radeon_sa.c

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/*
 * Copyright 2011 Red Hat Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors:
 *    Jerome Glisse <[email protected]>
 */
/* Algorithm:
 *
 * We store the last allocated bo in "hole", we always try to allocate
 * after the last allocated bo. Principle is that in a linear GPU ring
 * progression was is after last is the oldest bo we allocated and thus
 * the first one that should no longer be in use by the GPU.
 *
 * If it's not the case we skip over the bo after last to the closest
 * done bo if such one exist. If none exist and we are not asked to
 * block we report failure to allocate.
 *
 * If we are asked to block we wait on all the oldest fence of all
 * rings. We just wait for any of those fence to complete.
 */
#include <drm/drmP.h>
#include "radeon.h"

static void radeon_sa_bo_remove_locked(struct radeon_sa_bo *sa_bo);
static void radeon_sa_bo_try_free(struct radeon_sa_manager *sa_manager);

int radeon_sa_bo_manager_init(struct radeon_device *rdev,
                  struct radeon_sa_manager *sa_manager,
                  unsigned size, u32 domain)
{
    int i, r;

    init_waitqueue_head(&sa_manager->wq);
    sa_manager->bo = NULL;
    sa_manager->size = size;
    sa_manager->domain = domain;
    sa_manager->hole = &sa_manager->olist;
    INIT_LIST_HEAD(&sa_manager->olist);
    for (i = 0; i < RADEON_NUM_RINGS; ++i) {
        INIT_LIST_HEAD(&sa_manager->flist[i]);
    }

    r = radeon_bo_create(rdev, size, RADEON_GPU_PAGE_SIZE, true,
                 RADEON_GEM_DOMAIN_CPU, NULL, &sa_manager->bo);
    if (r) {
        dev_err(rdev->dev, "(%d) failed to allocate bo for manager\n", r);
        return r;
    }

    return r;
}

void radeon_sa_bo_manager_fini(struct radeon_device *rdev,
                   struct radeon_sa_manager *sa_manager)
{
    struct radeon_sa_bo *sa_bo, *tmp;

    if (!list_empty(&sa_manager->olist)) {
        sa_manager->hole = &sa_manager->olist,
        radeon_sa_bo_try_free(sa_manager);
        if (!list_empty(&sa_manager->olist)) {
            dev_err(rdev->dev, "sa_manager is not empty, clearing anyway\n");
        }
    }
    list_for_each_entry_safe(sa_bo, tmp, &sa_manager->olist, olist) {
        radeon_sa_bo_remove_locked(sa_bo);
    }
    radeon_bo_unref(&sa_manager->bo);
    sa_manager->size = 0;
}

int radeon_sa_bo_manager_start(struct radeon_device *rdev,
                   struct radeon_sa_manager *sa_manager)
{
    int r;

    if (sa_manager->bo == NULL) {
        dev_err(rdev->dev, "no bo for sa manager\n");
        return -EINVAL;
    }

    /* map the buffer */
    r = radeon_bo_reserve(sa_manager->bo, false);
    if (r) {
        dev_err(rdev->dev, "(%d) failed to reserve manager bo\n", r);
        return r;
    }
    r = radeon_bo_pin(sa_manager->bo, sa_manager->domain, &sa_manager->gpu_addr);
    if (r) {
        radeon_bo_unreserve(sa_manager->bo);
        dev_err(rdev->dev, "(%d) failed to pin manager bo\n", r);
        return r;
    }
    r = radeon_bo_kmap(sa_manager->bo, &sa_manager->cpu_ptr);
    radeon_bo_unreserve(sa_manager->bo);
    return r;
}

int radeon_sa_bo_manager_suspend(struct radeon_device *rdev,
                 struct radeon_sa_manager *sa_manager)
{
    int r;

    if (sa_manager->bo == NULL) {
        dev_err(rdev->dev, "no bo for sa manager\n");
        return -EINVAL;
    }

    r = radeon_bo_reserve(sa_manager->bo, false);
    if (!r) {
        radeon_bo_kunmap(sa_manager->bo);
        radeon_bo_unpin(sa_manager->bo);
        radeon_bo_unreserve(sa_manager->bo);
    }
    return r;
}

static void radeon_sa_bo_remove_locked(struct radeon_sa_bo *sa_bo)
{
    struct radeon_sa_manager *sa_manager = sa_bo->manager;
    if (sa_manager->hole == &sa_bo->olist) {
        sa_manager->hole = sa_bo->olist.prev;
    }
    list_del_init(&sa_bo->olist);
    list_del_init(&sa_bo->flist);
    radeon_fence_unref(&sa_bo->fence);
    kfree(sa_bo);
}

static void radeon_sa_bo_try_free(struct radeon_sa_manager *sa_manager)
{
    struct radeon_sa_bo *sa_bo, *tmp;

    if (sa_manager->hole->next == &sa_manager->olist)
        return;

    sa_bo = list_entry(sa_manager->hole->next, struct radeon_sa_bo, olist);
    list_for_each_entry_safe_from(sa_bo, tmp, &sa_manager->olist, olist) {
        if (sa_bo->fence == NULL || !radeon_fence_signaled(sa_bo->fence)) {
            return;
        }
        radeon_sa_bo_remove_locked(sa_bo);
    }
}

static inline unsigned radeon_sa_bo_hole_soffset(struct radeon_sa_manager *sa_manager)
{
    struct list_head *hole = sa_manager->hole;

    if (hole != &sa_manager->olist) {
        return list_entry(hole, struct radeon_sa_bo, olist)->eoffset;
    }
    return 0;
}

static inline unsigned radeon_sa_bo_hole_eoffset(struct radeon_sa_manager *sa_manager)
{
    struct list_head *hole = sa_manager->hole;

    if (hole->next != &sa_manager->olist) {
        return list_entry(hole->next, struct radeon_sa_bo, olist)->soffset;
    }
    return sa_manager->size;
}

static bool radeon_sa_bo_try_alloc(struct radeon_sa_manager *sa_manager,
                   struct radeon_sa_bo *sa_bo,
                   unsigned size, unsigned align)
{
    unsigned soffset, eoffset, wasted;

    soffset = radeon_sa_bo_hole_soffset(sa_manager);
    eoffset = radeon_sa_bo_hole_eoffset(sa_manager);
    wasted = (align - (soffset % align)) % align;

    if ((eoffset - soffset) >= (size + wasted)) {
        soffset += wasted;

        sa_bo->manager = sa_manager;
        sa_bo->soffset = soffset;
        sa_bo->eoffset = soffset + size;
        list_add(&sa_bo->olist, sa_manager->hole);
        INIT_LIST_HEAD(&sa_bo->flist);
        sa_manager->hole = &sa_bo->olist;
        return true;
    }
    return false;
}

static bool radeon_sa_event(struct radeon_sa_manager *sa_manager,
                unsigned size, unsigned align)
{
    unsigned soffset, eoffset, wasted;
    int i;

    for (i = 0; i < RADEON_NUM_RINGS; ++i) {
        if (!list_empty(&sa_manager->flist[i])) {
            return true;
        }
    }

    soffset = radeon_sa_bo_hole_soffset(sa_manager);
    eoffset = radeon_sa_bo_hole_eoffset(sa_manager);
    wasted = (align - (soffset % align)) % align;

    if ((eoffset - soffset) >= (size + wasted)) {
        return true;
    }

    return false;
}

static bool radeon_sa_bo_next_hole(struct radeon_sa_manager *sa_manager,
                   struct radeon_fence **fences,
                   unsigned *tries)
{
    struct radeon_sa_bo *best_bo = NULL;
    unsigned i, soffset, best, tmp;

    /* if hole points to the end of the buffer */
    if (sa_manager->hole->next == &sa_manager->olist) {
        /* try again with its beginning */
        sa_manager->hole = &sa_manager->olist;
        return true;
    }

    soffset = radeon_sa_bo_hole_soffset(sa_manager);
    /* to handle wrap around we add sa_manager->size */
    best = sa_manager->size * 2;
    /* go over all fence list and try to find the closest sa_bo
     * of the current last
     */
    for (i = 0; i < RADEON_NUM_RINGS; ++i) {
        struct radeon_sa_bo *sa_bo;

        if (list_empty(&sa_manager->flist[i])) {
            continue;
        }

        sa_bo = list_first_entry(&sa_manager->flist[i],
                     struct radeon_sa_bo, flist);

        if (!radeon_fence_signaled(sa_bo->fence)) {
            fences[i] = sa_bo->fence;
            continue;
        }

        /* limit the number of tries each ring gets */
        if (tries[i] > 2) {
            continue;
        }

        tmp = sa_bo->soffset;
        if (tmp < soffset) {
            /* wrap around, pretend it's after */
            tmp += sa_manager->size;
        }
        tmp -= soffset;
        if (tmp < best) {
            /* this sa bo is the closest one */
            best = tmp;
            best_bo = sa_bo;
        }
    }

    if (best_bo) {
        ++tries[best_bo->fence->ring];
        sa_manager->hole = best_bo->olist.prev;

        /* we knew that this one is signaled,
           so it's save to remote it */
        radeon_sa_bo_remove_locked(best_bo);
        return true;
    }
    return false;
}

int radeon_sa_bo_new(struct radeon_device *rdev,
             struct radeon_sa_manager *sa_manager,
             struct radeon_sa_bo **sa_bo,
             unsigned size, unsigned align, bool block)
{
    struct radeon_fence *fences[RADEON_NUM_RINGS];
    unsigned tries[RADEON_NUM_RINGS];
    int i, r;

    BUG_ON(align > RADEON_GPU_PAGE_SIZE);
    BUG_ON(size > sa_manager->size);

    *sa_bo = kmalloc(sizeof(struct radeon_sa_bo), GFP_KERNEL);
    if ((*sa_bo) == NULL) {
        return -ENOMEM;
    }
    (*sa_bo)->manager = sa_manager;
    (*sa_bo)->fence = NULL;
    INIT_LIST_HEAD(&(*sa_bo)->olist);
    INIT_LIST_HEAD(&(*sa_bo)->flist);

    spin_lock(&sa_manager->wq.lock);
    do {
        for (i = 0; i < RADEON_NUM_RINGS; ++i) {
            fences[i] = NULL;
            tries[i] = 0;
        }

        do {
            radeon_sa_bo_try_free(sa_manager);

            if (radeon_sa_bo_try_alloc(sa_manager, *sa_bo,
                           size, align)) {
                spin_unlock(&sa_manager->wq.lock);
                return 0;
            }

            /* see if we can skip over some allocations */
        } while (radeon_sa_bo_next_hole(sa_manager, fences, tries));

        spin_unlock(&sa_manager->wq.lock);
        r = radeon_fence_wait_any(rdev, fences, false);
        spin_lock(&sa_manager->wq.lock);
        /* if we have nothing to wait for block */
        if (r == -ENOENT && block) {
            r = wait_event_interruptible_locked(
                sa_manager->wq, 
                radeon_sa_event(sa_manager, size, align)
            );

        } else if (r == -ENOENT) {
            r = -ENOMEM;
        }

    } while (!r);

    spin_unlock(&sa_manager->wq.lock);
    kfree(*sa_bo);
    *sa_bo = NULL;
    return r;
}

void radeon_sa_bo_free(struct radeon_device *rdev, struct radeon_sa_bo **sa_bo,
               struct radeon_fence *fence)
{
    struct radeon_sa_manager *sa_manager;

    if (sa_bo == NULL || *sa_bo == NULL) {
        return;
    }

    sa_manager = (*sa_bo)->manager;
    spin_lock(&sa_manager->wq.lock);
    if (fence && !radeon_fence_signaled(fence)) {
        (*sa_bo)->fence = radeon_fence_ref(fence);
        list_add_tail(&(*sa_bo)->flist,
                  &sa_manager->flist[fence->ring]);
    } else {
        radeon_sa_bo_remove_locked(*sa_bo);
    }
    wake_up_all_locked(&sa_manager->wq);
    spin_unlock(&sa_manager->wq.lock);
    *sa_bo = NULL;
}

#if defined(CONFIG_DEBUG_FS)
void radeon_sa_bo_dump_debug_info(struct radeon_sa_manager *sa_manager,
                  struct seq_file *m)
{
    struct radeon_sa_bo *i;

    spin_lock(&sa_manager->wq.lock);
    list_for_each_entry(i, &sa_manager->olist, olist) {
        if (&i->olist == sa_manager->hole) {
            seq_printf(m, ">");
        } else {
            seq_printf(m, " ");
        }
        seq_printf(m, "[0x%08x 0x%08x] size %8d",
               i->soffset, i->eoffset, i->eoffset - i->soffset);
        if (i->fence) {
            seq_printf(m, " protected by 0x%016llx on ring %d",
                   i->fence->seq, i->fence->ring);
        }
        seq_printf(m, "\n");
    }
    spin_unlock(&sa_manager->wq.lock);
}
#endif