iommu/sva: Replace pasid_valid() helper with mm_valid_pasid()

Kernel has few users of pasid_valid() and all but one checks if the
process has PASID allocated. The helper takes ioasid_t as the input.

Replace the helper with mm_valid_pasid() that takes mm_struct as the
argument. The only call that checks PASID that is not tied to mm_struct
is open-codded now.

This is preparatory patch. It helps avoid ifdeffery: no need to
dereference mm->pasid in generic code to check if the process has PASID.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230312112612.31869-11-kirill.shutemov%40linux.intel.com

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index d317dc3d06a3a3f018f83e0fedfe0c898017e0d5..8b83d8fbce718024e284d3eb991099f0c6e24638 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -671,15 +671,15 @@ static bool try_fixup_enqcmd_gp(void)
        if (!cpu_feature_enabled(X86_FEATURE_ENQCMD))
                return false;
 
-       pasid = current->mm->pasid;
-
        /*
         * If the mm has not been allocated a
         * PASID, the #GP can not be fixed up.
         */
-       if (!pasid_valid(pasid))
+       if (!mm_valid_pasid(current->mm))
                return false;
 
+       pasid = current->mm->pasid;
+
        /*
         * Did this thread already have its PASID activated?
         * If so, the #GP must be from something else.

diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 24bf9b2b58aa6d2c2b84f390290b1d9253994d8e..4ee2929f0d7a0c5e4cd3128bfa4c93c8d8f70e66 100644 (file)
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -34,14 +34,14 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
 
        mutex_lock(&iommu_sva_lock);
        /* Is a PASID already associated with this mm? */
-       if (pasid_valid(mm->pasid)) {
+       if (mm_valid_pasid(mm)) {
                if (mm->pasid < min || mm->pasid >= max)
                        ret = -EOVERFLOW;
                goto out;
        }
 
        pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
-       if (!pasid_valid(pasid))
+       if (pasid == INVALID_IOASID)
                ret = -ENOMEM;
        else
                mm_pasid_set(mm, pasid);

diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index af1c9d62e64281ee27d75e368b58ef24a453dfed..836ae09e92c2720bcc4a152dba15c57d8d38a04a 100644 (file)
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -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,
@@ -74,10 +70,5 @@ static inline int ioasid_set_data(ioasid_t ioasid, void *data)
        return -ENOTSUPP;
 }
 
-static inline bool pasid_valid(ioasid_t ioasid)
-{
-       return false;
-}
-
 #endif /* CONFIG_IOASID */
 #endif /* __LINUX_IOASID_H */

diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 2a243616f222d85b12f2a799d605c90ccea40fbd..b69fe7e8c0ac8e6e91dd1cc25979ffb27081fc42 100644 (file)
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -457,6 +457,11 @@ static inline void mm_pasid_init(struct mm_struct *mm)
        mm->pasid = INVALID_IOASID;
 }
 
+static inline bool mm_valid_pasid(struct mm_struct *mm)
+{
+       return mm->pasid != INVALID_IOASID;
+}
+
 /* Associate a PASID with an mm_struct: */
 static inline void mm_pasid_set(struct mm_struct *mm, u32 pasid)
 {
@@ -465,13 +470,14 @@ static inline void mm_pasid_set(struct mm_struct *mm, u32 pasid)
 
 static inline void mm_pasid_drop(struct mm_struct *mm)
 {
-       if (pasid_valid(mm->pasid)) {
+       if (mm_valid_pasid(mm)) {
                ioasid_free(mm->pasid);
                mm->pasid = INVALID_IOASID;
        }
 }
 #else
 static inline void mm_pasid_init(struct mm_struct *mm) {}
+static inline bool mm_valid_pasid(struct mm_struct *mm) { return false; }
 static inline void mm_pasid_set(struct mm_struct *mm, u32 pasid) {}
 static inline void mm_pasid_drop(struct mm_struct *mm) {}
 #endif