[PATCH v4 10/13] iommu/rockchip: Use OF_IOMMU to attach devices automatically
Robin Murphy
robin.murphy at arm.com
Thu Jan 18 04:46:30 PST 2018
On 18/01/18 11:52, Jeffy Chen wrote:
> Converts the rockchip-iommu driver to use the OF_IOMMU infrastructure,
> which allows attaching master devices to their IOMMUs automatically
> according to DT properties.
>
> Signed-off-by: Jeffy Chen <jeffy.chen at rock-chips.com>
> ---
>
> Changes in v4: None
> Changes in v3:
> Add struct rk_iommudata.
> Squash iommu/rockchip: Use iommu_group_get_for_dev() for add_device
>
> Changes in v2: None
>
> drivers/iommu/rockchip-iommu.c | 139 +++++++++++++----------------------------
> 1 file changed, 44 insertions(+), 95 deletions(-)
>
> diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
> index bdb7c5de6fc2..b1f177ae03c7 100644
> --- a/drivers/iommu/rockchip-iommu.c
> +++ b/drivers/iommu/rockchip-iommu.c
> @@ -19,6 +19,7 @@
> #include <linux/mm.h>
> #include <linux/module.h>
> #include <linux/of.h>
> +#include <linux/of_iommu.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> @@ -97,6 +98,10 @@ struct rk_iommu {
> struct iommu_domain *domain; /* domain to which iommu is attached */
> };
>
> +struct rk_iommudata {
> + struct rk_iommu *iommu;
> +};
> +
> static struct device *dma_dev;
>
> static inline void rk_table_flush(struct rk_iommu_domain *dom, dma_addr_t dma,
> @@ -872,18 +877,9 @@ static size_t rk_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
>
> static struct rk_iommu *rk_iommu_from_dev(struct device *dev)
> {
> - struct iommu_group *group;
> - struct device *iommu_dev;
> - struct rk_iommu *rk_iommu;
> + struct rk_iommudata *data = dev->archdata.iommu;
>
> - group = iommu_group_get(dev);
> - if (!group)
> - return NULL;
> - iommu_dev = iommu_group_get_iommudata(group);
> - rk_iommu = dev_get_drvdata(iommu_dev);
> - iommu_group_put(group);
> -
> - return rk_iommu;
> + return data ? data->iommu : NULL;
> }
>
> static int rk_iommu_attach_device(struct iommu_domain *domain,
> @@ -1060,110 +1056,57 @@ static void rk_iommu_domain_free(struct iommu_domain *domain)
> iommu_put_dma_cookie(&rk_domain->domain);
> }
>
> -static bool rk_iommu_is_dev_iommu_master(struct device *dev)
> -{
> - struct device_node *np = dev->of_node;
> - int ret;
> -
> - /*
> - * An iommu master has an iommus property containing a list of phandles
> - * to iommu nodes, each with an #iommu-cells property with value 0.
> - */
> - ret = of_count_phandle_with_args(np, "iommus", "#iommu-cells");
> - return (ret > 0);
> -}
> -
> -static int rk_iommu_group_set_iommudata(struct iommu_group *group,
> - struct device *dev)
> +static int rk_iommu_add_device(struct device *dev)
> {
> - struct device_node *np = dev->of_node;
> - struct platform_device *pd;
> - int ret;
> - struct of_phandle_args args;
> + struct iommu_group *group;
> + struct rk_iommu *iommu;
>
> - /*
> - * An iommu master has an iommus property containing a list of phandles
> - * to iommu nodes, each with an #iommu-cells property with value 0.
> - */
> - ret = of_parse_phandle_with_args(np, "iommus", "#iommu-cells", 0,
> - &args);
> - if (ret) {
> - dev_err(dev, "of_parse_phandle_with_args(%pOF) => %d\n",
> - np, ret);
> - return ret;
> - }
> - if (args.args_count != 0) {
> - dev_err(dev, "incorrect number of iommu params found for %pOF (found %d, expected 0)\n",
> - args.np, args.args_count);
> - return -EINVAL;
> - }
> + iommu = rk_iommu_from_dev(dev);
> + if (!iommu)
> + return -ENODEV;
>
> - pd = of_find_device_by_node(args.np);
> - of_node_put(args.np);
> - if (!pd) {
> - dev_err(dev, "iommu %pOF not found\n", args.np);
> - return -EPROBE_DEFER;
> - }
> + group = iommu_group_get_for_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> + iommu_group_put(group);
>
> - /* TODO(djkurtz): handle multiple slave iommus for a single master */
> - iommu_group_set_iommudata(group, &pd->dev, NULL);
> + iommu_device_link(&iommu->iommu, dev);
>
> return 0;
> }
>
> -static int rk_iommu_add_device(struct device *dev)
> +static void rk_iommu_remove_device(struct device *dev)
> {
> - struct iommu_group *group;
> struct rk_iommu *iommu;
> - int ret;
> -
> - if (!rk_iommu_is_dev_iommu_master(dev))
> - return -ENODEV;
> -
> - group = iommu_group_get(dev);
> - if (!group) {
> - group = iommu_group_alloc();
> - if (IS_ERR(group)) {
> - dev_err(dev, "Failed to allocate IOMMU group\n");
> - return PTR_ERR(group);
> - }
> - }
> -
> - ret = iommu_group_add_device(group, dev);
> - if (ret)
> - goto err_put_group;
> -
> - ret = rk_iommu_group_set_iommudata(group, dev);
> - if (ret)
> - goto err_remove_device;
>
> iommu = rk_iommu_from_dev(dev);
> - if (iommu)
> - iommu_device_link(&iommu->iommu, dev);
> -
> - iommu_group_put(group);
> -
> - return 0;
>
> -err_remove_device:
> + iommu_device_unlink(&iommu->iommu, dev);
> iommu_group_remove_device(dev);
> -err_put_group:
> - iommu_group_put(group);
> - return ret;
> }
>
> -static void rk_iommu_remove_device(struct device *dev)
> +static int rk_iommu_of_xlate(struct device *dev,
> + struct of_phandle_args *args)
> {
> - struct rk_iommu *iommu;
> + struct platform_device *iommu_dev;
> + struct rk_iommudata *data;
>
> - if (!rk_iommu_is_dev_iommu_master(dev))
> - return;
> + data = devm_kzalloc(dma_dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
>
> - iommu = rk_iommu_from_dev(dev);
> - if (iommu)
> - iommu_device_unlink(&iommu->iommu, dev);
> + iommu_dev = of_find_device_by_node(args->np);
> + if (!iommu_dev) {
> + dev_err(dev, "iommu %pOF not found\n", args->np);
> + return -ENODEV;
Nit: I think this could only happen if the IOMMU device managed to probe
successfully enough to call iommu_device_register(), but then somehow
disappeared from the platform bus - given patch #1, that now seems
impossible enough that it's probably not worth checking for.
Either way, this looks pretty tidy now;
Reviewed-by: Robin Murphy <robin.murphy at arm.com>
> + }
>
> - iommu_group_remove_device(dev);
> + data->iommu = platform_get_drvdata(iommu_dev);
> + dev->archdata.iommu = data;
> +
> + of_dev_put(iommu_dev);
> +
> + return 0;
> }
>
> static const struct iommu_ops rk_iommu_ops = {
> @@ -1177,7 +1120,9 @@ static const struct iommu_ops rk_iommu_ops = {
> .add_device = rk_iommu_add_device,
> .remove_device = rk_iommu_remove_device,
> .iova_to_phys = rk_iommu_iova_to_phys,
> + .device_group = generic_device_group,
> .pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
> + .of_xlate = rk_iommu_of_xlate,
> };
>
> static int rk_iommu_probe(struct platform_device *pdev)
> @@ -1236,6 +1181,8 @@ static int rk_iommu_probe(struct platform_device *pdev)
> goto err_put_clocks;
>
> iommu_device_set_ops(&iommu->iommu, &rk_iommu_ops);
> + iommu_device_set_fwnode(&iommu->iommu, &dev->of_node->fwnode);
> +
> err = iommu_device_register(&iommu->iommu);
> if (err)
> goto err_remove_sysfs;
> @@ -1290,6 +1237,8 @@ static int __init rk_iommu_init(void)
> }
> subsys_initcall(rk_iommu_init);
>
> +IOMMU_OF_DECLARE(rk_iommu_of, "rockchip,iommu", NULL);
> +
> MODULE_DESCRIPTION("IOMMU API for Rockchip");
> MODULE_AUTHOR("Simon Xue <xxm at rock-chips.com> and Daniel Kurtz <djkurtz at chromium.org>");
> MODULE_ALIAS("platform:rockchip-iommu");
>
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