cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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pmem-dax.c (1280B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (c) 2014-2016, Intel Corporation.
      4 */
      5#include "test/nfit_test.h"
      6#include <linux/blkdev.h>
      7#include <linux/dax.h>
      8#include <pmem.h>
      9#include <nd.h>
     10
     11long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
     12		long nr_pages, enum dax_access_mode mode, void **kaddr,
     13		pfn_t *pfn)
     14{
     15	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
     16
     17	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
     18					PFN_PHYS(nr_pages))))
     19		return -EIO;
     20
     21	/*
     22	 * Limit dax to a single page at a time given vmalloc()-backed
     23	 * in the nfit_test case.
     24	 */
     25	if (get_nfit_res(pmem->phys_addr + offset)) {
     26		struct page *page;
     27
     28		if (kaddr)
     29			*kaddr = pmem->virt_addr + offset;
     30		page = vmalloc_to_page(pmem->virt_addr + offset);
     31		if (pfn)
     32			*pfn = page_to_pfn_t(page);
     33		pr_debug_ratelimited("%s: pmem: %p pgoff: %#lx pfn: %#lx\n",
     34				__func__, pmem, pgoff, page_to_pfn(page));
     35
     36		return 1;
     37	}
     38
     39	if (kaddr)
     40		*kaddr = pmem->virt_addr + offset;
     41	if (pfn)
     42		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
     43
     44	/*
     45	 * If badblocks are present, limit known good range to the
     46	 * requested range.
     47	 */
     48	if (unlikely(pmem->bb.count))
     49		return nr_pages;
     50	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
     51}