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[v2,00/11] PCI/ATS: Device-tree support and other improvements

Message ID 20200311124506.208376-1-jean-philippe@linaro.org
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Series PCI/ATS: Device-tree support and other improvements | expand

Message

Jean-Philippe Brucker March 11, 2020, 12:44 p.m. UTC 
Enable ATS on device-tree based systems, and factor the common ATS
enablement checks into pci_enable_ats().

Since v1 [1] I added acks and review tags, simplified patch 3 and tried
to clarify the comment in patch 2.

I'd like acks or comments on the following patches:
* PCI on patches 2, 3 and 5
* Arm SMMUv3 on patch 7
* Intel VT-d on patch 8
* arm64 DT on patch 10 

Thanks,
Jean

[1] https://lore.kernel.org/linux-iommu/20200213165049.508908-1-jean-philippe@linaro.org/

Jean-Philippe Brucker (11):
  dt-bindings: PCI: generic: Add ats-supported property
  PCI: Add ats_supported host bridge flag
  PCI: OF: Check whether the host bridge supports ATS
  ACPI/IORT: Check ATS capability in root complex node
  PCI/ATS: Gather checks into pci_ats_supported()
  iommu/amd: Use pci_ats_supported()
  iommu/arm-smmu-v3: Use pci_ats_supported()
  iommu/vt-d: Use pci_ats_supported()
  ACPI/IORT: Drop ATS fwspec flag
  arm64: dts: fast models: Enable PCIe ATS for Base RevC FVP
  Documentation: Generalize the "pci=noats" boot parameter

 .../admin-guide/kernel-parameters.txt         |  4 +-
 .../bindings/pci/host-generic-pci.yaml        |  6 +++
 arch/arm64/boot/dts/arm/fvp-base-revc.dts     |  1 +
 drivers/acpi/arm64/iort.c                     | 38 +++++++++++++------
 drivers/acpi/pci_root.c                       |  3 ++
 drivers/iommu/amd_iommu.c                     | 12 ++----
 drivers/iommu/arm-smmu-v3.c                   | 18 ++-------
 drivers/iommu/intel-iommu.c                   |  9 ++---
 drivers/pci/ats.c                             | 30 ++++++++++++++-
 drivers/pci/controller/pci-host-common.c      | 11 ++++++
 drivers/pci/probe.c                           |  8 ++++
 include/linux/acpi_iort.h                     |  8 ++++
 include/linux/iommu.h                         |  4 --
 include/linux/pci-ats.h                       |  3 ++
 include/linux/pci.h                           |  1 +
 15 files changed, 109 insertions(+), 47 deletions(-)

Comments

Baolu Lu March 12, 2020, 1:44 a.m. UTC | #1 
Hi Jean,

On 2020/3/11 20:45, Jean-Philippe Brucker wrote:
> The pci_ats_supported() function checks if a device supports ATS and is
> allowed to use it.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> ---
>   drivers/iommu/intel-iommu.c | 9 +++------
>   1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 6fa6de2b6ad5..17208280ef5c 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -1454,8 +1454,7 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
>   	    !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32))
>   		info->pri_enabled = 1;
>   #endif
> -	if (!pdev->untrusted && info->ats_supported &&
> -	    pci_ats_page_aligned(pdev) &&
> +	if (info->ats_supported && pci_ats_page_aligned(pdev) &&
>   	    !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
>   		info->ats_enabled = 1;
>   		domain_update_iotlb(info->domain);
> @@ -2611,10 +2610,8 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
>   	if (dev && dev_is_pci(dev)) {
>   		struct pci_dev *pdev = to_pci_dev(info->dev);
>   
> -		if (!pdev->untrusted &&
> -		    !pci_ats_disabled() &&

The pci_ats_disabled() couldn't be replaced by pci_ats_supported(). Even
pci_ats_supported() returns true, user still can disable it. Or move
ats_disabled into pci_ats_supported()?

Best regards,
baolu

> -		    ecap_dev_iotlb_support(iommu->ecap) &&
> -		    pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS) &&
> +		if (ecap_dev_iotlb_support(iommu->ecap) &&
> +		    pci_ats_supported(pdev) &&
>   		    dmar_find_matched_atsr_unit(pdev))
>   			info->ats_supported = 1;
Jean-Philippe Brucker March 12, 2020, 7:54 a.m. UTC | #2 
Hi Baolu,

On Thu, Mar 12, 2020 at 09:44:16AM +0800, Lu Baolu wrote:
> Hi Jean,
> 
> On 2020/3/11 20:45, Jean-Philippe Brucker wrote:
> > The pci_ats_supported() function checks if a device supports ATS and is
> > allowed to use it.
> > 
> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> > ---
> >   drivers/iommu/intel-iommu.c | 9 +++------
> >   1 file changed, 3 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> > index 6fa6de2b6ad5..17208280ef5c 100644
> > --- a/drivers/iommu/intel-iommu.c
> > +++ b/drivers/iommu/intel-iommu.c
> > @@ -1454,8 +1454,7 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
> >   	    !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32))
> >   		info->pri_enabled = 1;
> >   #endif
> > -	if (!pdev->untrusted && info->ats_supported &&
> > -	    pci_ats_page_aligned(pdev) &&
> > +	if (info->ats_supported && pci_ats_page_aligned(pdev) &&
> >   	    !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
> >   		info->ats_enabled = 1;
> >   		domain_update_iotlb(info->domain);
> > @@ -2611,10 +2610,8 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
> >   	if (dev && dev_is_pci(dev)) {
> >   		struct pci_dev *pdev = to_pci_dev(info->dev);
> > -		if (!pdev->untrusted &&
> > -		    !pci_ats_disabled() &&
> 
> The pci_ats_disabled() couldn't be replaced by pci_ats_supported(). Even
> pci_ats_supported() returns true, user still can disable it. Or move
> ats_disabled into pci_ats_supported()?

It is already there, but hidden behind the "if (!dev->ats_cap)":
pci_ats_init() only sets dev->ats_cap after checking that
pci_ats_disabled() returns false.

Thanks,
Jean

> 
> Best regards,
> baolu
> 
> > -		    ecap_dev_iotlb_support(iommu->ecap) &&
> > -		    pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS) &&
> > +		if (ecap_dev_iotlb_support(iommu->ecap) &&
> > +		    pci_ats_supported(pdev) &&
> >   		    dmar_find_matched_atsr_unit(pdev))
> >   			info->ats_supported = 1;
Baolu Lu March 12, 2020, 8:18 a.m. UTC | #3 
On 2020/3/12 15:54, Jean-Philippe Brucker wrote:
> Hi Baolu,
> 
> On Thu, Mar 12, 2020 at 09:44:16AM +0800, Lu Baolu wrote:
>> Hi Jean,
>>
>> On 2020/3/11 20:45, Jean-Philippe Brucker wrote:
>>> The pci_ats_supported() function checks if a device supports ATS and is
>>> allowed to use it.
>>>
>>> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
>>> ---
>>>    drivers/iommu/intel-iommu.c | 9 +++------
>>>    1 file changed, 3 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>>> index 6fa6de2b6ad5..17208280ef5c 100644
>>> --- a/drivers/iommu/intel-iommu.c
>>> +++ b/drivers/iommu/intel-iommu.c
>>> @@ -1454,8 +1454,7 @@ static void iommu_enable_dev_iotlb(struct device_domain_info *info)
>>>    	    !pci_reset_pri(pdev) && !pci_enable_pri(pdev, 32))
>>>    		info->pri_enabled = 1;
>>>    #endif
>>> -	if (!pdev->untrusted && info->ats_supported &&
>>> -	    pci_ats_page_aligned(pdev) &&
>>> +	if (info->ats_supported && pci_ats_page_aligned(pdev) &&
>>>    	    !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
>>>    		info->ats_enabled = 1;
>>>    		domain_update_iotlb(info->domain);
>>> @@ -2611,10 +2610,8 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
>>>    	if (dev && dev_is_pci(dev)) {
>>>    		struct pci_dev *pdev = to_pci_dev(info->dev);
>>> -		if (!pdev->untrusted &&
>>> -		    !pci_ats_disabled() &&
>>
>> The pci_ats_disabled() couldn't be replaced by pci_ats_supported(). Even
>> pci_ats_supported() returns true, user still can disable it. Or move
>> ats_disabled into pci_ats_supported()?
> 
> It is already there, but hidden behind the "if (!dev->ats_cap)":
> pci_ats_init() only sets dev->ats_cap after checking that
> pci_ats_disabled() returns false.
>

Ah! Yes.

Acked-by: Lu Baolu <baolu.lu@linux.intel.com>

> Thanks,
> Jean

Best regards,
baolu
Will Deacon March 18, 2020, 9:49 p.m. UTC | #4 
On Wed, Mar 11, 2020 at 01:45:02PM +0100, Jean-Philippe Brucker wrote:
> The new pci_ats_supported() function checks if a device supports ATS and
> is allowed to use it.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> ---
>  drivers/iommu/arm-smmu-v3.c | 18 +++---------------
>  1 file changed, 3 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 4f0a38dae6db..87ae31ef35a1 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2592,26 +2592,14 @@ static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
>  	}
>  }
>  
> -#ifdef CONFIG_PCI_ATS
>  static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
>  {
> -	struct pci_dev *pdev;
> +	struct device *dev = master->dev;
>  	struct arm_smmu_device *smmu = master->smmu;
> -	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(master->dev);
> -
> -	if (!(smmu->features & ARM_SMMU_FEAT_ATS) || !dev_is_pci(master->dev) ||
> -	    !(fwspec->flags & IOMMU_FWSPEC_PCI_RC_ATS) || pci_ats_disabled())
> -		return false;
>  
> -	pdev = to_pci_dev(master->dev);
> -	return !pdev->untrusted && pdev->ats_cap;
> +	return (smmu->features & ARM_SMMU_FEAT_ATS) && dev_is_pci(dev) &&
> +		pci_ats_supported(to_pci_dev(dev));
>  }
> -#else
> -static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
> -{
> -	return false;
> -}
> -#endif

Acked-by: Will Deacon <will@kernel.org>

Cheers for doing this.

Will