Re: [PATCH 08/11] iommu/msm: Make use of iommu_device_register interface

Robin Murphy
2017-02-10T14:35:47Z

On 09/02/17 11:32, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
>
> Register the MSM IOMMUs to the iommu core and add sysfs
> entries for that driver.
>
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
> drivers/iommu/msm_iommu.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/iommu/msm_iommu.h | 3 ++
> 2 files changed, 76 insertions(+)
>
> diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
> index b09692b..30795cb 100644
> --- a/drivers/iommu/msm_iommu.c
> +++ b/drivers/iommu/msm_iommu.c
> @@ -371,6 +371,58 @@ static int msm_iommu_domain_config(struct msm_priv *priv)
> return 0;
> }
>
> +/* Must be called under msm_iommu_lock */
> +static struct msm_iommu_dev *find_iommu_for_dev(struct device *dev)
> +{
> + struct msm_iommu_dev *iommu, *ret = NULL;
> + struct msm_iommu_ctx_dev *master;
> +
> + list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) {
> + master = list_first_entry(&iommu->ctx_list,
> + struct msm_iommu_ctx_dev,
> + list);
> + if (master->of_node == dev->of_node) {
> + ret = iommu;
> + break;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int msm_iommu_add_device(struct device *dev)
> +{
> + struct msm_iommu_dev *iommu;
> + unsigned long flags;
> + int ret = 0;
> +
> + spin_lock_irqsave(&msm_iommu_lock, flags);
> +
> + iommu = find_iommu_for_dev(dev);
> + if (iommu)
> + iommu_device_link(&iommu->iommu, dev);
> + else
> + ret = -ENODEV;
> +
> + spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +
> + return ret;
> +}
> +
> +static void msm_iommu_remove_device(struct device *dev)
> +{
> + struct msm_iommu_dev *iommu;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&msm_iommu_lock, flags);
> +
> + iommu = find_iommu_for_dev(dev);
> + if (iommu)
> + iommu_device_unlink(&iommu->iommu, dev);
> +
> + spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +}
> +
> static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
> {
> int ret = 0;
> @@ -646,6 +698,8 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
> .unmap = msm_iommu_unmap,
> .map_sg = default_iommu_map_sg,
> .iova_to_phys = msm_iommu_iova_to_phys,
> + .add_device = msm_iommu_add_device,
> + .remove_device = msm_iommu_remove_device,
> .pgsize_bitmap = MSM_IOMMU_PGSIZES,
> .of_xlate = qcom_iommu_of_xlate,
> };
> @@ -653,6 +707,7 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)
> static int msm_iommu_probe(struct platform_device *pdev)
> {
> struct resource *r;
> + resource_size_t ioaddr;
> struct msm_iommu_dev *iommu;
> int ret, par, val;
>
> @@ -696,6 +751,7 @@ static int msm_iommu_probe(struct platform_device *pdev)
> ret = PTR_ERR(iommu->base);
> goto fail;
> }
> + ioaddr = r->start;
>
> iommu->irq = platform_get_irq(pdev, 0);
> if (iommu->irq < 0) {
> @@ -737,6 +793,23 @@ static int msm_iommu_probe(struct platform_device *pdev)
> }
>
> list_add(&iommu->dev_node, &qcom_iommu_devices);
> +
> + ret = iommu_device_sysfs_add(&iommu->iommu, iommu->dev, NULL,
> + "msm-smmu.%pa", &ioaddr);
> + if (ret) {
> + pr_err("Could not add msm-smmu at %pa to sysfs\n", &ioaddr);
> + goto fail;
> + }

Nit: there's a bit of inconsistency with printing errors between the
various drivers (for both _sysfs_add and _register). I reckon if we want
error messages we may as well just fold them into the helper functions.

> +
> + iommu_device_set_ops(&iommu->iommu, &msm_iommu_ops);
> + iommu_device_set_fwnode(&iommu->iommu, &pdev->dev.of_node->fwnode);
> +
> + ret = iommu_device_register(&iommu->iommu);
> + if (ret) {
> + pr_err("Could not register msm-smmu at %pa\n", &ioaddr);
> + goto fail;
> + }

I think there's a corresponding unregister missing for
msm_iommu_remove() here (and similarly in the ARM SMMU drivers, looking
back). I know it's not strictly a problem at the moment, but I do now
have IOMMU-drivers-as-modules working on top of the probe deferral
series... ;)

Robin.

> +
> of_iommu_set_ops(pdev->dev.of_node, &msm_iommu_ops);
>
> pr_info("device mapped at %p, irq %d with %d ctx banks\n",
> diff --git a/drivers/iommu/msm_iommu.h b/drivers/iommu/msm_iommu.h
> index 4ca25d5..ae92d27 100644
> --- a/drivers/iommu/msm_iommu.h
> +++ b/drivers/iommu/msm_iommu.h
> @@ -19,6 +19,7 @@
> #define MSM_IOMMU_H
>
> #include <linux/interrupt.h>
> +#include <linux/iommu.h>
> #include <linux/clk.h>
>
> /* Sharability attributes of MSM IOMMU mappings */
> @@ -68,6 +69,8 @@ struct msm_iommu_dev {
> struct list_head dom_node;
> struct list_head ctx_list;
> DECLARE_BITMAP(context_map, IOMMU_MAX_CBS);
> +
> + struct iommu_device iommu;
> };
>
> /**
>