrepareForStore hint unusable we fall back to
 184                          * StoreRetained on the RM9000.  Once it is known which
 185                          * versions of the RM9000 we'll be able to condition-
 186                          * alize this.
 187                          */
 188
 189                 case CPU_R10000:
 190                 case CPU_R12000:
 191                 case CPU_R14000:
 192                         /*
 193                          * Those values have been experimentally tuned for an
 194                          * Origin 200.
 195                          */
 196                         pref_bias_clear_store = 512;
 197                         pref_bias_copy_load = 256;
 198                         pref_bias_copy_store = 256;
 199                         pref_src_mode = Pref_LoadStreamed;
 200                         pref_dst_mode = Pref_StoreStreamed;
 201                         break;
 202
 203                 case CPU_SB1:
 204                 case CPU_SB1A:
 205                         pref_bias_clear_store = 128;
 206                         pref_bias_copy_load = 128;
 207                         pref_bias_copy_store = 128;
 208                         /*
 209                          * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
 210                          * hints are broken.
 211                          */
 212                         if (current_cpu_type() == CPU_SB1 &&
 213                             (current_cpu_data.processor_id & 0xff) < 0x02) {
 214                                 pref_src_mode = Pref_Load;
 215                                 pref_dst_mode = Pref_Store;
 216                         } else {
 217                                 pref_src_mode = Pref_LoadStreamed;
 218                                 pref_dst_mode = Pref_StoreStreamed;
 219                         }
 220                         break;
 221
 222                 default:
 223                         pref_bias_clear_store = 128;
 224                         pref_bias_copy_load = 256;
 225                         pref_bias_copy_store = 128;
 226                         pref_src_mode = Pref_LoadStreamed;
 227                         pref_dst_mode = Pref_PrepareForStore;
 228                         break;
 229                 }
 230         } else {
 231                 if (cpu_has_cache_cdex_s)
 232                         cache_line_size = cpu_scache_line_size();
 233                 else if (cpu_has_cache_cdex_p)
 234                         cache_line_size = cpu_dcache_line_size();
 235         }
 236         /*
 237          * Too much unrolling will overflow the available space in
 238          * clear_space_array / copy_page_array.
 239          */
 240         half_clear_loop_size = min(16 * clear_word_size,
 241                                    max(cache_line_size >> 1,
 242                                        4 * clear_word_size));
 243         half_copy_loop_size = min(16 * copy_word_size,
 244                                   max(cache_line_size >> 1,
 245                                       4 * copy_word_size));
 246 }
 247
 248 static void __cpuinit build_clear_store(u32 **buf, int off)
 249 {
 250         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
 251                 uasm_i_sd(buf, ZERO, off, A0);
 252         } else {
 253                 uasm_i_sw(buf, ZERO, off, A0);
 254         }
 255 }
 256
 257 static inline void __cpuinit build_clear_pref(u32 **buf, int off)
 258 {
 259         if (off & cache_line_mask())
 260                 return;
 261
 262         if (pref_bias_clear_store) {
 263                 uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
 264                             A0);
 265         } else if (cache_line_size == (half_clear_loop_size << 1)) {
 266                 if (cpu_has_cache_cdex_s) {
 267                         uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 268                 } else if (cpu_has_cache_cdex_p) {
 269                         if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 270                                 uasm_i_nop(buf);
 271                                 uasm_i_nop(buf);
 272                                 uasm_i_nop(buf);
 273                                 uasm_i_nop(buf);
 274                         }
 275
 276                         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 277                                 uasm_i_lw(buf, ZERO, ZERO, AT);
 278
 279                         uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 280                 }
 281                 }
 282 }
 283
 284 void __cpuinit build_clear_page(void)
 285 {
 286         int off;
 287         u32 *buf = (u32 *)&clear_page_array;
 288         struct uasm_label *l = labels;
 289         struct uasm_reloc *r = relocs;
 290         int i;
 291
 292         memset(labels, 0, sizeof(labels));
 293         memset(relocs, 0, sizeof(relocs));
 294
 295         set_prefetch_parameters();
 296
 297         /*
 298          * This algorithm makes the following assumptions:
 299          *   - The prefetch bias is a multiple of 2 words.
 300          *   - The prefetch bias is less than one page.
 301          */
 302         BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
 303         BUG_ON(PAGE_SIZE < pref_bias_clear_store);
 304
 305         off = PAGE_SIZE - pref_bias_clear_store;
 306         if (off > 0xffff || !pref_bias_clear_store)
 307                 pg_addiu(&buf, A2, A0, off);
 308         else
 309                 uasm_i_ori(&buf, A2, A0, off);
 310
 311         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 312                 uasm_i_lui(&buf, AT, 0xa000);
 313
 314         off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
 315                                 * cache_line_size : 0;
 316         while (off) {
 317                 build_clear_pref(&buf, -off);
 318                 off -= cache_line_size;
 319         }
 320         uasm_l_clear_pref(&l, buf);
 321         do {
 322                 build_clear_pref(&buf, off);
 323                 build_clear_store(&buf, off);
 324                 off += clear_word_size;
 325         } while (off < half_clear_loop_size);
 326         pg_addiu(&buf, A0, A0, 2 * off);
 327         off = -off;
 328         do {
 329                 build_clear_pref(&buf, off);
 330                 if (off == -clear_word_size)
 331                         uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
 332                 build_clear_store(&buf, off);
 333                 off += clear_word_size;
 334         } while (off < 0);
 335
 336         if (pref_bias_clear_store) {
 337                 pg_addiu(&buf, A2, A0, pref_bias_clear_store);
 338                 uasm_l_clear_nopref(&l, buf);
 339                 off = 0;
 340                 do {
 341                         build_clear_store(&buf, off);
 342                         off += clear_word_size;
 343                 } while (off < half_clear_loop_size);
 344                 pg_addiu(&buf, A0, A0, 2 * off);
 345                 off = -off;
 346                 do {
 347                         if (off == -clear_word_size)
 348                                 uasm_il_bne(&buf, &r, A0, A2,
 349                                             label_clear_nopref);
 350                         build_clear_store(&buf, off);
 351                         off += clear_word_size;
 352                 } while (off < 0);
 353         }
 354
 355         uasm_i_jr(&buf, RA);
 356         uasm_i_nop(&buf);
 357
 358         BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
 359
 360         uasm_resolve_relocs(relocs, labels);
 361
 362         pr_debug("Synthesized clear page handler (%u instructions).\n",
 363                  (u32)(buf - clear_page_array));
 364
 365         pr_debug("\t.set push\n");
 366         pr_debug("\t.set noreorder\n");
 367         for (i = 0; i < (buf - clear_page_array); i++)
 368                 pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
 369         pr_debug("\t.set pop\n");
 370 }
 371
 372 static void __cpuinit build_copy_load(u32 **buf, int reg, int off)
 373 {
 374         if (cpu_has_64bit_gp_regs) {
 375                 uasm_i_ld(buf, reg, off, A1);
 376         } else {
 377                 uasm_i_lw(buf, reg, off, A1);
 378         }
 379 }
 380
 381 static void __cpuinit build_copy_store(u32 **buf, int reg, int off)
 382 {
 383         if (cpu_has_64bit_gp_regs) {
 384                 uasm_i_sd(buf, reg, off, A0);
 385         } else {
 386                 uasm_i_sw(buf, reg, off, A0);
 387         }
 388 }
 389
 390 static inline void build_copy_load_pref(u32 **buf, int off)
 391 {
 392         if (off & cache_line_mask())
 393                 return;
 394
 395         if (pref_bias_copy_load)
 396                 uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
 397 }
 398
 399 static inline void build_copy_store_pref(u32 **buf, int off)
 400 {
 401         if (off & cache_line_mask())
 402                 return;
 403
 404         if (pref_bias_copy_store) {
 405                 uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
 406                             A0);
 407         } else if (cache_line_size == (half_copy_loop_size << 1)) {
 408                 if (cpu_has_cache_cdex_s) {
 409                         uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 410                 } else if (cpu_has_cache_cdex_p) {
 411                         if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 412                                 uasm_i_nop(buf);
 413                                 uasm_i_nop(buf);
 414                                 uasm_i_nop(buf);
 415                                 uasm_i_nop(buf);
 416                         }
 417
 418                         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 419                                 uasm_i_lw(buf, ZERO, ZERO, AT);
 420
 421                         uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 422                 }
 423         }
 424 }
 425
 426 void __cpuinit build_copy_page(void)
 427 {
 428         int off;
 429         u32 *buf = (u32 *)&copy_page_array;
 430         struct uasm_label *l = labels;
 431         struct uasm_reloc *r = relocs;
 432         int i;
 433
 434         memset(labels, 0, sizeof(labels));
 435         memset(relocs, 0, sizeof(relocs));
 436
 437         set_prefetch_parameters();
 438
 439         /*
 440          * This algorithm makes the following assumptions:
 441          *   - All prefetch biases are multiples of 8 words.
 442          *   - The prefetch biases are less than one page.
 443          *   - The store prefetch bias isn't greater than the load
 444          *     prefetch bias.
 445          */
 446         BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
 447         BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
 448         BUG_ON(PAGE_SIZE < pref_bias_copy_load);
 449         BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
 450
 451         off = PAGE_SIZE - pref_bias_copy_load;
 452         if (off > 0xffff || !pref_bias_copy_load)
 453                 pg_addiu(&buf, A2, A0, off);
 454         else
 455                 uasm_i_ori(&buf, A2, A0, off);
 456
 457         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 458                 uasm_i_lui(&buf, AT, 0xa000);
 459
 460         off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
 461                                 cache_line_size : 0;
 462         while (off) {
 463                 build_copy_load_pref(&buf, -off);
 464                 off -= cache_line_size;
 465         }
 466         off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
 467                                 cache_line_size : 0;
 468         while (off) {
 469                 build_copy_store_pref(&buf, -off);
 470                 off -= cache_line_size;
 471         }
 472         uasm_l_copy_pref_both(&l, buf);
 473         do {
 474                 build_copy_load_pref(&buf, off);
 475                 build_copy_load(&buf, T0, off);
 476                 build_copy_load_pref(&buf, off + copy_word_size);
 477                 build_copy_load(&buf, T1, off + copy_word_size);
 478                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 479                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 480                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 481                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 482                 build_copy_store_pref(&buf, off);
 483                 build_copy_store(&buf, T0, off);
 484                 build_copy_store_pref(&buf, off + copy_word_size);
 485                 build_copy_store(&buf, T1, off + copy_word_size);
 486                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 487                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 488                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 489                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 490                 off += 4 * copy_word_size;
 491         } while (off < half_copy_loop_size);
 492         pg_addiu(&buf, A1, A1, 2 * off);
 493         pg_addiu(&buf, A0, A0, 2 * off);
 494         off = -off;
 495         do {
 496                 build_copy_load_pref(&buf, off);
 497                 build_copy_load(&buf, T0, off);
 498                 build_copy_load_pref(&buf, off + copy_word_size);
 499                 build_copy_load(&buf, T1, off + copy_word_size);
 500                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 501                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 502                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 503                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 504                 build_copy_store_pref(&buf, off);
 505                 build_copy_store(&buf, T0, off);
 506                 build_copy_store_pref(&buf, off + copy_word_size);
 507                 build_copy_store(&buf, T1, off + copy_word_size);
 508                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 509                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 510                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 511                 if (off == -(4 * copy_word_size))
 512                         uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
 513                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 514                 off += 4 * copy_word_size;
 515         } while (off < 0);
 516
 517         if (pref_bias_copy_load - pref_bias_copy_store) {
 518                 pg_addiu(&buf, A2, A0,
 519                          pref_bias_copy_load - pref_bias_copy_store);
 520                 uasm_l_copy_pref_store(&l, buf);
 521                 off = 0;
 522                 do {
 523                         build_copy_load(&buf, T0, off);
 524                         build_copy_load(&buf, T1, off + copy_word_size);
 525                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 526                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 527                         build_copy_store_pref(&buf, off);
 528                         build_copy_store(&buf, T0, off);
 529                         build_copy_store_pref(&buf, off + copy_word_size);
 530                         build_copy_store(&buf, T1, off + copy_word_size);
 531                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 532                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 533                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 534                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 535                         off += 4 * copy_word_size;
 536                 } while (off < half_copy_loop_size);
 537                 pg_addiu(&buf, A1, A1, 2 * off);
 538                 pg_addiu(&buf, A0, A0, 2 * off);
 539                 off = -off;
 540                 do {
 541                         build_copy_load(&buf, T0, off);
 542                         build_copy_load(&buf, T1, off + copy_word_size);
 543                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 544                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 545                         build_copy_store_pref(&buf, off);
 546                         build_copy_store(&buf, T0, off);
 547                         build_copy_store_pref(&buf, off + copy_word_size);
 548                         build_copy_store(&buf, T1, off + copy_word_size);
 549                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 550                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 551                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 552                         if (off == -(4 * copy_word_size))
 553                                 uasm_il_bne(&buf, &r, A2, A0,
 554                                             label_copy_pref_store);
 555                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 556                         off += 4 * copy_word_size;
 557                 } while (off < 0);
 558         }
 559
 560         if (pref_bias_copy_store) {
 561                 pg_addiu(&buf, A2, A0, pref_bias_copy_store);
 562                 uasm_l_copy_nopref(&l, buf);
 563                 off = 0;
 564                 do {
 565                         build_copy_load(&buf, T0, off);
 566                         build_copy_load(&buf, T1, off + copy_word_size);
 567                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 568                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 569                         build_copy_store(&buf, T0, off);
 570                         build_copy_store(&buf, T1, off + copy_word_size);
 571                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 572                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 573                         off += 4 * copy_word_size;
 574                 } while (off < half_copy_loop_size);
 575                 pg_addiu(&buf, A1, A1, 2 * off);
 576                 pg_addiu(&buf, A0, A0, 2 * off);
 577                 off = -off;
 578                 do {
 579                         build_copy_load(&buf, T0, off);
 580                         build_copy_load(&buf, T1, off + copy_word_size);
 581                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 582                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 583                         build_copy_store(&buf, T0, off);
 584                         build_copy_store(&buf, T1, off + copy_word_size);
 585                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 586                         if (off == -(4 * copy_word_size))
 587                                 uasm_il_bne(&buf, &r, A2, A0,
 588                                             label_copy_nopref);
 589                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 590                         off += 4 * copy_word_size;
 591                 } while (off < 0);
 592         }
 593
 594         uasm_i_jr(&buf, RA);
 595         uasm_i_nop(&buf);
 596
 597         BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array));
 598
 599         uasm_resolve_relocs(relocs, labels);
 600
 601         pr_debug("Synthesized copy page handler (%u instructions).\n",
 602                  (u32)(buf - copy_page_array));
 603
 604         pr_debug("\t.set push\n");
 605         pr_debug("\t.set noreorder\n");
 606         for (i = 0; i < (buf - copy_page_array); i++)
 607                 pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
 608         pr_debug("\t.set pop\n");
 609 }
 610
 611 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 612
 613 /*
 614  * Pad descriptors to cacheline, since each is exclusively owned by a
 615  * particular CPU.
 616  */
 617 struct dmadscr {
 618         u64 dscr_a;
 619         u64 dscr_b;
 620         u64 pad_a;
 621         u64 pad_b;
 622 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
 623
 624 void sb1_dma_init(void)
 625 {
 626         int i;
 627
 628         for (i = 0; i < DM_NUM_CHANNELS; i++) {
 629                 const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
 630                                      V_DM_DSCR_BASE_RINGSZ(1);
 631                 void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
 632
 633                 __raw_writeq(base_val, base_reg);
 634                 __raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
 635                 __raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
 636         }
 637 }
 638
 639 void clear_page(void *page)
 640 {
 641         u64 to_phys = CPHYSADDR((unsigned long)page);
 642         unsigned int cpu = smp_processor_id();
 643
 644         /* if the page is not in KSEG0, use old way */
 645         if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
 646                 return clear_page_cpu(page);
 647
 648         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
 649                                  M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
 650         page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 651         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 652
 653         /*
 654          * Don't really want to do it this way, but there's no
 655          * reliable way to delay completion detection.
 656          */
 657         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 658                  & M_DM_DSCR_BASE_INTERRUPT))
 659                 ;
 660         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 661 }
 662
 663 void copy_page(void *to, void *from)
 664 {
 665         u64 from_phys = CPHYSADDR((unsigned long)from);
 666         u64 to_phys = CPHYSADDR((unsigned long)to);
 667         unsigned int cpu = smp_processor_id();
 668
 669         /* if any page is not in KSEG0, use old way */
 670         if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
 671             || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
 672                 return copy_page_cpu(to, from);
 673
 674         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
 675                                  M_DM_DSCRA_INTERRUPT;
 676         page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 677         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 678
 679         /*
 680          * Don't really want to do it this way, but there's no
 681          * reliable way to delay completion detection.
 682          */
 683         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 684                  & M_DM_DSCR_BASE_INTERRUPT))
 685                 ;
 686         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 687 }
 688
 689 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */