linux/arch/mips/mm/page.c
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   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/proc_fs.h>
  16
  17#include <asm/bugs.h>
  18#include <asm/cacheops.h>
  19#include <asm/cpu-type.h>
  20#include <asm/inst.h>
  21#include <asm/io.h>
  22#include <asm/page.h>
  23#include <asm/pgtable.h>
  24#include <asm/prefetch.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 <asm/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). */
  53enum 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
  61UASM_L_LA(_clear_nopref)
  62UASM_L_LA(_clear_pref)
  63UASM_L_LA(_copy_nopref)
  64UASM_L_LA(_copy_pref_both)
  65UASM_L_LA(_copy_pref_store)
  66
  67/* We need one branch and therefore one relocation per target label. */
  68static struct uasm_label labels[5];
  69static struct uasm_reloc 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 * R6 has a limited offset of the pref instruction.
  76 * Skip it if the offset is more than 9 bits.
  77 */
  78#define _uasm_i_pref(a, b, c, d)                \
  79do {                                            \
  80        if (cpu_has_mips_r6) {                  \
  81                if (c <= 0xff && c >= -0x100)   \
  82                        uasm_i_pref(a, b, c, d);\
  83        } else {                                \
  84                uasm_i_pref(a, b, c, d);        \
  85        }                                       \
  86} while(0)
  87
  88static int pref_bias_clear_store;
  89static int pref_bias_copy_load;
  90static int pref_bias_copy_store;
  91
  92static u32 pref_src_mode;
  93static u32 pref_dst_mode;
  94
  95static int clear_word_size;
  96static int copy_word_size;
  97
  98static int half_clear_loop_size;
  99static int half_copy_loop_size;
 100
 101static int cache_line_size;
 102#define cache_line_mask() (cache_line_size - 1)
 103
 104static inline void
 105pg_addiu(u32 **buf, unsigned int reg1, unsigned int reg2, unsigned int off)
 106{
 107        if (cpu_has_64bit_gp_regs && DADDI_WAR && r4k_daddiu_bug()) {
 108                if (off > 0x7fff) {
 109                        uasm_i_lui(buf, T9, uasm_rel_hi(off));
 110                        uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 111                } else
 112                        uasm_i_addiu(buf, T9, ZERO, off);
 113                uasm_i_daddu(buf, reg1, reg2, T9);
 114        } else {
 115                if (off > 0x7fff) {
 116                        uasm_i_lui(buf, T9, uasm_rel_hi(off));
 117                        uasm_i_addiu(buf, T9, T9, uasm_rel_lo(off));
 118                        UASM_i_ADDU(buf, reg1, reg2, T9);
 119                } else
 120                        UASM_i_ADDIU(buf, reg1, reg2, off);
 121        }
 122}
 123
 124static void set_prefetch_parameters(void)
 125{
 126        if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg)
 127                clear_word_size = 8;
 128        else
 129                clear_word_size = 4;
 130
 131        if (cpu_has_64bit_gp_regs)
 132                copy_word_size = 8;
 133        else
 134                copy_word_size = 4;
 135
 136        /*
 137         * The pref's used here are using "streaming" hints, which cause the
 138         * copied data to be kicked out of the cache sooner.  A page copy often
 139         * ends up copying a lot more data than is commonly used, so this seems
 140         * to make sense in terms of reducing cache pollution, but I've no real
 141         * performance data to back this up.
 142         */
 143        if (cpu_has_prefetch) {
 144                /*
 145                 * XXX: Most prefetch bias values in here are based on
 146                 * guesswork.
 147                 */
 148                cache_line_size = cpu_dcache_line_size();
 149                switch (current_cpu_type()) {
 150                case CPU_R5500:
 151                case CPU_TX49XX:
 152                        /* These processors only support the Pref_Load. */
 153                        pref_bias_copy_load = 256;
 154                        break;
 155
 156                case CPU_R10000:
 157                case CPU_R12000:
 158                case CPU_R14000:
 159                case CPU_R16000:
 160                        /*
 161                         * Those values have been experimentally tuned for an
 162                         * Origin 200.
 163                         */
 164                        pref_bias_clear_store = 512;
 165                        pref_bias_copy_load = 256;
 166                        pref_bias_copy_store = 256;
 167                        pref_src_mode = Pref_LoadStreamed;
 168                        pref_dst_mode = Pref_StoreStreamed;
 169                        break;
 170
 171                case CPU_SB1:
 172                case CPU_SB1A:
 173                        pref_bias_clear_store = 128;
 174                        pref_bias_copy_load = 128;
 175                        pref_bias_copy_store = 128;
 176                        /*
 177                         * SB1 pass1 Pref_LoadStreamed/Pref_StoreStreamed
 178                         * hints are broken.
 179                         */
 180                        if (current_cpu_type() == CPU_SB1 &&
 181                            (current_cpu_data.processor_id & 0xff) < 0x02) {
 182                                pref_src_mode = Pref_Load;
 183                                pref_dst_mode = Pref_Store;
 184                        } else {
 185                                pref_src_mode = Pref_LoadStreamed;
 186                                pref_dst_mode = Pref_StoreStreamed;
 187                        }
 188                        break;
 189
 190                case CPU_LOONGSON64:
 191                        /* Loongson-3 only support the Pref_Load/Pref_Store. */
 192                        pref_bias_clear_store = 128;
 193                        pref_bias_copy_load = 128;
 194                        pref_bias_copy_store = 128;
 195                        pref_src_mode = Pref_Load;
 196                        pref_dst_mode = Pref_Store;
 197                        break;
 198
 199                default:
 200                        pref_bias_clear_store = 128;
 201                        pref_bias_copy_load = 256;
 202                        pref_bias_copy_store = 128;
 203                        pref_src_mode = Pref_LoadStreamed;
 204                        if (cpu_has_mips_r6)
 205                                /*
 206                                 * Bit 30 (Pref_PrepareForStore) has been
 207                                 * removed from MIPS R6. Use bit 5
 208                                 * (Pref_StoreStreamed).
 209                                 */
 210                                pref_dst_mode = Pref_StoreStreamed;
 211                        else
 212                                pref_dst_mode = Pref_PrepareForStore;
 213                        break;
 214                }
 215        } else {
 216                if (cpu_has_cache_cdex_s)
 217                        cache_line_size = cpu_scache_line_size();
 218                else if (cpu_has_cache_cdex_p)
 219                        cache_line_size = cpu_dcache_line_size();
 220        }
 221        /*
 222         * Too much unrolling will overflow the available space in
 223         * clear_space_array / copy_page_array.
 224         */
 225        half_clear_loop_size = min(16 * clear_word_size,
 226                                   max(cache_line_size >> 1,
 227                                       4 * clear_word_size));
 228        half_copy_loop_size = min(16 * copy_word_size,
 229                                  max(cache_line_size >> 1,
 230                                      4 * copy_word_size));
 231}
 232
 233static void build_clear_store(u32 **buf, int off)
 234{
 235        if (cpu_has_64bit_gp_regs || cpu_has_64bit_zero_reg) {
 236                uasm_i_sd(buf, ZERO, off, A0);
 237        } else {
 238                uasm_i_sw(buf, ZERO, off, A0);
 239        }
 240}
 241
 242static inline void build_clear_pref(u32 **buf, int off)
 243{
 244        if (off & cache_line_mask())
 245                return;
 246
 247        if (pref_bias_clear_store) {
 248                _uasm_i_pref(buf, pref_dst_mode, pref_bias_clear_store + off,
 249                            A0);
 250        } else if (cache_line_size == (half_clear_loop_size << 1)) {
 251                if (cpu_has_cache_cdex_s) {
 252                        uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 253                } else if (cpu_has_cache_cdex_p) {
 254                        if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 255                                uasm_i_nop(buf);
 256                                uasm_i_nop(buf);
 257                                uasm_i_nop(buf);
 258                                uasm_i_nop(buf);
 259                        }
 260
 261                        if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 262                                uasm_i_lw(buf, ZERO, ZERO, AT);
 263
 264                        uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 265                }
 266        }
 267}
 268
 269extern u32 __clear_page_start;
 270extern u32 __clear_page_end;
 271extern u32 __copy_page_start;
 272extern u32 __copy_page_end;
 273
 274void build_clear_page(void)
 275{
 276        int off;
 277        u32 *buf = &__clear_page_start;
 278        struct uasm_label *l = labels;
 279        struct uasm_reloc *r = relocs;
 280        int i;
 281        static atomic_t run_once = ATOMIC_INIT(0);
 282
 283        if (atomic_xchg(&run_once, 1)) {
 284                return;
 285        }
 286
 287        memset(labels, 0, sizeof(labels));
 288        memset(relocs, 0, sizeof(relocs));
 289
 290        set_prefetch_parameters();
 291
 292        /*
 293         * This algorithm makes the following assumptions:
 294         *   - The prefetch bias is a multiple of 2 words.
 295         *   - The prefetch bias is less than one page.
 296         */
 297        BUG_ON(pref_bias_clear_store % (2 * clear_word_size));
 298        BUG_ON(PAGE_SIZE < pref_bias_clear_store);
 299
 300        off = PAGE_SIZE - pref_bias_clear_store;
 301        if (off > 0xffff || !pref_bias_clear_store)
 302                pg_addiu(&buf, A2, A0, off);
 303        else
 304                uasm_i_ori(&buf, A2, A0, off);
 305
 306        if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 307                uasm_i_lui(&buf, AT, uasm_rel_hi(0xa0000000));
 308
 309        off = cache_line_size ? min(8, pref_bias_clear_store / cache_line_size)
 310                                * cache_line_size : 0;
 311        while (off) {
 312                build_clear_pref(&buf, -off);
 313                off -= cache_line_size;
 314        }
 315        uasm_l_clear_pref(&l, buf);
 316        do {
 317                build_clear_pref(&buf, off);
 318                build_clear_store(&buf, off);
 319                off += clear_word_size;
 320        } while (off < half_clear_loop_size);
 321        pg_addiu(&buf, A0, A0, 2 * off);
 322        off = -off;
 323        do {
 324                build_clear_pref(&buf, off);
 325                if (off == -clear_word_size)
 326                        uasm_il_bne(&buf, &r, A0, A2, label_clear_pref);
 327                build_clear_store(&buf, off);
 328                off += clear_word_size;
 329        } while (off < 0);
 330
 331        if (pref_bias_clear_store) {
 332                pg_addiu(&buf, A2, A0, pref_bias_clear_store);
 333                uasm_l_clear_nopref(&l, buf);
 334                off = 0;
 335                do {
 336                        build_clear_store(&buf, off);
 337                        off += clear_word_size;
 338                } while (off < half_clear_loop_size);
 339                pg_addiu(&buf, A0, A0, 2 * off);
 340                off = -off;
 341                do {
 342                        if (off == -clear_word_size)
 343                                uasm_il_bne(&buf, &r, A0, A2,
 344                                            label_clear_nopref);
 345                        build_clear_store(&buf, off);
 346                        off += clear_word_size;
 347                } while (off < 0);
 348        }
 349
 350        uasm_i_jr(&buf, RA);
 351        uasm_i_nop(&buf);
 352
 353        BUG_ON(buf > &__clear_page_end);
 354
 355        uasm_resolve_relocs(relocs, labels);
 356
 357        pr_debug("Synthesized clear page handler (%u instructions).\n",
 358                 (u32)(buf - &__clear_page_start));
 359
 360        pr_debug("\t.set push\n");
 361        pr_debug("\t.set noreorder\n");
 362        for (i = 0; i < (buf - &__clear_page_start); i++)
 363                pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]);
 364        pr_debug("\t.set pop\n");
 365}
 366
 367static void build_copy_load(u32 **buf, int reg, int off)
 368{
 369        if (cpu_has_64bit_gp_regs) {
 370                uasm_i_ld(buf, reg, off, A1);
 371        } else {
 372                uasm_i_lw(buf, reg, off, A1);
 373        }
 374}
 375
 376static void build_copy_store(u32 **buf, int reg, int off)
 377{
 378        if (cpu_has_64bit_gp_regs) {
 379                uasm_i_sd(buf, reg, off, A0);
 380        } else {
 381                uasm_i_sw(buf, reg, off, A0);
 382        }
 383}
 384
 385static inline void build_copy_load_pref(u32 **buf, int off)
 386{
 387        if (off & cache_line_mask())
 388                return;
 389
 390        if (pref_bias_copy_load)
 391                _uasm_i_pref(buf, pref_src_mode, pref_bias_copy_load + off, A1);
 392}
 393
 394static inline void build_copy_store_pref(u32 **buf, int off)
 395{
 396        if (off & cache_line_mask())
 397                return;
 398
 399        if (pref_bias_copy_store) {
 400                _uasm_i_pref(buf, pref_dst_mode, pref_bias_copy_store + off,
 401                            A0);
 402        } else if (cache_line_size == (half_copy_loop_size << 1)) {
 403                if (cpu_has_cache_cdex_s) {
 404                        uasm_i_cache(buf, Create_Dirty_Excl_SD, off, A0);
 405                } else if (cpu_has_cache_cdex_p) {
 406                        if (R4600_V1_HIT_CACHEOP_WAR && cpu_is_r4600_v1_x()) {
 407                                uasm_i_nop(buf);
 408                                uasm_i_nop(buf);
 409                                uasm_i_nop(buf);
 410                                uasm_i_nop(buf);
 411                        }
 412
 413                        if (R4600_V2_HIT_CACHEOP_WAR && cpu_is_r4600_v2_x())
 414                                uasm_i_lw(buf, ZERO, ZERO, AT);
 415
 416                        uasm_i_cache(buf, Create_Dirty_Excl_D, off, A0);
 417                }
 418        }
 419}
 420
 421void build_copy_page(void)
 422{
 423        int off;
 424        u32 *buf = &__copy_page_start;
 425        struct uasm_label *l = labels;
 426        struct uasm_reloc *r = relocs;
 427        int i;
 428        static atomic_t run_once = ATOMIC_INIT(0);
 429
 430        if (atomic_xchg(&run_once, 1)) {
 431                return;
 432        }
 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, uasm_rel_hi(0xa0000000));
 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_end);
 598
 599        uasm_resolve_relocs(relocs, labels);
 600
 601        pr_debug("Synthesized copy page handler (%u instructions).\n",
 602                 (u32)(buf - &__copy_page_start));
 603
 604        pr_debug("\t.set push\n");
 605        pr_debug("\t.set noreorder\n");
 606        for (i = 0; i < (buf - &__copy_page_start); i++)
 607                pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]);
 608        pr_debug("\t.set pop\n");
 609}
 610
 611#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
 612extern void clear_page_cpu(void *page);
 613extern void copy_page_cpu(void *to, void *from);
 614
 615/*
 616 * Pad descriptors to cacheline, since each is exclusively owned by a
 617 * particular CPU.
 618 */
 619struct dmadscr {
 620        u64 dscr_a;
 621        u64 dscr_b;
 622        u64 pad_a;
 623        u64 pad_b;
 624} ____cacheline_aligned_in_smp page_descr[DM_NUM_CHANNELS];
 625
 626void clear_page(void *page)
 627{
 628        u64 to_phys = CPHYSADDR((unsigned long)page);
 629        unsigned int cpu = smp_processor_id();
 630
 631        /* if the page is not in KSEG0, use old way */
 632        if ((long)KSEGX((unsigned long)page) != (long)CKSEG0)
 633                return clear_page_cpu(page);
 634
 635        page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_ZERO_MEM |
 636                                 M_DM_DSCRA_L2C_DEST | M_DM_DSCRA_INTERRUPT;
 637        page_descr[cpu].dscr_b = V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 638        __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 639
 640        /*
 641         * Don't really want to do it this way, but there's no
 642         * reliable way to delay completion detection.
 643         */
 644        while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 645                 & M_DM_DSCR_BASE_INTERRUPT))
 646                ;
 647        __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 648}
 649EXPORT_SYMBOL(clear_page);
 650
 651void copy_page(void *to, void *from)
 652{
 653        u64 from_phys = CPHYSADDR((unsigned long)from);
 654        u64 to_phys = CPHYSADDR((unsigned long)to);
 655        unsigned int cpu = smp_processor_id();
 656
 657        /* if any page is not in KSEG0, use old way */
 658        if ((long)KSEGX((unsigned long)to) != (long)CKSEG0
 659            || (long)KSEGX((unsigned long)from) != (long)CKSEG0)
 660                return copy_page_cpu(to, from);
 661
 662        page_descr[cpu].dscr_a = to_phys | M_DM_DSCRA_L2C_DEST |
 663                                 M_DM_DSCRA_INTERRUPT;
 664        page_descr[cpu].dscr_b = from_phys | V_DM_DSCRB_SRC_LENGTH(PAGE_SIZE);
 665        __raw_writeq(1, IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_COUNT)));
 666
 667        /*
 668         * Don't really want to do it this way, but there's no
 669         * reliable way to delay completion detection.
 670         */
 671        while (!(__raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE_DEBUG)))
 672                 & M_DM_DSCR_BASE_INTERRUPT))
 673                ;
 674        __raw_readq(IOADDR(A_DM_REGISTER(cpu, R_DM_DSCR_BASE)));
 675}
 676EXPORT_SYMBOL(copy_page);
 677
 678#endif /* CONFIG_SIBYTE_DMA_PAGEOPS */
 679