Commit 268af50f authored by Robin Murphy's avatar Robin Murphy Committed by Neil Armstrong
Browse files

drm/panfrost: Support cache-coherent integrations 



When the GPU's ACE-Lite interface is fully wired up and capable of
snooping CPU caches, it may be described as "dma-coherent" in
devicetree, which will already inform the DMA layer not to perform
unnecessary cache maintenance. However, we still need to ensure that
the GPU uses the appropriate cacheable outer-shareable attributes in
order to generate the requisite snoop signals, and that CPU mappings
don't create a mismatch by using a non-cacheable type either.

Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Tested-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Signed-off-by: default avatarNeil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7024ce18c1cb1a226e918037d49175571db0b436.1600780574.git.robin.murphy@arm.com
parent 728da60d

drivers/gpu/drm/panfrost/panfrost_device.h

+1 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ struct panfrost_device { 
	/* pm_domains for devices with more than one. */

	struct device *pm_domain_devs[MAX_PM_DOMAINS];

	struct device_link *pm_domain_links[MAX_PM_DOMAINS];

	bool coherent;



	struct panfrost_features features;

	const struct panfrost_compatible *comp;

drivers/gpu/drm/panfrost/panfrost_drv.c

+2 −0
Original line number Diff line number Diff line
@@ -587,6 +587,8 @@ static int panfrost_probe(struct platform_device *pdev) 
	if (!pfdev->comp)

		return -ENODEV;



	pfdev->coherent = device_get_dma_attr(&pdev->dev) == DEV_DMA_COHERENT;



	/* Allocate and initialze the DRM device. */

	ddev = drm_dev_alloc(&panfrost_drm_driver, &pdev->dev);

	if (IS_ERR(ddev))

drivers/gpu/drm/panfrost/panfrost_gem.c

+2 −0
Original line number Diff line number Diff line
@@ -220,6 +220,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = { 
 */

struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t size)

{

	struct panfrost_device *pfdev = dev->dev_private;

	struct panfrost_gem_object *obj;



	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
@@ -229,6 +230,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t 
	INIT_LIST_HEAD(&obj->mappings.list);

	mutex_init(&obj->mappings.lock);

	obj->base.base.funcs = &panfrost_gem_funcs;

	obj->base.map_cached = pfdev->coherent;



	return &obj->base.base;

}

drivers/gpu/drm/panfrost/panfrost_mmu.c

+1 −0
Original line number Diff line number Diff line
@@ -371,6 +371,7 @@ int panfrost_mmu_pgtable_alloc(struct panfrost_file_priv *priv) 
		.pgsize_bitmap	= SZ_4K | SZ_2M,

		.ias		= FIELD_GET(0xff, pfdev->features.mmu_features),

		.oas		= FIELD_GET(0xff00, pfdev->features.mmu_features),

		.coherent_walk	= pfdev->coherent,

		.tlb		= &mmu_tlb_ops,

		.iommu_dev	= pfdev->dev,

	};

CRA Git | Maintained and supported by SUSTech CRA and CCSE