diff options
| author | Fenghua Yu <fenghua.yu@intel.com> | 2022-02-07 15:02:48 -0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-02-15 11:31:35 +0100 |
| commit | 701fac40384f07197b106136012804c3cae0b3de (patch) | |
| tree | 1637d8cc005e07c28f7357b8a6dd8c538c9f5967 /include/linux/ioasid.h | |
| parent | a6cbd44093ef305b02ad5f80ed54abf0148a696c (diff) | |
iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit
PASIDs are process-wide. It was attempted to use refcounted PASIDs to
free them when the last thread drops the refcount. This turned out to
be complex and error prone. Given the fact that the PASID space is 20
bits, which allows up to 1M processes to have a PASID associated
concurrently, PASID resource exhaustion is not a realistic concern.
Therefore, it was decided to simplify the approach and stick with lazy
on demand PASID allocation, but drop the eager free approach and make an
allocated PASID's lifetime bound to the lifetime of the process.
Get rid of the refcounting mechanisms and replace/rename the interfaces
to reflect this new approach.
[ bp: Massage commit message. ]
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20220207230254.3342514-6-fenghua.yu@intel.com
Diffstat (limited to 'include/linux/ioasid.h')
| -rw-r--r-- | include/linux/ioasid.h | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h index 2237f64dbaae..af1c9d62e642 100644 --- a/include/linux/ioasid.h +++ b/include/linux/ioasid.h @@ -34,8 +34,7 @@ struct ioasid_allocator_ops { #if IS_ENABLED(CONFIG_IOASID) ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, void *private); -void ioasid_get(ioasid_t ioasid); -bool ioasid_put(ioasid_t ioasid); +void ioasid_free(ioasid_t ioasid); void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)); int ioasid_register_allocator(struct ioasid_allocator_ops *allocator); @@ -53,14 +52,7 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, return INVALID_IOASID; } -static inline void ioasid_get(ioasid_t ioasid) -{ -} - -static inline bool ioasid_put(ioasid_t ioasid) -{ - return false; -} +static inline void ioasid_free(ioasid_t ioasid) { } static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)) |