Re: [PATCH v7 08/12] iommu: Prepare for separating SVA and IOPF

[Yi Liu <yi.l.liu@intel.com>]

On 2023/11/15 11:02, Lu Baolu wrote:
> Move iopf_group data structure to iommu.h to make it a minimal set of
> faults that a domain's page fault handler should handle.
> 
> Add a new function, iopf_free_group(), to free a fault group after all
> faults in the group are handled. This function will be made global so
> that it can be called from other files, such as iommu-sva.c.
> 
> Move iopf_queue data structure to iommu.h to allow the workqueue to be
> scheduled out of this file.
> 
> This will simplify the sequential patches.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> Tested-by: Yan Zhao <yan.y.zhao@intel.com>
> ---
>   include/linux/iommu.h      | 20 +++++++++++++++++++-
>   drivers/iommu/io-pgfault.c | 37 +++++++++++++------------------------
>   2 files changed, 32 insertions(+), 25 deletions(-)

Reviewed-by:Yi Liu <yi.l.liu@intel.com>

> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 42b62bc8737a..0d3c5a56b078 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -41,7 +41,6 @@ struct iommu_dirty_ops;
>   struct notifier_block;
>   struct iommu_sva;
>   struct iommu_dma_cookie;
> -struct iopf_queue;
>   
>   #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
>   #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
> @@ -126,6 +125,25 @@ struct iopf_fault {
>   	struct list_head list;
>   };
>   
> +struct iopf_group {
> +	struct iopf_fault last_fault;
> +	struct list_head faults;
> +	struct work_struct work;
> +	struct device *dev;
> +};
> +
> +/**
> + * struct iopf_queue - IO Page Fault queue
> + * @wq: the fault workqueue
> + * @devices: devices attached to this queue
> + * @lock: protects the device list
> + */
> +struct iopf_queue {
> +	struct workqueue_struct *wq;
> +	struct list_head devices;
> +	struct mutex lock;
> +};
> +
>   /* iommu fault flags */
>   #define IOMMU_FAULT_READ	0x0
>   #define IOMMU_FAULT_WRITE	0x1
> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
> index c45977bb7da3..09e05f483b4f 100644
> --- a/drivers/iommu/io-pgfault.c
> +++ b/drivers/iommu/io-pgfault.c
> @@ -13,24 +13,17 @@
>   
>   #include "iommu-sva.h"
>   
> -/**
> - * struct iopf_queue - IO Page Fault queue
> - * @wq: the fault workqueue
> - * @devices: devices attached to this queue
> - * @lock: protects the device list
> - */
> -struct iopf_queue {
> -	struct workqueue_struct		*wq;
> -	struct list_head		devices;
> -	struct mutex			lock;
> -};
> +static void iopf_free_group(struct iopf_group *group)
> +{
> +	struct iopf_fault *iopf, *next;
>   
> -struct iopf_group {
> -	struct iopf_fault		last_fault;
> -	struct list_head		faults;
> -	struct work_struct		work;
> -	struct device			*dev;
> -};
> +	list_for_each_entry_safe(iopf, next, &group->faults, list) {
> +		if (!(iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
> +			kfree(iopf);
> +	}
> +
> +	kfree(group);
> +}
>   
>   static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
>   			       enum iommu_page_response_code status)
> @@ -50,9 +43,9 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
>   
>   static void iopf_handler(struct work_struct *work)
>   {
> +	struct iopf_fault *iopf;
>   	struct iopf_group *group;
>   	struct iommu_domain *domain;
> -	struct iopf_fault *iopf, *next;
>   	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
>   
>   	group = container_of(work, struct iopf_group, work);
> @@ -61,7 +54,7 @@ static void iopf_handler(struct work_struct *work)
>   	if (!domain || !domain->iopf_handler)
>   		status = IOMMU_PAGE_RESP_INVALID;
>   
> -	list_for_each_entry_safe(iopf, next, &group->faults, list) {
> +	list_for_each_entry(iopf, &group->faults, list) {
>   		/*
>   		 * For the moment, errors are sticky: don't handle subsequent
>   		 * faults in the group if there is an error.
> @@ -69,14 +62,10 @@ static void iopf_handler(struct work_struct *work)
>   		if (status == IOMMU_PAGE_RESP_SUCCESS)
>   			status = domain->iopf_handler(&iopf->fault,
>   						      domain->fault_data);
> -
> -		if (!(iopf->fault.prm.flags &
> -		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
> -			kfree(iopf);
>   	}
>   
>   	iopf_complete_group(group->dev, &group->last_fault, status);
> -	kfree(group);
> +	iopf_free_group(group);
>   }
>   
>   /**

-- 
Regards,
Yi Liu