LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Barret Rhoden <brho@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Dan Williams <dan.j.williams@intel.com>,
	David Hildenbrand <david@redhat.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: linux-nvdimm@lists.01.org, x86@kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, jason.zeng@intel.com
Subject: [PATCH v4 1/2] mm: make dev_pagemap_mapping_shift() externally visible
Date: Wed, 11 Dec 2019 16:32:06 -0500
Message-ID: <20191211213207.215936-2-brho@google.com> (raw)
In-Reply-To: <20191211213207.215936-1-brho@google.com>

KVM has a use case for determining the size of a dax mapping.  The KVM
code has easy access to the address and the mm; hence the change in
parameters.

Signed-off-by: Barret Rhoden <brho@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
---
 include/linux/mm.h  |  3 +++
 mm/memory-failure.c | 38 +++-----------------------------------
 mm/util.c           | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 35 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8b0ef04b6d15..f88bcc6a3bd1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -998,6 +998,9 @@ static inline bool is_pci_p2pdma_page(const struct page *page)
 #define page_ref_zero_or_close_to_overflow(page) \
 	((unsigned int) page_ref_count(page) + 127u <= 127u)
 
+unsigned long dev_pagemap_mapping_shift(unsigned long address,
+					struct mm_struct *mm);
+
 static inline void get_page(struct page *page)
 {
 	page = compound_head(page);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 41c634f45d45..9dc487e73d9b 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -261,40 +261,6 @@ void shake_page(struct page *p, int access)
 }
 EXPORT_SYMBOL_GPL(shake_page);
 
-static unsigned long dev_pagemap_mapping_shift(struct page *page,
-		struct vm_area_struct *vma)
-{
-	unsigned long address = vma_address(page, vma);
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *pte;
-
-	pgd = pgd_offset(vma->vm_mm, address);
-	if (!pgd_present(*pgd))
-		return 0;
-	p4d = p4d_offset(pgd, address);
-	if (!p4d_present(*p4d))
-		return 0;
-	pud = pud_offset(p4d, address);
-	if (!pud_present(*pud))
-		return 0;
-	if (pud_devmap(*pud))
-		return PUD_SHIFT;
-	pmd = pmd_offset(pud, address);
-	if (!pmd_present(*pmd))
-		return 0;
-	if (pmd_devmap(*pmd))
-		return PMD_SHIFT;
-	pte = pte_offset_map(pmd, address);
-	if (!pte_present(*pte))
-		return 0;
-	if (pte_devmap(*pte))
-		return PAGE_SHIFT;
-	return 0;
-}
-
 /*
  * Failure handling: if we can't find or can't kill a process there's
  * not much we can do.	We just print a message and ignore otherwise.
@@ -318,7 +284,9 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
 
 	tk->addr = page_address_in_vma(p, vma);
 	if (is_zone_device_page(p))
-		tk->size_shift = dev_pagemap_mapping_shift(p, vma);
+		tk->size_shift =
+			dev_pagemap_mapping_shift(vma_address(page, vma),
+						  vma->vm_mm);
 	else
 		tk->size_shift = page_shift(compound_head(p));
 
diff --git a/mm/util.c b/mm/util.c
index 988d11e6c17c..553fbe1692ed 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -911,3 +911,37 @@ int memcmp_pages(struct page *page1, struct page *page2)
 	kunmap_atomic(addr1);
 	return ret;
 }
+
+unsigned long dev_pagemap_mapping_shift(unsigned long address,
+					struct mm_struct *mm)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	pgd = pgd_offset(mm, address);
+	if (!pgd_present(*pgd))
+		return 0;
+	p4d = p4d_offset(pgd, address);
+	if (!p4d_present(*p4d))
+		return 0;
+	pud = pud_offset(p4d, address);
+	if (!pud_present(*pud))
+		return 0;
+	if (pud_devmap(*pud))
+		return PUD_SHIFT;
+	pmd = pmd_offset(pud, address);
+	if (!pmd_present(*pmd))
+		return 0;
+	if (pmd_devmap(*pmd))
+		return PMD_SHIFT;
+	pte = pte_offset_map(pmd, address);
+	if (!pte_present(*pte))
+		return 0;
+	if (pte_devmap(*pte))
+		return PAGE_SHIFT;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pagemap_mapping_shift);
-- 
2.24.0.525.g8f36a354ae-goog


  reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-11 21:32 [PATCH v4 0/2] kvm: Use huge pages for DAX-backed files Barret Rhoden
2019-12-11 21:32 ` Barret Rhoden [this message]
2019-12-11 21:32 ` [PATCH v4 2/2] " Barret Rhoden
2019-12-12  0:21   ` Paolo Bonzini
2019-12-12 12:22   ` David Hildenbrand
2019-12-12 16:31     ` Barret Rhoden
2019-12-12 12:33   ` Liran Alon
2019-12-12 16:54     ` Dan Williams
2019-12-12 17:39       ` Liran Alon
2019-12-12 17:59         ` Dan Williams
2019-12-12 18:32           ` Liran Alon
2019-12-12 17:03     ` Barret Rhoden
2019-12-12 17:34   ` Sean Christopherson
2019-12-12 17:37     ` Dan Williams
2019-12-12 19:16       ` Barret Rhoden
2019-12-12 19:48         ` Dan Williams
2019-12-12 20:08           ` Barret Rhoden
2019-12-12 17:45     ` Liran Alon
2019-12-12  0:22 ` [PATCH v4 0/2] " Paolo Bonzini

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191211213207.215936-2-brho@google.com \
    --to=brho@google.com \
    --cc=alexander.h.duyck@linux.intel.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.jiang@intel.com \
    --cc=david@redhat.com \
    --cc=jason.zeng@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nvdimm@lists.01.org \
    --cc=pbonzini@redhat.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git