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. 8 words sounds generous,
 239          * but a R4000 with 128 byte L2 line length can exceed even that.
 240          */
 241         half_clear_loop_size = min(8 * clear_word_size,
 242                                    max(cache_line_size >> 1,
 243                                        4 * clear_word_size));
 244         half_copy_loop_size = min(8 * copy_word_size,
 245                                   max(cache_line_size >> 1,
 246                                       4 * copy_word_size));
 247 }
 248
 249 static void __cpuinit build_clear_store(u32 **buf, int off)
 250 {
 251         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
 252                 uasm_i_sd(buf, ZERO, off, A0);
 253         } else {
 254                 uasm_i_sw(buf, ZERO, off, A0);
 255         }
 256 }
 257
 258 static inline void __cpuinit build_clear_pref(u32 **buf, int off)
 259 {
 260         if (off & cache_line_mask())
 261                 return;
 262
 263         if (pref_bias_clear_store) {
 264                 uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
 265                             A0);
 266         } else 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 void __cpuinit build_clear_page(void)
 284 {
 285         int off;
 286         u32 *buf = (u32 *)&clear_page_array;
 287         struct uasm_label *l = labels;
 288         struct uasm_reloc *r = relocs;
 289         int i;
 290
 291         memset(labels, 0, sizeof(labels));
 292         memset(relocs, 0, sizeof(relocs));
 293
 294         set_prefetch_parameters();
 295
 296         /*
 297          * This algorithm makes the following assumptions:
 298          *   - The prefetch bias is a multiple of 2 words.
 299          *   - The prefetch bias is less than one page.
 300          */
 301         BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
 302         BUG_ON(PAGE_SIZE < pref_bias_clear_store);
 303
 304         off = PAGE_SIZE - pref_bias_clear_store;
 305         if (off > 0xffff || !pref_bias_clear_store)
 306                 pg_addiu(&buf, A2, A0, off);
 307         else
 308                 uasm_i_ori(&buf, A2, A0, off);
 309
 310         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 311                 uasm_i_lui(&buf, AT, 0xa000);
 312
 313         off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
 314                                 * cache_line_size : 0;
 315         while (off) {
 316                 build_clear_pref(&buf, -off);
 317                 off -= cache_line_size;
 318         }
 319         uasm_l_clear_pref(&l, buf);
 320         do {
 321                 build_clear_pref(&buf, off);
 322                 build_clear_store(&buf, off);
 323                 off += clear_word_size;
 324         } while (off < half_clear_loop_size);
 325         pg_addiu(&buf, A0, A0, 2 * off);
 326         off = -off;
 327         do {
 328                 build_clear_pref(&buf, off);
 329                 if (off == -clear_word_size)
 330                         uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
 331                 build_clear_store(&buf, off);
 332                 off += clear_word_size;
 333         } while (off < 0);
 334
 335         if (pref_bias_clear_store) {
 336                 pg_addiu(&buf, A2, A0, pref_bias_clear_store);
 337                 uasm_l_clear_nopref(&l, buf);
 338                 off = 0;
 339                 do {
 340                         build_clear_store(&buf, off);
 341                         off += clear_word_size;
 342                 } while (off < half_clear_loop_size);
 343                 pg_addiu(&buf, A0, A0, 2 * off);
 344                 off = -off;
 345                 do {
 346                         if (off == -clear_word_size)
 347                                 uasm_il_bne(&buf, &r, A0, A2,
 348                                             label_clear_nopref);
 349                         build_clear_store(&buf, off);
 350                         off += clear_word_size;
 351                 } while (off < 0);
 352         }
 353
 354         uasm_i_jr(&buf, RA);
 355         uasm_i_nop(&buf);
 356
 357         BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array));
 358
 359         uasm_resolve_relocs(relocs, labels);
 360
 361         pr_debug("Synthesized clear page handler (%u instructions).\n",
 362                  (u32)(buf - clear_page_array));
 363
 364         pr_debug("\t.set push\n");
 365         pr_debug("\t.set noreorder\n");
 366         for (i = 0; i < (buf - clear_page_array); i++)
 367                 pr_debug("\t.word 0x%08x\n", clear_page_array[i]);
 368         pr_debug("\t.set pop\n");
 369 }
 370
 371 static void __cpuinit build_copy_load(u32 **buf, int reg, int off)
 372 {
 373         if (cpu_has_64bit_gp_regs) {
 374                 uasm_i_ld(buf, reg, off, A1);
 375         } else {
 376                 uasm_i_lw(buf, reg, off, A1);
 377         }
 378 }
 379
 380 static void __cpuinit build_copy_store(u32 **buf, int reg, int off)
 381 {
 382         if (cpu_has_64bit_gp_regs) {
 383                 uasm_i_sd(buf, reg, off, A0);
 384         } else {
 385                 uasm_i_sw(buf, reg, off, A0);
 386         }
 387 }
 388
 389 static inline void build_copy_load_pref(u32 **buf, int off)
 390 {
 391         if (off & cache_line_mask())
 392                 return;
 393
 394         if (pref_bias_copy_load)
 395                 uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
 396 }
 397
 398 static inline void build_copy_store_pref(u32 **buf, int off)
 399 {
 400         if (off & cache_line_mask())
 401                 return;
 402
 403         if (pref_bias_copy_store) {
 404                 uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
 405                             A0);
 406         } else if (cpu_has_cache_cdex_s) {
 407                 uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 408         } else if (cpu_has_cache_cdex_p) {
 409                 if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 410                         uasm_i_nop(buf);
 411                         uasm_i_nop(buf);
 412                         uasm_i_nop(buf);
 413                         uasm_i_nop(buf);
 414                 }
 415
 416                 if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 417                         uasm_i_lw(buf, ZERO, ZERO, AT);
 418
 419                 uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 420         }
 421 }
 422
 423 void __cpuinit build_copy_page(void)
 424 {
 425         int off;
 426         u32 *buf = (u32 *)&copy_page_array;
 427         struct uasm_label *l = labels;
 428         struct uasm_reloc *r = relocs;
 429         int i;
 430
 431         memset(labels, 0, sizeof(labels));
 432         memset(relocs, 0, sizeof(relocs));
 433
 434         set_prefetch_parameters();
 435
 436         /*
 437          * This algorithm makes the following assumptions:
 438          *   - All prefetch biases are multiples of 8 words.
 439          *   - The prefetch biases are less than one page.
 440          *   - The store prefetch bias isn't greater than the load
 441          *     prefetch bias.
 442          */
 443         BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
 444         BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
 445         BUG_ON(PAGE_SIZE < pref_bias_copy_load);
 446         BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
 447
 448         off = PAGE_SIZE - pref_bias_copy_load;
 449         if (off > 0xffff || !pref_bias_copy_load)
 450                 pg_addiu(&buf, A2, A0, off);
 451         else
 452                 uasm_i_ori(&buf, A2, A0, off);
 453
 454         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 455                 uasm_i_lui(&buf, AT, 0xa000);
 456
 457         off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
 458                                 cache_line_size : 0;
 459         while (off) {
 460                 build_copy_load_pref(&buf, -off);
 461                 off -= cache_line_size;
 462         }
 463         off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
 464                                 cache_line_size : 0;
 465         while (off) {
 466                 build_copy_store_pref(&buf, -off);
 467                 off -= cache_line_size;
 468         }
 469         uasm_l_copy_pref_both(&l, buf);
 470         do {
 471                 build_copy_load_pref(&buf, off);
 472                 build_copy_load(&buf, T0, off);
 473                 build_copy_load_pref(&buf, off + copy_word_size);
 474                 build_copy_load(&buf, T1, off + copy_word_size);
 475                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 476                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 477                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 478                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 479                 build_copy_store_pref(&buf, off);
 480                 build_copy_store(&buf, T0, off);
 481                 build_copy_store_pref(&buf, off + copy_word_size);
 482                 build_copy_store(&buf, T1, off + copy_word_size);
 483                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 484                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 485                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 486                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 487                 off += 4 * copy_word_size;
 488         } while (off < half_copy_loop_size);
 489         pg_addiu(&buf, A1, A1, 2 * off);
 490         pg_addiu(&buf, A0, A0, 2 * off);
 491         off = -off;
 492         do {
 493                 build_copy_load_pref(&buf, off);
 494                 build_copy_load(&buf, T0, off);
 495                 build_copy_load_pref(&buf, off + copy_word_size);
 496                 build_copy_load(&buf, T1, off + copy_word_size);
 497                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 498                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 499                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 500                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 501                 build_copy_store_pref(&buf, off);
 502                 build_copy_store(&buf, T0, off);
 503                 build_copy_store_pref(&buf, off + copy_word_size);
 504                 build_copy_store(&buf, T1, off + copy_word_size);
 505                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 506                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 507                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 508                 if (off == -(4 * copy_word_size))
 509                         uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
 510                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 511                 off += 4 * copy_word_size;
 512         } while (off < 0);
 513
 514         if (pref_bias_copy_load - pref_bias_copy_store) {
 515                 pg_addiu(&buf, A2, A0,
 516                          pref_bias_copy_load - pref_bias_copy_store);
 517                 uasm_l_copy_pref_store(&l, buf);
 518                 off = 0;
 519                 do {
 520                         build_copy_load(&buf, T0, off);
 521                         build_copy_load(&buf, T1, off + copy_word_size);
 522                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 523                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 524                         build_copy_store_pref(&buf, off);
 525                         build_copy_store(&buf, T0, off);
 526                         build_copy_store_pref(&buf, off + copy_word_size);
 527                         build_copy_store(&buf, T1, off + copy_word_size);
 528                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 529                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 530                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 531                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 532                         off += 4 * copy_word_size;
 533                 } while (off < half_copy_loop_size);
 534                 pg_addiu(&buf, A1, A1, 2 * off);
 535                 pg_addiu(&buf, A0, A0, 2 * off);
 536                 off = -off;
 537                 do {
 538                         build_copy_load(&buf, T0, off);
 539                         build_copy_load(&buf, T1, off + copy_word_size);
 540                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 541                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 542                         build_copy_store_pref(&buf, off);
 543                         build_copy_store(&buf, T0, off);
 544                         build_copy_store_pref(&buf, off + copy_word_size);
 545                         build_copy_store(&buf, T1, off + copy_word_size);
 546                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 547                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 548                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 549                         if (off == -(4 * copy_word_size))
 550                                 uasm_il_bne(&buf, &r, A2, A0,
 551                                             label_copy_pref_store);
 552                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 553                         off += 4 * copy_word_size;
 554                 } while (off < 0);
 555         }
 556
 557         if (pref_bias_copy_store) {
 558                 pg_addiu(&buf, A2, A0, pref_bias_copy_store);
 559                 uasm_l_copy_nopref(&l, buf);
 560                 off = 0;
 561                 do {
 562                         build_copy_load(&buf, T0, off);
 563                         build_copy_load(&buf, T1, off + copy_word_size);
 564                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 565                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 566                         build_copy_store(&buf, T0, off);
 567                         build_copy_store(&buf, T1, off + copy_word_size);
 568                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 569                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 570                         off += 4 * copy_word_size;
 571                 } while (off < half_copy_loop_size);
 572                 pg_addiu(&buf, A1, A1, 2 * off);
 573                 pg_addiu(&buf, A0, A0, 2 * off);
 574                 off = -off;
 575                 do {
 576                         build_copy_load(&buf, T0, off);
 577                         build_copy_load(&buf, T1, off + copy_word_size);
 578                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 579                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 580                         build_copy_store(&buf, T0, off);
 581                         build_copy_store(&buf, T1, off + copy_word_size);
 582                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 583                         if (off == -(4 * copy_word_size))
 584                                 uasm_il_bne(&buf, &r, A2, A0,
 585                                             label_copy_nopref);
 586                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 587                         off += 4 * copy_word_size;
 588                 } while (off < 0);
 589         }
 590
 591         uasm_i_jr(&buf, RA);
 592         uasm_i_nop(&buf);
 593
 594         BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array));
 595
 596         uasm_resolve_relocs(relocs, labels);
 597
 598         pr_debug("Synthesized copy page handler (%u instructions).\n",
 599                  (u32)(buf - copy_page_array));
 600
 601         pr_debug("\t.set push\n");
 602         pr_debug("\t.set noreorder\n");
 603         for (i = 0; i < (buf - copy_page_array); i++)
 604                 pr_debug("\t.word 0x%08x\n", copy_page_array[i]);
 605         pr_debug("\t.set pop\n");
 606 }
 607
 608 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 609
 610 /*
 611  * Pad descriptors to cacheline, since each is exclusively owned by a
 612  * particular CPU.
 613  */
 614 struct dmadscr {
 615         u64 dscr_a;
 616         u64 dscr_b;
 617         u64 pad_a;
 618         u64 pad_b;
 619 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
 620
 621 void sb1_dma_init(void)
 622 {
 623         int i;
 624
 625         for (i = 0; i < DM_NUM_CHANNELS; i++) {
 626                 const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
 627                                      V_DM_DSCR_BASE_RINGSZ(1);
 628                 void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
 629
 630                 __raw_writeq(base_val, base_reg);
 631                 __raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
 632                 __raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
 633         }
 634 }
 635
 636 void clear_page(void *page)
 637 {
 638         u64 to_phys = CPHYSADDR((unsigned long)page);
 639         unsigned int cpu = smp_processor_id();
 640
 641         /* if the page is not in KSEG0, use old way */
 642         if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
 643                 return clear_page_cpu(page);
 644
 645         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
 646                                  M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
 647         page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 648         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 649
 650         /*
 651          * Don't really want to do it this way, but there's no
 652          * reliable way to delay completion detection.
 653          */
 654         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 655                  & M_DM_DSCR_BASE_INTERRUPT))
 656                 ;
 657         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 658 }
 659
 660 void copy_page(void *to, void *from)
 661 {
 662         u64 from_phys = CPHYSADDR((unsigned long)from);
 663         u64 to_phys = CPHYSADDR((unsigned long)to);
 664         unsigned int cpu = smp_processor_id();
 665
 666         /* if any page is not in KSEG0, use old way */
 667         if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
 668             || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
 669                 return copy_page_cpu(to, from);
 670
 671         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
 672                                  M_DM_DSCRA_INTERRUPT;
 673         page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 674         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 675
 676         /*
 677          * Don't really want to do it this way, but there's no
 678          * reliable way to delay completion detection.
 679          */
 680         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 681                  & M_DM_DSCR_BASE_INTERRUPT))
 682                 ;
 683         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 684 }
 685
 686 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */