Remove VT-d virtual command interface and IOASID

Virtual command interface was introduced to allow using host PASIDs inside VMs. It is unused and abandoned due to architectural change.

With this patch, we can safely remove this feature and the related helpers.

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jacob Pan<[email protected]>

Reviewed-by Kevin Tian<[email protected]>

Reviewed-by Jason Gunthorpe<[email protected]>

From: Jason Gunthorpe <[email protected]>

Instead SVA drivers can use a simple global IDA to allocate PASIDs for each mm_struct.

Future work would be to allow drivers using the SVA APIs to reserve global PASIDs from this IDA for their internal use, eg with the DMA API PASID support.

Signed-off-by Jason Gunthorpe <[email protected]>

Signed-off-by Jacob Pan <[email protected]>

---
v2: minor fixes
- let idxd driver use iommu.h for ioasid_t
- return 0 after mm_pasid_set()

---
 drivers/dma/idxd/idxd.h   |  1 +
 drivers/iommu/iommu-sva.c | 53 +++++++++++----------------------------
 drivers/iommu/iommu-sva.h |  3 ---
 include/linux/sched/mm.h  |  8 +-----
 4 files changed, 17 insertions(+), 48 deletions(-)

drivers/dma/idxd/idxd.h +0 -0

index 7ced8d283d98..417e602a46b6 100644

drivers/dma/idxd/idxd.h +0 -0

 #include <uapi/linux/idxd.h>
 #include "registers.h"
 

drivers/iommu/iommu-sva.c +5 -16

index 24bf9b2b58aa..8fb6f1867af3 100644
@@ -9,24 +9,11 @@
 #include "iommu-sva.h"
 
 static DEFINE_MUTEX(iommu_sva_lock);
-static DECLARE_IOASID_SET(iommu_sva_pasid);
+static DEFINE_IDA(iommu_global_pasid_ida);
 
-/**
- * iommu_sva_alloc_pasid - Allocate a PASID for the mm
- * @mm: the mm
- * @min: minimum PASID value (inclusive)
- * @max: maximum PASID value (inclusive)
- *
- * Try to allocate a PASID for this mm, or take a reference to the existing one
- * provided it fits within the [@min, @max] range. On success the PASID is
- * available in mm->pasid and will be available for the lifetime of the mm.
- *
- * Returns 0 on success and < 0 on error.
- */
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
+static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 {
-	int ret = 0;
-	ioasid_t pasid;
+	int ret;
 
 	if (min == INVALID_IOASID || max == INVALID_IOASID ||
 	    min == 0 || max < min)

@@ -37,39 +24,29 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 	if (pasid_valid(mm->pasid)) {
 		if (mm->pasid < min || mm->pasid >= max)
 			ret = -EOVERFLOW;
+		else
+			ret = 0;

drivers/iommu/iommu-sva.c +3 -0

+		goto out;
+	mm_pasid_set(mm, ret);
+	ret = 0;
 out:
 	mutex_unlock(&iommu_sva_lock);
 	return ret;

drivers/iommu/iommu-sva.c +3 -12

+	if (likely(!pasid_valid(mm->pasid)))
+		return;
 
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */
-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
+	ida_free(&iommu_global_pasid_ida, mm->pasid);
 }
-EXPORT_SYMBOL_GPL(iommu_sva_find);
 
 /**
  * iommu_sva_bind_device() - Bind a process address space to a device

drivers/iommu/iommu-sva.h +0 -3

index 7215a761b962..c22d0174ad61 100644
@@ -8,9 +8,6 @@
 #include <linux/ioasid.h>
 #include <linux/mm_types.h>
 
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max);
-struct mm_struct *iommu_sva_find(ioasid_t pasid);
-
 /* I/O Page fault */
 struct device;
 struct iommu_fault;

include/linux/sched/mm.h +1 -7

index 2a243616f222..cdc138086230 100644
@@ -463,13 +463,7 @@ static inline void mm_pasid_set(struct mm_struct *mm, u32 pasid)
 	mm->pasid = pasid;
 }
 
-static inline void mm_pasid_drop(struct mm_struct *mm)
-{
-	if (pasid_valid(mm->pasid)) {
-		ioasid_free(mm->pasid);
-		mm->pasid = INVALID_IOASID;
-	}
-}
+void mm_pasid_drop(struct mm_struct *mm);
 #else
 static inline void mm_pasid_init(struct mm_struct *mm) {}
 static inline void mm_pasid_set(struct mm_struct *mm, u32 pasid) {}

Signature · 1 line

2.25.1

Quoted 22 lines · Jacob Pan

From: Jason Gunthorpe <[email protected]>

Instead SVA drivers can use a simple global IDA to allocate PASIDs for each mm_struct.

Future work would be to allow drivers using the SVA APIs to reserve global PASIDs from this IDA for their internal use, eg with the DMA API PASID support.

Signed-off-by Jason Gunthorpe <[email protected]>

Signed-off-by Jacob Pan <[email protected]>

---
v2: minor fixes
- let idxd driver use iommu.h for ioasid_t
- return 0 after mm_pasid_set()

---
 drivers/dma/idxd/idxd.h   |  1 +
 drivers/iommu/iommu-sva.c | 53 +++++++++++----------------------------
 drivers/iommu/iommu-sva.h |  3 ---
 include/linux/sched/mm.h  |  8 +-----
 4 files changed, 17 insertions(+), 48 deletions(-)

drivers/dma/idxd/idxd.h line 16

Quoted 9 lines

drivers/dma/idxd/idxd.h +1 -0

index 7ced8d283d98..417e602a46b6 100644
@@ -13,6 +13,7 @@
 #include <linux/ioasid.h>
 #include <linux/bitmap.h>
 #include <linux/perf_event.h>
+#include <linux/iommu.h>  

Unrelated

Quoted 47 lines

drivers/dma/idxd/idxd.h +0 -0

 #include <uapi/linux/idxd.h>
 #include "registers.h"
 

drivers/iommu/iommu-sva.c +1 -8

index 24bf9b2b58aa..8fb6f1867af3 100644
@@ -9,24 +9,11 @@
 #include "iommu-sva.h"
 
 static DEFINE_MUTEX(iommu_sva_lock);
-static DECLARE_IOASID_SET(iommu_sva_pasid);
+static DEFINE_IDA(iommu_global_pasid_ida);
 
-/**
- * iommu_sva_alloc_pasid - Allocate a PASID for the mm
- * @mm: the mm
- * @min: minimum PASID value (inclusive)
- * @max: maximum PASID value (inclusive)
- *
- * Try to allocate a PASID for this mm, or take a reference to the

existing one
- * provided it fits within the [@min, @max] range. On success the PASID is
- * available in mm->pasid and will be available for the lifetime of the mm.
- *
- * Returns 0 on success and < 0 on error.
- */
-int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) +static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) {

drivers/iommu/iommu-sva.c +3 -2

-	int ret = 0;
-	ioasid_t pasid;
+	int ret;
 
 	if (min == INVALID_IOASID || max == INVALID_IOASID ||
 	    min == 0 || max < min)

@@ -37,39 +24,29 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm,
 ioasid_t min, ioasid_t max) if (pasid_valid(mm->pasid)) {
 		if (mm->pasid < min || mm->pasid >= max)
 			ret = -EOVERFLOW;
+		else
+			ret = 0;
 		goto out;
 	}
 

drivers/iommu/iommu-sva.c int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) · line 33

Quoted 8 lines

drivers/iommu/iommu-sva.c +2 -5

-	pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
-	if (!pasid_valid(pasid))
-		ret = -ENOMEM;
-	else
-		mm_pasid_set(mm, pasid);
+	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max,
 GFP_KERNEL);
+	if (ret < min)  

Just check ret < 0

Quoted 9 lines

drivers/iommu/iommu-sva.c +3 -1

+		goto out;
+	mm_pasid_set(mm, ret);
+	ret = 0;
 out:
 	mutex_unlock(&iommu_sva_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
 

drivers/iommu/iommu-sva.c int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) · line 44

Quoted 7 lines

drivers/iommu/iommu-sva.c +2 -4

-/* ioasid_find getter() requires a void * argument */
-static bool __mmget_not_zero(void *mm)
+void mm_pasid_drop(struct mm_struct *mm)
 {
-	return mmget_not_zero(mm);
-}
+	pr_alert("%s %d", __func__, mm->pasid);  

Debug print

Quoted 10 lines

drivers/iommu/iommu-sva.c int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) · line 33

Quoted 8 lines

drivers/iommu/iommu-sva.c +1 -5

-	pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
-	if (!pasid_valid(pasid))
-		ret = -ENOMEM;
-	else
-		mm_pasid_set(mm, pasid);
+	ret = ida_alloc_range(&iommu_global_pasid_ida, min, max,

GFP_KERNEL);

drivers/iommu/iommu-sva.c +1 -0

+	if (ret < min)  

Just check ret < 0

yes, but i thought < min is safe too.

From: Jacob Pan <[email protected]>
Sent: Tuesday, February 14, 2023 2:44 PM

From: Jason Gunthorpe <[email protected]>

Instead SVA drivers can use a simple global IDA to allocate PASIDs for each mm_struct.

Future work would be to allow drivers using the SVA APIs to reserve global PASIDs from this IDA for their internal use, eg with the DMA API PASID support.

drivers/iommu/iommu-sva.c +4 -7

+void mm_pasid_drop(struct mm_struct *mm)
 {
-	return mmget_not_zero(mm);
-}
+	pr_alert("%s %d", __func__, mm->pasid);
+	if (likely(!pasid_valid(mm->pasid)))
+		return;
 
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with

mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */

Quoted 11 lines

From: Jacob Pan <[email protected]>
Sent: Tuesday, February 14, 2023 2:44 PM

From: Jason Gunthorpe <[email protected]>

Instead SVA drivers can use a simple global IDA to allocate PASIDs for each mm_struct.

Future work would be to allow drivers using the SVA APIs to reserve global PASIDs from this IDA for their internal use, eg with the DMA API PASID support.

I think DMA API PASID will need new API around this IDA. SVA APIs should be just for SVA.

Quoted 18 lines

drivers/iommu/iommu-sva.c +4 -7

+void mm_pasid_drop(struct mm_struct *mm)
 {
-	return mmget_not_zero(mm);
-}
+	pr_alert("%s %d", __func__, mm->pasid);
+	if (likely(!pasid_valid(mm->pasid)))
+		return;
 
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with

mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */

drivers/iommu/iommu-sva.c int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) · line 49

Quoted 5 lines

drivers/iommu/iommu-sva.c +1 -3

-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
+	ida_free(&iommu_global_pasid_ida, mm->pasid);
 }  

when moving this function following line is missed:

	mm->pasid = INVALID_IOASID;

btw the current placement looks asymmetric. We now have mm_pasid_init() and mm_pasid_set() in mm.h while mm_pasid_drop() in iommu-sva.c.
Is it cleaner to introduce a iommu_sva_free_pasid() helper and then call it from mm_pasid_drop() in mm.h?

Hi Kevin,

Quoted 41 lines · Kevin

Quoted 11 lines

From: Jacob Pan <[email protected]>
Sent: Tuesday, February 14, 2023 2:44 PM

From: Jason Gunthorpe <[email protected]>

Instead SVA drivers can use a simple global IDA to allocate PASIDs for each mm_struct.

Future work would be to allow drivers using the SVA APIs to reserve global PASIDs from this IDA for their internal use, eg with the DMA API PASID support.

I think DMA API PASID will need new API around this IDA. SVA APIs should be just for SVA.

Quoted 18 lines

drivers/iommu/iommu-sva.c +4 -7

+void mm_pasid_drop(struct mm_struct *mm)
 {
-	return mmget_not_zero(mm);
-}
+	pr_alert("%s %d", __func__, mm->pasid);
+	if (likely(!pasid_valid(mm->pasid)))
+		return;
 
-/**
- * iommu_sva_find() - Find mm associated to the given PASID
- * @pasid: Process Address Space ID assigned to the mm
- *
- * On success a reference to the mm is taken, and must be released with

mmput().
- *
- * Returns the mm corresponding to this PASID, or an error if not found.
- */

drivers/iommu/iommu-sva.c int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) · line 49

Quoted 5 lines

drivers/iommu/iommu-sva.c +1 -3

-struct mm_struct *iommu_sva_find(ioasid_t pasid)
-{
-	return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
+	ida_free(&iommu_global_pasid_ida, mm->pasid);
 }  

when moving this function following line is missed:

Quoted 2 lines

	mm->pasid = INVALID_IOASID;

not needed, mm is gone by now.

Quoted 5 lines

btw the current placement looks asymmetric. We now have mm_pasid_init() and mm_pasid_set() in mm.h while mm_pasid_drop() in iommu-sva.c.
Is it cleaner to introduce a iommu_sva_free_pasid() helper and then call it from mm_pasid_drop() in mm.h?

That is what we had before, it seems logical to me. Jason?

This has no use anymore, delete it all.

Signed-off-by Jason Gunthorpe <[email protected]>

Signed-off-by Jacob Pan <[email protected]>

---
v2:
- fix compile issue w/o CONFIG_IOMMU_SVA
- consolidate INVALID_IOASID w/ IOMMU_PASID_INVALID

---
 Documentation/x86/sva.rst   |   2 +-
 arch/x86/kernel/traps.c     |   5 +-
 drivers/dma/idxd/device.c   |   8 +-
 drivers/dma/idxd/idxd.h     |   1 -
 drivers/dma/idxd/init.c     |   2 +-
 drivers/dma/idxd/irq.c      |   2 +-
 drivers/iommu/intel/dmar.c  |   4 +-
 drivers/iommu/intel/iommu.c |   2 +-
 drivers/iommu/intel/iommu.h |   1 -
 drivers/iommu/intel/svm.c   |   3 +-

 drivers/iommu/ioasid.c      | 422 ------------------------------------
 drivers/iommu/iommu-sva.c   |   2 +-
 drivers/iommu/iommu-sva.h   |   1 -
 include/linux/ioasid.h      |  83 -------
 include/linux/iommu.h       |  11 +-
 include/linux/sched/mm.h    |   4 +-
 include/uapi/linux/iommu.h  |   1 +
 mm/init-mm.c                |   4 +-

 18 files changed, 29 insertions(+), 529 deletions(-)
 delete mode 100644 drivers/iommu/ioasid.c
 delete mode 100644 include/linux/ioasid.h

include/linux/iommu.h +0 -1

index 46e1347bfa22..7cbcf37df8cd 100644
@@ -13,7 +13,6 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/of.h>
-#include <linux/ioasid.h>
 #include <uapi/linux/iommu.h>
 
 #define IOMMU_READ	(1 << 0)

include/linux/iommu.h +0 -0

 #ifdef CONFIG_IOMMU_API
 
 /**

include/linux/sched/mm.h +2 -2

index cdc138086230..4c52835d3359 100644
@@ -8,7 +8,7 @@
 #include <linux/mm_types.h>
 #include <linux/gfp.h>
 #include <linux/sync_core.h>
-#include <linux/ioasid.h>
+#include <uapi/linux/iommu.h>
 
 /*
  * Routines for handling mm_structs

@@ -454,7 +454,7 @@ static inline void membarrier_update_current_mm(struct mm_struct *next_mm)
 #ifdef CONFIG_IOMMU_SVA
 static inline void mm_pasid_init(struct mm_struct *mm)
 {
-	mm->pasid = INVALID_IOASID;
+	mm->pasid = IOMMU_PASID_INVALID;
 }
 
 /* Associate a PASID with an mm_struct: */

include/uapi/linux/iommu.h +0 -0

index 65d8b0234f69..a95f07f0c98c 100644

include/uapi/linux/iommu.h +0 -0

 #endif /* _UAPI_IOMMU_H */

mm/init-mm.c +2 -2

index c9327abb771c..a084039f55d8 100644
@@ -10,7 +10,7 @@
 
 #include <linux/atomic.h>
 #include <linux/user_namespace.h>
-#include <linux/ioasid.h>
+#include <linux/iommu.h>
 #include <asm/mmu.h>
 
 #ifndef INIT_MM_CONTEXT

@@ -40,7 +40,7 @@ struct mm_struct init_mm = {
 	.user_ns	= &init_user_ns,
 	.cpu_bitmap	= CPU_BITS_NONE,
 #ifdef CONFIG_IOMMU_SVA
-	.pasid		= INVALID_IOASID,
+	.pasid		= IOMMU_PASID_INVALID,
 #endif
 	INIT_MM_CONTEXT(init_mm)
 };

Signature · 1 line

2.25.1

include/uapi/linux/iommu.h struct iommu_page_response { · line 160

Quoted 9 lines

include/uapi/linux/iommu.h +1 -0

index 65d8b0234f69..a95f07f0c98c 100644
@@ -157,5 +157,6 @@ struct iommu_page_response {
 	__u32	grpid;
 	__u32	code;
 };
+#define IOMMU_PASID_INVALID	(-1U)

Why change UAPI?

Quoted 11 lines · Jean-Philippe Brucker

include/uapi/linux/iommu.h struct iommu_page_response { · line 160

Quoted 9 lines

include/uapi/linux/iommu.h +1 -0

index 65d8b0234f69..a95f07f0c98c 100644
@@ -157,5 +157,6 @@ struct iommu_page_response {
 	__u32	grpid;
 	__u32	code;
 };
+#define IOMMU_PASID_INVALID	(-1U)  

Why change UAPI?

There is no uapi, this whole file needs to be deleted too

Hi Jason,

Quoted 13 lines · Jason Gunthorpe

Quoted 11 lines · Jean-Philippe Brucker

include/uapi/linux/iommu.h struct iommu_page_response { · line 160

Quoted 9 lines

include/uapi/linux/iommu.h +1 -0

index 65d8b0234f69..a95f07f0c98c 100644
@@ -157,5 +157,6 @@ struct iommu_page_response {
 	__u32	grpid;
 	__u32	code;
 };
+#define IOMMU_PASID_INVALID	(-1U)  

Why change UAPI?

Quoted 2 lines

There is no uapi, this whole file needs to be deleted too

ok. another clean up.

As I also replied to Jean, I ran into a circular #include problem if mm.h #include iommu.h, I guess I could also create another header, e.g. iommu_defs.h to avoid it. any other suggestions?

Quoted 20 lines · Jacob Pan

Hi Jason,

Quoted 16 lines · Jason Gunthorpe

Quoted 11 lines · Jean-Philippe Brucker

include/uapi/linux/iommu.h struct iommu_page_response { · line 160

Quoted 9 lines

(quoted diff) +0 -0

b/include/uapi/linux/iommu.h index 65d8b0234f69..a95f07f0c98c 100644 --- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h

include/uapi/linux/iommu.h +1 -0

@@ -157,5 +157,6 @@ struct iommu_page_response {
 	__u32	grpid;
 	__u32	code;
 };
+#define IOMMU_PASID_INVALID	(-1U)    

Why change UAPI?

There is no uapi, this whole file needs to be deleted too

Quoted 5 lines

ok. another clean up.

As I also replied to Jean, I ran into a circular #include problem if mm.h #include iommu.h, I guess I could also create another header, e.g. iommu_defs.h to avoid it. any other suggestions?

Given this header is not used, just delete things from it to resolve the problem?

Hi Jason,

Quoted 23 lines · Jason Gunthorpe

Quoted 22 lines · Jacob Pan

Hi Jason,

Quoted 14 lines · Jason Gunthorpe

Quoted 11 lines · Jean-Philippe Brucker

include/uapi/linux/iommu.h struct iommu_page_response { · line 160

Quoted 9 lines

(quoted diff) +0 -0

b/include/uapi/linux/iommu.h index 65d8b0234f69..a95f07f0c98c 100644 --- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h

include/uapi/linux/iommu.h +1 -0

@@ -157,5 +157,6 @@ struct iommu_page_response {
 	__u32	grpid;
 	__u32	code;
 };
+#define IOMMU_PASID_INVALID	(-1U)    

Why change UAPI?

Quoted 2 lines

There is no uapi, this whole file needs to be deleted too

ok. another clean up.

Quoted 6 lines

Quoted 3 lines

As I also replied to Jean, I ran into a circular #include problem if mm.h #include iommu.h, I guess I could also create another header, e.g. iommu_defs.h to avoid it. any other suggestions?

Given this header is not used, just delete things from it to resolve the problem?

no, sorry i didn't make it clear. I meant if we do #include <linux/iommu.h> in sched/mm.h, then I got circular include problem.

Quoted 4 lines · Jacob Pan

This has no use anymore, delete it all.

Signed-off-by Jason Gunthorpe <[email protected]>

Signed-off-by Jacob Pan <[email protected]>

Yes, a number of intended users haven't materialized yet. They can re-introduce the allocator when they need it.

Quoted 4 lines

---
v2:
- fix compile issue w/o CONFIG_IOMMU_SVA
- consolidate INVALID_IOASID w/ IOMMU_PASID_INVALID

Why not rename ioasid_t as well? Probably better to move all the renaming to a separate patch

Quoted 11 lines

---
 Documentation/x86/sva.rst   |   2 +-
 arch/x86/kernel/traps.c     |   5 +-
 drivers/dma/idxd/device.c   |   8 +-
 drivers/dma/idxd/idxd.h     |   1 -
 drivers/dma/idxd/init.c     |   2 +-
 drivers/dma/idxd/irq.c      |   2 +-
 drivers/iommu/intel/dmar.c  |   4 +-
 drivers/iommu/intel/iommu.c |   2 +-
 drivers/iommu/intel/iommu.h |   1 -
 drivers/iommu/intel/svm.c   |   3 +-

Quoted 8 lines

 drivers/iommu/ioasid.c      | 422 ------------------------------------
 drivers/iommu/iommu-sva.c   |   2 +-
 drivers/iommu/iommu-sva.h   |   1 -
 include/linux/ioasid.h      |  83 -------
 include/linux/iommu.h       |  11 +-
 include/linux/sched/mm.h    |   4 +-
 include/uapi/linux/iommu.h  |   1 +
 mm/init-mm.c                |   4 +-  

drivers/iommu/{Makefile,Kconfig} also need updates

Quoted 20 lines

 18 files changed, 29 insertions(+), 529 deletions(-)
 delete mode 100644 drivers/iommu/ioasid.c
 delete mode 100644 include/linux/ioasid.h  

include/linux/iommu.h +0 -1

index 46e1347bfa22..7cbcf37df8cd 100644
@@ -13,7 +13,6 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/of.h>
-#include <linux/ioasid.h>
 #include <uapi/linux/iommu.h>
 
 #define IOMMU_READ	(1 << 0)

@@ -192,8 +191,14 @@ enum iommu_dev_features {
 	IOMMU_DEV_FEAT_IOPF,
 };
 

include/linux/iommu.h enum iommu_dev_features { · line 194

Quoted 3 lines

include/linux/iommu.h +1 -2

-#define IOMMU_PASID_INVALID	(-1U)
-
+//#define IOMMU_PASID_INVALID	(-1U)  

Remove this

include/linux/iommu.h enum iommu_dev_features { · line 201

Quoted 7 lines

include/linux/iommu.h +7 -0

+typedef unsigned int ioasid_t;
+#ifdef CONFIG_IOMMU_SVA
+static inline bool pasid_valid(ioasid_t ioasid)
+{
+	return ioasid != IOMMU_PASID_INVALID;
+}
+#endif  

This isn't specific to SVA, doesn't need an ifdef

Quoted 24 lines

include/linux/iommu.h +0 -0

 #ifdef CONFIG_IOMMU_API
 
 /**

include/linux/sched/mm.h +1 -1

index cdc138086230..4c52835d3359 100644
@@ -8,7 +8,7 @@
 #include <linux/mm_types.h>
 #include <linux/gfp.h>
 #include <linux/sync_core.h>
-#include <linux/ioasid.h>
+#include <uapi/linux/iommu.h>
 
 /*
  * Routines for handling mm_structs

@@ -454,7 +454,7 @@ static inline void

membarrier_update_current_mm(struct mm_struct *next_mm) #ifdef CONFIG_IOMMU_SVA static inline void mm_pasid_init(struct mm_struct *mm)
{

include/linux/sched/mm.h +1 -1

-	mm->pasid = INVALID_IOASID;
+	mm->pasid = IOMMU_PASID_INVALID;
 }

include/uapi/linux/iommu.h struct iommu_page_response { · line 160

Quoted 10 lines

/* Associate a PASID with an mm_struct: */

include/uapi/linux/iommu.h +1 -0

index 65d8b0234f69..a95f07f0c98c 100644
@@ -157,5 +157,6 @@ struct iommu_page_response {
 	__u32	grpid;
 	__u32	code;
 };
+#define IOMMU_PASID_INVALID	(-1U)  

Why change UAPI?

Quoted 14 lines

include/uapi/linux/iommu.h +0 -0

 #endif /* _UAPI_IOMMU_H */

mm/init-mm.c +1 -1

index c9327abb771c..a084039f55d8 100644
@@ -10,7 +10,7 @@
 
 #include <linux/atomic.h>
 #include <linux/user_namespace.h>
-#include <linux/ioasid.h>
+#include <linux/iommu.h>
 #include <asm/mmu.h>
 

Quoted 13 lines

mm/init-mm.c +1 -1

 #ifndef INIT_MM_CONTEXT

@@ -40,7 +40,7 @@ struct mm_struct init_mm = {
 	.user_ns	= &init_user_ns,
 	.cpu_bitmap	= CPU_BITS_NONE,
 #ifdef CONFIG_IOMMU_SVA
-	.pasid		= INVALID_IOASID,
+	.pasid		= IOMMU_PASID_INVALID,
 #endif
 	INIT_MM_CONTEXT(init_mm)
 };

Signature · 1 line

2.25.1

From: Jacob Pan <[email protected]>
Sent: Wednesday, February 15, 2023 1:05 AM

Hi Jean-Philippe,

Quoted 11 lines · Jean-Philippe Brucker

include/linux/iommu.h enum iommu_dev_features { · line 201

Quoted 7 lines · Jacob Pan

include/linux/iommu.h +7 -0

+typedef unsigned int ioasid_t;
+#ifdef CONFIG_IOMMU_SVA
+static inline bool pasid_valid(ioasid_t ioasid)
+{
+	return ioasid != IOMMU_PASID_INVALID;
+}
+#endif

This isn't specific to SVA, doesn't need an ifdef

until DMA API PASID support is in, this is SVA only? at least on x86?