[RFC 3/21] DRM: Add VIA DRM driver
James Simmons
jsimmons at infradead.org
Sat Jun 8 09:45:33 PDT 2013
commit 30a9dda2deeebcf611cbeaffb38f0f94c708a976
Author: James Simmons <jsimmons at infradead.org>
Date: Thu Jun 6 20:28:33 2013 -0400
via: fence implementation
For each buffer object we create a fence in order to know what
its state is. A fence notifies us when a object is consumed by
the command queue or if it lost in the queue so we can time it
out. In our design each fence (struct via_fence) belongs to a
fence_pool. A fence_pool represents the way the hardware
handles the buffer object i.e DMA, 2D etc. Each pool itself
will have a number of fence engines to represent each hardware
channel. For exmaple for via hardare we have four DMA engines
which is represented by one type of pool.
Signed-Off-by: James Simmons <jsimmons at infradead.org>
diff --git a/drivers/gpu/drm/via/via_fence.c b/drivers/gpu/drm/via/via_fence.c
new file mode 100644
index 0000000..98489d5
--- /dev/null
+++ b/drivers/gpu/drm/via/via_fence.c
@@ -0,0 +1,282 @@
+/*
+ * Copyright 2013 James Simmons <jsimmons at infradead.org>
+ *
+ * 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) OR COPYRIGHT HOLDER(S) 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.
+ */
+#include <linux/random.h>
+#include "drmP.h"
+
+#include "via_drv.h"
+
+static void
+via_fence_destroy(struct kref *kref)
+{
+ struct via_fence *fence = container_of(kref, struct via_fence, kref);
+
+ if (fence->pool->fence_cleanup)
+ fence->pool->fence_cleanup(fence);
+ kfree(fence);
+}
+
+struct via_fence *
+via_fence_create_and_emit(struct via_fence_pool *pool, void *data,
+ unsigned int engine)
+{
+ struct via_fence *fence = NULL;
+
+ fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+ if (fence) {
+ unsigned long flags;
+ int ret = -EINVAL;
+
+ fence->timeout = jiffies + 3 * HZ;
+ fence->engine = engine;
+ fence->pool = pool;
+ fence->priv = data;
+ kref_init(&fence->kref);
+
+ if (engine >= pool->num_engines) {
+ via_fence_unref((void **) &fence);
+ return ERR_PTR(-ENXIO);
+ }
+ spin_lock_irqsave(&pool->lock, flags);
+try_again:
+ /* I like to use get_random_init but it is not exported :-( */
+ get_random_bytes(&fence->seq.key, 3);
+ /* For the small change you get a zero */
+ if (unlikely(fence->seq.key == 0))
+ goto try_again;
+
+ ret = drm_ht_insert_item_rcu(&pool->pending, &fence->seq);
+ if (unlikely(ret))
+ goto try_again;
+
+ ret = pool->fence_emit(fence);
+ if (ret) {
+ DRM_INFO("Failed to emit fence\n");
+ drm_ht_remove_item_rcu(&pool->pending, &fence->seq);
+ via_fence_unref((void **) &fence);
+ fence = ERR_PTR(ret);
+ }
+ spin_unlock_irqrestore(&pool->lock, flags);
+ }
+ return fence;
+}
+
+static void
+via_fence_work(struct work_struct *work)
+{
+ struct via_fence_engine *eng = container_of(work, struct via_fence_engine,
+ fence_work);
+ unsigned long seq = readl(eng->read_seq), flags;
+ struct via_fence_pool *pool = eng->pool;
+ struct drm_hash_item *hash = NULL;
+ int ret;
+
+ spin_lock_irqsave(&eng->pool->lock, flags);
+ ret = drm_ht_find_item_rcu(&pool->pending, seq, &hash);
+ if (likely(ret == 0)) {
+ ret = drm_ht_remove_item_rcu(&pool->pending, hash);
+ if (ret < 0)
+ DRM_DEBUG("Failed to remove seq %lx\n", seq);
+ }
+ if (eng->pool->fence_signaled)
+ eng->pool->fence_signaled(eng);
+ spin_unlock_irqrestore(&eng->pool->lock, flags);
+}
+
+static bool
+via_fence_seq_signaled(struct via_fence *fence, u64 seq)
+{
+ struct drm_hash_item *key;
+ unsigned long flags;
+ bool ret = false;
+
+ /* If the fence is no longer pending then its signaled */
+ spin_lock_irqsave(&fence->pool->lock, flags);
+ if (drm_ht_find_item_rcu(&fence->pool->pending, seq, &key))
+ ret = true;
+ spin_unlock_irqrestore(&fence->pool->lock, flags);
+ return ret;
+}
+
+/* TTM fence methods */
+bool
+via_fence_signaled(void *sync_obj)
+{
+ struct via_fence *fence = sync_obj;
+
+ if (!fence || !fence->seq.key)
+ return true;
+
+ if (via_fence_seq_signaled(fence, fence->seq.key)) {
+ fence->seq.key = 0;
+ return true;
+ }
+ return false;
+}
+
+int
+via_fence_wait(void *sync_obj, bool lazy, bool interruptible)
+{
+ struct via_fence *fence = sync_obj;
+ int ret = 0;
+
+ while (!via_fence_seq_signaled(fence, fence->seq.key)) {
+ if (time_after(jiffies, fence->timeout)) {
+ DRM_INFO("The fence wait timeout timeout = %lu, jiffies = %lu.\n",
+ fence->timeout, jiffies);
+ ret = -EBUSY;
+ break;
+ }
+
+ set_current_state(interruptible ? TASK_INTERRUPTIBLE :
+ TASK_UNINTERRUPTIBLE);
+
+ if (interruptible && signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+ }
+ set_current_state(TASK_RUNNING);
+ return ret;
+}
+
+int
+via_fence_flush(void *sync_obj)
+{
+ return 0;
+}
+
+void
+via_fence_unref(void **sync_obj)
+{
+ struct via_fence *fence = *sync_obj;
+
+ *sync_obj = NULL;
+ if (fence)
+ kref_put(&fence->kref, &via_fence_destroy);
+}
+
+void *
+via_fence_ref(void *sync_obj)
+{
+ struct via_fence *fence = sync_obj;
+
+ kref_get(&fence->kref);
+ return sync_obj;
+}
+
+/* We assert 30 * sizeof(uint32_t) is enough for emit fence sequence */
+#define FENCE_CMD_BUFFER (256 * sizeof(uint32_t))
+
+struct via_fence_pool *
+via_fence_pool_init(struct drm_device *dev, char *name, int domain,
+ int num_engines)
+{
+ struct drm_via_private *dev_priv = dev->dev_private;
+ struct via_fence_pool *pool = NULL;
+ int ret = 0, size, i;
+ void *par = NULL;
+
+ size = sizeof(*pool) + num_engines * sizeof(*pool->engines);
+ pool = kzalloc(size, GFP_KERNEL);
+ if (!pool)
+ return ERR_PTR(-ENOMEM);
+
+ /* allocate fence sync bo */
+ ret = ttm_allocate_kernel_buffer(&dev_priv->bdev, PAGE_SIZE, 16,
+ domain, &pool->fence_sync);
+ if (unlikely(ret)) {
+ DRM_ERROR("allocate fence sync bo error.\n");
+ goto out_err;
+ }
+ ret = -ENOMEM;
+
+ pool->cmd_buffer = kzalloc(FENCE_CMD_BUFFER, GFP_KERNEL);
+ if (!pool->cmd_buffer)
+ goto out_err;
+
+ spin_lock_init(&pool->lock);
+ pool->num_engines = num_engines;
+ pool->dev = dev;
+
+ if (domain == TTM_PL_FLAG_TT) {
+ pool->bus_addr = dma_map_page(dev->dev, pool->fence_sync.bo->ttm->pages[0],
+ 0, PAGE_SIZE, DMA_BIDIRECTIONAL);
+ par = pool->fence_sync.virtual;
+ } else if (domain == TTM_PL_FLAG_VRAM) {
+ pool->bus_addr = dma_map_single(dev->dev, pool->cmd_buffer,
+ FENCE_CMD_BUFFER, DMA_TO_DEVICE);
+ par = pool->cmd_buffer;
+ }
+
+ for (i = 0; i < pool->num_engines; i++) {
+ struct via_fence_engine *eng = &pool->engines[i];
+
+ INIT_WORK(&eng->fence_work, via_fence_work);
+ eng->read_seq = par + VIA_FENCE_SIZE * i;
+ eng->pool = pool;
+ eng->index = i;
+ }
+
+ pool->fence_wq = alloc_workqueue(name, 0, 0);
+ if (!pool->fence_wq)
+ goto out_err;
+
+ ret = drm_ht_create(&pool->pending, 12);
+out_err:
+ if (ret) {
+ via_fence_pool_fini(pool);
+ pool = ERR_PTR(ret);
+ }
+ return pool;
+}
+
+void
+via_fence_pool_fini(struct via_fence_pool *pool)
+{
+ struct ttm_buffer_object *sync_bo;
+ int i;
+
+ if (!pool)
+ return;
+
+ drm_ht_remove(&pool->pending);
+
+ flush_workqueue(pool->fence_wq);
+ destroy_workqueue(pool->fence_wq);
+
+ for (i = 0; i < pool->num_engines; i++)
+ cancel_work_sync(&pool->engines[i].fence_work);
+
+ kfree(pool->cmd_buffer);
+
+ sync_bo = pool->fence_sync.bo;
+ if (sync_bo) {
+ ttm_bo_unpin(sync_bo, &pool->fence_sync);
+ ttm_bo_unref(&sync_bo);
+ }
+
+ if (pool->bus_addr)
+ dma_unmap_page(pool->dev->dev, pool->bus_addr, PAGE_SIZE,
+ DMA_BIDIRECTIONAL);
+ kfree(pool);
+}
diff --git a/drivers/gpu/drm/via/via_fence.h b/drivers/gpu/drm/via/via_fence.h
new file mode 100644
index 0000000..eb4f462
--- /dev/null
+++ b/drivers/gpu/drm/via/via_fence.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2013 James Simmons <jsimmons at infradead.org>
+ *
+ * Influenced by sample code from VIA Technologies and the radeon driver.
+ *
+ * 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) OR COPYRIGHT HOLDER(S) 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.
+ */
+#ifndef _VIA_FENCE_H_
+#define _VIA_FENCE_H_
+
+#define VIA_FENCE_SIZE 32
+
+struct via_fence;
+
+struct via_fence_engine {
+ struct work_struct fence_work;
+ struct via_fence_pool *pool;
+
+ /* virtual address for getting seq value */
+ void *read_seq;
+
+ /* which engine we are */
+ int index;
+};
+
+struct via_fence_pool {
+ struct ttm_bo_kmap_obj fence_sync;
+ /* BUS address used for fencing */
+ dma_addr_t bus_addr;
+
+ /* for access synchronization */
+ spinlock_t lock;
+
+ /* Fence command bounce buffer */
+ uint32_t *cmd_buffer;
+
+ struct workqueue_struct *fence_wq;
+ struct drm_open_hash pending;
+ struct drm_device *dev;
+
+ void (*fence_signaled)(struct via_fence_engine *eng);
+ void (*fence_cleanup)(struct via_fence *fence);
+ int (*fence_emit)(struct via_fence *fence);
+
+ unsigned int num_engines;
+ struct via_fence_engine engines[];
+};
+
+struct via_fence {
+ /* Which fence pool (DMA or other), this fence is associated with */
+ struct via_fence_pool *pool;
+ /* the sequence number that the fence object emit,
+ * stored in a hash key */
+ struct drm_hash_item seq;
+ /* the time to wait for the fence object signal */
+ unsigned long timeout;
+ /* Which engine this belongs too */
+ int engine;
+ /* the reference information of this fence object */
+ struct kref kref;
+ /* place holder for special data specific to fence type */
+ void *priv;
+};
+
+extern bool via_fence_signaled(void *sync_obj);
+extern int via_fence_wait(void *sync_obj, bool lazy, bool interruptible);
+extern int via_fence_flush(void *sync_obj);
+extern void via_fence_unref(void **sync_obj);
+extern void *via_fence_ref(void *sync_obj);
+
+extern struct via_fence *
+via_fence_create_and_emit(struct via_fence_pool *pool, void *data,
+ unsigned int engine);
+
+extern struct via_fence_pool *
+via_fence_pool_init(struct drm_device *dev, char *name, int domain,
+ int num_engines);
+extern void via_fence_pool_fini(struct via_fence_pool *pool);
+
+#endif
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