diff options
Diffstat (limited to 'drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c')
| -rw-r--r-- | drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c new file mode 100644 index 000000000000..2d0236b963a6 --- /dev/null +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_smp.c @@ -0,0 +1,173 @@ +/* + * Copyright (C) 2013 Red Hat + * Author: Rob Clark <robdclark@gmail.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + + +#include "mdp5_kms.h" +#include "mdp5_smp.h" + + +/* SMP - Shared Memory Pool + * + * These are shared between all the clients, where each plane in a + * scanout buffer is a SMP client. Ie. scanout of 3 plane I420 on + * pipe VIG0 => 3 clients: VIG0_Y, VIG0_CB, VIG0_CR. + * + * Based on the size of the attached scanout buffer, a certain # of + * blocks must be allocated to that client out of the shared pool. + * + * For each block, it can be either free, or pending/in-use by a + * client. The updates happen in three steps: + * + * 1) mdp5_smp_request(): + * When plane scanout is setup, calculate required number of + * blocks needed per client, and request. Blocks not inuse or + * pending by any other client are added to client's pending + * set. + * + * 2) mdp5_smp_configure(): + * As hw is programmed, before FLUSH, MDP5_SMP_ALLOC registers + * are configured for the union(pending, inuse) + * + * 3) mdp5_smp_commit(): + * After next vblank, copy pending -> inuse. Optionally update + * MDP5_SMP_ALLOC registers if there are newly unused blocks + * + * On the next vblank after changes have been committed to hw, the + * client's pending blocks become it's in-use blocks (and no-longer + * in-use blocks become available to other clients). + * + * btw, hurray for confusing overloaded acronyms! :-/ + * + * NOTE: for atomic modeset/pageflip NONBLOCK operations, step #1 + * should happen at (or before)? atomic->check(). And we'd need + * an API to discard previous requests if update is aborted or + * (test-only). + * + * TODO would perhaps be nice to have debugfs to dump out kernel + * inuse and pending state of all clients.. + */ + +static DEFINE_SPINLOCK(smp_lock); + + +/* step #1: update # of blocks pending for the client: */ +int mdp5_smp_request(struct mdp5_kms *mdp5_kms, + enum mdp5_client_id cid, int nblks) +{ + struct mdp5_client_smp_state *ps = &mdp5_kms->smp_client_state[cid]; + int i, ret, avail, cur_nblks, cnt = mdp5_kms->smp_blk_cnt; + unsigned long flags; + + spin_lock_irqsave(&smp_lock, flags); + + avail = cnt - bitmap_weight(mdp5_kms->smp_state, cnt); + if (nblks > avail) { + ret = -ENOSPC; + goto fail; + } + + cur_nblks = bitmap_weight(ps->pending, cnt); + if (nblks > cur_nblks) { + /* grow the existing pending reservation: */ + for (i = cur_nblks; i < nblks; i++) { + int blk = find_first_zero_bit(mdp5_kms->smp_state, cnt); + set_bit(blk, ps->pending); + set_bit(blk, mdp5_kms->smp_state); + } + } else { + /* shrink the existing pending reservation: */ + for (i = cur_nblks; i > nblks; i--) { + int blk = find_first_bit(ps->pending, cnt); + clear_bit(blk, ps->pending); + /* don't clear in global smp_state until _commit() */ + } + } + +fail: + spin_unlock_irqrestore(&smp_lock, flags); + return 0; +} + +static void update_smp_state(struct mdp5_kms *mdp5_kms, + enum mdp5_client_id cid, mdp5_smp_state_t *assigned) +{ + int cnt = mdp5_kms->smp_blk_cnt; + uint32_t blk, val; + + for_each_set_bit(blk, *assigned, cnt) { + int idx = blk / 3; + int fld = blk % 3; + + val = mdp5_read(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(idx)); + + switch (fld) { + case 0: + val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT0__MASK; + val |= MDP5_SMP_ALLOC_W_REG_CLIENT0(cid); + break; + case 1: + val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT1__MASK; + val |= MDP5_SMP_ALLOC_W_REG_CLIENT1(cid); + break; + case 2: + val &= ~MDP5_SMP_ALLOC_W_REG_CLIENT2__MASK; + val |= MDP5_SMP_ALLOC_W_REG_CLIENT2(cid); + break; + } + + mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_W_REG(idx), val); + mdp5_write(mdp5_kms, REG_MDP5_SMP_ALLOC_R_REG(idx), val); + } +} + +/* step #2: configure hw for union(pending, inuse): */ +void mdp5_smp_configure(struct mdp5_kms *mdp5_kms, enum mdp5_client_id cid) +{ + struct mdp5_client_smp_state *ps = &mdp5_kms->smp_client_state[cid]; + int cnt = mdp5_kms->smp_blk_cnt; + mdp5_smp_state_t assigned; + + bitmap_or(assigned, ps->inuse, ps->pending, cnt); + update_smp_state(mdp5_kms, cid, &assigned); +} + +/* step #3: after vblank, copy pending -> inuse: */ +void mdp5_smp_commit(struct mdp5_kms *mdp5_kms, enum mdp5_client_id cid) +{ + struct mdp5_client_smp_state *ps = &mdp5_kms->smp_client_state[cid]; + int cnt = mdp5_kms->smp_blk_cnt; + mdp5_smp_state_t released; + + /* + * Figure out if there are any blocks we where previously + * using, which can be released and made available to other + * clients: + */ + if (bitmap_andnot(released, ps->inuse, ps->pending, cnt)) { + unsigned long flags; + + spin_lock_irqsave(&smp_lock, flags); + /* clear released blocks: */ + bitmap_andnot(mdp5_kms->smp_state, mdp5_kms->smp_state, + released, cnt); + spin_unlock_irqrestore(&smp_lock, flags); + + update_smp_state(mdp5_kms, CID_UNUSED, &released); + } + + bitmap_copy(ps->inuse, ps->pending, cnt); +} |