[tip: x86/pasid] iommu/ioasid: Introduce a helper to check for valid PASIDs

[tip-bot2 for Fenghua Yu]

The following commit has been merged into the x86/pasid branch of tip:

Commit-ID:     7a5fbc9bcba5325a45297a4ba00091f39a63a1ed
Gitweb:        https://git.kernel.org/tip/7a5fbc9bcba5325a45297a4ba00091f39a63a1ed
Author:        Fenghua Yu <fenghua.yu@xxxxxxxxx>
AuthorDate:    Mon, 07 Feb 2022 15:02:46 -08:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Mon, 14 Feb 2022 19:41:39 +01:00

iommu/ioasid: Introduce a helper to check for valid PASIDs

Define a pasid_valid() helper to check if a given PASID is valid.

  [ bp: Massage commit message. ]

Suggested-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Suggested-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220207230254.3342514-4-fenghua.yu@xxxxxxxxx
---
 include/linux/ioasid.h |  9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h
index e9dacd4..2237f64 100644
--- a/include/linux/ioasid.h
+++ b/include/linux/ioasid.h
@@ -41,6 +41,10 @@ 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,
@@ -78,5 +82,10 @@ 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 */