drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c

   1 /*
   2  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
   3  * Copyright (C) 2013 Red Hat
   4  * Author: Rob Clark <robdclark@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #include "mdp5_kms.h"
  21 #include "mdp5_smp.h"
  22
  23
  24 /* SMP - Shared Memory Pool
  25  *
  26  * These are shared between all the clients, where each plane in a
  27  * scanout buffer is a SMP client.  Ie. scanout of 3 plane I420 on
  28  * pipe VIG0 => 3 clients: VIG0_Y, VIG0_CB, VIG0_CR.
  29  *
  30  * Based on the size of the attached scanout buffer, a certain # of
  31  * blocks must be allocated to that client out of the shared pool.
  32  *
  33  * In some hw, some blocks are statically allocated for certain pipes
  34  * and CANNOT be re-allocated (eg: MMB0 and MMB1 both tied to RGB0).
  35  *
  36  * For each block that can be dynamically allocated, it can be either
  37  *     free:
  38  *     The block is free.
  39  *
  40  *     pending:
  41  *     The block is allocated to some client and not free.
  42  *
  43  *     configured:
  44  *     The block is allocated to some client, and assigned to that
  45  *     client in MDP5_SMP_ALLOC registers.
  46  *
  47  *     inuse:
  48  *     The block is being actively used by a client.
  49  *
  50  * The updates happen in the following steps:
  51  *
  52  *  1) mdp5_smp_request():
  53  *     When plane scanout is setup, calculate required number of
  54  *     blocks needed per client, and request. Blocks neither inuse nor
  55  *     configured nor pending by any other client are added to client's
  56  *     pending set.
  57  *     For shrinking, blocks in pending but not in configured can be freed
  58  *     directly, but those already in configured will be freed later by
  59  *     mdp5_smp_commit.
  60  *
  61  *  2) mdp5_smp_configure():
  62  *     As hw is programmed, before FLUSH, MDP5_SMP_ALLOC registers
  63  *     are configured for the union(pending, inuse)
  64  *     Current pending is copied to configured.
  65  *     It is assumed that mdp5_smp_request and mdp5_smp_configure not run
  66  *     concurrently for the same pipe.
  67  *
  68  *  3) mdp5_smp_commit():
  69  *     After next vblank, copy configured -> inuse.  Optionally update
  70  *     MDP5_SMP_ALLOC registers if there are newly unused blocks
  71  *
  72  *  4) mdp5_smp_release():
  73  *     Must be called after the pipe is disabled and no longer uses any SMB
  74  *
  75  * On the next vblank after changes have been committed to hw, the
  76  * client's pending blocks become it's in-use blocks (and no-longer
  77  * in-use blocks become available to other clients).
  78  *
  79  * btw, hurray for confusing overloaded acronyms!  :-/
  80  *
  81  * NOTE: for atomic modeset/pageflip NONBLOCK operations, step #1
  82  * should happen at (or before)? atomic->check().  And we'd need
  83  * an API to discard previous requests if update is aborted or
  84  * (test-only).
  85  *
  86  * TODO would perhaps be nice to have debugfs to dump out kernel
  87  * inuse and pending state of all clients..
  88  */
  89
  90 struct mdp5_smp {
  91         struct drm_device *dev;
  92
  93         uint8_t reserved[MAX_CLIENTS]; /* fixed MMBs allocation per client */
  94
  95         int blk_cnt;
  96         int blk_size;
  97
  98         spinlock_t state_lock;
  99         mdp5_smp_state_t state; /* to track smp allocation amongst pipes: */
 100
 101         struct mdp5_client_smp_state client_state[MAX_CLIENTS];
 102 };
 103
 104 static void update_smp_state(struct mdp5_smp *smp,
 105                 u32 cid, mdp5_smp_state_t *assigned);
 106
 107 static inline
 108 struct mdp5_kms *get_kms(struct mdp5_smp *smp)
 109 {
 110         struct msm_drm_private *priv = smp->dev->dev_private;
 111
 112         return to_mdp5_kms(to_mdp_kms(priv->kms));
 113 }
 114
 115 static inline u32 pipe2client(enum mdp5_pipe pipe, int plane)
 116 {
 117 #define CID_UNUSED      0
 118
 119         if (WARN_ON(plane >= pipe2nclients(pipe)))
 120                 return CID_UNUSED;
 121
 122         /*
 123          * Note on SMP clients:
 124          * For ViG pipes, fetch Y/Cr/Cb-components clients are always
 125          * consecutive, and in that order.
 126          *
 127          * e.g.:
 128          * if mdp5_cfg->smp.clients[SSPP_VIG0] = N,
 129          *      Y  plane's client ID is N
 130          *      Cr plane's client ID is N + 1
 131          *      Cb plane's client ID is N + 2
 132          */
 133
 134         return mdp5_cfg->smp.clients[pipe] + plane;
 135 }
 136
 137 /* step #1: update # of blocks pending for the client: */
 138 static int smp_request_block(struct mdp5_smp *smp,
 139                 u32 cid, int nblks)
 140 {
 141         struct mdp5_kms *mdp5_kms = get_kms(smp);
 142         struct mdp5_client_smp_state *ps = &smp->client_state[cid];
 143         int i, ret, avail, cur_nblks, cnt = smp->blk_cnt;
 144         uint8_t reserved;
 145         unsigned long flags;
 146
 147         reserved = smp->reserved[cid];
 148
 149         spin_lock_irqsave(&smp->state_lock, flags);
 150
 151         if (reserved) {
 152                 nblks = max(0, nblks - reserved);
 153                 DBG("%d MMBs allocated (%d reserved)", nblks, reserved);
 154         }
 155
 156         avail = cnt - bitmap_weight(smp->state, cnt);
 157         if (nblks > avail) {
 158                 dev_err(mdp5_kms->dev->dev, "out of blks (req=%d > avail=%d)\n",
 159                                 nblks, avail);
 160                 ret = -ENOSPC;
 161                 goto fail;
 162         }
 163
 164         cur_nblks = bitmap_weight(ps->pending, cnt);
 165         if (nblks > cur_nblks) {
 166                 /* grow the existing pending reservation: */
 167                 for (i = cur_nblks; i < nblks; i++) {
 168                         int blk = find_first_zero_bit(smp->state, cnt);
 169                         set_bit(blk, ps->pending);
 170                         set_bit(blk, smp->state);
 171                 }
 172         } else {
 173                 /* shrink the existing pending reservation: */
 174                 for (i = cur_nblks; i > nblks; i--) {
 175                         int blk = find_first_bit(ps->pending, cnt);
 176                         clear_bit(blk, ps->pending);
 177
 178                         /* clear in global smp_state if not in configured
 179                          * otherwise until _commit()
 180                          */
 181                         if (!test_bit(blk, ps->configured))
 182                                 clear_bit(blk, smp->state);
 183                 }
 184         }
 185
 186 fail:
 187         spin_unlock_irqrestore(&smp->state_lock, flags);
 188         return 0;
 189 }
 190
 191 static void set_fifo_thresholds(struct mdp5_smp *smp,
 192                 enum mdp5_pipe pipe, int nblks)
 193 {
 194         struct mdp5_kms *mdp5_kms = get_kms(smp);
 195         u32 smp_entries_per_blk = smp->blk_size / (128 / BITS_PER_BYTE);
 196         u32 val;
 197
 198         /* 1/4 of SMP pool that is being fetched */
 199         val = (nblks * smp_entries_per_blk) / 4;
 200
 201         mdp5_write(mdp5_kms, REG_MDP5_PIPE_REQPRIO_FIFO_WM_0(pipe), val * 1);
 202         mdp5_write(mdp5_kms, REG_MDP5_PIPE_REQPRIO_FIFO_WM_1(pipe), val * 2);
 203         mdp5_write(mdp5_kms, REG_MDP5_PIPE_REQPRIO_FIFO_WM_2(pipe), val * 3);
 204 }
 205
 206 /*
 207  * NOTE: looks like if horizontal decimation is used (if we supported that)
 208  * then the width used to calculate SMP block requirements is the post-
 209  * decimated width.  Ie. SMP buffering sits downstream of decimation (which
 210  * presumably happens during the dma from scanout buffer).
 211  */
 212 int mdp5_smp_request(struct mdp5_smp *smp, enum mdp5_pipe pipe,
 213                 const struct mdp_format *format, u32 width, bool hdecim)
 214 {
 215         struct mdp5_kms *mdp5_kms = get_kms(smp);
 216         struct drm_device *dev = mdp5_kms->dev;
 217         int rev = mdp5_cfg_get_hw_rev(mdp5_kms->cfg);
 218         int i, hsub, nplanes, nlines, nblks, ret;
 219         u32 fmt = format->base.pixel_format;
 220
 221         nplanes = drm_format_num_planes(fmt);
 222         hsub = drm_format_horz_chroma_subsampling(fmt);
 223
 224         /* different if BWC (compressed framebuffer?) enabled: */
 225         nlines = 2;
 226
 227         /* Newer MDPs have split/packing logic, which fetches sub-sampled
 228          * U and V components (splits them from Y if necessary) and packs
 229          * them together, writes to SMP using a single client.
 230          */
 231         if ((rev > 0) && (format->chroma_sample > CHROMA_FULL)) {
 232                 fmt = DRM_FORMAT_NV24;
 233                 nplanes = 2;
 234
 235                 /* if decimation is enabled, HW decimates less on the
 236                  * sub sampled chroma components
 237                  */
 238                 if (hdecim && (hsub > 1))
 239                         hsub = 1;
 240         }
 241
 242         for (i = 0, nblks = 0; i < nplanes; i++) {
 243                 int n, fetch_stride, cpp;
 244
 245                 cpp = drm_format_plane_cpp(fmt, i);
 246                 fetch_stride = width * cpp / (i ? hsub : 1);
 247
 248                 n = DIV_ROUND_UP(fetch_stride * nlines, smp->blk_size);
 249
 250                 /* for hw rev v1.00 */
 251                 if (rev == 0)
 252                         n = roundup_pow_of_two(n);
 253
 254                 DBG("%s[%d]: request %d SMP blocks", pipe2name(pipe), i, n);
 255                 ret = smp_request_block(smp, pipe2client(pipe, i), n);
 256                 if (ret) {
 257                         dev_err(dev->dev, "Cannot allocate %d SMP blocks: %d\n",
 258                                         n, ret);
 259                         return ret;
 260                 }
 261
 262                 nblks += n;
 263         }
 264
 265         set_fifo_thresholds(smp, pipe, nblks);
 266
 267         return 0;
 268 }
 269
 270 /* Release SMP blocks for all clients of the pipe */
 271 void mdp5_smp_release(struct mdp5_smp *smp, enum mdp5_pipe pipe)
 272 {
 273         int i;
 274         unsigned long flags;
 275         int cnt = smp->blk_cnt;
 276
 277         for (i = 0; i < pipe2nclients(pipe); i++) {
 278                 mdp5_smp_state_t assigned;
 279                 u32 cid = pipe2client(pipe, i);
 280                 struct mdp5_client_smp_state *ps = &smp->client_state[cid];
 281
 282                 spin_lock_irqsave(&smp->state_lock, flags);
 283
 284                 /* clear hw assignment */
 285                 bitmap_or(assigned, ps->inuse, ps->configured, cnt);
 286                 update_smp_state(smp, CID_UNUSED, &assigned);
 287
 288                 /* free to global pool */
 289                 bitmap_andnot(smp->state, smp->state, ps->pending, cnt);
 290                 bitmap_andnot(smp->state, smp->state, assigned, cnt);
 291
 292                 /* clear client's infor */
 293                 bitmap_zero(ps->pending, cnt);
 294                 bitmap_zero(ps->configured, cnt);
 295                 bitmap_zero(ps->inuse, cnt);
 296
 297                 spin_unlock_irqrestore(&smp->state_lock, flags);
 298         }
 299
 300         set_fifo_thresholds(smp, pipe, 0);
 301 }
 302
 303 static void update_smp_state(struct mdp5_smp *smp,
 304                 u32 cid, mdp5_smp_state_t *assigned)
 305 {
 306         struct mdp5_kms *mdp5_kms = get_kms(smp);
 307         int cnt = smp->blk_cnt;
 308         u32 blk, val;
 309
 310         for_each_set_bit(blk, *assigned, cnt) {
 311                 int idx = blk / 3;
 312                 int fld = blk % 3;
 313
 314                 val = mdp5_read(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(idx));
 315
 316                 switch (fld) {
 317                 case 0:
 318                         val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT0__MASK;
 319                         val |= MDP5_SMP_ALLOC_W_REG_CLIENT0(cid);
 320                         break;
 321                 case 1:
 322                         val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT1__MASK;
 323                         val |= MDP5_SMP_ALLOC_W_REG_CLIENT1(cid);
 324                         break;
 325                 case 2:
 326                         val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT2__MASK;
 327                         val |= MDP5_SMP_ALLOC_W_REG_CLIENT2(cid);
 328                         break;
 329                 }
 330
 331                 mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(idx), val);
 332                 mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_R_REG(idx), val);
 333         }
 334 }
 335
 336 /* step #2: configure hw for union(pending, inuse): */
 337 void mdp5_smp_configure(struct mdp5_smp *smp, enum mdp5_pipe pipe)
 338 {
 339         int cnt = smp->blk_cnt;
 340         mdp5_smp_state_t assigned;
 341         int i;
 342
 343         for (i = 0; i < pipe2nclients(pipe); i++) {
 344                 u32 cid = pipe2client(pipe, i);
 345                 struct mdp5_client_smp_state *ps = &smp->client_state[cid];
 346
 347                 /*
 348                  * if vblank has not happened since last smp_configure
 349                  * skip the configure for now
 350                  */
 351                 if (!bitmap_equal(ps->inuse, ps->configured, cnt))
 352                         continue;
 353
 354                 bitmap_copy(ps->configured, ps->pending, cnt);
 355                 bitmap_or(assigned, ps->inuse, ps->configured, cnt);
 356                 update_smp_state(smp, cid, &assigned);
 357         }
 358 }
 359
 360 /* step #3: after vblank, copy configured -> inuse: */
 361 void mdp5_smp_commit(struct mdp5_smp *smp, enum mdp5_pipe pipe)
 362 {
 363         int cnt = smp->blk_cnt;
 364         mdp5_smp_state_t released;
 365         int i;
 366
 367         for (i = 0; i < pipe2nclients(pipe); i++) {
 368                 u32 cid = pipe2client(pipe, i);
 369                 struct mdp5_client_smp_state *ps = &smp->client_state[cid];
 370
 371                 /*
 372                  * Figure out if there are any blocks we where previously
 373                  * using, which can be released and made available to other
 374                  * clients:
 375                  */
 376                 if (bitmap_andnot(released, ps->inuse, ps->configured, cnt)) {
 377                         unsigned long flags;
 378
 379                         spin_lock_irqsave(&smp->state_lock, flags);
 380                         /* clear released blocks: */
 381                         bitmap_andnot(smp->state, smp->state, released, cnt);
 382                         spin_unlock_irqrestore(&smp->state_lock, flags);
 383
 384                         update_smp_state(smp, CID_UNUSED, &released);
 385                 }
 386
 387                 bitmap_copy(ps->inuse, ps->configured, cnt);
 388         }
 389 }
 390
 391 void mdp5_smp_destroy(struct mdp5_smp *smp)
 392 {
 393         kfree(smp);
 394 }
 395
 396 struct mdp5_smp *mdp5_smp_init(struct drm_device *dev, const struct mdp5_smp_block *cfg)
 397 {
 398         struct mdp5_smp *smp = NULL;
 399         int ret;
 400
 401         smp = kzalloc(sizeof(*smp), GFP_KERNEL);
 402         if (unlikely(!smp)) {
 403                 ret = -ENOMEM;
 404                 goto fail;
 405         }
 406
 407         smp->dev = dev;
 408         smp->blk_cnt = cfg->mmb_count;
 409         smp->blk_size = cfg->mmb_size;
 410
 411         /* statically tied MMBs cannot be re-allocated: */
 412         bitmap_copy(smp->state, cfg->reserved_state, smp->blk_cnt);
 413         memcpy(smp->reserved, cfg->reserved, sizeof(smp->reserved));
 414         spin_lock_init(&smp->state_lock);
 415
 416         return smp;
 417 fail:
 418         if (smp)
 419                 mdp5_smp_destroy(smp);
 420
 421         return ERR_PTR(ret);
 422 }