kernel/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  * Copyright (C) 2012  MIPS Technologies, Inc.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/smp.h>
  14 #include <linux/mm.h>
  15 #include <linux/module.h>
  16 #include <linux/proc_fs.h>
  17
  18 #include <asm/bugs.h>
  19 #include <asm/cacheops.h>
  20 #include <asm/cpu-type.h>
  21 #include <asm/inst.h>
  22 #include <asm/io.h>
  23 #include <asm/page.h>
  24 #include <asm/pgtable.h>
  25 #include <asm/prefetch.h>
  26 #include <asm/bootinfo.h>
  27 #include <asm/mipsregs.h>
  28 #include <asm/mmu_context.h>
  29 #include <asm/cpu.h>
  30 #include <asm/war.h>
  31
  32 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
  33 #include <asm/sibyte/sb1250.h>
  34 #include <asm/sibyte/sb1250_regs.h>
  35 #include <asm/sibyte/sb1250_dma.h>
  36 #endif
  37
  38 #include <asm/uasm.h>
  39
  40 /* Registers used in the assembled routines. */
  41 #define ZERO 0
  42 #define AT 2
  43 #define A0 4
  44 #define A1 5
  45 #define A2 6
  46 #define T0 8
  47 #define T1 9
  48 #define T2 10
  49 #define T3 11
  50 #define T9 25
  51 #define RA 31
  52
  53 /* Handle labels (which must be positive integers). */
  54 enum label_id {
  55         label_clear_nopref = 1,
  56         label_clear_pref,
  57         label_copy_nopref,
  58         label_copy_pref_both,
  59         label_copy_pref_store,
  60 };
  61
  62 UASM_L_LA(_clear_nopref)
  63 UASM_L_LA(_clear_pref)
  64 UASM_L_LA(_copy_nopref)
  65 UASM_L_LA(_copy_pref_both)
  66 UASM_L_LA(_copy_pref_store)
  67
  68 /* We need one branch and therefore one relocation per target label. */
  69 static struct uasm_label labels[5];
  70 static struct uasm_reloc relocs[5];
  71
  72 #define cpu_is_r4600_v1_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002010)
  73 #define cpu_is_r4600_v2_x()     ((read_c0_prid() & 0xfffffff0) == 0x00002020)
  74
  75 /*
  76  * R6 has a limited offset of the pref instruction.
  77  * Skip it if the offset is more than 9 bits.
  78  */
  79 #define _uasm_i_pref(a, b, c, d)                \
  80 do {                                            \
  81         if (cpu_has_mips_r6) {                  \
  82                 if (c <= 0xff && c >= -0x100)   \
  83                         uasm_i_pref(a, b, c, d);\
  84         } else {                                \
  85                 uasm_i_pref(a, b, c, d);        \
  86         }                                       \
  87 } while(0)
  88
  89 static int pref_bias_clear_store;
  90 static int pref_bias_copy_load;
  91 static int pref_bias_copy_store;
  92
  93 static u32 pref_src_mode;
  94 static u32 pref_dst_mode;
  95
  96 static int clear_word_size;
  97 static int copy_word_size;
  98
  99 static int half_clear_loop_size;
 100 static int half_copy_loop_size;
 101
 102 static int cache_line_size;
 103 #define cache_line_mask() (cache_line_size - 1)
 104
 105 static inline void
 106 pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
 107 {
 108         if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
 109                 if (off > 0x7fff) {
 110                         uasm_i_lui(buf, T9, uasm_rel_hi(off));
 111                         uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 112                 } else
 113                         uasm_i_addiu(buf, T9, ZERO, off);
 114                 uasm_i_daddu(buf, reg1, reg2, T9);
 115         } else {
 116                 if (off > 0x7fff) {
 117                         uasm_i_lui(buf, T9, uasm_rel_hi(off));
 118                         uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 119                         UASM_i_ADDU(buf, reg1, reg2, T9);
 120                 } else
 121                         UASM_i_ADDIU(buf, reg1, reg2, off);
 122         }
 123 }
 124
 125 static void set_prefetch_parameters(void)
 126 {
 127         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
 128                 clear_word_size = 8;
 129         else
 130                 clear_word_size = 4;
 131
 132         if (cpu_has_64bit_gp_regs)
 133                 copy_word_size = 8;
 134         else
 135                 copy_word_size = 4;
 136
 137         /*
 138          * The pref's used here are using "streaming" hints, which cause the
 139          * copied data to be kicked out of the cache sooner.  A page copy often
 140          * ends up copying a lot more data than is commonly used, so this seems
 141          * to make sense in terms of reducing cache pollution, but I've no real
 142          * performance data to back this up.
 143          */
 144         if (cpu_has_prefetch) {
 145                 /*
 146                  * XXX: Most prefetch bias values in here are based on
 147                  * guesswork.
 148                  */
 149                 cache_line_size = cpu_dcache_line_size();
 150                 switch (current_cpu_type()) {
 151                 case CPU_R5500:
 152                 case CPU_TX49XX:
 153                         /* These processors only support the Pref_Load. */
 154                         pref_bias_copy_load = 256;
 155                         break;
 156
 157                 case CPU_R10000:
 158                 case CPU_R12000:
 159                 case CPU_R14000:
 160                 case CPU_R16000:
 161                         /*
 162                          * Those values have been experimentally tuned for an
 163                          * Origin 200.
 164                          */
 165                         pref_bias_clear_store = 512;
 166                         pref_bias_copy_load = 256;
 167                         pref_bias_copy_store = 256;
 168                         pref_src_mode = Pref_LoadStreamed;
 169                         pref_dst_mode = Pref_StoreStreamed;
 170                         break;
 171
 172                 case CPU_SB1:
 173                 case CPU_SB1A:
 174                         pref_bias_clear_store = 128;
 175                         pref_bias_copy_load = 128;
 176                         pref_bias_copy_store = 128;
 177                         /*
 178                          * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
 179                          * hints are broken.
 180                          */
 181                         if (current_cpu_type() == CPU_SB1 &&
 182                             (current_cpu_data.processor_id & 0xff) < 0x02) {
 183                                 pref_src_mode = Pref_Load;
 184                                 pref_dst_mode = Pref_Store;
 185                         } else {
 186                                 pref_src_mode = Pref_LoadStreamed;
 187                                 pref_dst_mode = Pref_StoreStreamed;
 188                         }
 189                         break;
 190
 191                 default:
 192                         pref_bias_clear_store = 128;
 193                         pref_bias_copy_load = 256;
 194                         pref_bias_copy_store = 128;
 195                         pref_src_mode = Pref_LoadStreamed;
 196                         if (cpu_has_mips_r6)
 197                                 /*
 198                                  * Bit 30 (Pref_PrepareForStore) has been
 199                                  * removed from MIPS R6. Use bit 5
 200                                  * (Pref_StoreStreamed).
 201                                  */
 202                                 pref_dst_mode = Pref_StoreStreamed;
 203                         else
 204                                 pref_dst_mode = Pref_PrepareForStore;
 205                         break;
 206                 }
 207         } else {
 208                 if (cpu_has_cache_cdex_s)
 209                         cache_line_size = cpu_scache_line_size();
 210                 else if (cpu_has_cache_cdex_p)
 211                         cache_line_size = cpu_dcache_line_size();
 212         }
 213         /*
 214          * Too much unrolling will overflow the available space in
 215          * clear_space_array / copy_page_array.
 216          */
 217         half_clear_loop_size = min(16 * clear_word_size,
 218                                    max(cache_line_size >> 1,
 219                                        4 * clear_word_size));
 220         half_copy_loop_size = min(16 * copy_word_size,
 221                                   max(cache_line_size >> 1,
 222                                       4 * copy_word_size));
 223 }
 224
 225 static void build_clear_store(u32 **buf, int off)
 226 {
 227         if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
 228                 uasm_i_sd(buf, ZERO, off, A0);
 229         } else {
 230                 uasm_i_sw(buf, ZERO, off, A0);
 231         }
 232 }
 233
 234 static inline void build_clear_pref(u32 **buf, int off)
 235 {
 236         if (off & cache_line_mask())
 237                 return;
 238
 239         if (pref_bias_clear_store) {
 240                 _uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
 241                             A0);
 242         } else if (cache_line_size == (half_clear_loop_size << 1)) {
 243                 if (cpu_has_cache_cdex_s) {
 244                         uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 245                 } else if (cpu_has_cache_cdex_p) {
 246                         if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 247                                 uasm_i_nop(buf);
 248                                 uasm_i_nop(buf);
 249                                 uasm_i_nop(buf);
 250                                 uasm_i_nop(buf);
 251                         }
 252
 253                         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 254                                 uasm_i_lw(buf, ZERO, ZERO, AT);
 255
 256                         uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 257                 }
 258         }
 259 }
 260
 261 extern u32 __clear_page_start;
 262 extern u32 __clear_page_end;
 263 extern u32 __copy_page_start;
 264 extern u32 __copy_page_end;
 265
 266 void build_clear_page(void)
 267 {
 268         int off;
 269         u32 *buf = &__clear_page_start;
 270         struct uasm_label *l = labels;
 271         struct uasm_reloc *r = relocs;
 272         int i;
 273         static atomic_t run_once = ATOMIC_INIT(0);
 274
 275         if (atomic_xchg(&run_once, 1)) {
 276                 return;
 277         }
 278
 279         memset(labels, 0, sizeof(labels));
 280         memset(relocs, 0, sizeof(relocs));
 281
 282         set_prefetch_parameters();
 283
 284         /*
 285          * This algorithm makes the following assumptions:
 286          *   - The prefetch bias is a multiple of 2 words.
 287          *   - The prefetch bias is less than one page.
 288          */
 289         BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
 290         BUG_ON(PAGE_SIZE < pref_bias_clear_store);
 291
 292         off = PAGE_SIZE - pref_bias_clear_store;
 293         if (off > 0xffff || !pref_bias_clear_store)
 294                 pg_addiu(&buf, A2, A0, off);
 295         else
 296                 uasm_i_ori(&buf, A2, A0, off);
 297
 298         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 299                 uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
 300
 301         off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
 302                                 * cache_line_size : 0;
 303         while (off) {
 304                 build_clear_pref(&buf, -off);
 305                 off -= cache_line_size;
 306         }
 307         uasm_l_clear_pref(&l, buf);
 308         do {
 309                 build_clear_pref(&buf, off);
 310                 build_clear_store(&buf, off);
 311                 off += clear_word_size;
 312         } while (off < half_clear_loop_size);
 313         pg_addiu(&buf, A0, A0, 2 * off);
 314         off = -off;
 315         do {
 316                 build_clear_pref(&buf, off);
 317                 if (off == -clear_word_size)
 318                         uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
 319                 build_clear_store(&buf, off);
 320                 off += clear_word_size;
 321         } while (off < 0);
 322
 323         if (pref_bias_clear_store) {
 324                 pg_addiu(&buf, A2, A0, pref_bias_clear_store);
 325                 uasm_l_clear_nopref(&l, buf);
 326                 off = 0;
 327                 do {
 328                         build_clear_store(&buf, off);
 329                         off += clear_word_size;
 330                 } while (off < half_clear_loop_size);
 331                 pg_addiu(&buf, A0, A0, 2 * off);
 332                 off = -off;
 333                 do {
 334                         if (off == -clear_word_size)
 335                                 uasm_il_bne(&buf, &r, A0, A2,
 336                                             label_clear_nopref);
 337                         build_clear_store(&buf, off);
 338                         off += clear_word_size;
 339                 } while (off < 0);
 340         }
 341
 342         uasm_i_jr(&buf, RA);
 343         uasm_i_nop(&buf);
 344
 345         BUG_ON(buf > &__clear_page_end);
 346
 347         uasm_resolve_relocs(relocs, labels);
 348
 349         pr_debug("Synthesized clear page handler (%u instructions).\n",
 350                  (u32)(buf - &__clear_page_start));
 351
 352         pr_debug("\t.set push\n");
 353         pr_debug("\t.set noreorder\n");
 354         for (i = 0; i < (buf - &__clear_page_start); i++)
 355                 pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
 356         pr_debug("\t.set pop\n");
 357 }
 358
 359 static void build_copy_load(u32 **buf, int reg, int off)
 360 {
 361         if (cpu_has_64bit_gp_regs) {
 362                 uasm_i_ld(buf, reg, off, A1);
 363         } else {
 364                 uasm_i_lw(buf, reg, off, A1);
 365         }
 366 }
 367
 368 static void build_copy_store(u32 **buf, int reg, int off)
 369 {
 370         if (cpu_has_64bit_gp_regs) {
 371                 uasm_i_sd(buf, reg, off, A0);
 372         } else {
 373                 uasm_i_sw(buf, reg, off, A0);
 374         }
 375 }
 376
 377 static inline void build_copy_load_pref(u32 **buf, int off)
 378 {
 379         if (off & cache_line_mask())
 380                 return;
 381
 382         if (pref_bias_copy_load)
 383                 _uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
 384 }
 385
 386 static inline void build_copy_store_pref(u32 **buf, int off)
 387 {
 388         if (off & cache_line_mask())
 389                 return;
 390
 391         if (pref_bias_copy_store) {
 392                 _uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
 393                             A0);
 394         } else if (cache_line_size == (half_copy_loop_size << 1)) {
 395                 if (cpu_has_cache_cdex_s) {
 396                         uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 397                 } else if (cpu_has_cache_cdex_p) {
 398                         if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 399                                 uasm_i_nop(buf);
 400                                 uasm_i_nop(buf);
 401                                 uasm_i_nop(buf);
 402                                 uasm_i_nop(buf);
 403                         }
 404
 405                         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 406                                 uasm_i_lw(buf, ZERO, ZERO, AT);
 407
 408                         uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 409                 }
 410         }
 411 }
 412
 413 void build_copy_page(void)
 414 {
 415         int off;
 416         u32 *buf = &__copy_page_start;
 417         struct uasm_label *l = labels;
 418         struct uasm_reloc *r = relocs;
 419         int i;
 420         static atomic_t run_once = ATOMIC_INIT(0);
 421
 422         if (atomic_xchg(&run_once, 1)) {
 423                 return;
 424         }
 425
 426         memset(labels, 0, sizeof(labels));
 427         memset(relocs, 0, sizeof(relocs));
 428
 429         set_prefetch_parameters();
 430
 431         /*
 432          * This algorithm makes the following assumptions:
 433          *   - All prefetch biases are multiples of 8 words.
 434          *   - The prefetch biases are less than one page.
 435          *   - The store prefetch bias isn't greater than the load
 436          *     prefetch bias.
 437          */
 438         BUG_ON(pref_bias_copy_load % (8 * copy_word_size));
 439         BUG_ON(pref_bias_copy_store % (8 * copy_word_size));
 440         BUG_ON(PAGE_SIZE < pref_bias_copy_load);
 441         BUG_ON(pref_bias_copy_store > pref_bias_copy_load);
 442
 443         off = PAGE_SIZE - pref_bias_copy_load;
 444         if (off > 0xffff || !pref_bias_copy_load)
 445                 pg_addiu(&buf, A2, A0, off);
 446         else
 447                 uasm_i_ori(&buf, A2, A0, off);
 448
 449         if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 450                 uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
 451
 452         off = cache_line_size ? min(8, pref_bias_copy_load / cache_line_size) *
 453                                 cache_line_size : 0;
 454         while (off) {
 455                 build_copy_load_pref(&buf, -off);
 456                 off -= cache_line_size;
 457         }
 458         off = cache_line_size ? min(8, pref_bias_copy_store / cache_line_size) *
 459                                 cache_line_size : 0;
 460         while (off) {
 461                 build_copy_store_pref(&buf, -off);
 462                 off -= cache_line_size;
 463         }
 464         uasm_l_copy_pref_both(&l, buf);
 465         do {
 466                 build_copy_load_pref(&buf, off);
 467                 build_copy_load(&buf, T0, off);
 468                 build_copy_load_pref(&buf, off + copy_word_size);
 469                 build_copy_load(&buf, T1, off + copy_word_size);
 470                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 471                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 472                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 473                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 474                 build_copy_store_pref(&buf, off);
 475                 build_copy_store(&buf, T0, off);
 476                 build_copy_store_pref(&buf, off + copy_word_size);
 477                 build_copy_store(&buf, T1, off + copy_word_size);
 478                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 479                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 480                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 481                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 482                 off += 4 * copy_word_size;
 483         } while (off < half_copy_loop_size);
 484         pg_addiu(&buf, A1, A1, 2 * off);
 485         pg_addiu(&buf, A0, A0, 2 * off);
 486         off = -off;
 487         do {
 488                 build_copy_load_pref(&buf, off);
 489                 build_copy_load(&buf, T0, off);
 490                 build_copy_load_pref(&buf, off + copy_word_size);
 491                 build_copy_load(&buf, T1, off + copy_word_size);
 492                 build_copy_load_pref(&buf, off + 2 * copy_word_size);
 493                 build_copy_load(&buf, T2, off + 2 * copy_word_size);
 494                 build_copy_load_pref(&buf, off + 3 * copy_word_size);
 495                 build_copy_load(&buf, T3, off + 3 * copy_word_size);
 496                 build_copy_store_pref(&buf, off);
 497                 build_copy_store(&buf, T0, off);
 498                 build_copy_store_pref(&buf, off + copy_word_size);
 499                 build_copy_store(&buf, T1, off + copy_word_size);
 500                 build_copy_store_pref(&buf, off + 2 * copy_word_size);
 501                 build_copy_store(&buf, T2, off + 2 * copy_word_size);
 502                 build_copy_store_pref(&buf, off + 3 * copy_word_size);
 503                 if (off == -(4 * copy_word_size))
 504                         uasm_il_bne(&buf, &r, A2, A0, label_copy_pref_both);
 505                 build_copy_store(&buf, T3, off + 3 * copy_word_size);
 506                 off += 4 * copy_word_size;
 507         } while (off < 0);
 508
 509         if (pref_bias_copy_load - pref_bias_copy_store) {
 510                 pg_addiu(&buf, A2, A0,
 511                          pref_bias_copy_load - pref_bias_copy_store);
 512                 uasm_l_copy_pref_store(&l, buf);
 513                 off = 0;
 514                 do {
 515                         build_copy_load(&buf, T0, off);
 516                         build_copy_load(&buf, T1, off + copy_word_size);
 517                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 518                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 519                         build_copy_store_pref(&buf, off);
 520                         build_copy_store(&buf, T0, off);
 521                         build_copy_store_pref(&buf, off + copy_word_size);
 522                         build_copy_store(&buf, T1, off + copy_word_size);
 523                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 524                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 525                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 526                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 527                         off += 4 * copy_word_size;
 528                 } while (off < half_copy_loop_size);
 529                 pg_addiu(&buf, A1, A1, 2 * off);
 530                 pg_addiu(&buf, A0, A0, 2 * off);
 531                 off = -off;
 532                 do {
 533                         build_copy_load(&buf, T0, off);
 534                         build_copy_load(&buf, T1, off + copy_word_size);
 535                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 536                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 537                         build_copy_store_pref(&buf, off);
 538                         build_copy_store(&buf, T0, off);
 539                         build_copy_store_pref(&buf, off + copy_word_size);
 540                         build_copy_store(&buf, T1, off + copy_word_size);
 541                         build_copy_store_pref(&buf, off + 2 * copy_word_size);
 542                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 543                         build_copy_store_pref(&buf, off + 3 * copy_word_size);
 544                         if (off == -(4 * copy_word_size))
 545                                 uasm_il_bne(&buf, &r, A2, A0,
 546                                             label_copy_pref_store);
 547                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 548                         off += 4 * copy_word_size;
 549                 } while (off < 0);
 550         }
 551
 552         if (pref_bias_copy_store) {
 553                 pg_addiu(&buf, A2, A0, pref_bias_copy_store);
 554                 uasm_l_copy_nopref(&l, buf);
 555                 off = 0;
 556                 do {
 557                         build_copy_load(&buf, T0, off);
 558                         build_copy_load(&buf, T1, off + copy_word_size);
 559                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 560                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 561                         build_copy_store(&buf, T0, off);
 562                         build_copy_store(&buf, T1, off + copy_word_size);
 563                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 564                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 565                         off += 4 * copy_word_size;
 566                 } while (off < half_copy_loop_size);
 567                 pg_addiu(&buf, A1, A1, 2 * off);
 568                 pg_addiu(&buf, A0, A0, 2 * off);
 569                 off = -off;
 570                 do {
 571                         build_copy_load(&buf, T0, off);
 572                         build_copy_load(&buf, T1, off + copy_word_size);
 573                         build_copy_load(&buf, T2, off + 2 * copy_word_size);
 574                         build_copy_load(&buf, T3, off + 3 * copy_word_size);
 575                         build_copy_store(&buf, T0, off);
 576                         build_copy_store(&buf, T1, off + copy_word_size);
 577                         build_copy_store(&buf, T2, off + 2 * copy_word_size);
 578                         if (off == -(4 * copy_word_size))
 579                                 uasm_il_bne(&buf, &r, A2, A0,
 580                                             label_copy_nopref);
 581                         build_copy_store(&buf, T3, off + 3 * copy_word_size);
 582                         off += 4 * copy_word_size;
 583                 } while (off < 0);
 584         }
 585
 586         uasm_i_jr(&buf, RA);
 587         uasm_i_nop(&buf);
 588
 589         BUG_ON(buf > &__copy_page_end);
 590
 591         uasm_resolve_relocs(relocs, labels);
 592
 593         pr_debug("Synthesized copy page handler (%u instructions).\n",
 594                  (u32)(buf - &__copy_page_start));
 595
 596         pr_debug("\t.set push\n");
 597         pr_debug("\t.set noreorder\n");
 598         for (i = 0; i < (buf - &__copy_page_start); i++)
 599                 pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
 600         pr_debug("\t.set pop\n");
 601 }
 602
 603 #ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 604 extern void clear_page_cpu(void *page);
 605 extern void copy_page_cpu(void *to, void *from);
 606
 607 /*
 608  * Pad descriptors to cacheline, since each is exclusively owned by a
 609  * particular CPU.
 610  */
 611 struct dmadscr {
 612         u64 dscr_a;
 613         u64 dscr_b;
 614         u64 pad_a;
 615         u64 pad_b;
 616 } ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
 617
 618 void sb1_dma_init(void)
 619 {
 620         int i;
 621
 622         for (i = 0; i < DM_NUM_CHANNELS; i++) {
 623                 const u64 base_val = CPHYSADDR((unsigned long)&page_descr[i]) |
 624                                      V_DM_DSCR_BASE_RINGSZ(1);
 625                 void *base_reg = IOADDR(A_DM_REGISTER(i, R_DM_DSCR_BASE));
 626
 627                 __raw_writeq(base_val, base_reg);
 628                 __raw_writeq(base_val | M_DM_DSCR_BASE_RESET, base_reg);
 629                 __raw_writeq(base_val | M_DM_DSCR_BASE_ENABL, base_reg);
 630         }
 631 }
 632
 633 void clear_page(void *page)
 634 {
 635         u64 to_phys = CPHYSADDR((unsigned long)page);
 636         unsigned int cpu = smp_processor_id();
 637
 638         /* if the page is not in KSEG0, use old way */
 639         if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
 640                 return clear_page_cpu(page);
 641
 642         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
 643                                  M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
 644         page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 645         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 646
 647         /*
 648          * Don't really want to do it this way, but there's no
 649          * reliable way to delay completion detection.
 650          */
 651         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 652                  & M_DM_DSCR_BASE_INTERRUPT))
 653                 ;
 654         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 655 }
 656
 657 void copy_page(void *to, void *from)
 658 {
 659         u64 from_phys = CPHYSADDR((unsigned long)from);
 660         u64 to_phys = CPHYSADDR((unsigned long)to);
 661         unsigned int cpu = smp_processor_id();
 662
 663         /* if any page is not in KSEG0, use old way */
 664         if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
 665             || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
 666                 return copy_page_cpu(to, from);
 667
 668         page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
 669                                  M_DM_DSCRA_INTERRUPT;
 670         page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 671         __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 672
 673         /*
 674          * Don't really want to do it this way, but there's no
 675          * reliable way to delay completion detection.
 676          */
 677         while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 678                  & M_DM_DSCR_BASE_INTERRUPT))
 679                 ;
 680         __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 681 }
 682
 683 #endif /* CONFIG_SIBYTE_DMA_PAGEOPS */