public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-18 22:14:16 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

mm: convert track_pfn_insert() to pfnmap_setup_cachemode*()

Browse source 
...  by factoring it out from track_pfn_remap() into
pfnmap_setup_cachemode() and provide pfnmap_setup_cachemode_pfn() as a
replacement for track_pfn_insert().

For PMDs/PUDs, we keep checking a single pfn only.  Add some
documentation, and also document why it is valid to not check the whole
pfn range.

We'll reuse pfnmap_setup_cachemode() from core MM next.

Link: https://lkml.kernel.org/r/20250512123424.637989-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>	[x86 bits]
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Airlie <airlied@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Tvrtko Ursulin <tursulin@ursulin.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2025-05-12 14:34:15 +02:00 • committed by Andrew Morton
parent ed1a781403
commit e1e1a3ae7f
4 changed files with 57 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

24
arch/x86/mm/pat/memtype.c
View file

@ -1031,7 +1031,6 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long addr, unsigned long size)
{
resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT;
enum page_cache_mode pcm;
/* reserve the whole chunk starting from paddr */
if (!vma || (addr == vma->vm_start
@ -1044,13 +1043,17 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
return ret;
}
return pfnmap_setup_cachemode(pfn, size, prot);
}
int pfnmap_setup_cachemode(unsigned long pfn, unsigned long size, pgprot_t *prot)
{
resource_size_t paddr = (resource_size_t)pfn << PAGE_SHIFT;
enum page_cache_mode pcm;
if (!pat_enabled())
return 0;
/*
* For anything smaller than the vma size we set prot based on the
* lookup.
*/
pcm = lookup_memtype(paddr);
/* Check memtype for the remaining pages */
@ -1065,17 +1068,6 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
return 0;
}
void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot, pfn_t pfn)
{
enum page_cache_mode pcm;
if (!pat_enabled())
return;
pcm = lookup_memtype(pfn_t_to_phys(pfn));
pgprot_set_cachemode(prot, pcm);
}
/*
* 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

52
include/linux/pgtable.h
View file

@ -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)

5
mm/huge_memory.c
View file

@ -1455,7 +1455,8 @@ vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write)
return VM_FAULT_OOM;
}
track_pfn_insert(vma, &pgprot, pfn);
pfnmap_setup_cachemode_pfn(pfn_t_to_pfn(pfn), &pgprot);
ptl = pmd_lock(vma->vm_mm, vmf->pmd);
error = insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write,
pgtable);
@ -1577,7 +1578,7 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write)
if (addr < vma->vm_start || addr >= vma->vm_end)
return VM_FAULT_SIGBUS;
track_pfn_insert(vma, &pgprot, pfn);
pfnmap_setup_cachemode_pfn(pfn_t_to_pfn(pfn), &pgprot);
ptl = pud_lock(vma->vm_mm, vmf->pud);
insert_pfn_pud(vma, addr, vmf->pud, pfn, write);

4
mm/memory.c
View file

@ -2564,7 +2564,7 @@ vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
if (!pfn_modify_allowed(pfn, pgprot))
return VM_FAULT_SIGBUS;
track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV));
pfnmap_setup_cachemode_pfn(pfn, &pgprot);
return insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot,
false);
@ -2627,7 +2627,7 @@ static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
if (addr < vma->vm_start || addr >= vma->vm_end)
return VM_FAULT_SIGBUS;
track_pfn_insert(vma, &pgprot, pfn);
pfnmap_setup_cachemode_pfn(pfn_t_to_pfn(pfn), &pgprot);
if (!pfn_modify_allowed(pfn_t_to_pfn(pfn), pgprot))
return VM_FAULT_SIGBUS;