Subject: [PATCH v5 7/8] drm/rockchip: Use common IOMMU API to attach devices

From: [email-masked] (Mark yao)
Date: Fri, 8 Jul 2016 08:54:26 +0800

On 2016?06?24? 10:13, Shunqian Zheng wrote:
> Rockchip DRM used the arm special API, arm_iommu_*(), to attach
> iommu for ARM32 SoCs. This patch convert to common iommu API
> so it would support ARM64 like RK3399.
>
> Since previous patch added support for direct IOMMU address space
> management, there is no need to use DMA API anymore and this patch wires
> things to use the new method.
>
> Signed-off-by: Shunqian Zheng <[email-masked]>
> Signed-off-by: Tomasz Figa <[email-masked]>

Looks good for me, and it works on rk3399 board, so

Acked-by: Mark Yao <[email-masked]>

> ---
>   drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 100 +++++++++++++++-------------
>   1 file changed, 53 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
> index 8b96c69..ca9624f 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
> @@ -14,18 +14,18 @@
>    * GNU General Public License for more details.
>    */
>   
> -#include <asm/dma-iommu.h>
> -
>   #include <drm/drmP.h>
>   #include <drm/drm_crtc_helper.h>
>   #include <drm/drm_fb_helper.h>
>   #include <drm/drm_gem_cma_helper.h>
>   #include <linux/dma-mapping.h>
> +#include <linux/dma-iommu.h>
>   #include <linux/pm_runtime.h>
>   #include <linux/module.h>
>   #include <linux/of_graph.h>
>   #include <linux/component.h>
>   #include <linux/console.h>
> +#include <linux/iommu.h>
>   
>   #include <drm/rockchip_drm.h>
>   
> @@ -51,28 +51,31 @@ static struct drm_driver rockchip_drm_driver;
>   int rockchip_drm_dma_attach_device(struct drm_device *drm_dev,
>   				   struct device *dev)
>   {
> -	struct dma_iommu_mapping *mapping = drm_dev->dev->archdata.mapping;
> +	struct rockchip_drm_private *private = drm_dev->dev_private;
>   	int ret;
>   
>   	if (!is_support_iommu)
>   		return 0;
>   
> -	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
> -	if (ret)
> +	ret = iommu_attach_device(private->domain, dev);
> +	if (ret) {
> +		dev_err(dev, "Failed to attach iommu device\n");
>   		return ret;
> +	}
>   
> -	dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> -
> -	return arm_iommu_attach_device(dev, mapping);
> +	return 0;
>   }
>   
>   void rockchip_drm_dma_detach_device(struct drm_device *drm_dev,
>   				    struct device *dev)
>   {
> +	struct rockchip_drm_private *private = drm_dev->dev_private;
> +	struct iommu_domain *domain = private->domain;
> +
>   	if (!is_support_iommu)
>   		return;
>   
> -	arm_iommu_detach_device(dev);
> +	iommu_detach_device(domain, dev);
>   }
>   
>   int rockchip_register_crtc_funcs(struct drm_crtc *crtc,
> @@ -137,11 +140,45 @@ static void rockchip_drm_crtc_disable_vblank(struct drm_device *dev,
>   		priv->crtc_funcs[pipe]->disable_vblank(crtc);
>   }
>   
> +static int rockchip_drm_init_iommu(struct drm_device *drm_dev)
> +{
> +	struct rockchip_drm_private *private = drm_dev->dev_private;
> +	struct iommu_domain_geometry *geometry;
> +	u64 start, end;
> +
> +	if (!is_support_iommu)
> +		return 0;
> +
> +	private->domain = iommu_domain_alloc(&platform_bus_type);
> +	if (!private->domain)
> +		return -ENOMEM;
> +
> +	geometry = &private->domain->geometry;
> +	start = geometry->aperture_start;
> +	end = geometry->aperture_end;
> +
> +	DRM_DEBUG("IOMMU context initialized (aperture: %#llx-%#llx)\n",
> +		  start, end);
> +	drm_mm_init(&private->mm, start, end - start + 1);
> +
> +	return 0;
> +}
> +
> +static void rockchip_iommu_cleanup(struct drm_device *drm_dev)
> +{
> +	struct rockchip_drm_private *private = drm_dev->dev_private;
> +
> +	if (!is_support_iommu)
> +		return;
> +
> +	drm_mm_takedown(&private->mm);
> +	iommu_domain_free(private->domain);
> +}
> +
>   static int rockchip_drm_bind(struct device *dev)
>   {
>   	struct drm_device *drm_dev;
>   	struct rockchip_drm_private *private;
> -	struct dma_iommu_mapping *mapping = NULL;
>   	int ret;
>   
>   	drm_dev = drm_dev_alloc(&rockchip_drm_driver, dev);
> @@ -162,38 +199,14 @@ static int rockchip_drm_bind(struct device *dev)
>   
>   	rockchip_drm_mode_config_init(drm_dev);
>   
> -	dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
> -				      GFP_KERNEL);
> -	if (!dev->dma_parms) {
> -		ret = -ENOMEM;
> +	ret = rockchip_drm_init_iommu(drm_dev);
> +	if (ret)
>   		goto err_config_cleanup;
> -	}
> -
> -	if (is_support_iommu) {
> -		/* TODO(djkurtz): fetch the mapping start/size from somewhere */
> -		mapping = arm_iommu_create_mapping(&platform_bus_type,
> -						   0x00000000,
> -						   SZ_2G);
> -		if (IS_ERR(mapping)) {
> -			ret = PTR_ERR(mapping);
> -			goto err_config_cleanup;
> -		}
> -
> -		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
> -		if (ret)
> -			goto err_release_mapping;
> -
> -		dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> -
> -		ret = arm_iommu_attach_device(dev, mapping);
> -		if (ret)
> -			goto err_release_mapping;
> -	}
>   
>   	/* Try to bind all sub drivers. */
>   	ret = component_bind_all(dev, drm_dev);
>   	if (ret)
> -		goto err_detach_device;
> +		goto err_iommu_cleanup;
>   
>   	/* init kms poll for handling hpd */
>   	drm_kms_helper_poll_init(drm_dev);
> @@ -218,8 +231,6 @@ static int rockchip_drm_bind(struct device *dev)
>   	if (ret)
>   		goto err_fbdev_fini;
>   
> -	if (is_support_iommu)
> -		arm_iommu_release_mapping(mapping);
>   	return 0;
>   err_fbdev_fini:
>   	rockchip_drm_fbdev_fini(drm_dev);
> @@ -228,12 +239,8 @@ err_vblank_cleanup:
>   err_kms_helper_poll_fini:
>   	drm_kms_helper_poll_fini(drm_dev);
>   	component_unbind_all(dev, drm_dev);
> -err_detach_device:
> -	if (is_support_iommu)
> -		arm_iommu_detach_device(dev);
> -err_release_mapping:
> -	if (is_support_iommu)
> -		arm_iommu_release_mapping(mapping);
> +err_iommu_cleanup:
> +	rockchip_iommu_cleanup(drm_dev);
>   err_config_cleanup:
>   	drm_mode_config_cleanup(drm_dev);
>   	drm_dev->dev_private = NULL;
> @@ -250,8 +257,7 @@ static void rockchip_drm_unbind(struct device *dev)
>   	drm_vblank_cleanup(drm_dev);
>   	drm_kms_helper_poll_fini(drm_dev);
>   	component_unbind_all(dev, drm_dev);
> -	if (is_support_iommu)
> -		arm_iommu_detach_device(dev);
> +	rockchip_iommu_cleanup(drm_dev);
>   	drm_mode_config_cleanup(drm_dev);
>   	drm_dev->dev_private = NULL;
>   	drm_dev_unregister(drm_dev);

-- 
?ark Yao