[PATCH v7 2/7] iommu/sva: Move PASID helpers to sva code

[Jacob Pan <jacob.jun.pan@linux.intel.com>]

Preparing to remove IOASID infrastructure, PASID management will be
under SVA code. Decouple mm code from IOASID.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
v7:
	- use CONFIG_IOMMU_SVA around PASID helpers in fork.c, Fixes a
	compile problem.
v6:
	- put helpers under iommu.h instead of iommu-helper.h
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    |  6 +-----
 include/linux/iommu.h     | 14 +++++++++++++-
 include/linux/sched/mm.h  | 26 --------------------------
 kernel/fork.c             |  5 +++++
 5 files changed, 28 insertions(+), 33 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..bdee937da907 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.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);
@@ -40,10 +40,6 @@ void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
 int ioasid_register_allocator(struct ioasid_allocator_ops *allocator);
 void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator);
 int ioasid_set_data(ioasid_t ioasid, void *data);
-static inline bool pasid_valid(ioasid_t ioasid)
-{
-	return ioasid != INVALID_IOASID;
-}
 
 #else /* !CONFIG_IOASID */
 static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 6595454d4f48..d3f81dc6e4dd 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -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)
@@ -192,6 +191,8 @@ enum iommu_dev_features {
 };
 
 #define IOMMU_PASID_INVALID	(-1U)
+typedef unsigned int ioasid_t;
+#define INVALID_IOASID ((ioasid_t)-1)
 
 #ifdef CONFIG_IOMMU_API
 
@@ -1172,7 +1173,16 @@ static inline bool tegra_dev_iommu_get_stream_id(struct device *dev, u32 *stream
 	return false;
 }
 
+static inline bool pasid_valid(ioasid_t ioasid)
+{
+	return ioasid != INVALID_IOASID;
+}
 #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);
 struct iommu_sva *iommu_sva_bind_device(struct device *dev,
 					struct mm_struct *mm);
 void iommu_sva_unbind_device(struct iommu_sva *handle);
@@ -1192,6 +1202,8 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle)
 {
 	return IOMMU_PASID_INVALID;
 }
+static inline void mm_pasid_init(struct mm_struct *mm) {}
+static inline void mm_pasid_drop(struct mm_struct *mm) {}
 #endif /* CONFIG_IOMMU_SVA */
 
 #endif /* __LINUX_IOMMU_H */
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 2a243616f222..da9712a3ba73 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -8,7 +8,6 @@
 #include <linux/mm_types.h>
 #include <linux/gfp.h>
 #include <linux/sync_core.h>
-#include <linux/ioasid.h>
 
 /*
  * Routines for handling mm_structs
@@ -451,29 +450,4 @@ 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 */
diff --git a/kernel/fork.c b/kernel/fork.c
index f68954d05e89..a53be375a2dd 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -97,6 +97,7 @@
 #include <linux/io_uring.h>
 #include <linux/bpf.h>
 #include <linux/stackprotector.h>
+#include <linux/iommu.h>
 
 #include <asm/pgalloc.h>
 #include <linux/uaccess.h>
@@ -794,7 +795,9 @@ void __mmdrop(struct mm_struct *mm)
 	mmu_notifier_subscriptions_destroy(mm);
 	check_mm(mm);
 	put_user_ns(mm->user_ns);
+#ifdef CONFIG_IOMMU_SVA	
 	mm_pasid_drop(mm);
+#endif
 
 	for (i = 0; i < NR_MM_COUNTERS; i++)
 		percpu_counter_destroy(&mm->rss_stat[i]);
@@ -1140,7 +1143,9 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 	mm_init_cpumask(mm);
 	mm_init_aio(mm);
 	mm_init_owner(mm, p);
+#ifdef CONFIG_IOMMU_SVA	
 	mm_pasid_init(mm);
+#endif
 	RCU_INIT_POINTER(mm->exe_file, NULL);
 	mmu_notifier_subscriptions_init(mm);
 	init_tlb_flush_pending(mm);
-- 
2.25.1