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Commit 3cbd0c58 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Tomi Valkeinen
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drm/omap: gem: Replace struct_mutex usage with omap_obj private lock 



The DRM device struct_mutex is used to protect against concurrent GEM
object operations that deal with memory allocation and pinning. All
those operations are local to a GEM object and don't need to be
serialized across different GEM objects. Replace the struct_mutex with
a local omap_obj.lock or drop it altogether where not needed.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
parent dc8c9aee

drivers/gpu/drm/omapdrm/omap_debugfs.c

+0 −7
Original line number Diff line number Diff line
@@ -30,17 +30,10 @@ static int gem_show(struct seq_file *m, void *arg) 
	struct drm_info_node *node = (struct drm_info_node *) m->private;

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

	struct omap_drm_private *priv = dev->dev_private;

	int ret;



	ret = mutex_lock_interruptible(&dev->struct_mutex);

	if (ret)

		return ret;



	seq_printf(m, "All Objects:\n");

	omap_gem_describe_objects(&priv->obj_list, m);



	mutex_unlock(&dev->struct_mutex);



	return 0;

}

drivers/gpu/drm/omapdrm/omap_fbdev.c

+1 −7
Original line number Diff line number Diff line
@@ -170,13 +170,11 @@ static int omap_fbdev_create(struct drm_fb_helper *helper, 
		goto fail;

	}



	mutex_lock(&dev->struct_mutex);



	fbi = drm_fb_helper_alloc_fbi(helper);

	if (IS_ERR(fbi)) {

		dev_err(dev->dev, "failed to allocate fb info\n");

		ret = PTR_ERR(fbi);

		goto fail_unlock;

		goto fail;

	}



	DBG("fbi=%p, dev=%p", fbi, dev);
@@ -212,12 +210,8 @@ static int omap_fbdev_create(struct drm_fb_helper *helper, 
	DBG("par=%p, %dx%d", fbi->par, fbi->var.xres, fbi->var.yres);

	DBG("allocated %dx%d fb", fbdev->fb->width, fbdev->fb->height);



	mutex_unlock(&dev->struct_mutex);



	return 0;



fail_unlock:

	mutex_unlock(&dev->struct_mutex);

fail:



	if (ret) {

drivers/gpu/drm/omapdrm/omap_gem.c

+85 −42
Original line number Diff line number Diff line
@@ -47,6 +47,9 @@ struct omap_gem_object { 
	/** roll applied when mapping to DMM */

	u32 roll;



	/** protects dma_addr_cnt, block, pages, dma_addrs and vaddr */

	struct mutex lock;



	/**

	 * dma_addr contains the buffer DMA address. It is valid for

	 *
@@ -220,7 +223,10 @@ static void omap_gem_evict(struct drm_gem_object *obj) 
 * Page Management

 */



/* Ensure backing pages are allocated. */

/*

 * Ensure backing pages are allocated. Must be called with the omap_obj.lock

 * held.

 */

static int omap_gem_attach_pages(struct drm_gem_object *obj)

{

	struct drm_device *dev = obj->dev;
@@ -230,6 +236,8 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj) 
	int i, ret;

	dma_addr_t *addrs;



	lockdep_assert_held(&omap_obj->lock);



	/*

	 * If not using shmem (in which case backing pages don't need to be

	 * allocated) or if pages are already allocated we're done.
@@ -291,13 +299,15 @@ static int omap_gem_attach_pages(struct drm_gem_object *obj) 
	return ret;

}



/** release backing pages */

/* Release backing pages. Must be called with the omap_obj.lock held. */

static void omap_gem_detach_pages(struct drm_gem_object *obj)

{

	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	unsigned int npages = obj->size >> PAGE_SHIFT;

	unsigned int i;



	lockdep_assert_held(&omap_obj->lock);



	for (i = 0; i < npages; i++) {

		if (omap_obj->dma_addrs[i])

			dma_unmap_page(obj->dev->dev, omap_obj->dma_addrs[i],
@@ -491,14 +501,13 @@ vm_fault_t omap_gem_fault(struct vm_fault *vmf) 
	struct vm_area_struct *vma = vmf->vma;

	struct drm_gem_object *obj = vma->vm_private_data;

	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	struct drm_device *dev = obj->dev;

	int err;

	vm_fault_t ret;



	/* Make sure we don't parallel update on a fault, nor move or remove

	 * something from beneath our feet

	 */

	mutex_lock(&dev->struct_mutex);

	mutex_lock(&omap_obj->lock);



	/* if a shmem backed object, make sure we have pages attached now */

	err = omap_gem_attach_pages(obj);
@@ -520,7 +529,7 @@ vm_fault_t omap_gem_fault(struct vm_fault *vmf) 




fail:

	mutex_unlock(&dev->struct_mutex);

	mutex_unlock(&omap_obj->lock);

	return ret;

}
@@ -654,7 +663,7 @@ int omap_gem_roll(struct drm_gem_object *obj, u32 roll) 


	omap_obj->roll = roll;



	mutex_lock(&obj->dev->struct_mutex);

	mutex_lock(&omap_obj->lock);



	/* if we aren't mapped yet, we don't need to do anything */

	if (omap_obj->block) {
@@ -669,7 +678,7 @@ int omap_gem_roll(struct drm_gem_object *obj, u32 roll) 
	}



fail:

	mutex_unlock(&obj->dev->struct_mutex);

	mutex_unlock(&omap_obj->lock);



	return ret;

}
@@ -770,7 +779,7 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr) 
	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	int ret = 0;



	mutex_lock(&obj->dev->struct_mutex);

	mutex_lock(&omap_obj->lock);



	if (!omap_gem_is_contiguous(omap_obj) && priv->has_dmm) {

		if (omap_obj->dma_addr_cnt == 0) {
@@ -826,7 +835,7 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr) 
	}



fail:

	mutex_unlock(&obj->dev->struct_mutex);

	mutex_unlock(&omap_obj->lock);



	return ret;

}
@@ -844,7 +853,8 @@ void omap_gem_unpin(struct drm_gem_object *obj) 
	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	int ret;



	mutex_lock(&obj->dev->struct_mutex);

	mutex_lock(&omap_obj->lock);



	if (omap_obj->dma_addr_cnt > 0) {

		omap_obj->dma_addr_cnt--;

		if (omap_obj->dma_addr_cnt == 0) {
@@ -863,7 +873,7 @@ void omap_gem_unpin(struct drm_gem_object *obj) 
		}

	}



	mutex_unlock(&obj->dev->struct_mutex);

	mutex_unlock(&omap_obj->lock);

}



/* Get rotated scanout address (only valid if already pinned), at the
@@ -876,13 +886,16 @@ int omap_gem_rotated_dma_addr(struct drm_gem_object *obj, u32 orient, 
	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	int ret = -EINVAL;



	mutex_lock(&obj->dev->struct_mutex);

	mutex_lock(&omap_obj->lock);



	if ((omap_obj->dma_addr_cnt > 0) && omap_obj->block &&

			(omap_obj->flags & OMAP_BO_TILED)) {

		*dma_addr = tiler_tsptr(omap_obj->block, orient, x, y);

		ret = 0;

	}

	mutex_unlock(&obj->dev->struct_mutex);



	mutex_unlock(&omap_obj->lock);



	return ret;

}
@@ -910,18 +923,26 @@ int omap_gem_get_pages(struct drm_gem_object *obj, struct page ***pages, 
		bool remap)

{

	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	int ret;

	int ret = 0;



	if (!remap) {

		if (!omap_obj->pages)

			return -ENOMEM;

		*pages = omap_obj->pages;

		return 0;

	}

	mutex_lock(&obj->dev->struct_mutex);

	mutex_lock(&omap_obj->lock);



	if (remap) {

		ret = omap_gem_attach_pages(obj);

		if (ret)

			goto unlock;

	}



	if (!omap_obj->pages) {

		ret = -ENOMEM;

		goto unlock;

	}



	*pages = omap_obj->pages;

	mutex_unlock(&obj->dev->struct_mutex);



unlock:

	mutex_unlock(&omap_obj->lock);



	return ret;

}
@@ -936,24 +957,34 @@ int omap_gem_put_pages(struct drm_gem_object *obj) 
}



#ifdef CONFIG_DRM_FBDEV_EMULATION

/* Get kernel virtual address for CPU access.. this more or less only

 * exists for omap_fbdev.  This should be called with struct_mutex

 * held.

/*

 * Get kernel virtual address for CPU access.. this more or less only

 * exists for omap_fbdev.

 */

void *omap_gem_vaddr(struct drm_gem_object *obj)

{

	struct omap_gem_object *omap_obj = to_omap_bo(obj);

	WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));

	if (!omap_obj->vaddr) {

	void *vaddr;

	int ret;



	mutex_lock(&omap_obj->lock);



	if (!omap_obj->vaddr) {

		ret = omap_gem_attach_pages(obj);

		if (ret)

			return ERR_PTR(ret);

		if (ret) {

			vaddr = ERR_PTR(ret);

			goto unlock;

		}



		omap_obj->vaddr = vmap(omap_obj->pages, obj->size >> PAGE_SHIFT,

				VM_MAP, pgprot_writecombine(PAGE_KERNEL));

	}

	return omap_obj->vaddr;



	vaddr = omap_obj->vaddr;



unlock:

	mutex_unlock(&omap_obj->lock);

	return vaddr;

}

#endif
@@ -1001,6 +1032,8 @@ void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m) 


	off = drm_vma_node_start(&obj->vma_node);



	mutex_lock(&omap_obj->lock);



	seq_printf(m, "%08x: %2d (%2d) %08llx %pad (%2d) %p %4d",

			omap_obj->flags, obj->name, kref_read(&obj->refcount),

			off, &omap_obj->dma_addr, omap_obj->dma_addr_cnt,
@@ -1018,6 +1051,8 @@ void omap_gem_describe(struct drm_gem_object *obj, struct seq_file *m) 
		seq_printf(m, " %zu", obj->size);

	}



	mutex_unlock(&omap_obj->lock);



	seq_printf(m, "\n");

}
@@ -1051,15 +1086,19 @@ void omap_gem_free_object(struct drm_gem_object *obj) 


	omap_gem_evict(obj);



	WARN_ON(!mutex_is_locked(&dev->struct_mutex));



	spin_lock(&priv->list_lock);

	list_del(&omap_obj->mm_list);

	spin_unlock(&priv->list_lock);



	/* this means the object is still pinned.. which really should

	 * not happen.  I think..

	/*

	 * We own the sole reference to the object at this point, but to keep

	 * lockdep happy, we must still take the omap_obj_lock to call

	 * omap_gem_detach_pages(). This should hardly make any difference as

	 * there can't be any lock contention.

	 */

	mutex_lock(&omap_obj->lock);



	/* The object should not be pinned. */

	WARN_ON(omap_obj->dma_addr_cnt > 0);



	if (omap_obj->pages) {
@@ -1078,8 +1117,12 @@ void omap_gem_free_object(struct drm_gem_object *obj) 
		drm_prime_gem_destroy(obj, omap_obj->sgt);

	}



	mutex_unlock(&omap_obj->lock);



	drm_gem_object_release(obj);



	mutex_destroy(&omap_obj->lock);



	kfree(omap_obj);

}
@@ -1135,6 +1178,7 @@ struct drm_gem_object *omap_gem_new(struct drm_device *dev, 


	obj = &omap_obj->base;

	omap_obj->flags = flags;

	mutex_init(&omap_obj->lock);



	if (flags & OMAP_BO_TILED) {

		/*
@@ -1199,16 +1243,15 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, 
	if (sgt->orig_nents != 1 && !priv->has_dmm)

		return ERR_PTR(-EINVAL);



	mutex_lock(&dev->struct_mutex);



	gsize.bytes = PAGE_ALIGN(size);

	obj = omap_gem_new(dev, gsize, OMAP_BO_MEM_DMABUF | OMAP_BO_WC);

	if (!obj) {

		obj = ERR_PTR(-ENOMEM);

		goto done;

	}

	if (!obj)

		return ERR_PTR(-ENOMEM);



	omap_obj = to_omap_bo(obj);



	mutex_lock(&omap_obj->lock);



	omap_obj->sgt = sgt;



	if (sgt->orig_nents == 1) {
@@ -1244,7 +1287,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, 
	}



done:

	mutex_unlock(&dev->struct_mutex);

	mutex_unlock(&omap_obj->lock);

	return obj;

}