Re: [PATCH v3 14/14] iommu/amd: Adopt IO page table framework

[Jonathan Cameron]

On Sun, 4 Oct 2020 01:45:49 +0000
Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx> wrote:

> Switch to using IO page table framework for AMD IOMMU v1 page table.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>

One minor thing inline.


> ---
>  drivers/iommu/amd/iommu.c | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> index 77f44b927ae7..6f8316206fb8 100644
> --- a/drivers/iommu/amd/iommu.c
> +++ b/drivers/iommu/amd/iommu.c
> @@ -32,6 +32,7 @@
>  #include <linux/irqdomain.h>
>  #include <linux/percpu.h>
>  #include <linux/iova.h>
> +#include <linux/io-pgtable.h>
>  #include <asm/irq_remapping.h>
>  #include <asm/io_apic.h>
>  #include <asm/apic.h>
> @@ -1573,6 +1574,22 @@ static int pdev_iommuv2_enable(struct pci_dev *pdev)
>  	return ret;
>  }
>  
> +struct io_pgtable_ops *
> +amd_iommu_setup_io_pgtable_ops(struct iommu_dev_data *dev_data,
> +			       struct protection_domain *domain)
> +{
> +	struct amd_iommu *iommu = amd_iommu_rlookup_table[dev_data->devid];
> +
> +	domain->iop.pgtbl_cfg = (struct io_pgtable_cfg) {
> +		.pgsize_bitmap	= AMD_IOMMU_PGSIZES,
> +		.ias		= IOMMU_IN_ADDR_BIT_SIZE,
> +		.oas		= IOMMU_OUT_ADDR_BIT_SIZE,
> +		.iommu_dev	= &iommu->dev->dev,
> +	};
> +
> +	return alloc_io_pgtable_ops(AMD_IOMMU_V1, &domain->iop.pgtbl_cfg, domain);
> +}
> +
>  /*
>   * If a device is not yet associated with a domain, this function makes the
>   * device visible in the domain
> @@ -1580,6 +1597,7 @@ static int pdev_iommuv2_enable(struct pci_dev *pdev)
>  static int attach_device(struct device *dev,
>  			 struct protection_domain *domain)
>  {
> +	struct io_pgtable_ops *pgtbl_ops;
>  	struct iommu_dev_data *dev_data;
>  	struct pci_dev *pdev;
>  	unsigned long flags;
> @@ -1623,6 +1641,12 @@ static int attach_device(struct device *dev,
>  skip_ats_check:
>  	ret = 0;
>  
> +	pgtbl_ops = amd_iommu_setup_io_pgtable_ops(dev_data, domain);
> +	if (!pgtbl_ops) {

Perhaps cleaner to not store in a local variable if you aren't going to use it?

	if (!amd_iommu_setup_io_pgtable_ops(dev_data, domain)) {

> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
>  	do_attach(dev_data, domain);
>  
>  	/*
> @@ -1958,6 +1982,8 @@ static void amd_iommu_domain_free(struct iommu_domain *dom)
>  	if (domain->dev_cnt > 0)
>  		cleanup_domain(domain);
>  
> +	free_io_pgtable_ops(&domain->iop.iop.ops);
> +
>  	BUG_ON(domain->dev_cnt != 0);
>  
>  	if (!dom)