Add iommu map_sg/unmap_sg API
Subsystems (2)
v4 cover Add iommu map_sg/unmap_sg API
Patch for adding map_sg/unmap_sg to the generic IOMMU API.
v3 -> v4:
* Removed BUG_ON in both map_sg and unmap_sg
* Removed PAGE_ALIGN of length of mapping
v2 -> v3:
* Updated commit text
* Simplifed fallback code and fixed variable types in map_sg function.
* Renamed and changed arguments to map and unmap functions
v1 -> v2:
* Added support for "option" argument to unmap call. This can be used by IOMMU driver implentations to allow clients to signal to the driver not to do TLB invalidate for example.
* Added fallback in case iommu_{map,unmap}_range is called for an IOMMU driver that does not have these implemented.
* Rebased on top of Joerg's tree.
* Split out patch from the rest of the patches.
Olav Haugan (1):
iommu-api: Add map_sg/unmap_sg functions
drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Mapping and unmapping are more often than not in the critical path. map_sg and unmap_sg allows IOMMU driver implementations to optimize the process of mapping and unmapping buffers into the IOMMU page tables.
Instead of mapping a buffer one page at a time and requiring potentially expensive TLB operations for each page, this function allows the driver to map all pages in one go and defer TLB maintenance until after all pages have been mapped.
Additionally, the mapping operation would be faster in general since clients does not have to keep calling map API over and over again for each physically contiguous chunk of memory that needs to be mapped to a virtually contiguous region.
--- drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)
drivers/iommu/iommu.c +44 -0
@@ -1088,6 +1088,50 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) }EXPORT_SYMBOL_GPL (iommu_unmap); +int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents, +int prot,unsigned long flags) +{ +int ret =0 ; +unsigned long offset =0 ; + +if (unlikely (domain->ops->map_sg ==NULL )) { +unsigned int i; +struct scatterlist *s; + +for_each_sg (sg, s, nents, i) { +phys_addr_t phys =page_to_phys (sg_page (s)); +size_t page_len = s->offset + s->length; + + ret =iommu_map (domain, iova + offset, phys, page_len, + prot); +if (ret) + goto fail; + + offset += page_len; + } + }else { + ret = domain->ops->map_sg (domain, iova, sg, nents, prot, flags); + } + goto out; + +fail: +/* undo mappings already done in case of error */ +iommu_unmap (domain, iova, offset); +out: +return ret; +} +EXPORT_SYMBOL_GPL (iommu_map_sg); + +int iommu_unmap_sg (struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags) +{ +if (unlikely (domain->ops->unmap_sg ==NULL )) +return iommu_unmap (domain, iova, size); +else +return domain->ops->unmap_sg (domain, iova, size, flags); +} +EXPORT_SYMBOL_GPL (iommu_unmap_sg);int iommu_domain_window_enable (struct iommu_domain *domain,u32 wnd_nr,phys_addr_t paddr,u64 size,int prot)
include/linux/iommu.h +28 -0
@@ -22,6 +22,7 @@#include <linux/errno.h> #include <linux/err.h> #include <linux/types.h> +#include <linux/scatterlist.h> #include <trace/events/iommu.h> #define IOMMU_READ (1 << 0)
@@ -93,6 +94,10 @@ enum iommu_attr {* @detach_dev: detach device from an iommu domain * @map: map a physically contiguous memory region to an iommu domain * @unmap: unmap a physically contiguous memory region from an iommu domain +* @map_sg: map a scatter-gather list of physically contiguous memory chunks +* to an iommu domain +* @unmap_sg: unmap a scatter-gather list of physically contiguous memory +* chunks from an iommu domain * @iova_to_phys: translate iova to physical address * @domain_has_cap: domain capabilities query * @add_device: add device to iommu grouping
@@ -110,6 +115,11 @@ struct iommu_ops { phys_addr_t paddr, size_t size, int prot);size_t (*unmap)(struct iommu_domain *domain,unsigned long iova,size_t size); +int (*map_sg)(struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags); +int (*unmap_sg)(struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags);phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,dma_addr_t iova);int (*domain_has_cap)(struct iommu_domain *domain,unsigned long cap);
@@ -153,6 +163,11 @@ extern int iommu_map(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot);extern size_t iommu_unmap (struct iommu_domain *domain,unsigned long iova,size_t size); +extern int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags); +extern int iommu_unmap_sg (struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags);extern phys_addr_t iommu_iova_to_phys (struct iommu_domain *domain,dma_addr_t iova);extern int iommu_domain_has_cap (struct iommu_domain *domain,unsigned long cap);
@@ -287,6 +302,19 @@ static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,return -ENODEV ; } +static inline int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags) +{ +return -ENODEV ; +} + +static inline int iommu_unmap_sg (struct iommu_domain *domain, +unsigned long iova,size_t size,unsigned long flags) +{ +return -ENODEV ; +} +static inline int iommu_domain_window_enable (struct iommu_domain *domain,u32 wnd_nr,phys_addr_t paddr,u64 size,int prot)
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Hi Olav,
Quoted 9 lines · Olav Haugan
Mapping and unmapping are more often than not in the critical path.
map_sgandunmap_sgallows IOMMU driver implementations to optimize the process of mapping and unmapping buffers into the IOMMU page tables.Instead of mapping a buffer one page at a time and requiring potentially expensive TLB operations for each page, this function allows the driver to map all pages in one go and defer TLB maintenance until after all pages have been mapped.
Quoted 4 lines
Additionally, the mapping operation would be faster in general since clients does not have to keep calling map API over and over again for each physically contiguous chunk of memory that needs to be mapped to a virtually contiguous region.
Just a couple of minor comments, but I think this is almost there now.
Quoted 11 lines
Signed-off-by Olav Haugan <[email protected]>--- drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)drivers/iommu/iommu.c +0
-0
drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1094
Quoted 7 lines
drivers/iommu/iommu.c +4
-0@@ -1088,6 +1088,50 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) }EXPORT_SYMBOL_GPL (iommu_unmap); +int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents, +int prot,unsigned long flags) +{
What do you anticipate passing in the flags parameter? I assume it's something specific to the scatterlist, since we can't provide this to iommu_map as it stands?
Quoted 16 lines
drivers/iommu/iommu.c +16
-0+int ret =0 ; +unsigned long offset =0 ; + +if (unlikely (domain->ops->map_sg ==NULL )) { +unsigned int i; +struct scatterlist *s; + +for_each_sg (sg, s, nents, i) { +phys_addr_t phys =page_to_phys (sg_page (s)); +size_t page_len = s->offset + s->length; + + ret =iommu_map (domain, iova + offset, phys, page_len, + prot); +if (ret) + goto fail; +
drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1120
Quoted 10 lines
drivers/iommu/iommu.c +10
-0+ offset += page_len; + } + }else { + ret = domain->ops->map_sg (domain, iova, sg, nents, prot, flags); + } + goto out; + +fail: +/* undo mappings already done in case of error */ +iommu_unmap (domain, iova, offset);
I think this would be cleaner if you stuck it in the loop above and removed all these labels:
if (ret) {
iommu_unmap(...);
break;}
Will
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Hi Will,
Quoted 33 lines · Will Deacon
Hi Olav,
Quoted 9 lines · Olav Haugan
Mapping and unmapping are more often than not in the critical path.
map_sgandunmap_sgallows IOMMU driver implementations to optimize the process of mapping and unmapping buffers into the IOMMU page tables.Instead of mapping a buffer one page at a time and requiring potentially expensive TLB operations for each page, this function allows the driver to map all pages in one go and defer TLB maintenance until after all pages have been mapped.
Quoted 4 lines
Additionally, the mapping operation would be faster in general since clients does not have to keep calling map API over and over again for each physically contiguous chunk of memory that needs to be mapped to a virtually contiguous region.
Just a couple of minor comments, but I think this is almost there now.
Quoted 14 lines
Signed-off-by Olav Haugan <[email protected]>--- drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)drivers/iommu/iommu.c +0
-0@@ -1088,6 +1088,50 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) }EXPORT_SYMBOL_GPL (iommu_unmap);
Quoted 8 lines
drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1094
Quoted 4 lines
drivers/iommu/iommu.c +4
-0+int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents, +int prot,unsigned long flags) +{What do you anticipate passing in the flags parameter? I assume it's something specific to the scatterlist, since we can't provide this to
iommu_mapas it stands?
Initially the flags argument is planned to be used by clients to indicate to the driver that no TLB operation is necessary. This allows clients to for example map/unmap multiple scatter-gather lists without doing expensive TLB invalidate operations for each call but just do this at the last mapping/unmapping call instead. I believe Rob Clark was looking for this feature and I can see the benefit for our use cases also.
Quoted 30 lines
Quoted 16 lines
drivers/iommu/iommu.c +16
-0+int ret =0 ; +unsigned long offset =0 ; + +if (unlikely (domain->ops->map_sg ==NULL )) { +unsigned int i; +struct scatterlist *s; + +for_each_sg (sg, s, nents, i) { +phys_addr_t phys =page_to_phys (sg_page (s)); +size_t page_len = s->offset + s->length; + + ret =iommu_map (domain, iova + offset, phys, page_len, + prot); +if (ret) + goto fail; +drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1120
Quoted 10 lines
drivers/iommu/iommu.c +10
-0+ offset += page_len; + } + }else { + ret = domain->ops->map_sg (domain, iova, sg, nents, prot, flags); + } + goto out; + +fail: +/* undo mappings already done in case of error */ +iommu_unmap (domain, iova, offset);I think this would be cleaner if you stuck it in the loop above and removed all these labels:
Quoted 4 lines
if (ret) { iommu_unmap(...); break;}
Sure, I can do that.
Thanks,
Olav
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Any more comments on this from anyone before I submit v5?
Quoted 87 lines · Olav Haugan
Hi Will,
Quoted 33 lines · Will Deacon
Hi Olav,
Quoted 9 lines · Olav Haugan
Mapping and unmapping are more often than not in the critical path.
map_sgandunmap_sgallows IOMMU driver implementations to optimize the process of mapping and unmapping buffers into the IOMMU page tables.Instead of mapping a buffer one page at a time and requiring potentially expensive TLB operations for each page, this function allows the driver to map all pages in one go and defer TLB maintenance until after all pages have been mapped.
Quoted 4 lines
Additionally, the mapping operation would be faster in general since clients does not have to keep calling map API over and over again for each physically contiguous chunk of memory that needs to be mapped to a virtually contiguous region.
Just a couple of minor comments, but I think this is almost there now.
Quoted 14 lines
Signed-off-by Olav Haugan <[email protected]>--- drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)drivers/iommu/iommu.c +0
-0@@ -1088,6 +1088,50 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) }EXPORT_SYMBOL_GPL (iommu_unmap);Quoted 8 lines
drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1094
Quoted 4 lines
drivers/iommu/iommu.c +4
-0+int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents, +int prot,unsigned long flags) +{What do you anticipate passing in the flags parameter? I assume it's something specific to the scatterlist, since we can't provide this to
iommu_mapas it stands?Initially the flags argument is planned to be used by clients to indicate to the driver that no TLB operation is necessary. This allows clients to for example map/unmap multiple scatter-gather lists without doing expensive TLB invalidate operations for each call but just do this at the last mapping/unmapping call instead. I believe Rob Clark was looking for this feature and I can see the benefit for our use cases also.
Quoted 30 lines
Quoted 16 lines
drivers/iommu/iommu.c +16
-0+int ret =0 ; +unsigned long offset =0 ; + +if (unlikely (domain->ops->map_sg ==NULL )) { +unsigned int i; +struct scatterlist *s; + +for_each_sg (sg, s, nents, i) { +phys_addr_t phys =page_to_phys (sg_page (s)); +size_t page_len = s->offset + s->length; + + ret =iommu_map (domain, iova + offset, phys, page_len, + prot); +if (ret) + goto fail; +drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1120
Quoted 10 lines
drivers/iommu/iommu.c +10
-0+ offset += page_len; + } + }else { + ret = domain->ops->map_sg (domain, iova, sg, nents, prot, flags); + } + goto out; + +fail: +/* undo mappings already done in case of error */ +iommu_unmap (domain, iova, offset);I think this would be cleaner if you stuck it in the loop above and removed all these labels:
Quoted 4 lines
if (ret) { iommu_unmap(...); break;}
Quoted 6 lines
Sure, I can do that.
Thanks,
Olav
Olav
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
In reply to Olav HauganQuoted 9 lines · Olav Haugan
Mapping and unmapping are more often than not in the critical path.
map_sgandunmap_sgallows IOMMU driver implementations to optimize the process of mapping and unmapping buffers into the IOMMU page tables.Instead of mapping a buffer one page at a time and requiring potentially expensive TLB operations for each page, this function allows the driver to map all pages in one go and defer TLB maintenance until after all pages have been mapped.
Quoted 4 lines
Additionally, the mapping operation would be faster in general since clients does not have to keep calling map API over and over again for each physically contiguous chunk of memory that needs to be mapped to a virtually contiguous region.
That is assuming that physical == bus topology.
Quoted 27 lines
Signed-off-by Olav Haugan <[email protected]>--- drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)drivers/iommu/iommu.c +12
-0@@ -1088,6 +1088,50 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) }EXPORT_SYMBOL_GPL (iommu_unmap); +int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents, +int prot,unsigned long flags) +{ +int ret =0 ; +unsigned long offset =0 ; + +if (unlikely (domain->ops->map_sg ==NULL )) { +unsigned int i; +struct scatterlist *s; + +for_each_sg (sg, s, nents, i) {
drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1112
Quoted 10 lines
drivers/iommu/iommu.c +10
-0+phys_addr_t phys =page_to_phys (sg_page (s)); +size_t page_len = s->offset + s->length; + + ret =iommu_map (domain, iova + offset, phys, page_len, + prot); +if (ret) + goto fail; + + offset += page_len; + }
I think it would be better if you had an 'default_iommu_map_sg' with the implementation above. And then the default ops->map_sg would point to that and each IOMMU would over-write with its own version.
That way you don't need any of this 'if' and can have the 'iommu_map_sg' be in the header file (either as static inline or an macro).
Quoted 100 lines
drivers/iommu/iommu.c +22
-0+ }else { + ret = domain->ops->map_sg (domain, iova, sg, nents, prot, flags); + } + goto out; + +fail: +/* undo mappings already done in case of error */ +iommu_unmap (domain, iova, offset); +out: +return ret; +} +EXPORT_SYMBOL_GPL (iommu_map_sg); + +int iommu_unmap_sg (struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags) +{ +if (unlikely (domain->ops->unmap_sg ==NULL )) +return iommu_unmap (domain, iova, size); +else +return domain->ops->unmap_sg (domain, iova, size, flags); +} +EXPORT_SYMBOL_GPL (iommu_unmap_sg);int iommu_domain_window_enable (struct iommu_domain *domain,u32 wnd_nr,phys_addr_t paddr,u64 size,int prot)include/linux/iommu.h +28
-0@@ -22,6 +22,7 @@#include <linux/errno.h> #include <linux/err.h> #include <linux/types.h> +#include <linux/scatterlist.h> #include <trace/events/iommu.h> #define IOMMU_READ (1 << 0)@@ -93,6 +94,10 @@ enum iommu_attr {* @detach_dev: detach device from an iommu domain * @map: map a physically contiguous memory region to an iommu domain * @unmap: unmap a physically contiguous memory region from an iommu domain +* @map_sg: map a scatter-gather list of physically contiguous memory chunks +* to an iommu domain +* @unmap_sg: unmap a scatter-gather list of physically contiguous memory +* chunks from an iommu domain * @iova_to_phys: translate iova to physical address * @domain_has_cap: domain capabilities query * @add_device: add device to iommu grouping @@ -110,6 +115,11 @@ struct iommu_ops { phys_addr_t paddr, size_t size, int prot);size_t (*unmap)(struct iommu_domain *domain,unsigned long iova,size_t size); +int (*map_sg)(struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags); +int (*unmap_sg)(struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags);phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,dma_addr_t iova);int (*domain_has_cap)(struct iommu_domain *domain,unsigned long cap);@@ -153,6 +163,11 @@ extern int iommu_map(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot);extern size_t iommu_unmap (struct iommu_domain *domain,unsigned long iova,size_t size); +extern int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags); +extern int iommu_unmap_sg (struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags);extern phys_addr_t iommu_iova_to_phys (struct iommu_domain *domain,dma_addr_t iova);extern int iommu_domain_has_cap (struct iommu_domain *domain,unsigned long cap);@@ -287,6 +302,19 @@ static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,return -ENODEV ; } +static inline int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags) +{ +return -ENODEV ; +} + +static inline int iommu_unmap_sg (struct iommu_domain *domain, +unsigned long iova,size_t size,unsigned long flags) +{ +return -ENODEV ; +} +static inline int iommu_domain_window_enable (struct iommu_domain *domain,u32 wnd_nr,phys_addr_t paddr,u64 size,int prot)Signature · 7 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation _______________________________________________ iommu mailing list iommu at lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Quoted 59 lines · Konrad Rzeszutek Wilk
Quoted 9 lines · Olav Haugan
Mapping and unmapping are more often than not in the critical path.
map_sgandunmap_sgallows IOMMU driver implementations to optimize the process of mapping and unmapping buffers into the IOMMU page tables.Instead of mapping a buffer one page at a time and requiring potentially expensive TLB operations for each page, this function allows the driver to map all pages in one go and defer TLB maintenance until after all pages have been mapped.
Quoted 4 lines
Additionally, the mapping operation would be faster in general since clients does not have to keep calling map API over and over again for each physically contiguous chunk of memory that needs to be mapped to a virtually contiguous region.
That is assuming that physical == bus topology.
Quoted 27 lines
Signed-off-by Olav Haugan <[email protected]>--- drivers/iommu/iommu.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/iommu.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+)drivers/iommu/iommu.c +12
-0@@ -1088,6 +1088,50 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) }EXPORT_SYMBOL_GPL (iommu_unmap); +int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents, +int prot,unsigned long flags) +{ +int ret =0 ; +unsigned long offset =0 ; + +if (unlikely (domain->ops->map_sg ==NULL )) { +unsigned int i; +struct scatterlist *s; + +for_each_sg (sg, s, nents, i) {drivers/iommu/iommu.c size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) · line 1112
Quoted 10 lines
drivers/iommu/iommu.c +10
-0+phys_addr_t phys =page_to_phys (sg_page (s)); +size_t page_len = s->offset + s->length; + + ret =iommu_map (domain, iova + offset, phys, page_len, + prot); +if (ret) + goto fail; + + offset += page_len; + }I think it would be better if you had an '
default_iommu_map_sg' with the implementation above. And then the defaultops->map_sgwould point to that and each IOMMU would over-write with its own version.
Quoted 2 lines
That way you don't need any of this 'if' and can have the '
iommu_map_sg' be in the header file (either as static inline or an macro).
so you are suggesting that I check in "bus_set_iommu()" whether the driver has set the map_sg/unmap_sg function pointers or not and if not set it to the default? Is bus_set_iommu() the only way drivers can set up the callbacks?
Quoted 97 lines
Quoted 97 lines
drivers/iommu/iommu.c +22
-0+ }else { + ret = domain->ops->map_sg (domain, iova, sg, nents, prot, flags); + } + goto out; + +fail: +/* undo mappings already done in case of error */ +iommu_unmap (domain, iova, offset); +out: +return ret; +} +EXPORT_SYMBOL_GPL (iommu_map_sg); + +int iommu_unmap_sg (struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags) +{ +if (unlikely (domain->ops->unmap_sg ==NULL )) +return iommu_unmap (domain, iova, size); +else +return domain->ops->unmap_sg (domain, iova, size, flags); +} +EXPORT_SYMBOL_GPL (iommu_unmap_sg);int iommu_domain_window_enable (struct iommu_domain *domain,u32 wnd_nr,phys_addr_t paddr,u64 size,int prot)include/linux/iommu.h +28
-0@@ -22,6 +22,7 @@#include <linux/errno.h> #include <linux/err.h> #include <linux/types.h> +#include <linux/scatterlist.h> #include <trace/events/iommu.h> #define IOMMU_READ (1 << 0)@@ -93,6 +94,10 @@ enum iommu_attr {* @detach_dev: detach device from an iommu domain * @map: map a physically contiguous memory region to an iommu domain * @unmap: unmap a physically contiguous memory region from an iommu domain +* @map_sg: map a scatter-gather list of physically contiguous memory chunks +* to an iommu domain +* @unmap_sg: unmap a scatter-gather list of physically contiguous memory +* chunks from an iommu domain * @iova_to_phys: translate iova to physical address * @domain_has_cap: domain capabilities query * @add_device: add device to iommu grouping @@ -110,6 +115,11 @@ struct iommu_ops { phys_addr_t paddr, size_t size, int prot);size_t (*unmap)(struct iommu_domain *domain,unsigned long iova,size_t size); +int (*map_sg)(struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags); +int (*unmap_sg)(struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags);phys_addr_t (*iova_to_phys)(struct iommu_domain *domain,dma_addr_t iova);int (*domain_has_cap)(struct iommu_domain *domain,unsigned long cap);@@ -153,6 +163,11 @@ extern int iommu_map(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot);extern size_t iommu_unmap (struct iommu_domain *domain,unsigned long iova,size_t size); +extern int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags); +extern int iommu_unmap_sg (struct iommu_domain *domain,unsigned long iova, +size_t size,unsigned long flags);extern phys_addr_t iommu_iova_to_phys (struct iommu_domain *domain,dma_addr_t iova);extern int iommu_domain_has_cap (struct iommu_domain *domain,unsigned long cap);@@ -287,6 +302,19 @@ static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,return -ENODEV ; } +static inline int iommu_map_sg (struct iommu_domain *domain,unsigned long iova, +struct scatterlist *sg,unsigned int nents,int prot, +unsigned long flags) +{ +return -ENODEV ; +} + +static inline int iommu_unmap_sg (struct iommu_domain *domain, +unsigned long iova,size_t size,unsigned long flags) +{ +return -ENODEV ; +} +static inline int iommu_domain_window_enable (struct iommu_domain *domain,u32 wnd_nr,phys_addr_t paddr,u64 size,int prot)Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
Quoted 10 lines
Quoted 4 lines
_______________________________________________
iommu mailing list
iommu at lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu_______________________________________________
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linux-arm-kernel at lists.infradead.org
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Olav
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
Joerg Roedel
maintainerPATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Quoted 4 lines · Olav Haugan
so you are suggesting that I check in "
bus_set_iommu()" whether the driver has set the map_sg/unmap_sg function pointers or not and if not set it to the default? Isbus_set_iommu()the only way drivers can set up the callbacks?
This doesn't work as the iommu_ops are now const. You have to either update the iommu drivers individually to point to the default function, or you do the check in the API function itself and fall back to the default it no call-back is provided.
Joerg
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Quoted 11 lines · Joerg Roedel
Quoted 4 lines · Olav Haugan
so you are suggesting that I check in "
bus_set_iommu()" whether the driver has set the map_sg/unmap_sg function pointers or not and if not set it to the default? Isbus_set_iommu()the only way drivers can set up the callbacks?This doesn't work as the
iommu_opsare now const. You have to either update the iommu drivers individually to point to the default function, or you do the check in the API function itself and fall back to the default it no call-back is provided.
Ok, then I think it is better to just leave the fallback where it is now in the function itself.
Thanks,
Olav
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Quoted 7 lines · Olav Haugan
Quoted 6 lines · Joerg Roedel
Quoted 4 lines · Olav Haugan
so you are suggesting that I check in "
bus_set_iommu()" whether the driver has set the map_sg/unmap_sg function pointers or not and if not set it to the default? Isbus_set_iommu()the only way drivers can set up the callbacks?
Quoted 8 lines
Quoted 5 lines
This doesn't work as the
iommu_opsare now const. You have to either update the iommu drivers individually to point to the default function, or you do the check in the API function itself and fall back to the default it no call-back is provided.Ok, then I think it is better to just leave the fallback where it is now in the function itself.
What Konrad was suggesting is what I also proposed. The idea is to implement a fallback as standalone function, then make all drivers use that by default in the struct iommu_ops that they register. When drivers implement an optimized version they can simply replace the fallback implementation with their own.
Thierry
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PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Quoted 14 lines · Thierry Reding
Quoted 13 lines · Olav Haugan
Quoted 11 lines · Joerg Roedel
Quoted 4 lines · Olav Haugan
so you are suggesting that I check in "
bus_set_iommu()" whether the driver has set the map_sg/unmap_sg function pointers or not and if not set it to the default? Isbus_set_iommu()the only way drivers can set up the callbacks?This doesn't work as the
iommu_opsare now const. You have to either update the iommu drivers individually to point to the default function, or you do the check in the API function itself and fall back to the default it no call-back is provided.
Quoted 9 lines
Quoted 2 lines
Ok, then I think it is better to just leave the fallback where it is now in the function itself.
What Konrad was suggesting is what I also proposed. The idea is to implement a fallback as standalone function, then make all drivers use that by default in the struct
iommu_opsthat they register. When drivers implement an optimized version they can simply replace the fallback implementation with their own.
Ok, I can do that. I misunderstood the point of the fallback. I thought the point of the fallback was to catch drivers that forget/neglect to implement this callback. If that is not a concern I will update my patch to create a separate function that I will point all existing drivers to.
Thanks,
Olav
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
PATCH v4 1/1 iommu-api: Add map_sg/unmap_sg functions
Quoted 25 lines · Olav Haugan
Quoted 14 lines · Thierry Reding
Quoted 13 lines · Olav Haugan
Quoted 11 lines · Joerg Roedel
Quoted 4 lines · Olav Haugan
so you are suggesting that I check in "
bus_set_iommu()" whether the driver has set the map_sg/unmap_sg function pointers or not and if not set it to the default? Isbus_set_iommu()the only way drivers can set up the callbacks?This doesn't work as the
iommu_opsare now const. You have to either update the iommu drivers individually to point to the default function, or you do the check in the API function itself and fall back to the default it no call-back is provided.Quoted 9 lines
Quoted 2 lines
Ok, then I think it is better to just leave the fallback where it is now in the function itself.
What Konrad was suggesting is what I also proposed. The idea is to implement a fallback as standalone function, then make all drivers use that by default in the struct
iommu_opsthat they register. When drivers implement an optimized version they can simply replace the fallback implementation with their own.
Quoted 3 lines
Ok, I can do that. I misunderstood the point of the fallback. I thought the point of the fallback was to catch drivers that forget/neglect to implement this callback. If that is not a concern I will update my patch
Nah. We want those drivers to crash and burn so we can see that and fix it. And by fix I meant it would just point do:
.map_sg = generic_map_sg,
.unmap_sg = generic_unmap_sg,
In other words, none of the function ops will have an NULL functions.
Quoted 1 line
to create a separate function that I will point all existing drivers to.
Excellent!
Quoted 8 lines
Thanks,
Olav
Signature · 2 lines
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation