[PATCH 13/15] mm, dax: convert vmf_insert_pfn_pmd() to __pfn_t

From: Dan Williams
Date: Wed Sep 23 2015 - 00:48:26 EST


Similar to the conversion of vm_insert_mixed() use __pfn_t in the
vmf_insert_pfn_pmd() to tag the resulting pte with _PAGE_DEVICE when the
pfn is backed by a devm_memremap_pages() mapping.

Cc: Dave Hansen <dave@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
arch/sparc/include/asm/pgtable_64.h | 2 ++
arch/x86/include/asm/pgtable.h | 6 ++++++
arch/x86/mm/pat.c | 4 ++--
fs/dax.c | 2 +-
include/asm-generic/pgtable.h | 6 ++++--
include/linux/huge_mm.h | 2 +-
include/linux/mm.h | 27 +++++++++++++++++----------
include/linux/pfn.h | 9 +++++++++
mm/huge_memory.c | 10 ++++++----
mm/memory.c | 2 +-
10 files changed, 49 insertions(+), 21 deletions(-)

diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 131d36fcd07a..496ef783c68c 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -234,6 +234,7 @@ extern struct page *mem_map_zero;
* the first physical page in the machine is at some huge physical address,
* such as 4GB. This is common on a partitioned E10000, for example.
*/
+#define pfn_pte pfn_pte
static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
{
unsigned long paddr = pfn << PAGE_SHIFT;
@@ -244,6 +245,7 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define pfn_pmd pfn_pmd
static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
pte_t pte = pfn_pte(page_nr, pgprot);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 02a54e5b7930..84d1346e1cda 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -282,6 +282,11 @@ static inline pmd_t pmd_mkdirty(pmd_t pmd)
return pmd_set_flags(pmd, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
}

+static inline pmd_t pmd_mkdevmap(pmd_t pmd)
+{
+ return pmd_set_flags(pmd, _PAGE_DEVMAP);
+}
+
static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_PSE);
@@ -346,6 +351,7 @@ static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
massage_pgprot(pgprot));
}

+#define pfn_pmd pfn_pmd
static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
{
return __pmd(((phys_addr_t)page_nr << PAGE_SHIFT) |
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 188e3e07eeeb..2e02064dbe45 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -949,7 +949,7 @@ int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
}

int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
- unsigned long pfn)
+ __pfn_t pfn)
{
enum page_cache_mode pcm;

@@ -957,7 +957,7 @@ int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
return 0;

/* Set prot based on lookup */
- pcm = lookup_memtype((resource_size_t)pfn << PAGE_SHIFT);
+ pcm = lookup_memtype(__pfn_t_to_phys(pfn));
*prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) |
cachemode2protval(pcm));

diff --git a/fs/dax.c b/fs/dax.c
index b93dbf363dc2..321966335f33 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -681,7 +681,7 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address,
goto fallback;

result |= vmf_insert_pfn_pmd(vma, address, pmd,
- __pfn_t_to_pfn(pfn), write);
+ pfn, write);
}

out:
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 29c57b2cb344..a65f86061563 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -1,6 +1,8 @@
#ifndef _ASM_GENERIC_PGTABLE_H
#define _ASM_GENERIC_PGTABLE_H

+#include <linux/pfn.h>
+
#ifndef __ASSEMBLY__
#ifdef CONFIG_MMU

@@ -521,7 +523,7 @@ static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
* by vm_insert_pfn().
*/
static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
- unsigned long pfn)
+ __pfn_t pfn)
{
return 0;
}
@@ -549,7 +551,7 @@ extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long addr,
unsigned long size);
extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
- unsigned long pfn);
+ __pfn_t pfn);
extern int track_pfn_copy(struct vm_area_struct *vma);
extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
unsigned long size);
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index ecb080d6ff42..824eb98c53fc 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -34,7 +34,7 @@ extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, pgprot_t newprot,
int prot_numa);
int vmf_insert_pfn_pmd(struct vm_area_struct *, unsigned long addr, pmd_t *,
- unsigned long pfn, bool write);
+ __pfn_t pfn, bool write);

enum transparent_hugepage_flag {
TRANSPARENT_HUGEPAGE_FLAG,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 54fbeda5b896..989c5459bee7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -906,15 +906,6 @@ static inline void set_page_links(struct page *page, enum zone_type zone,
}

/*
- * __pfn_t: encapsulates a page-frame number that is optionally backed
- * by memmap (struct page). Whether a __pfn_t has a 'struct page'
- * backing is indicated by flags in the low bits of the value;
- */
-typedef struct {
- unsigned long val;
-} __pfn_t;
-
-/*
* PFN_SG_CHAIN - pfn is a pointer to the next scatterlist entry
* PFN_SG_LAST - pfn references a page and is the last scatterlist entry
* PFN_DEV - pfn is not covered by system memmap by default
@@ -989,7 +980,14 @@ static inline pte_t __pfn_t_pte(__pfn_t pfn, pgprot_t pgprot)
}
#endif

-#ifdef __HAVE_ARCH_PTE_DEVICE
+#ifdef pfn_pmd
+static inline pmd_t __pfn_t_pmd(__pfn_t pfn, pgprot_t pgprot)
+{
+ return pfn_pmd(__pfn_t_to_pfn(pfn), pgprot);
+}
+#endif
+
+#ifdef __HAVE_ARCH_PTE_DEVMAP
static inline bool __pfn_t_has_dev_pagemap(__pfn_t pfn)
{
const unsigned long flags = PFN_DEV|PFN_MAP;
@@ -1002,6 +1000,7 @@ static inline bool __pfn_t_has_dev_pagemap(__pfn_t pfn)
return false;
}
pte_t pte_mkdevmap(pte_t pte);
+pmd_t pmd_mkdevmap(pmd_t pmd);
#endif

/*
@@ -1767,6 +1766,14 @@ static inline void pgtable_pmd_page_dtor(struct page *page) {}

#endif

+#ifndef pmd_devmap
+#define pmd_devmap(x) (0)
+#endif
+
+#ifndef pte_devmap
+#define pte_devmap(x) (0)
+#endif
+
static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
{
spinlock_t *ptl = pmd_lockptr(mm, pmd);
diff --git a/include/linux/pfn.h b/include/linux/pfn.h
index 7646637221f3..ebe7b30ff912 100644
--- a/include/linux/pfn.h
+++ b/include/linux/pfn.h
@@ -3,6 +3,15 @@

#ifndef __ASSEMBLY__
#include <linux/types.h>
+
+/*
+ * __pfn_t: encapsulates a page-frame number that is optionally backed
+ * by memmap (struct page). Whether a __pfn_t has a 'struct page'
+ * backing is indicated by flags in the low bits of the value;
+ */
+typedef struct {
+ unsigned long val;
+} __pfn_t;
#endif

#define PFN_ALIGN(x) (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4b06b8db9df2..d8f01783ab88 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -870,7 +870,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
}

static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
- pmd_t *pmd, unsigned long pfn, pgprot_t prot, bool write)
+ pmd_t *pmd, __pfn_t pfn, pgprot_t prot, bool write)
{
struct mm_struct *mm = vma->vm_mm;
pmd_t entry;
@@ -878,7 +878,9 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,

ptl = pmd_lock(mm, pmd);
if (pmd_none(*pmd)) {
- entry = pmd_mkhuge(pfn_pmd(pfn, prot));
+ entry = pmd_mkhuge(__pfn_t_pmd(pfn, prot));
+ if (__pfn_t_has_dev_pagemap(pfn))
+ entry = pmd_mkdevmap(entry);
if (write) {
entry = pmd_mkyoung(pmd_mkdirty(entry));
entry = maybe_pmd_mkwrite(entry, vma);
@@ -890,7 +892,7 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
}

int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
- pmd_t *pmd, unsigned long pfn, bool write)
+ pmd_t *pmd, __pfn_t pfn, bool write)
{
pgprot_t pgprot = vma->vm_page_prot;
/*
@@ -902,7 +904,7 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
(VM_PFNMAP|VM_MIXEDMAP));
BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
- BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
+ BUG_ON((vma->vm_flags & VM_MIXEDMAP) && __pfn_t_valid(pfn));

if (addr < vma->vm_start || addr >= vma->vm_end)
return VM_FAULT_SIGBUS;
diff --git a/mm/memory.c b/mm/memory.c
index 6ec61c120289..2e178d8fdeba 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1583,7 +1583,7 @@ int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,

if (addr < vma->vm_start || addr >= vma->vm_end)
return -EFAULT;
- if (track_pfn_insert(vma, &pgprot, pfn))
+ if (track_pfn_insert(vma, &pgprot, pfn_to_pfn_t(pfn, PFN_DEV)))
return -EINVAL;

ret = insert_pfn(vma, addr, pfn_to_pfn_t(pfn, PFN_DEV), pgprot);

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