Commit 9b590783 authored by Thomas Hellstrom's avatar Thomas Hellstrom
Browse files

drm/vmwgfx: Avoid cmdbuf alloc sleeping if !TASK_RUNNING 



If the command buffer pool is out of space, the code waits until space is
available. However since the condition code tries to allocate a range manager
node while !TASK_RUNNING we get a kernel warning.

Avoid this by pre-allocating the mm node. This will also probably be more
efficient.

Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: default avatarSinclair Yeh <syeh@vmware.com>
parent 6bf6bf03

drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c

+34 −49
Original line number Diff line number Diff line
@@ -33,7 +33,8 @@ 
 * multiple of the DMA pool allocation size.

 */

#define VMW_CMDBUF_INLINE_ALIGN 64

#define VMW_CMDBUF_INLINE_SIZE (1024 - VMW_CMDBUF_INLINE_ALIGN)

#define VMW_CMDBUF_INLINE_SIZE \

	(1024 - ALIGN(sizeof(SVGACBHeader), VMW_CMDBUF_INLINE_ALIGN))



/**

 * struct vmw_cmdbuf_context - Command buffer context queues
@@ -145,7 +146,7 @@ struct vmw_cmdbuf_header { 
	SVGACBHeader *cb_header;

	SVGACBContext cb_context;

	struct list_head list;

	struct drm_mm_node *node;

	struct drm_mm_node node;

	dma_addr_t handle;

	u8 *cmd;

	size_t size;
@@ -169,13 +170,13 @@ struct vmw_cmdbuf_dheader { 
 * struct vmw_cmdbuf_alloc_info - Command buffer space allocation metadata

 *

 * @page_size: Size of requested command buffer space in pages.

 * @node: The range manager node if allocation succeeded.

 * @ret: Error code if failure. Otherwise 0.

 * @node: Pointer to the range manager node.

 * @done: True if this allocation has succeeded.

 */

struct vmw_cmdbuf_alloc_info {

	size_t page_size;

	struct drm_mm_node *node;

	int ret;

	bool done;

};



/* Loop over each context in the command buffer manager. */
@@ -253,9 +254,7 @@ static void __vmw_cmdbuf_header_free(struct vmw_cmdbuf_header *header) 
		return;

	}



	drm_mm_remove_node(header->node);

	kfree(header->node);

	header->node = NULL;

	drm_mm_remove_node(&header->node);

	wake_up_all(&man->alloc_queue);

	if (header->cb_header)

		dma_pool_free(man->headers, header->cb_header,
@@ -669,32 +668,26 @@ static bool vmw_cmdbuf_try_alloc(struct vmw_cmdbuf_man *man, 
{

	int ret;



	if (info->node)

		return true;



	info->node = kzalloc(sizeof(*info->node), GFP_KERNEL);

	if (!info->node) {

		info->ret = -ENOMEM;

	if (info->done)

		return true;

	}

 

	memset(info->node, 0, sizeof(*info->node));

	spin_lock_bh(&man->lock);

	ret = drm_mm_insert_node_generic(&man->mm, info->node, info->page_size, 0, 0,

	ret = drm_mm_insert_node_generic(&man->mm, info->node, info->page_size,

					 0, 0,

					 DRM_MM_SEARCH_DEFAULT,

					 DRM_MM_CREATE_DEFAULT);

	spin_unlock_bh(&man->lock);

	if (ret) {

		kfree(info->node);

		info->node = NULL;

	}

	info->done = !ret;



	return !!info->node;

	return info->done;

}



/**

 * vmw_cmdbuf_alloc_space - Allocate buffer space from the main pool.

 *

 * @man: The command buffer manager.

 * @node: Pointer to pre-allocated range-manager node.

 * @size: The size of the allocation.

 * @interruptible: Whether to sleep interruptible while waiting for space.

 *
@@ -702,15 +695,16 @@ static bool vmw_cmdbuf_try_alloc(struct vmw_cmdbuf_man *man, 
 * no space available ATM, it turns on IRQ handling and sleeps waiting for it to

 * become available.

 */

static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,

int vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man,

			   struct drm_mm_node *node,

			   size_t size,

			   bool interruptible)

{

	struct vmw_cmdbuf_alloc_info info;



	info.page_size = PAGE_ALIGN(size) >> PAGE_SHIFT;

	info.node = NULL;

	info.ret = 0;

	info.node = node;

	info.done = false;



	/*

	 * To prevent starvation of large requests, only one allocating call
@@ -718,22 +712,14 @@ static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man, 
	 */

	if (interruptible) {

		if (mutex_lock_interruptible(&man->space_mutex))

			return ERR_PTR(-ERESTARTSYS);

			return -ERESTARTSYS;

	} else {

		mutex_lock(&man->space_mutex);

	}



	/* Try to allocate space without waiting. */

	(void) vmw_cmdbuf_try_alloc(man, &info);

	if (info.ret && !info.node) {

		mutex_unlock(&man->space_mutex);

		return ERR_PTR(info.ret);

	}



	if (info.node) {

		mutex_unlock(&man->space_mutex);

		return info.node;

	}

	if (vmw_cmdbuf_try_alloc(man, &info))

		goto out_unlock;



	vmw_generic_waiter_add(man->dev_priv,

			       SVGA_IRQFLAG_COMMAND_BUFFER,
@@ -749,7 +735,7 @@ static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man, 
				(man->dev_priv, SVGA_IRQFLAG_COMMAND_BUFFER,

				 &man->dev_priv->cmdbuf_waiters);

			mutex_unlock(&man->space_mutex);

			return ERR_PTR(ret);

			return ret;

		}

	} else {

		wait_event(man->alloc_queue, vmw_cmdbuf_try_alloc(man, &info));
@@ -757,11 +743,11 @@ static struct drm_mm_node *vmw_cmdbuf_alloc_space(struct vmw_cmdbuf_man *man, 
	vmw_generic_waiter_remove(man->dev_priv,

				  SVGA_IRQFLAG_COMMAND_BUFFER,

				  &man->dev_priv->cmdbuf_waiters);



out_unlock:

	mutex_unlock(&man->space_mutex);

	if (info.ret && !info.node)

		return ERR_PTR(info.ret);



	return info.node;

	return 0;

}



/**
@@ -785,10 +771,10 @@ static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man, 
	if (!man->has_pool)

		return -ENOMEM;



	header->node = vmw_cmdbuf_alloc_space(man, size, interruptible);

	ret = vmw_cmdbuf_alloc_space(man, &header->node,  size, interruptible);



	if (IS_ERR(header->node))

		return PTR_ERR(header->node);

	if (ret)

		return ret;



	header->cb_header = dma_pool_alloc(man->headers, GFP_KERNEL,

					   &header->handle);
@@ -797,9 +783,9 @@ static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man, 
		goto out_no_cb_header;

	}



	header->size = header->node->size << PAGE_SHIFT;

	header->size = header->node.size << PAGE_SHIFT;

	cb_hdr = header->cb_header;

	offset = header->node->start << PAGE_SHIFT;

	offset = header->node.start << PAGE_SHIFT;

	header->cmd = man->map + offset;

	memset(cb_hdr, 0, sizeof(*cb_hdr));

	if (man->using_mob) {
@@ -814,9 +800,8 @@ static int vmw_cmdbuf_space_pool(struct vmw_cmdbuf_man *man, 


out_no_cb_header:

	spin_lock_bh(&man->lock);

	drm_mm_remove_node(header->node);

	drm_mm_remove_node(&header->node);

	spin_unlock_bh(&man->lock);

	kfree(header->node);



	return ret;

}

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