panfrost: Rename pan_bo_cache.c into pan_bo.c

So we can move all the BO logic into this file instead of having it
spread over pan_resource.c, pan_drm.c and pan_bo_cache.c.

Signed-off-by: Boris Brezillon <[email protected]>
Reviewed-by: Alyssa Rosenzweig <[email protected]>

1 files changed, 167 insertions, 0 deletions

diff --git a/src/gallium/drivers/panfrost/pan_bo.c b/src/gallium/drivers/panfrost/pan_bo.c
new file mode 100644
index 00000000000..f2f49437a89
--- /dev/null
+++ b/src/gallium/drivers/panfrost/pan_bo.c
@@ -0,0 +1,167 @@
+/*
+ * Copyright 2019 Collabora, Ltd.
+ *
+ * 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, sublicense,
+ * 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 above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ *
+ * Authors (Collabora):
+ *   Alyssa Rosenzweig <[email protected]>
+ */
+#include <xf86drm.h>
+#include <pthread.h>
+#include "drm-uapi/panfrost_drm.h"
+
+#include "pan_screen.h"
+#include "util/u_math.h"
+
+/* This file implements a userspace BO cache. Allocating and freeing
+ * GPU-visible buffers is very expensive, and even the extra kernel roundtrips
+ * adds more work than we would like at this point. So caching BOs in userspace
+ * solves both of these problems and does not require kernel updates.
+ *
+ * Cached BOs are sorted into a bucket based on rounding their size down to the
+ * nearest power-of-two. Each bucket contains a linked list of free panfrost_bo
+ * objects. Putting a BO into the cache is accomplished by adding it to the
+ * corresponding bucket. Getting a BO from the cache consists of finding the
+ * appropriate bucket and sorting. A cache eviction is a kernel-level free of a
+ * BO and removing it from the bucket. We special case evicting all BOs from
+ * the cache, since that's what helpful in practice and avoids extra logic
+ * around the linked list.
+ */
+
+/* Helper to calculate the bucket index of a BO */
+
+static unsigned
+pan_bucket_index(unsigned size)
+{
+        /* Round down to POT to compute a bucket index */
+
+        unsigned bucket_index = util_logbase2(size);
+
+        /* Clamp the bucket index; all huge allocations will be
+         * sorted into the largest bucket */
+
+        bucket_index = MIN2(bucket_index, MAX_BO_CACHE_BUCKET);
+
+        /* The minimum bucket size must equal the minimum allocation
+         * size; the maximum we clamped */
+
+        assert(bucket_index >= MIN_BO_CACHE_BUCKET);
+        assert(bucket_index <= MAX_BO_CACHE_BUCKET);
+
+        /* Reindex from 0 */
+        return (bucket_index - MIN_BO_CACHE_BUCKET);
+}
+
+static struct list_head *
+pan_bucket(struct panfrost_screen *screen, unsigned size)
+{
+        return &screen->bo_cache[pan_bucket_index(size)];
+}
+
+/* Tries to fetch a BO of sufficient size with the appropriate flags from the
+ * BO cache. If it succeeds, it returns that BO and removes the BO from the
+ * cache. If it fails, it returns NULL signaling the caller to allocate a new
+ * BO. */
+
+struct panfrost_bo *
+panfrost_bo_cache_fetch(
+                struct panfrost_screen *screen,
+                size_t size, uint32_t flags)
+{
+        pthread_mutex_lock(&screen->bo_cache_lock);
+        struct list_head *bucket = pan_bucket(screen, size);
+        struct panfrost_bo *bo = NULL;
+
+        /* Iterate the bucket looking for something suitable */
+        list_for_each_entry_safe(struct panfrost_bo, entry, bucket, link) {
+                if (entry->size >= size &&
+                    entry->flags == flags) {
+                        int ret;
+                        struct drm_panfrost_madvise madv;
+
+                        /* This one works, splice it out of the cache */
+                        list_del(&entry->link);
+
+                        madv.handle = entry->gem_handle;
+                        madv.madv = PANFROST_MADV_WILLNEED;
+                        madv.retained = 0;
+
+                        ret = drmIoctl(screen->fd, DRM_IOCTL_PANFROST_MADVISE, &madv);
+                        if (!ret && !madv.retained) {
+                                panfrost_drm_release_bo(screen, entry, false);
+                                continue;
+                        }
+                        /* Let's go! */
+                        bo = entry;
+                        break;
+                }
+        }
+        pthread_mutex_unlock(&screen->bo_cache_lock);
+
+        return bo;
+}
+
+/* Tries to add a BO to the cache. Returns if it was
+ * successful */
+
+bool
+panfrost_bo_cache_put(
+                struct panfrost_screen *screen,
+                struct panfrost_bo *bo)
+{
+        pthread_mutex_lock(&screen->bo_cache_lock);
+        struct list_head *bucket = pan_bucket(screen, bo->size);
+        struct drm_panfrost_madvise madv;
+
+        madv.handle = bo->gem_handle;
+        madv.madv = PANFROST_MADV_DONTNEED;
+	madv.retained = 0;
+
+        drmIoctl(screen->fd, DRM_IOCTL_PANFROST_MADVISE, &madv);
+
+        /* Add us to the bucket */
+        list_addtail(&bo->link, bucket);
+        pthread_mutex_unlock(&screen->bo_cache_lock);
+
+        return true;
+}
+
+/* Evicts all BOs from the cache. Called during context
+ * destroy or during low-memory situations (to free up
+ * memory that may be unused by us just sitting in our
+ * cache, but still reserved from the perspective of the
+ * OS) */
+
+void
+panfrost_bo_cache_evict_all(
+                struct panfrost_screen *screen)
+{
+        pthread_mutex_lock(&screen->bo_cache_lock);
+        for (unsigned i = 0; i < ARRAY_SIZE(screen->bo_cache); ++i) {
+                struct list_head *bucket = &screen->bo_cache[i];
+
+                list_for_each_entry_safe(struct panfrost_bo, entry, bucket, link) {
+                        list_del(&entry->link);
+                        panfrost_drm_release_bo(screen, entry, false);
+                }
+        }
+        pthread_mutex_unlock(&screen->bo_cache_lock);
+}
+