495 lines
12 KiB
C
495 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 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 = dev_dax->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 (!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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int i;
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for (i = 0; i < dev_dax->nr_range; i++) {
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struct dev_dax_range *dax_range = &dev_dax->ranges[i];
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struct range *range = &dax_range->range;
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unsigned long long pgoff_end;
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phys_addr_t phys;
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pgoff_end = dax_range->pgoff + PHYS_PFN(range_len(range)) - 1;
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if (pgoff < dax_range->pgoff || pgoff > pgoff_end)
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continue;
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phys = PFN_PHYS(pgoff - dax_range->pgoff) + range->start;
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if (phys + size - 1 <= range->end)
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return phys;
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break;
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}
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return -1;
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}
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static void dax_set_mapping(struct vm_fault *vmf, pfn_t pfn,
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unsigned long fault_size)
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{
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unsigned long i, nr_pages = fault_size / PAGE_SIZE;
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struct file *filp = vmf->vma->vm_file;
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struct dev_dax *dev_dax = filp->private_data;
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pgoff_t pgoff;
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/* mapping is only set on the head */
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if (dev_dax->pgmap->vmemmap_shift)
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nr_pages = 1;
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pgoff = linear_page_index(vmf->vma,
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ALIGN(vmf->address, fault_size));
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for (i = 0; i < nr_pages; i++) {
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struct page *page = pfn_to_page(pfn_t_to_pfn(pfn) + i);
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page = compound_head(page);
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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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static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
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struct vm_fault *vmf)
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{
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struct device *dev = &dev_dax->dev;
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phys_addr_t phys;
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pfn_t pfn;
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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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if (dev_dax->align > PAGE_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dev_dax->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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if (fault_size != dev_dax->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, PFN_DEV|PFN_MAP);
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dax_set_mapping(vmf, pfn, fault_size);
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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)
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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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phys_addr_t phys;
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pgoff_t pgoff;
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pfn_t pfn;
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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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if (dev_dax->align > PMD_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dev_dax->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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if (fault_size < dev_dax->align)
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return VM_FAULT_SIGBUS;
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else if (fault_size > dev_dax->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, PFN_DEV|PFN_MAP);
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dax_set_mapping(vmf, pfn, fault_size);
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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)
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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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phys_addr_t phys;
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pgoff_t pgoff;
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pfn_t pfn;
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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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if (dev_dax->align > PUD_SIZE) {
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dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
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dev_dax->align, fault_size);
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return VM_FAULT_SIGBUS;
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}
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if (fault_size < dev_dax->align)
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return VM_FAULT_SIGBUS;
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else if (fault_size > dev_dax->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, PFN_DEV|PFN_MAP);
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dax_set_mapping(vmf, pfn, fault_size);
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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)
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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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vm_fault_t rc = VM_FAULT_SIGBUS;
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int id;
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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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rc = __dev_dax_pte_fault(dev_dax, vmf);
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break;
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case PE_SIZE_PMD:
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rc = __dev_dax_pmd_fault(dev_dax, vmf);
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break;
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case PE_SIZE_PUD:
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rc = __dev_dax_pud_fault(dev_dax, vmf);
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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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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_may_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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if (!IS_ALIGNED(addr, dev_dax->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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return dev_dax->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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.may_split = dev_dax_may_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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vm_flags_set(vma, 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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if (!dev_dax || addr)
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goto out;
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align = dev_dax->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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.dirty_folio = noop_dirty_folio,
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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->f_sb_err = file_sample_sb_err(filp);
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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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static int dev_dax_probe(struct dev_dax *dev_dax)
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{
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struct dax_device *dax_dev = dev_dax->dax_dev;
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struct device *dev = &dev_dax->dev;
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struct dev_pagemap *pgmap;
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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, i;
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if (static_dev_dax(dev_dax)) {
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if (dev_dax->nr_range > 1) {
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dev_warn(dev,
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"static pgmap / multi-range device conflict\n");
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return -EINVAL;
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}
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pgmap = dev_dax->pgmap;
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} else {
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if (dev_dax->pgmap) {
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dev_warn(dev,
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"dynamic-dax with pre-populated page map\n");
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return -EINVAL;
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}
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pgmap = devm_kzalloc(dev,
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struct_size(pgmap, ranges, dev_dax->nr_range - 1),
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GFP_KERNEL);
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if (!pgmap)
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return -ENOMEM;
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pgmap->nr_range = dev_dax->nr_range;
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dev_dax->pgmap = pgmap;
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for (i = 0; i < dev_dax->nr_range; i++) {
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struct range *range = &dev_dax->ranges[i].range;
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pgmap->ranges[i] = *range;
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}
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}
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for (i = 0; i < dev_dax->nr_range; i++) {
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struct range *range = &dev_dax->ranges[i].range;
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if (!devm_request_mem_region(dev, range->start,
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range_len(range), dev_name(dev))) {
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dev_warn(dev, "mapping%d: %#llx-%#llx could not reserve range\n",
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i, range->start, range->end);
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return -EBUSY;
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}
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}
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pgmap->type = MEMORY_DEVICE_GENERIC;
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if (dev_dax->align > PAGE_SIZE)
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pgmap->vmemmap_shift =
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order_base_2(dev_dax->align >> PAGE_SHIFT);
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addr = devm_memremap_pages(dev, 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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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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static struct dax_device_driver device_dax_driver = {
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.probe = dev_dax_probe,
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.type = DAXDRV_DEVICE_TYPE,
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};
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static int __init dax_init(void)
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{
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return dax_driver_register(&device_dax_driver);
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}
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static void __exit dax_exit(void)
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{
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dax_driver_unregister(&device_dax_driver);
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}
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MODULE_AUTHOR("Intel Corporation");
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MODULE_LICENSE("GPL v2");
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module_init(dax_init);
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module_exit(dax_exit);
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MODULE_ALIAS_DAX_DEVICE(0);
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