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

Yong Wu
2020-08-29T09:57:30Z

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);
>