Re: [PATCH 7/7] iommu: Add iommu_domain::domain_ops
From: Lu Baolu
Date: Tue Jan 25 2022 - 01:43:05 EST
On 1/25/22 8:57 AM, Robin Murphy wrote:
On 2022-01-24 07:11, Lu Baolu wrote:
Add a domain specific callback set, domain_ops, for vendor iommu driver
to provide domain specific operations. Move domain-specific callbacks
from iommu_ops to the domain_ops and hook them when a domain is
allocated.
I think it would make a lot of sense for iommu_domain_ops to be a
substructure *within* iommu_ops. That way we can save most of the driver
boilerplate here by not needing extra variables everywhere, and letting
iommu_domain_alloc() still do a default initialisation like "domain->ops
= bus->iommu_ops->domain_ops;"
In the new model, iommu_domain_ops and iommu_ops are not 1:1 mapped.
For example, a PASID-capable IOMMU could support DMA domain (which
supports map/unmap), SVA domain (which does not), and others in the
future. Different type of domain has its own domain_ops.
I do like the future possibility of trying to flatten some of the
io-pgtable indirection by having the SMMU drivers subsequently swizzle
in alternate domain ops once they've picked a format, though. That was a
bit too clunky to achieve at the whole iommu_ops level when I
experimented with it years ago, but now it might well be worth another
try...
One other comment below.
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
include/linux/iommu.h | 93 ++++++++++++---------
drivers/iommu/amd/iommu.c | 21 +++--
drivers/iommu/apple-dart.c | 24 ++++--
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 22 +++--
drivers/iommu/arm/arm-smmu/arm-smmu.c | 23 +++--
drivers/iommu/arm/arm-smmu/qcom_iommu.c | 17 ++--
drivers/iommu/exynos-iommu.c | 17 ++--
drivers/iommu/fsl_pamu_domain.c | 13 ++-
drivers/iommu/intel/iommu.c | 25 ++++--
drivers/iommu/iommu.c | 15 ++--
drivers/iommu/ipmmu-vmsa.c | 21 +++--
drivers/iommu/msm_iommu.c | 17 ++--
drivers/iommu/mtk_iommu.c | 24 ++++--
drivers/iommu/mtk_iommu_v1.c | 19 +++--
drivers/iommu/omap-iommu.c | 15 ++--
drivers/iommu/rockchip-iommu.c | 17 ++--
drivers/iommu/s390-iommu.c | 15 ++--
drivers/iommu/sprd-iommu.c | 19 +++--
drivers/iommu/sun50i-iommu.c | 18 ++--
drivers/iommu/tegra-gart.c | 15 ++--
drivers/iommu/tegra-smmu.c | 16 ++--
drivers/iommu/virtio-iommu.c | 18 ++--
22 files changed, 305 insertions(+), 179 deletions(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 111b3e9c79bb..33c5c0e5c465 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -88,7 +88,7 @@ struct iommu_domain_geometry {
struct iommu_domain {
unsigned type;
- const struct iommu_ops *ops;
+ const struct domain_ops *ops;
unsigned long pgsize_bitmap; /* Bitmap of page sizes in use */
iommu_fault_handler_t handler;
void *handler_token;
@@ -192,26 +192,11 @@ struct iommu_iotlb_gather {
* struct iommu_ops - iommu ops and capabilities
* @capable: check capability
* @domain_alloc: allocate iommu domain
- * @domain_free: free iommu domain
- * @attach_dev: attach device to an iommu domain
- * @detach_dev: detach device from an iommu domain
- * @map: map a physically contiguous memory region to an iommu domain
- * @map_pages: map a physically contiguous set of pages of the same
size to
- * an iommu domain.
- * @unmap: unmap a physically contiguous memory region from an iommu
domain
- * @unmap_pages: unmap a number of pages of the same size from an
iommu domain
- * @flush_iotlb_all: Synchronously flush all hardware TLBs for this
domain
- * @iotlb_sync_map: Sync mappings created recently using @map to the
hardware
- * @iotlb_sync: Flush all queued ranges from the hardware TLBs and
empty flush
- * queue
- * @iova_to_phys: translate iova to physical address
* @probe_device: Add device to iommu driver handling
* @release_device: Remove device from iommu driver handling
* @probe_finalize: Do final setup work after the device is added to
an IOMMU
* group and attached to the groups domain
* @device_group: find iommu group for a particular device
- * @enable_nesting: Enable nesting
- * @set_pgtable_quirks: Set io page table quirks (IO_PGTABLE_QUIRK_*)
* @get_resv_regions: Request list of reserved regions for a device
* @put_resv_regions: Free list of reserved regions for a device
* @apply_resv_region: Temporary helper call-back for iova reserved
ranges
@@ -237,33 +222,11 @@ struct iommu_ops {
/* Domain allocation and freeing by the iommu driver */
struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type);
- void (*domain_free)(struct iommu_domain *);
- int (*attach_dev)(struct iommu_domain *domain, struct device *dev);
- void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
- int (*map)(struct iommu_domain *domain, unsigned long iova,
- phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
- int (*map_pages)(struct iommu_domain *domain, unsigned long iova,
- phys_addr_t paddr, size_t pgsize, size_t pgcount,
- int prot, gfp_t gfp, size_t *mapped);
- size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
- size_t size, struct iommu_iotlb_gather *iotlb_gather);
- size_t (*unmap_pages)(struct iommu_domain *domain, unsigned long
iova,
- size_t pgsize, size_t pgcount,
- struct iommu_iotlb_gather *iotlb_gather);
- void (*flush_iotlb_all)(struct iommu_domain *domain);
- void (*iotlb_sync_map)(struct iommu_domain *domain, unsigned long
iova,
- size_t size);
- void (*iotlb_sync)(struct iommu_domain *domain,
- struct iommu_iotlb_gather *iotlb_gather);
- phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,
dma_addr_t iova);
struct iommu_device *(*probe_device)(struct device *dev);
void (*release_device)(struct device *dev);
void (*probe_finalize)(struct device *dev);
struct iommu_group *(*device_group)(struct device *dev);
- int (*enable_nesting)(struct iommu_domain *domain);
- int (*set_pgtable_quirks)(struct iommu_domain *domain,
- unsigned long quirks);
/* Request/Free a list of reserved regions for a device */
void (*get_resv_regions)(struct device *dev, struct list_head
*list);
@@ -296,6 +259,60 @@ struct iommu_ops {
struct module *owner;
};
+/**
+ * struct domain_ops - per-domain ops
+ * @attach_dev: attach an iommu domain to a device
+ * @detach_dev: detach an iommu domain from a device
+ * @map: map a physically contiguous memory region to an iommu domain
+ * @map_pages: map a physically contiguous set of pages of the same
size to
+ * an iommu domain.
+ * @unmap: unmap a physically contiguous memory region from an iommu
domain
+ * @unmap_pages: unmap a number of pages of the same size from an
iommu domain
+ * @flush_iotlb_all: Synchronously flush all hardware TLBs for this
domain
+ * @iotlb_sync_map: Sync mappings created recently using @map to the
hardware
+ * @iotlb_sync: Flush all queued ranges from the hardware TLBs and
empty flush
+ * queue
+ * @iova_to_phys: translate iova to physical address
+ * @enable_nesting: Enable nesting
+ * @set_pgtable_quirks: Set io page table quirks (IO_PGTABLE_QUIRK_*)
+ * @release: Release the domain after use.
Not sure about the name change here - it's still logically a "free" that
matches an "alloc", we're not doing anything clever like refcounting or
devres, which is what I'd tend to associate with a "release" function
for an allocated resource.
Yes. "free" is better.
Robin.
Best regards,
baolu