[PATCH 3/6] drm/tegra: Implement buffer object cache
Thierry Reding
thierry.reding at gmail.com
Thu Sep 16 09:44:01 UTC 2021
From: Thierry Reding <treding at nvidia.com>
This cache is used to avoid mapping and unmapping buffer objects
unnecessarily. Mappings are cached per client and stay hot until
the buffer object is destroyed.
Signed-off-by: Thierry Reding <treding at nvidia.com>
---
drivers/gpu/drm/tegra/gem.c | 14 +++++--
drivers/gpu/drm/tegra/plane.c | 2 +-
drivers/gpu/drm/tegra/uapi.c | 3 +-
drivers/gpu/host1x/bus.c | 78 +++++++++++++++++++++++++++++++++++
drivers/gpu/host1x/dev.c | 2 +
drivers/gpu/host1x/dev.h | 2 +
drivers/gpu/host1x/job.c | 4 +-
include/linux/host1x.h | 53 +++++++++++++++++++-----
8 files changed, 141 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 79a609f981d1..e3f0578fc411 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -39,6 +39,7 @@ static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_
if (!map)
return ERR_PTR(-ENOMEM);
+ kref_init(&map->ref);
map->bo = host1x_bo_get(bo);
map->direction = direction;
map->dev = dev;
@@ -129,9 +130,6 @@ static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_
static void tegra_bo_unpin(struct host1x_bo_mapping *map)
{
- if (!map)
- return;
-
if (map->attach) {
dma_buf_unmap_attachment(map->attach, map->sgt, map->direction);
dma_buf_detach(map->attach->dmabuf, map->attach);
@@ -465,8 +463,18 @@ static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
void tegra_bo_free_object(struct drm_gem_object *gem)
{
struct tegra_drm *tegra = gem->dev->dev_private;
+ struct host1x_bo_mapping *mapping, *tmp;
struct tegra_bo *bo = to_tegra_bo(gem);
+ /* remove all mappings of this buffer object from any caches */
+ list_for_each_entry_safe(mapping, tmp, &bo->base.mappings, list) {
+ if (mapping->cache)
+ host1x_bo_unpin(mapping);
+ else
+ dev_err(gem->dev->dev, "mapping %p stale for device %s\n", mapping,
+ dev_name(mapping->dev));
+ }
+
if (tegra->domain)
tegra_bo_iommu_unmap(tegra, bo);
diff --git a/drivers/gpu/drm/tegra/plane.c b/drivers/gpu/drm/tegra/plane.c
index e579d966e8dc..f8e8afcbcbf2 100644
--- a/drivers/gpu/drm/tegra/plane.c
+++ b/drivers/gpu/drm/tegra/plane.c
@@ -145,7 +145,7 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
struct tegra_bo *bo = tegra_fb_get_plane(state->base.fb, i);
struct host1x_bo_mapping *map;
- map = host1x_bo_pin(dc->dev, &bo->base, DMA_TO_DEVICE);
+ map = host1x_bo_pin(dc->dev, &bo->base, DMA_TO_DEVICE, &dc->client.cache);
if (IS_ERR(map)) {
err = PTR_ERR(map);
goto unpin;
diff --git a/drivers/gpu/drm/tegra/uapi.c b/drivers/gpu/drm/tegra/uapi.c
index 794c400c38b1..66fe8717e747 100644
--- a/drivers/gpu/drm/tegra/uapi.c
+++ b/drivers/gpu/drm/tegra/uapi.c
@@ -201,7 +201,8 @@ int tegra_drm_ioctl_channel_map(struct drm_device *drm, void *data, struct drm_f
goto put_gem;
}
- mapping->map = host1x_bo_pin(context->client->base.dev, mapping->bo, direction);
+ mapping->map = host1x_bo_pin(context->client->base.dev, mapping->bo, direction,
+ &context->client->base.cache);
if (IS_ERR(mapping->map)) {
err = PTR_ERR(mapping->map);
goto put_gem;
diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
index 218e3718fd68..0b67d894470d 100644
--- a/drivers/gpu/host1x/bus.c
+++ b/drivers/gpu/host1x/bus.c
@@ -742,6 +742,7 @@ EXPORT_SYMBOL(host1x_driver_unregister);
*/
void __host1x_client_init(struct host1x_client *client, struct lock_class_key *key)
{
+ host1x_bo_cache_init(&client->cache);
INIT_LIST_HEAD(&client->list);
__mutex_init(&client->lock, "host1x client lock", key);
client->usecount = 0;
@@ -830,6 +831,8 @@ int host1x_client_unregister(struct host1x_client *client)
mutex_unlock(&clients_lock);
+ host1x_bo_cache_destroy(&client->cache);
+
return 0;
}
EXPORT_SYMBOL(host1x_client_unregister);
@@ -904,3 +907,78 @@ int host1x_client_resume(struct host1x_client *client)
return err;
}
EXPORT_SYMBOL(host1x_client_resume);
+
+struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
+ enum dma_data_direction dir,
+ struct host1x_bo_cache *cache)
+{
+ struct host1x_bo_mapping *mapping;
+
+ if (cache) {
+ mutex_lock(&cache->lock);
+
+ list_for_each_entry(mapping, &cache->mappings, entry) {
+ if (mapping->bo == bo && mapping->direction == dir) {
+ kref_get(&mapping->ref);
+ goto unlock;
+ }
+ }
+ }
+
+ mapping = bo->ops->pin(dev, bo, dir);
+ if (IS_ERR(mapping))
+ goto unlock;
+
+ spin_lock(&mapping->bo->lock);
+ list_add_tail(&mapping->list, &bo->mappings);
+ spin_unlock(&mapping->bo->lock);
+
+ if (cache) {
+ INIT_LIST_HEAD(&mapping->entry);
+ mapping->cache = cache;
+
+ list_add_tail(&mapping->entry, &cache->mappings);
+
+ /* bump reference count to track the copy in the cache */
+ kref_get(&mapping->ref);
+ }
+
+unlock:
+ if (cache)
+ mutex_unlock(&cache->lock);
+
+ return mapping;
+}
+EXPORT_SYMBOL(host1x_bo_pin);
+
+static void __host1x_bo_unpin(struct kref *ref)
+{
+ struct host1x_bo_mapping *mapping = to_host1x_bo_mapping(ref);
+
+ /*
+ * When the last reference of the mapping goes away, make sure to remove the mapping from
+ * the cache.
+ */
+ if (mapping->cache)
+ list_del(&mapping->entry);
+
+ spin_lock(&mapping->bo->lock);
+ list_del(&mapping->list);
+ spin_unlock(&mapping->bo->lock);
+
+ mapping->bo->ops->unpin(mapping);
+}
+
+void host1x_bo_unpin(struct host1x_bo_mapping *mapping)
+{
+ struct host1x_bo_cache *cache = mapping->cache;
+
+ if (cache)
+ mutex_lock(&cache->lock);
+
+ kref_put(&mapping->ref, __host1x_bo_unpin);
+
+ if (cache)
+ mutex_unlock(&cache->lock);
+}
+EXPORT_SYMBOL(host1x_bo_unpin);
diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index e2ddf3fcaa9a..3d4cabdbc78d 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -404,6 +404,7 @@ static int host1x_probe(struct platform_device *pdev)
if (syncpt_irq < 0)
return syncpt_irq;
+ host1x_bo_cache_init(&host->cache);
mutex_init(&host->devices_lock);
INIT_LIST_HEAD(&host->devices);
INIT_LIST_HEAD(&host->list);
@@ -530,6 +531,7 @@ static int host1x_remove(struct platform_device *pdev)
reset_control_assert(host->rst);
clk_disable_unprepare(host->clk);
host1x_iommu_exit(host);
+ host1x_bo_cache_destroy(&host->cache);
return 0;
}
diff --git a/drivers/gpu/host1x/dev.h b/drivers/gpu/host1x/dev.h
index fa6d4bc46e98..5b7fdea5d169 100644
--- a/drivers/gpu/host1x/dev.h
+++ b/drivers/gpu/host1x/dev.h
@@ -149,6 +149,8 @@ struct host1x {
struct list_head list;
struct device_dma_parameters dma_parms;
+
+ struct host1x_bo_cache cache;
};
void host1x_hypervisor_writel(struct host1x *host1x, u32 r, u32 v);
diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index 7a27895e0d28..5b7dcbdefcab 100644
--- a/drivers/gpu/host1x/job.c
+++ b/drivers/gpu/host1x/job.c
@@ -177,7 +177,7 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
goto unpin;
}
- map = host1x_bo_pin(dev, bo, direction);
+ map = host1x_bo_pin(dev, bo, direction, &client->cache);
if (IS_ERR(map)) {
err = PTR_ERR(map);
goto unpin;
@@ -224,7 +224,7 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
goto unpin;
}
- map = host1x_bo_pin(host->dev, g->bo, DMA_TO_DEVICE);
+ map = host1x_bo_pin(host->dev, g->bo, DMA_TO_DEVICE, &host->cache);
if (IS_ERR(map)) {
err = PTR_ERR(map);
goto unpin;
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 56851523378a..2ca53d7ed7ca 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -8,6 +8,7 @@
#include <linux/device.h>
#include <linux/dma-direction.h>
+#include <linux/spinlock.h>
#include <linux/types.h>
enum host1x_class {
@@ -26,6 +27,28 @@ struct iommu_group;
u64 host1x_get_dma_mask(struct host1x *host1x);
+/**
+ * struct host1x_bo_cache - host1x buffer object cache
+ * @mappings: list of mappings
+ * @lock: synchronizes accesses to the list of mappings
+ */
+struct host1x_bo_cache {
+ struct list_head mappings;
+ struct mutex lock;
+};
+
+static inline void host1x_bo_cache_init(struct host1x_bo_cache *cache)
+{
+ INIT_LIST_HEAD(&cache->mappings);
+ mutex_init(&cache->lock);
+}
+
+static inline void host1x_bo_cache_destroy(struct host1x_bo_cache *cache)
+{
+ /* XXX warn if not empty? */
+ mutex_destroy(&cache->lock);
+}
+
/**
* struct host1x_client_ops - host1x client operations
* @early_init: host1x client early initialization code
@@ -76,6 +99,8 @@ struct host1x_client {
struct host1x_client *parent;
unsigned int usecount;
struct mutex lock;
+
+ struct host1x_bo_cache cache;
};
/*
@@ -86,16 +111,26 @@ struct host1x_bo;
struct sg_table;
struct host1x_bo_mapping {
+ struct kref ref;
struct dma_buf_attachment *attach;
enum dma_data_direction direction;
+ struct list_head list;
struct host1x_bo *bo;
struct sg_table *sgt;
unsigned int chunks;
struct device *dev;
dma_addr_t phys;
size_t size;
+
+ struct host1x_bo_cache *cache;
+ struct list_head entry;
};
+static inline struct host1x_bo_mapping *to_host1x_bo_mapping(struct kref *ref)
+{
+ return container_of(ref, struct host1x_bo_mapping, ref);
+}
+
struct host1x_bo_ops {
struct host1x_bo *(*get)(struct host1x_bo *bo);
void (*put)(struct host1x_bo *bo);
@@ -108,11 +143,15 @@ struct host1x_bo_ops {
struct host1x_bo {
const struct host1x_bo_ops *ops;
+ struct list_head mappings;
+ spinlock_t lock;
};
static inline void host1x_bo_init(struct host1x_bo *bo,
const struct host1x_bo_ops *ops)
{
+ INIT_LIST_HEAD(&bo->mappings);
+ spin_lock_init(&bo->lock);
bo->ops = ops;
}
@@ -126,16 +165,10 @@ static inline void host1x_bo_put(struct host1x_bo *bo)
bo->ops->put(bo);
}
-static inline struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
- enum dma_data_direction dir)
-{
- return bo->ops->pin(dev, bo, dir);
-}
-
-static inline void host1x_bo_unpin(struct host1x_bo_mapping *map)
-{
- map->bo->ops->unpin(map);
-}
+struct host1x_bo_mapping *host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
+ enum dma_data_direction dir,
+ struct host1x_bo_cache *cache);
+void host1x_bo_unpin(struct host1x_bo_mapping *map);
static inline void *host1x_bo_mmap(struct host1x_bo *bo)
{
--
2.33.0
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