[PATCH v5 2/7] iommu/sva: Move PASID helpers to sva code

[Jacob Pan]

Preparing to remove IOASID infrastructure, PASID management will be
under SVA code. Decouple mm code from IOASID. Use iommu-help.h instead
of iommu.h to prevent circular inclusion.

Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
v5:
	- move definition of helpers to iommu code to be consistent with
	  declarations. (Kevin)
	- fix patch partitioning bug (Baolu)
v4:
	- delete and open code mm_set_pasid
	- keep mm_init_pasid() as inline for fork performance
---
 drivers/iommu/iommu-sva.c    | 10 +++++++++-
 include/linux/ioasid.h       |  2 +-
 include/linux/iommu-helper.h | 12 ++++++++++++
 include/linux/sched/mm.h     | 27 +--------------------------
 4 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 24bf9b2b58aa..fcfdc80a3939 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -44,7 +44,7 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 	if (!pasid_valid(pasid))
 		ret = -ENOMEM;
 	else
-		mm_pasid_set(mm, pasid);
+		mm->pasid = pasid;
 out:
 	mutex_unlock(&iommu_sva_lock);
 	return ret;
@@ -238,3 +238,11 @@ iommu_sva_handle_iopf(struct iommu_fault *fault, void *data)
 
 	return status;
 }
+
+void mm_pasid_drop(struct mm_struct *mm)
+{
+	if (pasid_valid(mm->pasid)) {
+		ioasid_free(mm->pasid);
+		mm->pasid = INVALID_IOASID;
+	}
+}
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index af1c9d62e642..2c502e77ee78 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -4,8 +4,8 @@
 
 #include <linux/types.h>
 #include <linux/errno.h>
+#include <linux/iommu-helper.h>
 
-#define INVALID_IOASID ((ioasid_t)-1)
 typedef unsigned int ioasid_t;
 typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t max, void *data);
 typedef void (*ioasid_free_fn_t)(ioasid_t ioasid, void *data);
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 74be34f3a20a..be1451a05a15 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -6,6 +6,7 @@
 #include <linux/log2.h>
 #include <linux/math.h>
 #include <linux/types.h>
+#include <linux/mm_types.h>
 
 static inline unsigned long iommu_device_max_index(unsigned long size,
 						   unsigned long offset,
@@ -41,4 +42,15 @@ static inline unsigned long iommu_num_pages(unsigned long addr,
 	return DIV_ROUND_UP(size, io_page_size);
 }
 
+#define INVALID_IOASID	(-1U)
+#ifdef CONFIG_IOMMU_SVA
+static inline void mm_pasid_init(struct mm_struct *mm)
+{
+	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_drop(struct mm_struct *mm) {}
+#endif
 #endif
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 2a243616f222..f341a7a855e8 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -8,7 +8,7 @@
 #include <linux/mm_types.h>
 #include <linux/gfp.h>
 #include <linux/sync_core.h>
-#include <linux/ioasid.h>
+#include <linux/iommu-helper.h>
 
 /*
  * Routines for handling mm_structs
@@ -451,29 +451,4 @@ static inline void membarrier_update_current_mm(struct mm_struct *next_mm)
 }
 #endif
 
-#ifdef CONFIG_IOMMU_SVA
-static inline void mm_pasid_init(struct mm_struct *mm)
-{
-	mm->pasid = INVALID_IOASID;
-}
-
-/* Associate a PASID with an mm_struct: */
-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;
-	}
-}
-#else
-static inline void mm_pasid_init(struct mm_struct *mm) {}
-static inline void mm_pasid_set(struct mm_struct *mm, u32 pasid) {}
-static inline void mm_pasid_drop(struct mm_struct *mm) {}
-#endif
-
 #endif /* _LINUX_SCHED_MM_H */
-- 
2.25.1