From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 9 Nov 2018 15:39:20 -0500 In-Reply-To: <20181109203921.178363-1-brho@google.com> Message-Id: <20181109203921.178363-2-brho@google.com> Mime-Version: 1.0 References: <20181109203921.178363-1-brho@google.com> Subject: [PATCH 1/2] mm: make dev_pagemap_mapping_shift() externally visible From: Barret Rhoden Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org To: Dan Williams , Dave Jiang , Ross Zwisler , Vishal Verma , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Naoya Horiguchi Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, yu.c.zhang@intel.com, yi.z.zhang@intel.com, linux-mm@kvack.org List-ID: 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 --- 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 5411de93a363..51215d695753 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -935,6 +935,9 @@ static inline bool is_pci_p2pdma_page(const struct page *page) } #endif /* CONFIG_DEV_PAGEMAP_OPS */ +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 0cd3de3550f0..c3f2c6a8607e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -265,40 +265,6 @@ 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. @@ -329,7 +295,9 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, tk->addr = page_address_in_vma(p, vma); tk->addr_valid = 1; 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 = compound_order(compound_head(p)) + PAGE_SHIFT; diff --git a/mm/util.c b/mm/util.c index 8bf08b5b5760..61bc9bab931d 100644 --- a/mm/util.c +++ b/mm/util.c @@ -780,3 +780,37 @@ int get_cmdline(struct task_struct *task, char *buffer, int buflen) out: return res; } + +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); -- 2.19.1.930.g4563a0d9d0-goog