xref: /openbmc/linux/tools/testing/nvdimm/pmem-dax.c (revision c4c3c32d)
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 
11 long __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 }
52