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

Jacob Pan
2023-03-20T19:04:16Z

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