[09/18] iommu/mediatek-v1: Add IOMMU_DOMAIN_DMA support

Now that arch/arm is wired up for default domains and iommu-dma,
implement the corresponding driver-side support for groups and DMA
domains to replace the shared mapping workaround.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/mtk_iommu.h    |   2 -
 drivers/iommu/mtk_iommu_v1.c | 153 +++++++++++------------------------
 2 files changed, 48 insertions(+), 107 deletions(-)

On Thu, 2020-08-20 at 16:08 +0100, Robin Murphy wrote:
> Now that arch/arm is wired up for default domains and iommu-dma,

> implement the corresponding driver-side support for groups and DMA

> domains to replace the shared mapping workaround.

> 

> Signed-off-by: Robin Murphy <robin.murphy@arm.com>

> ---

>  drivers/iommu/mtk_iommu.h    |   2 -

>  drivers/iommu/mtk_iommu_v1.c | 153 +++++++++++------------------------

>  2 files changed, 48 insertions(+), 107 deletions(-)


Hi Robin,

Thanks very much for this patch, It makes the code much cleaner.

Please help squash the little change in this patch,

--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -555,6 +555,7 @@ static int mtk_iommu_probe(struct platform_device
*pdev)
 		return ret;
 
 	iommu_device_set_ops(&data->iommu, &mtk_iommu_ops);
+	iommu_device_set_fwnode(&data->iommu, &dev->of_node->fwnode);
 
 	ret = iommu_device_register(&data->iommu);
 	if (ret)


Then,
Tested-by: Yong Wu <yong.wu@mediatek.com>


> 

> diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h

> index 122925dbe547..6253e98d810c 100644

> --- a/drivers/iommu/mtk_iommu.h

> +++ b/drivers/iommu/mtk_iommu.h

> @@ -67,8 +67,6 @@ struct mtk_iommu_data {

>  	struct iommu_device		iommu;

>  	const struct mtk_iommu_plat_data *plat_data;

>  

> -	struct dma_iommu_mapping	*mapping; /* For mtk_iommu_v1.c */

> -

>  	struct list_head		list;

>  	struct mtk_smi_larb_iommu	larb_imu[MTK_LARB_NR_MAX];

>  };

> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c

> index 82ddfe9170d4..40c89b8d3ac4 100644

> --- a/drivers/iommu/mtk_iommu_v1.c

> +++ b/drivers/iommu/mtk_iommu_v1.c

> @@ -28,7 +28,6 @@

>  #include <linux/slab.h>

>  #include <linux/spinlock.h>

>  #include <asm/barrier.h>

> -#include <asm/dma-iommu.h>

>  #include <linux/init.h>

>  #include <dt-bindings/memory/mt2701-larb-port.h>

>  #include <soc/mediatek/smi.h>

> @@ -240,13 +239,18 @@ static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)

>  {

>  	struct mtk_iommu_domain *dom;

>  

> -	if (type != IOMMU_DOMAIN_UNMANAGED)

> +	if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)

>  		return NULL;

>  

>  	dom = kzalloc(sizeof(*dom), GFP_KERNEL);

>  	if (!dom)

>  		return NULL;

>  

> +	if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(&dom->domain)) {

> +		kfree(dom);

> +		return NULL;

> +	}

> +

>  	return &dom->domain;

>  }

>  

> @@ -257,6 +261,7 @@ static void mtk_iommu_domain_free(struct iommu_domain *domain)

>  

>  	dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,

>  			dom->pgt_va, dom->pgt_pa);

> +	iommu_put_dma_cookie(domain);

>  	kfree(to_mtk_domain(domain));

>  }

>  

> @@ -265,14 +270,8 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,

>  {

>  	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);

>  	struct mtk_iommu_domain *dom = to_mtk_domain(domain);

> -	struct dma_iommu_mapping *mtk_mapping;

>  	int ret;

>  

> -	/* Only allow the domain created internally. */

> -	mtk_mapping = data->mapping;

> -	if (mtk_mapping->domain != domain)

> -		return 0;

> -

>  	if (!data->m4u_dom) {

>  		data->m4u_dom = dom;

>  		ret = mtk_iommu_domain_finalise(data);

> @@ -358,18 +357,39 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,

>  

>  static const struct iommu_ops mtk_iommu_ops;

>  

> -/*

> - * MTK generation one iommu HW only support one iommu domain, and all the client

> - * sharing the same iova address space.

> - */

> -static int mtk_iommu_create_mapping(struct device *dev,

> -				    struct of_phandle_args *args)

> +static struct iommu_device *mtk_iommu_probe_device(struct device *dev)

>  {

>  	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

>  	struct mtk_iommu_data *data;

> +

> +	if (!fwspec || fwspec->ops != &mtk_iommu_ops)

> +		return ERR_PTR(-ENODEV); /* Not a iommu client device */

> +

> +	data = dev_iommu_priv_get(dev);

> +

> +	return &data->iommu;

> +}

> +

> +static void mtk_iommu_release_device(struct device *dev)

> +{

> +	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

> +

> +	if (!fwspec || fwspec->ops != &mtk_iommu_ops)

> +		return;

> +

> +	iommu_fwspec_free(dev);

> +}

> +

> +static struct iommu_group *mtk_iommu_device_group(struct device *dev)

> +{

> +	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);

> +

> +	return iommu_group_ref_get(data->m4u_group);

> +}

> +

> +static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)

> +{

>  	struct platform_device *m4updev;

> -	struct dma_iommu_mapping *mtk_mapping;

> -	int ret;

>  

>  	if (args->args_count != 1) {

>  		dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",

> @@ -377,15 +397,6 @@ static int mtk_iommu_create_mapping(struct device *dev,

>  		return -EINVAL;

>  	}

>  

> -	if (!fwspec) {

> -		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);

> -		if (ret)

> -			return ret;

> -		fwspec = dev_iommu_fwspec_get(dev);

> -	} else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) {

> -		return -EINVAL;

> -	}

> -

>  	if (!dev_iommu_priv_get(dev)) {

>  		/* Get the m4u device */

>  		m4updev = of_find_device_by_node(args->np);

> @@ -395,83 +406,7 @@ static int mtk_iommu_create_mapping(struct device *dev,

>  		dev_iommu_priv_set(dev, platform_get_drvdata(m4updev));

>  	}

>  

> -	ret = iommu_fwspec_add_ids(dev, args->args, 1);

> -	if (ret)

> -		return ret;

> -

> -	data = dev_iommu_priv_get(dev);

> -	mtk_mapping = data->mapping;

> -	if (!mtk_mapping) {

> -		/* MTK iommu support 4GB iova address space. */

> -		mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,

> -						0, 1ULL << 32);

> -		if (IS_ERR(mtk_mapping))

> -			return PTR_ERR(mtk_mapping);

> -

> -		data->mapping = mtk_mapping;

> -	}

> -

> -	return 0;

> -}

> -

> -static int mtk_iommu_def_domain_type(struct device *dev)

> -{

> -	return IOMMU_DOMAIN_UNMANAGED;

> -}

> -

> -static struct iommu_device *mtk_iommu_probe_device(struct device *dev)

> -{

> -	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

> -	struct of_phandle_args iommu_spec;

> -	struct of_phandle_iterator it;

> -	struct mtk_iommu_data *data;

> -	int err;

> -

> -	of_for_each_phandle(&it, err, dev->of_node, "iommus",

> -			"#iommu-cells", -1) {

> -		int count = of_phandle_iterator_args(&it, iommu_spec.args,

> -					MAX_PHANDLE_ARGS);

> -		iommu_spec.np = of_node_get(it.node);

> -		iommu_spec.args_count = count;

> -

> -		mtk_iommu_create_mapping(dev, &iommu_spec);

> -

> -		/* dev->iommu_fwspec might have changed */

> -		fwspec = dev_iommu_fwspec_get(dev);

> -

> -		of_node_put(iommu_spec.np);

> -	}

> -

> -	if (!fwspec || fwspec->ops != &mtk_iommu_ops)

> -		return ERR_PTR(-ENODEV); /* Not a iommu client device */

> -

> -	data = dev_iommu_priv_get(dev);

> -

> -	return &data->iommu;

> -}

> -

> -static void mtk_iommu_probe_finalize(struct device *dev)

> -{

> -	struct dma_iommu_mapping *mtk_mapping;

> -	struct mtk_iommu_data *data;

> -	int err;

> -

> -	data        = dev_iommu_priv_get(dev);

> -	mtk_mapping = data->mapping;

> -

> -	err = arm_iommu_attach_device(dev, mtk_mapping);

> -	if (err)

> -		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");

> -}

> -

> -static void mtk_iommu_release_device(struct device *dev)

> -{

> -	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

> -

> -	if (!fwspec || fwspec->ops != &mtk_iommu_ops)

> -		return;

> -

> -	iommu_fwspec_free(dev);

> +	return iommu_fwspec_add_ids(dev, args->args, 1);

>  }

>  

>  static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)

> @@ -524,10 +459,9 @@ static const struct iommu_ops mtk_iommu_ops = {

>  	.unmap		= mtk_iommu_unmap,

>  	.iova_to_phys	= mtk_iommu_iova_to_phys,

>  	.probe_device	= mtk_iommu_probe_device,

> -	.probe_finalize = mtk_iommu_probe_finalize,

>  	.release_device	= mtk_iommu_release_device,

> -	.def_domain_type = mtk_iommu_def_domain_type,

> -	.device_group	= generic_device_group,

> +	.device_group	= mtk_iommu_device_group,

> +	.of_xlate	= mtk_iommu_of_xlate,

>  	.pgsize_bitmap	= ~0UL << MT2701_IOMMU_PAGE_SHIFT,

>  };

>  

> @@ -626,6 +560,14 @@ static int mtk_iommu_probe(struct platform_device *pdev)

>  	if (ret)

>  		return ret;

>  

> +	/*

> +	 * MTK generation one iommu HW only support one iommu domain,

> +	 * and all the client sharing the same iova address space.

> +	 */

> +	data->m4u_group = iommu_group_alloc();

> +	if (IS_ERR(data->m4u_group))

> +		return PTR_ERR(data->m4u_group);

> +

>  	if (!iommu_present(&platform_bus_type))

>  		bus_set_iommu(&platform_bus_type,  &mtk_iommu_ops);

>  

> @@ -636,6 +578,7 @@ static int mtk_iommu_remove(struct platform_device *pdev)

>  {

>  	struct mtk_iommu_data *data = platform_get_drvdata(pdev);

>  

> +	iommu_group_put(data->m4u_group);

>  	iommu_device_sysfs_remove(&data->iommu);

>  	iommu_device_unregister(&data->iommu);

>