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ea31d5859f
The functionality is identical to the one currently open coded in device-dax. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
487 lines
12 KiB
C
487 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright(c) 2016-2018 Intel Corporation. All rights reserved. */
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#include <linux/memremap.h>
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#include <linux/pagemap.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/pfn_t.h>
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#include <linux/cdev.h>
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#include <linux/slab.h>
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#include <linux/dax.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include "dax-private.h"
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#include "bus.h"
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static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
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const char *func)
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{
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struct dax_region *dax_region = dev_dax->region;
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struct device *dev = &dev_dax->dev;
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unsigned long mask;
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if (!dax_alive(dev_dax->dax_dev))
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return -ENXIO;
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/* prevent private mappings from being established */
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if ((vma->vm_flags & VM_MAYSHARE) != VM_MAYSHARE) {
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dev_info_ratelimited(dev,
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"%s: %s: fail, attempted private mapping\n",
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current->comm, func);
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return -EINVAL;
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}
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mask = dax_region->align - 1;
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if (vma->vm_start & mask || vma->vm_end & mask) {
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dev_info_ratelimited(dev,
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"%s: %s: fail, unaligned vma (%#lx - %#lx, %#lx)\n",
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current->comm, func, vma->vm_start, vma->vm_end,
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mask);
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return -EINVAL;
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}
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if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) == PFN_DEV
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&& (vma->vm_flags & VM_DONTCOPY) == 0) {
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dev_info_ratelimited(dev,
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"%s: %s: fail, dax range requires MADV_DONTFORK\n",
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current->comm, func);
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return -EINVAL;
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}
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if (!vma_is_dax(vma)) {
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dev_info_ratelimited(dev,
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"%s: %s: fail, vma is not DAX capable\n",
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current->comm, func);
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return -EINVAL;
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}
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return 0;
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}
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/* see "strong" declaration in tools/testing/nvdimm/dax-dev.c */
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__weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
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unsigned long size)
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{
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struct resource *res = &dev_dax->region->res;
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phys_addr_t phys;
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phys = pgoff * PAGE_SIZE + res->start;
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if (phys >= res->start && phys <= res->end) {
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if (phys + size - 1 <= res->end)
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return phys;
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}
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return -1;
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}
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static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
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struct vm_fault *vmf, pfn_t *pfn)
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{
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struct device *dev = &dev_dax->dev;
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struct dax_region *dax_region;
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phys_addr_t phys;
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unsigned int fault_size = PAGE_SIZE;
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if (check_vma(dev_dax, vmf->vma, __func__))
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return VM_FAULT_SIGBUS;
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dax_region = dev_dax->region;
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if (dax_region->align > PAGE_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dax_region->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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if (fault_size != dax_region->align)
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return VM_FAULT_SIGBUS;
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phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE);
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if (phys == -1) {
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dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", vmf->pgoff);
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return VM_FAULT_SIGBUS;
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}
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*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
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return vmf_insert_mixed(vmf->vma, vmf->address, *pfn);
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}
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static vm_fault_t __dev_dax_pmd_fault(struct dev_dax *dev_dax,
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struct vm_fault *vmf, pfn_t *pfn)
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{
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unsigned long pmd_addr = vmf->address & PMD_MASK;
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struct device *dev = &dev_dax->dev;
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struct dax_region *dax_region;
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phys_addr_t phys;
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pgoff_t pgoff;
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unsigned int fault_size = PMD_SIZE;
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if (check_vma(dev_dax, vmf->vma, __func__))
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return VM_FAULT_SIGBUS;
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dax_region = dev_dax->region;
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if (dax_region->align > PMD_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dax_region->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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/* dax pmd mappings require pfn_t_devmap() */
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if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
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dev_dbg(dev, "region lacks devmap flags\n");
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return VM_FAULT_SIGBUS;
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}
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if (fault_size < dax_region->align)
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return VM_FAULT_SIGBUS;
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else if (fault_size > dax_region->align)
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return VM_FAULT_FALLBACK;
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/* if we are outside of the VMA */
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if (pmd_addr < vmf->vma->vm_start ||
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(pmd_addr + PMD_SIZE) > vmf->vma->vm_end)
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return VM_FAULT_SIGBUS;
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pgoff = linear_page_index(vmf->vma, pmd_addr);
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phys = dax_pgoff_to_phys(dev_dax, pgoff, PMD_SIZE);
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if (phys == -1) {
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dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", pgoff);
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return VM_FAULT_SIGBUS;
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}
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*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
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return vmf_insert_pfn_pmd(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
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}
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#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
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static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
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struct vm_fault *vmf, pfn_t *pfn)
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{
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unsigned long pud_addr = vmf->address & PUD_MASK;
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struct device *dev = &dev_dax->dev;
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struct dax_region *dax_region;
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phys_addr_t phys;
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pgoff_t pgoff;
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unsigned int fault_size = PUD_SIZE;
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if (check_vma(dev_dax, vmf->vma, __func__))
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return VM_FAULT_SIGBUS;
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dax_region = dev_dax->region;
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if (dax_region->align > PUD_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dax_region->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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/* dax pud mappings require pfn_t_devmap() */
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if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
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dev_dbg(dev, "region lacks devmap flags\n");
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return VM_FAULT_SIGBUS;
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}
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if (fault_size < dax_region->align)
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return VM_FAULT_SIGBUS;
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else if (fault_size > dax_region->align)
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return VM_FAULT_FALLBACK;
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/* if we are outside of the VMA */
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if (pud_addr < vmf->vma->vm_start ||
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(pud_addr + PUD_SIZE) > vmf->vma->vm_end)
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return VM_FAULT_SIGBUS;
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pgoff = linear_page_index(vmf->vma, pud_addr);
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phys = dax_pgoff_to_phys(dev_dax, pgoff, PUD_SIZE);
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if (phys == -1) {
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dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", pgoff);
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return VM_FAULT_SIGBUS;
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}
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*pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
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return vmf_insert_pfn_pud(vmf, *pfn, vmf->flags & FAULT_FLAG_WRITE);
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}
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#else
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static vm_fault_t __dev_dax_pud_fault(struct dev_dax *dev_dax,
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struct vm_fault *vmf, pfn_t *pfn)
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{
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return VM_FAULT_FALLBACK;
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}
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#endif /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
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static vm_fault_t dev_dax_huge_fault(struct vm_fault *vmf,
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enum page_entry_size pe_size)
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{
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struct file *filp = vmf->vma->vm_file;
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unsigned long fault_size;
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vm_fault_t rc = VM_FAULT_SIGBUS;
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int id;
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pfn_t pfn;
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struct dev_dax *dev_dax = filp->private_data;
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dev_dbg(&dev_dax->dev, "%s: %s (%#lx - %#lx) size = %d\n", current->comm,
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(vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read",
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vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
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id = dax_read_lock();
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switch (pe_size) {
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case PE_SIZE_PTE:
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fault_size = PAGE_SIZE;
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rc = __dev_dax_pte_fault(dev_dax, vmf, &pfn);
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break;
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case PE_SIZE_PMD:
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fault_size = PMD_SIZE;
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rc = __dev_dax_pmd_fault(dev_dax, vmf, &pfn);
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break;
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case PE_SIZE_PUD:
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fault_size = PUD_SIZE;
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rc = __dev_dax_pud_fault(dev_dax, vmf, &pfn);
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break;
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default:
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rc = VM_FAULT_SIGBUS;
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}
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if (rc == VM_FAULT_NOPAGE) {
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unsigned long i;
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pgoff_t pgoff;
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/*
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* In the device-dax case the only possibility for a
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* VM_FAULT_NOPAGE result is when device-dax capacity is
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* mapped. No need to consider the zero page, or racing
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* conflicting mappings.
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*/
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pgoff = linear_page_index(vmf->vma, vmf->address
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& ~(fault_size - 1));
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for (i = 0; i < fault_size / PAGE_SIZE; i++) {
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struct page *page;
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page = pfn_to_page(pfn_t_to_pfn(pfn) + i);
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if (page->mapping)
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continue;
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page->mapping = filp->f_mapping;
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page->index = pgoff + i;
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}
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}
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dax_read_unlock(id);
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return rc;
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}
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static vm_fault_t dev_dax_fault(struct vm_fault *vmf)
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{
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return dev_dax_huge_fault(vmf, PE_SIZE_PTE);
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}
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static int dev_dax_split(struct vm_area_struct *vma, unsigned long addr)
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{
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struct file *filp = vma->vm_file;
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struct dev_dax *dev_dax = filp->private_data;
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struct dax_region *dax_region = dev_dax->region;
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if (!IS_ALIGNED(addr, dax_region->align))
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return -EINVAL;
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return 0;
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}
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static unsigned long dev_dax_pagesize(struct vm_area_struct *vma)
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{
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struct file *filp = vma->vm_file;
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struct dev_dax *dev_dax = filp->private_data;
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struct dax_region *dax_region = dev_dax->region;
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return dax_region->align;
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}
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static const struct vm_operations_struct dax_vm_ops = {
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.fault = dev_dax_fault,
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.huge_fault = dev_dax_huge_fault,
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.split = dev_dax_split,
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.pagesize = dev_dax_pagesize,
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};
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static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
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{
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struct dev_dax *dev_dax = filp->private_data;
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int rc, id;
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dev_dbg(&dev_dax->dev, "trace\n");
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/*
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* We lock to check dax_dev liveness and will re-check at
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* fault time.
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*/
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id = dax_read_lock();
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rc = check_vma(dev_dax, vma, __func__);
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dax_read_unlock(id);
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if (rc)
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return rc;
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vma->vm_ops = &dax_vm_ops;
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vma->vm_flags |= VM_HUGEPAGE;
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return 0;
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}
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/* return an unmapped area aligned to the dax region specified alignment */
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static unsigned long dax_get_unmapped_area(struct file *filp,
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unsigned long addr, unsigned long len, unsigned long pgoff,
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unsigned long flags)
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{
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unsigned long off, off_end, off_align, len_align, addr_align, align;
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struct dev_dax *dev_dax = filp ? filp->private_data : NULL;
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struct dax_region *dax_region;
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if (!dev_dax || addr)
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goto out;
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dax_region = dev_dax->region;
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align = dax_region->align;
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off = pgoff << PAGE_SHIFT;
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off_end = off + len;
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off_align = round_up(off, align);
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if ((off_end <= off_align) || ((off_end - off_align) < align))
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goto out;
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len_align = len + align;
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if ((off + len_align) < off)
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goto out;
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addr_align = current->mm->get_unmapped_area(filp, addr, len_align,
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pgoff, flags);
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if (!IS_ERR_VALUE(addr_align)) {
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addr_align += (off - addr_align) & (align - 1);
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return addr_align;
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}
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out:
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return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
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}
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static const struct address_space_operations dev_dax_aops = {
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.set_page_dirty = noop_set_page_dirty,
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.invalidatepage = noop_invalidatepage,
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};
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static int dax_open(struct inode *inode, struct file *filp)
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{
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struct dax_device *dax_dev = inode_dax(inode);
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struct inode *__dax_inode = dax_inode(dax_dev);
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struct dev_dax *dev_dax = dax_get_private(dax_dev);
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dev_dbg(&dev_dax->dev, "trace\n");
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inode->i_mapping = __dax_inode->i_mapping;
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inode->i_mapping->host = __dax_inode;
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inode->i_mapping->a_ops = &dev_dax_aops;
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filp->f_mapping = inode->i_mapping;
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filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
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filp->private_data = dev_dax;
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inode->i_flags = S_DAX;
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return 0;
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}
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static int dax_release(struct inode *inode, struct file *filp)
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{
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struct dev_dax *dev_dax = filp->private_data;
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dev_dbg(&dev_dax->dev, "trace\n");
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return 0;
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}
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static const struct file_operations dax_fops = {
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.llseek = noop_llseek,
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.owner = THIS_MODULE,
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.open = dax_open,
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.release = dax_release,
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.get_unmapped_area = dax_get_unmapped_area,
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.mmap = dax_mmap,
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.mmap_supported_flags = MAP_SYNC,
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};
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static void dev_dax_cdev_del(void *cdev)
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{
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cdev_del(cdev);
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}
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static void dev_dax_kill(void *dev_dax)
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{
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kill_dev_dax(dev_dax);
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}
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int dev_dax_probe(struct device *dev)
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{
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struct dev_dax *dev_dax = to_dev_dax(dev);
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struct dax_device *dax_dev = dev_dax->dax_dev;
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struct resource *res = &dev_dax->region->res;
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struct inode *inode;
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struct cdev *cdev;
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void *addr;
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int rc;
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/* 1:1 map region resource range to device-dax instance range */
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if (!devm_request_mem_region(dev, res->start, resource_size(res),
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dev_name(dev))) {
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dev_warn(dev, "could not reserve region %pR\n", res);
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return -EBUSY;
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}
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dev_dax->pgmap.type = MEMORY_DEVICE_DEVDAX;
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addr = devm_memremap_pages(dev, &dev_dax->pgmap);
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if (IS_ERR(addr))
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return PTR_ERR(addr);
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inode = dax_inode(dax_dev);
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cdev = inode->i_cdev;
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cdev_init(cdev, &dax_fops);
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if (dev->class) {
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/* for the CONFIG_DEV_DAX_PMEM_COMPAT case */
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cdev->owner = dev->parent->driver->owner;
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} else
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cdev->owner = dev->driver->owner;
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cdev_set_parent(cdev, &dev->kobj);
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rc = cdev_add(cdev, dev->devt, 1);
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if (rc)
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return rc;
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rc = devm_add_action_or_reset(dev, dev_dax_cdev_del, cdev);
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if (rc)
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return rc;
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run_dax(dax_dev);
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return devm_add_action_or_reset(dev, dev_dax_kill, dev_dax);
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}
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EXPORT_SYMBOL_GPL(dev_dax_probe);
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static int dev_dax_remove(struct device *dev)
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{
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/* all probe actions are unwound by devm */
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return 0;
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}
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static struct dax_device_driver device_dax_driver = {
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.drv = {
|
|
.probe = dev_dax_probe,
|
|
.remove = dev_dax_remove,
|
|
},
|
|
.match_always = 1,
|
|
};
|
|
|
|
static int __init dax_init(void)
|
|
{
|
|
return dax_driver_register(&device_dax_driver);
|
|
}
|
|
|
|
static void __exit dax_exit(void)
|
|
{
|
|
dax_driver_unregister(&device_dax_driver);
|
|
}
|
|
|
|
MODULE_AUTHOR("Intel Corporation");
|
|
MODULE_LICENSE("GPL v2");
|
|
module_init(dax_init);
|
|
module_exit(dax_exit);
|
|
MODULE_ALIAS_DAX_DEVICE(0);
|