Re: [PATCH] iommu/amd - Set the device table entry PPR bit for IOMMU V2 devices

[Gary R Hook <gary.hook@amd.com>]

Please ignore. I've uncovered a problem and will re-submit.

On 12/04/2017 01:52 PM, Gary R Hook wrote:
> The AMD IOMMU specification Rev 3.00 (December 2016) introduces a
> new Enhanced PPR Handling Support (EPHSup) bit in the MMIO register
> offset 0030h (IOMMU Extended Feature Register).
> 
> When EPHSup=1, the IOMMU hardware requires the PPR bit of the
> device table entry (DTE) to be set in order to support PPR for a
> particular endpoint device.
> 
> Please see https://support.amd.com/TechDocs/48882_IOMMU.pdf for
> this revision of the AMD IOMMU specification.
> 
> Signed-off-by: Gary R Hook <gary.hook@amd.com>
> ---
>   drivers/iommu/amd_iommu.c       |   20 +++++++++++++++-----
>   drivers/iommu/amd_iommu_types.h |    2 ++
>   2 files changed, 17 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index cb78933ef53f..329940ffb8c1 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -1818,7 +1818,8 @@ static bool dma_ops_domain(struct protection_domain *domain)
>   	return domain->flags & PD_DMA_OPS_MASK;
>   }
>   
> -static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
> +static void set_dte_entry(u16 devid, struct protection_domain *domain,
> +			  bool ats, bool ppr)
>   {
>   	u64 pte_root = 0;
>   	u64 flags = 0;
> @@ -1835,6 +1836,13 @@ static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
>   	if (ats)
>   		flags |= DTE_FLAG_IOTLB;
>   
> +	if (ppr) {
> +		struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
> +
> +		if (iommu_feature(iommu, FEATURE_EPHSUP))
> +			pte_root |= DEV_ENTRY_PPR;
> +	}
> +
>   	if (domain->flags & PD_IOMMUV2_MASK) {
>   		u64 gcr3 = iommu_virt_to_phys(domain->gcr3_tbl);
>   		u64 glx  = domain->glx;
> @@ -1897,9 +1905,9 @@ static void do_attach(struct iommu_dev_data *dev_data,
>   	domain->dev_cnt                 += 1;
>   
>   	/* Update device table */
> -	set_dte_entry(dev_data->devid, domain, ats);
> +	set_dte_entry(dev_data->devid, domain, ats, dev_data->iommu_v2);
>   	if (alias != dev_data->devid)
> -		set_dte_entry(alias, domain, ats);
> +		set_dte_entry(alias, domain, ats, dev_data->iommu_v2);
>   
>   	device_flush_dte(dev_data);
>   }
> @@ -2278,13 +2286,15 @@ static void update_device_table(struct protection_domain *domain)
>   	struct iommu_dev_data *dev_data;
>   
>   	list_for_each_entry(dev_data, &domain->dev_list, list) {
> -		set_dte_entry(dev_data->devid, domain, dev_data->ats.enabled);
> +		set_dte_entry(dev_data->devid, domain, dev_data->ats.enabled,
> +			      dev_data->iommu_v2);
>   
>   		if (dev_data->devid == dev_data->alias)
>   			continue;
>   
>   		/* There is an alias, update device table entry for it */
> -		set_dte_entry(dev_data->alias, domain, dev_data->ats.enabled);
> +		set_dte_entry(dev_data->alias, domain, dev_data->ats.enabled,
> +			      dev_data->iommu_v2);
>   	}
>   }
>   
> diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
> index f6b24c7d8b70..6a877ebd058b 100644
> --- a/drivers/iommu/amd_iommu_types.h
> +++ b/drivers/iommu/amd_iommu_types.h
> @@ -98,6 +98,7 @@
>   #define FEATURE_HE		(1ULL<<8)
>   #define FEATURE_PC		(1ULL<<9)
>   #define FEATURE_GAM_VAPIC	(1ULL<<21)
> +#define FEATURE_EPHSUP		(1ULL<<50)
>   
>   #define FEATURE_PASID_SHIFT	32
>   #define FEATURE_PASID_MASK	(0x1fULL << FEATURE_PASID_SHIFT)
> @@ -192,6 +193,7 @@
>   /* macros and definitions for device table entries */
>   #define DEV_ENTRY_VALID         0x00
>   #define DEV_ENTRY_TRANSLATION   0x01
> +#define DEV_ENTRY_PPR           0x34
>   #define DEV_ENTRY_IR            0x3d
>   #define DEV_ENTRY_IW            0x3e
>   #define DEV_ENTRY_NO_PAGE_FAULT	0x62
> 
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