Commit 400b9b93 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Dave Hansen
Browse files

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: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230312112612.31869-11-kirill.shutemov%40linux.intel.com
parent f7d30434

arch/x86/kernel/traps.c

+3 −3
Original line number Diff line number Diff line
@@ -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.

drivers/iommu/iommu-sva.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

include/linux/ioasid.h

+0 −9
Original line number Diff line number Diff line
@@ -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 */

include/linux/sched/mm.h

+7 −1
Original line number Diff line number Diff line
@@ -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