diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pgtable.h | 52 |
1 files changed, 44 insertions, 8 deletions
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index f1e890b60460..be1745839871 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1496,13 +1496,10 @@ static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, return 0; } -/* - * track_pfn_insert is called when a _new_ single pfn is established - * by vmf_insert_pfn(). - */ -static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, - pfn_t pfn) +static inline int pfnmap_setup_cachemode(unsigned long pfn, unsigned long size, + pgprot_t *prot) { + return 0; } /* @@ -1552,8 +1549,32 @@ static inline void untrack_pfn_clear(struct vm_area_struct *vma) extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, unsigned long pfn, unsigned long addr, unsigned long size); -extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, - pfn_t pfn); + +/** + * pfnmap_setup_cachemode - setup the cachemode in the pgprot for a pfn range + * @pfn: the start of the pfn range + * @size: the size of the pfn range in bytes + * @prot: the pgprot to modify + * + * Lookup the cachemode for the pfn range starting at @pfn with the size + * @size and store it in @prot, leaving other data in @prot unchanged. + * + * This allows for a hardware implementation to have fine-grained control of + * memory cache behavior at page level granularity. Without a hardware + * implementation, this function does nothing. + * + * Currently there is only one implementation for this - x86 Page Attribute + * Table (PAT). See Documentation/arch/x86/pat.rst for more details. + * + * This function can fail if the pfn range spans pfns that require differing + * cachemodes. If the pfn range was previously verified to have a single + * cachemode, it is sufficient to query only a single pfn. The assumption is + * that this is the case for drivers using the vmf_insert_pfn*() interface. + * + * Returns 0 on success and -EINVAL on error. + */ +int pfnmap_setup_cachemode(unsigned long pfn, unsigned long size, + pgprot_t *prot); extern int track_pfn_copy(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, unsigned long *pfn); extern void untrack_pfn_copy(struct vm_area_struct *dst_vma, @@ -1563,6 +1584,21 @@ extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, extern void untrack_pfn_clear(struct vm_area_struct *vma); #endif +/** + * pfnmap_setup_cachemode_pfn - setup the cachemode in the pgprot for a pfn + * @pfn: the pfn + * @prot: the pgprot to modify + * + * Lookup the cachemode for @pfn and store it in @prot, leaving other + * data in @prot unchanged. + * + * See pfnmap_setup_cachemode() for details. + */ +static inline void pfnmap_setup_cachemode_pfn(unsigned long pfn, pgprot_t *prot) +{ + pfnmap_setup_cachemode(pfn, PAGE_SIZE, prot); +} + #ifdef CONFIG_MMU #ifdef __HAVE_COLOR_ZERO_PAGE static inline int is_zero_pfn(unsigned long pfn) |