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Commit 493018dc authored by Brad Volkin's avatar Brad Volkin Committed by Daniel Vetter
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drm/i915: Implement a framework for batch buffer pools 



This adds a small module for managing a pool of batch buffers.
The only current use case is for the command parser, as described
in the kerneldoc in the patch. The code is simple, but separating
it out makes it easier to change the underlying algorithms and to
extend to future use cases should they arise.

The interface is simple: init to create an empty pool, fini to
clean it up, get to obtain a new buffer. Note that all buffers are
expected to be inactive before cleaning up the pool.

Locking is currently based on the caller holding the struct_mutex.
We already do that in the places where we will use the batch pool
for the command parser.

v2:
- s/BUG_ON/WARN_ON/ for locking assertions
- Remove the cap on pool size
- Switch from alloc/free to init/fini

v3:
- Idiomatic looping structure in _fini
- Correct handling of purged objects
- Don't return a buffer that's too much larger than needed

v4:
- Rebased to latest -nightly

v5:
- Remove _put() function and clean up comments to match

v6:
- Move purged check inside the loop (danvet, from v4 1/7 feedback)

v7:
- Use single list instead of two. (Chris W)
- s/active_list/cache_list
- Squashed in debug patches (Chris W)
  drm/i915: Add a batch pool debugfs file

  It provides some useful information about the buffers in
  the global command parser batch pool.

  v2: rebase on global pool instead of per-ring pools
  v3: rebase

  drm/i915: Add batch pool details to i915_gem_objects debugfs

  To better account for the potentially large memory consumption
  of the batch pool.

v8:
- Keep cache in LRU order (danvet, from v6 1/5 feedback)

Issue: VIZ-4719
Signed-off-by: default avatarBrad Volkin <bradley.d.volkin@intel.com>
Reviewed-By: default avatarJon Bloomfield <jon.bloomfield@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent c8bd0e49

Documentation/DocBook/drm.tmpl

+5 −0
Original line number Diff line number Diff line
@@ -4032,6 +4032,11 @@ int num_ioctls;</synopsis> 
        <title>Batchbuffer Parsing</title>

!Pdrivers/gpu/drm/i915/i915_cmd_parser.c batch buffer command parser

!Idrivers/gpu/drm/i915/i915_cmd_parser.c

      </sect2>

      <sect2>

        <title>Batchbuffer Pools</title>

!Pdrivers/gpu/drm/i915/i915_gem_batch_pool.c batch pool

!Idrivers/gpu/drm/i915/i915_gem_batch_pool.c

      </sect2>

      <sect2>

        <title>Logical Rings, Logical Ring Contexts and Execlists</title>

drivers/gpu/drm/i915/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ i915-$(CONFIG_DEBUG_FS) += i915_debugfs.o 


# GEM code

i915-y += i915_cmd_parser.o \

	  i915_gem_batch_pool.o \

	  i915_gem_context.o \

	  i915_gem_render_state.o \

	  i915_gem_debug.o \

drivers/gpu/drm/i915/i915_debugfs.c

+62 −9
Original line number Diff line number Diff line
@@ -360,6 +360,33 @@ static int per_file_stats(int id, void *ptr, void *data) 
	return 0;

}



#define print_file_stats(m, name, stats) \

	seq_printf(m, "%s: %u objects, %zu bytes (%zu active, %zu inactive, %zu global, %zu shared, %zu unbound)\n", \

		   name, \

		   stats.count, \

		   stats.total, \

		   stats.active, \

		   stats.inactive, \

		   stats.global, \

		   stats.shared, \

		   stats.unbound)



static void print_batch_pool_stats(struct seq_file *m,

				   struct drm_i915_private *dev_priv)

{

	struct drm_i915_gem_object *obj;

	struct file_stats stats;



	memset(&stats, 0, sizeof(stats));



	list_for_each_entry(obj,

			    &dev_priv->mm.batch_pool.cache_list,

			    batch_pool_list)

		per_file_stats(0, obj, &stats);



	print_file_stats(m, "batch pool", stats);

}



#define count_vmas(list, member) do { \

	list_for_each_entry(vma, list, member) { \

		size += i915_gem_obj_ggtt_size(vma->obj); \
@@ -441,6 +468,9 @@ static int i915_gem_object_info(struct seq_file *m, void* data) 
		   dev_priv->gtt.base.total,

		   dev_priv->gtt.mappable_end - dev_priv->gtt.base.start);



	seq_putc(m, '\n');

	print_batch_pool_stats(m, dev_priv);



	seq_putc(m, '\n');

	list_for_each_entry_reverse(file, &dev->filelist, lhead) {

		struct file_stats stats;
@@ -459,15 +489,7 @@ static int i915_gem_object_info(struct seq_file *m, void* data) 
		 */

		rcu_read_lock();

		task = pid_task(file->pid, PIDTYPE_PID);

		seq_printf(m, "%s: %u objects, %zu bytes (%zu active, %zu inactive, %zu global, %zu shared, %zu unbound)\n",

			   task ? task->comm : "<unknown>",

			   stats.count,

			   stats.total,

			   stats.active,

			   stats.inactive,

			   stats.global,

			   stats.shared,

			   stats.unbound);

		print_file_stats(m, task ? task->comm : "<unknown>", stats);

		rcu_read_unlock();

	}
@@ -584,6 +606,36 @@ static int i915_gem_pageflip_info(struct seq_file *m, void *data) 
	return 0;

}



static int i915_gem_batch_pool_info(struct seq_file *m, void *data)

{

	struct drm_info_node *node = m->private;

	struct drm_device *dev = node->minor->dev;

	struct drm_i915_private *dev_priv = dev->dev_private;

	struct drm_i915_gem_object *obj;

	int count = 0;

	int ret;



	ret = mutex_lock_interruptible(&dev->struct_mutex);

	if (ret)

		return ret;



	seq_puts(m, "cache:\n");

	list_for_each_entry(obj,

			    &dev_priv->mm.batch_pool.cache_list,

			    batch_pool_list) {

		seq_puts(m, "   ");

		describe_obj(m, obj);

		seq_putc(m, '\n');

		count++;

	}



	seq_printf(m, "total: %d\n", count);



	mutex_unlock(&dev->struct_mutex);



	return 0;

}



static int i915_gem_request_info(struct seq_file *m, void *data)

{

	struct drm_info_node *node = m->private;
@@ -4357,6 +4409,7 @@ static const struct drm_info_list i915_debugfs_list[] = { 
	{"i915_gem_hws_blt", i915_hws_info, 0, (void *)BCS},

	{"i915_gem_hws_bsd", i915_hws_info, 0, (void *)VCS},

	{"i915_gem_hws_vebox", i915_hws_info, 0, (void *)VECS},

	{"i915_gem_batch_pool", i915_gem_batch_pool_info, 0},

	{"i915_frequency_info", i915_frequency_info, 0},

	{"i915_drpc_info", i915_drpc_info, 0},

	{"i915_emon_status", i915_emon_status, 0},

drivers/gpu/drm/i915/i915_drv.h

+21 −0
Original line number Diff line number Diff line
@@ -1141,6 +1141,11 @@ struct intel_l3_parity { 
	int which_slice;

};



struct i915_gem_batch_pool {

	struct drm_device *dev;

	struct list_head cache_list;

};



struct i915_gem_mm {

	/** Memory allocator for GTT stolen memory */

	struct drm_mm stolen;
@@ -1154,6 +1159,13 @@ struct i915_gem_mm { 
	 */

	struct list_head unbound_list;



	/*

	 * A pool of objects to use as shadow copies of client batch buffers

	 * when the command parser is enabled. Prevents the client from

	 * modifying the batch contents after software parsing.

	 */

	struct i915_gem_batch_pool batch_pool;



	/** Usable portion of the GTT for GEM */

	unsigned long stolen_base; /* limited to low memory (32-bit) */
@@ -1885,6 +1897,8 @@ struct drm_i915_gem_object { 
	/** Used in execbuf to temporarily hold a ref */

	struct list_head obj_exec_link;



	struct list_head batch_pool_list;



	/**

	 * This is set if the object is on the active lists (has pending

	 * rendering and so a non-zero seqno), and is not set if it i s on
@@ -2935,6 +2949,13 @@ void i915_destroy_error_state(struct drm_device *dev); 
void i915_get_extra_instdone(struct drm_device *dev, uint32_t *instdone);

const char *i915_cache_level_str(struct drm_i915_private *i915, int type);



/* i915_gem_batch_pool.c */

void i915_gem_batch_pool_init(struct drm_device *dev,

			      struct i915_gem_batch_pool *pool);

void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool);

struct drm_i915_gem_object*

i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool, size_t size);



/* i915_cmd_parser.c */

int i915_cmd_parser_get_version(void);

int i915_cmd_parser_init_ring(struct intel_engine_cs *ring);

drivers/gpu/drm/i915/i915_gem.c

+1 −0
Original line number Diff line number Diff line
@@ -4393,6 +4393,7 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj, 
	INIT_LIST_HEAD(&obj->ring_list);

	INIT_LIST_HEAD(&obj->obj_exec_link);

	INIT_LIST_HEAD(&obj->vma_list);

	INIT_LIST_HEAD(&obj->batch_pool_list);



	obj->ops = ops;