diff options
| -rw-r--r-- | arch/x86/mm/pat/memtype.c | 14 | ||||
| -rw-r--r-- | include/linux/pgtable.h | 39 | ||||
| -rw-r--r-- | mm/memremap.c | 8 |
3 files changed, 57 insertions, 4 deletions
diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c index fa78facc6f63..1ec8af6cad6b 100644 --- a/arch/x86/mm/pat/memtype.c +++ b/arch/x86/mm/pat/memtype.c @@ -1068,6 +1068,20 @@ int pfnmap_setup_cachemode(unsigned long pfn, unsigned long size, pgprot_t *prot return 0; } +int pfnmap_track(unsigned long pfn, unsigned long size, pgprot_t *prot) +{ + const resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT; + + return reserve_pfn_range(paddr, size, prot, 0); +} + +void pfnmap_untrack(unsigned long pfn, unsigned long size) +{ + const resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT; + + free_pfn_range(paddr, size); +} + /* * untrack_pfn is called while unmapping a pfnmap for a region. * untrack can be called for a specific region indicated by pfn and size or diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index be1745839871..90f72cd35839 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -1502,6 +1502,16 @@ static inline int pfnmap_setup_cachemode(unsigned long pfn, unsigned long size, return 0; } +static inline int pfnmap_track(unsigned long pfn, unsigned long size, + pgprot_t *prot) +{ + return 0; +} + +static inline void pfnmap_untrack(unsigned long pfn, unsigned long size) +{ +} + /* * track_pfn_copy is called when a VM_PFNMAP VMA is about to get the page * tables copied during copy_page_range(). Will store the pfn to be @@ -1575,6 +1585,35 @@ extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot, */ int pfnmap_setup_cachemode(unsigned long pfn, unsigned long size, pgprot_t *prot); + +/** + * pfnmap_track - track a pfn range + * @pfn: the start of the pfn range + * @size: the size of the pfn range in bytes + * @prot: the pgprot to track + * + * Requested the pfn range to be 'tracked' by a hardware implementation and + * setup the cachemode in @prot similar to pfnmap_setup_cachemode(). + * + * This allows for fine-grained control of memory cache behaviour at page + * level granularity. Tracking memory this way is persisted across VMA splits + * (VMA merging does not apply for VM_PFNMAP). + * + * Currently, there is only one implementation for this - x86 Page Attribute + * Table (PAT). See Documentation/arch/x86/pat.rst for more details. + * + * Returns 0 on success and -EINVAL on error. + */ +int pfnmap_track(unsigned long pfn, unsigned long size, pgprot_t *prot); + +/** + * pfnmap_untrack - untrack a pfn range + * @pfn: the start of the pfn range + * @size: the size of the pfn range in bytes + * + * Untrack a pfn range previously tracked through pfnmap_track(). + */ +void pfnmap_untrack(unsigned long pfn, unsigned long size); 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, diff --git a/mm/memremap.c b/mm/memremap.c index 2aebc1b192da..c417c843e9b1 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -130,7 +130,7 @@ static void pageunmap_range(struct dev_pagemap *pgmap, int range_id) } mem_hotplug_done(); - untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range), true); + pfnmap_untrack(PHYS_PFN(range->start), range_len(range)); pgmap_array_delete(range); } @@ -211,8 +211,8 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, if (nid < 0) nid = numa_mem_id(); - error = track_pfn_remap(NULL, ¶ms->pgprot, PHYS_PFN(range->start), 0, - range_len(range)); + error = pfnmap_track(PHYS_PFN(range->start), range_len(range), + ¶ms->pgprot); if (error) goto err_pfn_remap; @@ -277,7 +277,7 @@ err_add_memory: if (!is_private) kasan_remove_zero_shadow(__va(range->start), range_len(range)); err_kasan: - untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range), true); + pfnmap_untrack(PHYS_PFN(range->start), range_len(range)); err_pfn_remap: pgmap_array_delete(range); return error; |