| Message ID | 37ec2f9f67098d0caf60dcec558fbe1756ea2621.1649089693.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | thunderbolt: Make iommu_dma_protection more accurate | expand |
On Tue, Apr 05, 2022 at 11:41:01AM +0100, Robin Murphy wrote: > iommu_capable() only really works for systems where all IOMMU instances > are completely homogeneous, and all devices are IOMMU-mapped. Implement > the new variant which can give an accurate answer for whichever device > the caller is actually interested in. > > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > > v3: New patch; now that the dev_iommu_ops() work has landed we can go > straight to a proper implementation. Also s/dev/device/ to match > the precedent of device_iommu_mapped() for the public API. I'm a little worrited about a method with a parameter than can be NULL. Also usnic, vmd, and vdpa really want to use your new device_iommu_capable as they check based on a device. Just VFIO is special as usual..
On 2022-04-06 06:28, Christoph Hellwig wrote: > On Tue, Apr 05, 2022 at 11:41:01AM +0100, Robin Murphy wrote: >> iommu_capable() only really works for systems where all IOMMU instances >> are completely homogeneous, and all devices are IOMMU-mapped. Implement >> the new variant which can give an accurate answer for whichever device >> the caller is actually interested in. >> >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> >> v3: New patch; now that the dev_iommu_ops() work has landed we can go >> straight to a proper implementation. Also s/dev/device/ to match >> the precedent of device_iommu_mapped() for the public API. > > I'm a little worrited about a method with a parameter than can be > NULL. FWIW, the intent is that that's only temporary. > Also usnic, vmd, and vdpa really want to use your new > device_iommu_capable as they check based on a device. Just VFIO > is special as usual.. Indeed, I have those patches in my stack already, I'm just waiting for this to land before I think about posting them. Once the DMA ownership series lands in parallel, VFIO can also get converted and iommu_capable() goes away entirely. At that point I have a patch for the Arm SMMU drivers to start actually using the new device argument, but Jason's new proposal now puts a twist on that... On reflection, there's no real need for the internal method to change in lock-step with the external interface. I've no objection to holding off on adding that new parameter until it's reliably useful, and indeed now that I'm looking at it outside the context of the entire cleanup mission, that does sound like the right thing to do anyway :) (also it turns out I need to respin this patch regardless since I generated it from the wrong point in my branch, where iommu_present() was already gone from the context in iommu.h...) Cheers, Robin.
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 1160a13c80ab..e412a50dce59 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2132,7 +2132,7 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom, return ops->iova_to_phys(ops, iova); } -static bool amd_iommu_capable(enum iommu_cap cap) +static bool amd_iommu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index 73b7b1b17b77..b221525c31b9 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1981,7 +1981,7 @@ static const struct iommu_flush_ops arm_smmu_flush_ops = { }; /* IOMMU API */ -static bool arm_smmu_capable(enum iommu_cap cap) +static bool arm_smmu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index f0bec4a35df5..34cab56b9c6d 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1313,7 +1313,7 @@ static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain, return ops->iova_to_phys(ops, iova); } -static bool arm_smmu_capable(enum iommu_cap cap) +static bool arm_smmu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c index 80af00f468b4..028649203d33 100644 --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c @@ -493,7 +493,7 @@ static phys_addr_t qcom_iommu_iova_to_phys(struct iommu_domain *domain, return ret; } -static bool qcom_iommu_capable(enum iommu_cap cap) +static bool qcom_iommu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c index 7274f86b2bc4..ddf5ab28615c 100644 --- a/drivers/iommu/fsl_pamu_domain.c +++ b/drivers/iommu/fsl_pamu_domain.c @@ -177,7 +177,7 @@ static phys_addr_t fsl_pamu_iova_to_phys(struct iommu_domain *domain, return iova; } -static bool fsl_pamu_capable(enum iommu_cap cap) +static bool fsl_pamu_capable(struct device *dev, enum iommu_cap cap) { return cap == IOMMU_CAP_CACHE_COHERENCY; } diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 21111491ddfd..255304eb3b1f 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4544,7 +4544,7 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, return phys; } -static bool intel_iommu_capable(enum iommu_cap cap) +static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap) { if (cap == IOMMU_CAP_CACHE_COHERENCY) return domain_update_iommu_snooping(NULL); diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index efad7c1675e0..469574e84e6a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1889,12 +1889,35 @@ static int iommu_bus_init(struct bus_type *bus) return err; } +/** + * device_iommu_capable() - check for a general IOMMU capability + * @dev: device to which the capability would be relevant, if available + * @cap: IOMMU capability + * + * Return: true if an IOMMU is present and supports the given capability + * for the given device, otherwise false. + */ +bool device_iommu_capable(struct device *dev, enum iommu_cap cap) +{ + const struct iommu_ops *ops; + + if (!dev->iommu || !dev->iommu->iommu_dev) + return false; + + ops = dev_iommu_ops(dev); + if (!ops->capable) + return false; + + return ops->capable(dev, cap); +} +EXPORT_SYMBOL_GPL(device_iommu_capable); + bool iommu_capable(struct bus_type *bus, enum iommu_cap cap) { if (!bus->iommu_ops || !bus->iommu_ops->capable) return false; - return bus->iommu_ops->capable(cap); + return bus->iommu_ops->capable(NULL, cap); } EXPORT_SYMBOL_GPL(iommu_capable); diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index 5f5f4bd91e6f..ea4ba9de04af 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -39,7 +39,7 @@ static struct s390_domain *to_s390_domain(struct iommu_domain *dom) return container_of(dom, struct s390_domain, domain); } -static bool s390_iommu_capable(enum iommu_cap cap) +static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap) { switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 4a25f8241207..1fa927e6f1c6 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -219,7 +219,7 @@ struct iommu_iotlb_gather { * @owner: Driver module providing these ops */ struct iommu_ops { - bool (*capable)(enum iommu_cap); + bool (*capable)(struct device *dev, enum iommu_cap); /* Domain allocation and freeing by the iommu driver */ struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type); @@ -415,6 +415,7 @@ static inline const struct iommu_ops *dev_iommu_ops(struct device *dev) #define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER 6 /* Post Driver unbind */ extern int bus_iommu_probe(struct bus_type *bus); +extern bool device_iommu_capable(struct device *dev, enum iommu_cap cap); extern bool iommu_capable(struct bus_type *bus, enum iommu_cap cap); extern struct iommu_domain *iommu_domain_alloc(struct device *dev); extern struct iommu_group *iommu_group_get_by_id(int id); @@ -682,6 +683,11 @@ struct iommu_device {}; struct iommu_fault_param {}; struct iommu_iotlb_gather {}; +static inline bool device_iommu_capable(struct device *dev, enum iommu_cap cap) +{ + return false; +} + static inline bool iommu_capable(struct bus_type *bus, enum iommu_cap cap) { return false;
iommu_capable() only really works for systems where all IOMMU instances are completely homogeneous, and all devices are IOMMU-mapped. Implement the new variant which can give an accurate answer for whichever device the caller is actually interested in. Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- v3: New patch; now that the dev_iommu_ops() work has landed we can go straight to a proper implementation. Also s/dev/device/ to match the precedent of device_iommu_mapped() for the public API. drivers/iommu/amd/iommu.c | 2 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +- drivers/iommu/arm/arm-smmu/arm-smmu.c | 2 +- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 2 +- drivers/iommu/fsl_pamu_domain.c | 2 +- drivers/iommu/intel/iommu.c | 2 +- drivers/iommu/iommu.c | 25 ++++++++++++++++++++- drivers/iommu/s390-iommu.c | 2 +- include/linux/iommu.h | 8 ++++++- 9 files changed, 38 insertions(+), 9 deletions(-)