| Message ID | 20190610184714.6786-9-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iommu: Add auxiliary domain and PASID support to Arm SMMUv3 | expand |
On Mon, 10 Jun 2019 19:47:14 +0100 Jean-Philippe Brucker <jean-philippe.brucker@arm.com> wrote: > Enable PASID for PCI devices that support it. Since the SSID tables are > allocated by arm_smmu_attach_dev(), PASID has to be enabled early enough. > arm_smmu_dev_feature_enable() would be too late, since by that time the > main DMA domain has already been attached. Do it in add_device() instead. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Nitpick in line. Thanks, Jonathan > --- > drivers/iommu/arm-smmu-v3.c | 51 ++++++++++++++++++++++++++++++++++++- > 1 file changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 972bfb80f964..a8a516d9ff10 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -2197,6 +2197,49 @@ static void arm_smmu_disable_ats(struct arm_smmu_master *master) > master->ats_enabled = false; > } > > +static int arm_smmu_enable_pasid(struct arm_smmu_master *master) > +{ > + int ret; > + int features; > + int num_pasids; > + struct pci_dev *pdev; > + > + if (!dev_is_pci(master->dev)) > + return -ENOSYS; > + > + pdev = to_pci_dev(master->dev); > + > + features = pci_pasid_features(pdev); > + if (features < 0) > + return -ENOSYS; > + > + num_pasids = pci_max_pasids(pdev); > + if (num_pasids <= 0) > + return -ENOSYS; > + > + ret = pci_enable_pasid(pdev, features); > + if (!ret) > + master->ssid_bits = min_t(u8, ilog2(num_pasids), > + master->smmu->ssid_bits); > + return ret; > +} > + > +static void arm_smmu_disable_pasid(struct arm_smmu_master *master) > +{ > + struct pci_dev *pdev; > + > + if (!dev_is_pci(master->dev)) > + return; > + > + pdev = to_pci_dev(master->dev); > + > + if (!pdev->pasid_enabled) > + return; > + > + pci_disable_pasid(pdev); > + master->ssid_bits = 0; If we are being really fussy about ordering, why have this set of ssid_bits after pci_disable_pasid rather than before (to reverse order of .._enable_pasid)? > +} > + > static void arm_smmu_detach_dev(struct arm_smmu_master *master) > { > unsigned long flags; > @@ -2413,6 +2456,9 @@ static int arm_smmu_add_device(struct device *dev) > > master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); > > + /* Note that PASID must be enabled before, and disabled after ATS */ > + arm_smmu_enable_pasid(master); > + > /* > * If the SMMU doesn't support 2-stage CD, limit the linear > * tables to a reasonable number of contexts, let's say > @@ -2423,7 +2469,7 @@ static int arm_smmu_add_device(struct device *dev) > > ret = iommu_device_link(&smmu->iommu, dev); > if (ret) > - goto err_free_master; > + goto err_disable_pasid; > > group = iommu_group_get_for_dev(dev); > if (IS_ERR(group)) { > @@ -2436,6 +2482,8 @@ static int arm_smmu_add_device(struct device *dev) > > err_unlink: > iommu_device_unlink(&smmu->iommu, dev); > +err_disable_pasid: > + arm_smmu_disable_pasid(master); > err_free_master: > kfree(master); > fwspec->iommu_priv = NULL; > @@ -2456,6 +2504,7 @@ static void arm_smmu_remove_device(struct device *dev) > arm_smmu_detach_dev(master); > iommu_group_remove_device(dev); > iommu_device_unlink(&smmu->iommu, dev); > + arm_smmu_disable_pasid(master); > kfree(master); > iommu_fwspec_free(dev); > }
On 11/06/2019 11:45, Jonathan Cameron wrote: >> + pci_disable_pasid(pdev); >> + master->ssid_bits = 0; > > If we are being really fussy about ordering, why have this set of > ssid_bits after pci_disable_pasid rather than before (to reverse order > of .._enable_pasid)? Sure, I'll change that Thanks, Jean
Hi Jean, On 6/10/19 8:47 PM, Jean-Philippe Brucker wrote: > Enable PASID for PCI devices that support it. Since the SSID tables are > allocated by arm_smmu_attach_dev(), PASID has to be enabled early enough. > arm_smmu_dev_feature_enable() would be too late, since by that time the > main DMA domain has already been attached. Do it in add_device() instead. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > drivers/iommu/arm-smmu-v3.c | 51 ++++++++++++++++++++++++++++++++++++- > 1 file changed, 50 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index 972bfb80f964..a8a516d9ff10 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -2197,6 +2197,49 @@ static void arm_smmu_disable_ats(struct arm_smmu_master *master) > master->ats_enabled = false; > } > > +static int arm_smmu_enable_pasid(struct arm_smmu_master *master) > +{ > + int ret; > + int features; > + int num_pasids; > + struct pci_dev *pdev; > + > + if (!dev_is_pci(master->dev)) > + return -ENOSYS; > + > + pdev = to_pci_dev(master->dev); > + > + features = pci_pasid_features(pdev); > + if (features < 0) > + return -ENOSYS; > + > + num_pasids = pci_max_pasids(pdev); > + if (num_pasids <= 0) > + return -ENOSYS; > + > + ret = pci_enable_pasid(pdev, features); > + if (!ret) > + master->ssid_bits = min_t(u8, ilog2(num_pasids), > + master->smmu->ssid_bits); I don't really get why this setting is conditional to the success of pci_enabled_pasid and not num_pasids > 0. If it fails the ssid_bits is set to min(smmu->ssid_bits, fwspec->num_pasid_bits) anyway. > + return ret; > +} > + > +static void arm_smmu_disable_pasid(struct arm_smmu_master *master) > +{ > + struct pci_dev *pdev; > + > + if (!dev_is_pci(master->dev)) > + return; > + > + pdev = to_pci_dev(master->dev); > + > + if (!pdev->pasid_enabled) > + return; > + > + pci_disable_pasid(pdev); > + master->ssid_bits = 0; in case of a platform device you leave the ssid_bits to a value != 0. Is that what you want? > +} > + > static void arm_smmu_detach_dev(struct arm_smmu_master *master) > { > unsigned long flags; > @@ -2413,6 +2456,9 @@ static int arm_smmu_add_device(struct device *dev) > > master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); > > + /* Note that PASID must be enabled before, and disabled after ATS */ > + arm_smmu_enable_pasid(master); In case the call fails, don't you want to handle the error and reset the ssid_bits? > + > /* > * If the SMMU doesn't support 2-stage CD, limit the linear > * tables to a reasonable number of contexts, let's say > @@ -2423,7 +2469,7 @@ static int arm_smmu_add_device(struct device *dev) > > ret = iommu_device_link(&smmu->iommu, dev); > if (ret) > - goto err_free_master; > + goto err_disable_pasid; > > group = iommu_group_get_for_dev(dev); > if (IS_ERR(group)) { > @@ -2436,6 +2482,8 @@ static int arm_smmu_add_device(struct device *dev) > > err_unlink: > iommu_device_unlink(&smmu->iommu, dev); > +err_disable_pasid: > + arm_smmu_disable_pasid(master); > err_free_master: > kfree(master); > fwspec->iommu_priv = NULL; > @@ -2456,6 +2504,7 @@ static void arm_smmu_remove_device(struct device *dev) > arm_smmu_detach_dev(master); > iommu_group_remove_device(dev); > iommu_device_unlink(&smmu->iommu, dev); > + arm_smmu_disable_pasid(master); > kfree(master); > iommu_fwspec_free(dev); > } > Thanks Eric
On Mon, Jul 08, 2019 at 09:58:16AM +0200, Auger Eric wrote: > > + ret = pci_enable_pasid(pdev, features); > > + if (!ret) > > + master->ssid_bits = min_t(u8, ilog2(num_pasids), > > + master->smmu->ssid_bits); > I don't really get why this setting is conditional to the success of > pci_enabled_pasid and not num_pasids > 0. num_pasids only contains the value of the PCIe PASID capability. If pci_enable_pasid() fails then we want to leave master->ssid_bits to 0 so that we report to users that SVA and AUXD aren't supported. > If it fails the ssid_bits is set to min(smmu->ssid_bits, > fwspec->num_pasid_bits) anyway. > > > + return ret; > > +} > > + > > +static void arm_smmu_disable_pasid(struct arm_smmu_master *master) > > +{ > > + struct pci_dev *pdev; > > + > > + if (!dev_is_pci(master->dev)) > > + return; > > + > > + pdev = to_pci_dev(master->dev); > > + > > + if (!pdev->pasid_enabled) > > + return; > > + > > + pci_disable_pasid(pdev); > > + master->ssid_bits = 0; > in case of a platform device you leave the ssid_bits to a value != 0. Is > that what you want? Yes, this is only for PCI devices, there is no standard way of disabling PASID in platform devices. We just take whatever the firmware gives us. > > +} > > + > > static void arm_smmu_detach_dev(struct arm_smmu_master *master) > > { > > unsigned long flags; > > @@ -2413,6 +2456,9 @@ static int arm_smmu_add_device(struct device *dev) > > > > master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); > > > > + /* Note that PASID must be enabled before, and disabled after ATS */ > > + arm_smmu_enable_pasid(master); > In case the call fails, don't you want to handle the error and reset the > ssid_bits? This function fails if the device doesn't support PASID, and we leave ssid_bits to 0. That said, I think it would be nicer to move the above line (that deals with fwspec) into arm_smmu_enable_pasid() Thanks, Jean
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 972bfb80f964..a8a516d9ff10 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2197,6 +2197,49 @@ static void arm_smmu_disable_ats(struct arm_smmu_master *master) master->ats_enabled = false; } +static int arm_smmu_enable_pasid(struct arm_smmu_master *master) +{ + int ret; + int features; + int num_pasids; + struct pci_dev *pdev; + + if (!dev_is_pci(master->dev)) + return -ENOSYS; + + pdev = to_pci_dev(master->dev); + + features = pci_pasid_features(pdev); + if (features < 0) + return -ENOSYS; + + num_pasids = pci_max_pasids(pdev); + if (num_pasids <= 0) + return -ENOSYS; + + ret = pci_enable_pasid(pdev, features); + if (!ret) + master->ssid_bits = min_t(u8, ilog2(num_pasids), + master->smmu->ssid_bits); + return ret; +} + +static void arm_smmu_disable_pasid(struct arm_smmu_master *master) +{ + struct pci_dev *pdev; + + if (!dev_is_pci(master->dev)) + return; + + pdev = to_pci_dev(master->dev); + + if (!pdev->pasid_enabled) + return; + + pci_disable_pasid(pdev); + master->ssid_bits = 0; +} + static void arm_smmu_detach_dev(struct arm_smmu_master *master) { unsigned long flags; @@ -2413,6 +2456,9 @@ static int arm_smmu_add_device(struct device *dev) master->ssid_bits = min(smmu->ssid_bits, fwspec->num_pasid_bits); + /* Note that PASID must be enabled before, and disabled after ATS */ + arm_smmu_enable_pasid(master); + /* * If the SMMU doesn't support 2-stage CD, limit the linear * tables to a reasonable number of contexts, let's say @@ -2423,7 +2469,7 @@ static int arm_smmu_add_device(struct device *dev) ret = iommu_device_link(&smmu->iommu, dev); if (ret) - goto err_free_master; + goto err_disable_pasid; group = iommu_group_get_for_dev(dev); if (IS_ERR(group)) { @@ -2436,6 +2482,8 @@ static int arm_smmu_add_device(struct device *dev) err_unlink: iommu_device_unlink(&smmu->iommu, dev); +err_disable_pasid: + arm_smmu_disable_pasid(master); err_free_master: kfree(master); fwspec->iommu_priv = NULL; @@ -2456,6 +2504,7 @@ static void arm_smmu_remove_device(struct device *dev) arm_smmu_detach_dev(master); iommu_group_remove_device(dev); iommu_device_unlink(&smmu->iommu, dev); + arm_smmu_disable_pasid(master); kfree(master); iommu_fwspec_free(dev); }
Enable PASID for PCI devices that support it. Since the SSID tables are allocated by arm_smmu_attach_dev(), PASID has to be enabled early enough. arm_smmu_dev_feature_enable() would be too late, since by that time the main DMA domain has already been attached. Do it in add_device() instead. Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> --- drivers/iommu/arm-smmu-v3.c | 51 ++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 1 deletion(-)