From: Dave Jiang Subject: [PATCH v2 3/3] dax: Support for transparent PUD pages for device DAX Date: Thu, 26 Jan 2017 10:10:00 -0700 Message-ID: <148545060002.17912.6765687780007547551.stgit@djiang5-desk3.ch.intel.com> References: <148545012634.17912.13951763606410303827.stgit@djiang5-desk3.ch.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: mawilcox-0li6OtcxBFHby3iVrkZq2A@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, dave.hansen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, linux-xfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, kirill.shutemov-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, jack-IBi9RG/b67k@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, vbabka-AlSwsSmVLrQ@public.gmane.org To: akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org Return-path: In-Reply-To: <148545012634.17912.13951763606410303827.stgit-Cxk7aZI4ujnJARH06PadV2t3HXsI98Cx0E9HWUfgJXw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org Adding transparent huge PUD pages support for device DAX by adding a pud_fault handler. Signed-off-by: Dave Jiang --- drivers/dax/dax.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index 922ec46..b90bb30 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/dax.c @@ -493,6 +493,51 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev, struct vm_fault *vmf) vmf->flags & FAULT_FLAG_WRITE); } +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf) +{ + unsigned long pud_addr = vmf->address & PUD_MASK; + struct device *dev = &dax_dev->dev; + struct dax_region *dax_region; + phys_addr_t phys; + pgoff_t pgoff; + pfn_t pfn; + + if (check_vma(dax_dev, vmf->vma, __func__)) + return VM_FAULT_SIGBUS; + + dax_region = dax_dev->region; + if (dax_region->align > PUD_SIZE) { + dev_dbg(dev, "%s: alignment > fault size\n", __func__); + return VM_FAULT_SIGBUS; + } + + /* dax pud mappings require pfn_t_devmap() */ + if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) { + dev_dbg(dev, "%s: alignment > fault size\n", __func__); + return VM_FAULT_SIGBUS; + } + + pgoff = linear_page_index(vmf->vma, pud_addr); + phys = pgoff_to_phys(dax_dev, pgoff, PUD_SIZE); + if (phys == -1) { + dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__, + pgoff); + return VM_FAULT_SIGBUS; + } + + pfn = phys_to_pfn_t(phys, dax_region->pfn_flags); + + return vmf_insert_pfn_pud(vmf->vma, vmf->address, vmf->pud, pfn, + vmf->flags & FAULT_FLAG_WRITE); +} +#else +static int __dax_dev_pud_fault(struct dax_dev *dax_dev, struct vm_fault *vmf) +{ + return VM_FAULT_FALLBACK; +} +#endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ + static int dax_dev_fault(struct vm_fault *vmf) { int rc; @@ -512,6 +557,9 @@ static int dax_dev_fault(struct vm_fault *vmf) case FAULT_FLAG_SIZE_PMD: rc = __dax_dev_pmd_fault(dax_dev, vmf); break; + case FAULT_FLAG_SIZE_PUD: + rc = __dax_dev_pud_fault(dax_dev, vmf); + break; default: return VM_FAULT_FALLBACK; }