mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-29 04:09:39 +00:00
701fac4038
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
83 lines
2.1 KiB
C
83 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __LINUX_IOASID_H
|
|
#define __LINUX_IOASID_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/errno.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);
|
|
|
|
struct ioasid_set {
|
|
int dummy;
|
|
};
|
|
|
|
/**
|
|
* struct ioasid_allocator_ops - IOASID allocator helper functions and data
|
|
*
|
|
* @alloc: helper function to allocate IOASID
|
|
* @free: helper function to free IOASID
|
|
* @list: for tracking ops that share helper functions but not data
|
|
* @pdata: data belong to the allocator, provided when calling alloc()
|
|
*/
|
|
struct ioasid_allocator_ops {
|
|
ioasid_alloc_fn_t alloc;
|
|
ioasid_free_fn_t free;
|
|
struct list_head list;
|
|
void *pdata;
|
|
};
|
|
|
|
#define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 }
|
|
|
|
#if IS_ENABLED(CONFIG_IOASID)
|
|
ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max,
|
|
void *private);
|
|
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);
|
|
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,
|
|
ioasid_t max, void *private)
|
|
{
|
|
return INVALID_IOASID;
|
|
}
|
|
|
|
static inline void ioasid_free(ioasid_t ioasid) { }
|
|
|
|
static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid,
|
|
bool (*getter)(void *))
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline int ioasid_register_allocator(struct ioasid_allocator_ops *allocator)
|
|
{
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
static inline void ioasid_unregister_allocator(struct ioasid_allocator_ops *allocator)
|
|
{
|
|
}
|
|
|
|
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 */
|