Re: [PATCH 06/15] iommu: Move iommu_fwspec to struct dev_iommu

Jean-Philippe Brucker
2020-03-16T15:46:54Z

On Tue, Mar 10, 2020 at 10:12:20AM +0100, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
>
> Move the iommu_fwspec pointer in struct device into struct dev_iommu.
> This is a step in the effort to reduce the iommu related pointers in
> struct device to one.
>
> Tested-by: Will Deacon <will@kernel.org> # arm-smmu
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
> drivers/iommu/iommu.c | 3 +++
> include/linux/device.h | 1 -
> include/linux/iommu.h | 12 ++++++++----
> 3 files changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index beac2ef063dd..826a67ba247f 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -2405,6 +2405,9 @@ int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
> if (fwspec)
> return ops == fwspec->ops ? 0 : -EINVAL;
>
> + if (!dev_iommu_get(dev))
> + return -ENOMEM;
> +
> fwspec = kzalloc(sizeof(*fwspec), GFP_KERNEL);
> if (!fwspec)
> return -ENOMEM;
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 405a8f11bec1..ca29c39a6480 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -613,7 +613,6 @@ struct device {
>
> void (*release)(struct device *dev);
> struct iommu_group *iommu_group;
> - struct iommu_fwspec *iommu_fwspec;
> struct dev_iommu *iommu;
>
> bool offline_disabled:1;
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 1c9fa5c1174b..f5edc21a644d 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -368,14 +368,15 @@ struct iommu_fault_param {
> * struct dev_iommu - Collection of per-device IOMMU data
> *
> * @fault_param: IOMMU detected device fault reporting data
> + * @fwspec: IOMMU fwspec data
> *
> * TODO: migrate other per device data pointers under iommu_dev_data, e.g.
> * struct iommu_group *iommu_group;
> - * struct iommu_fwspec *iommu_fwspec;
> */
> struct dev_iommu {
> struct mutex lock;
> - struct iommu_fault_param *fault_param;
> + struct iommu_fault_param *fault_param;
> + struct iommu_fwspec *fwspec;
> };
>
> int iommu_device_register(struct iommu_device *iommu);
> @@ -614,13 +615,16 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode);
>
> static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
> {
> - return dev->iommu_fwspec;
> + if (dev->iommu)
> + return dev->iommu->fwspec;
> + else
> + return NULL;
> }
>
> static inline void dev_iommu_fwspec_set(struct device *dev,
> struct iommu_fwspec *fwspec)
> {
> - dev->iommu_fwspec = fwspec;
> + dev->iommu->fwspec = fwspec;

It may be worth moving the set() to iommu.c and prevent any misuse.
Regardless:

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

> }
>
> int iommu_probe_device(struct device *dev);
> --
> 2.17.1
>