xref: /openbmc/linux/tools/testing/nvdimm/pmem-dax.c (revision 09c434b8)
1 /*
2  * Copyright (c) 2014-2016, Intel Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  */
13 #include "test/nfit_test.h"
14 #include <linux/blkdev.h>
15 #include <pmem.h>
16 #include <nd.h>
17 
18 long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
19 		long nr_pages, void **kaddr, pfn_t *pfn)
20 {
21 	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
22 
23 	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
24 					PFN_PHYS(nr_pages))))
25 		return -EIO;
26 
27 	/*
28 	 * Limit dax to a single page at a time given vmalloc()-backed
29 	 * in the nfit_test case.
30 	 */
31 	if (get_nfit_res(pmem->phys_addr + offset)) {
32 		struct page *page;
33 
34 		if (kaddr)
35 			*kaddr = pmem->virt_addr + offset;
36 		page = vmalloc_to_page(pmem->virt_addr + offset);
37 		if (pfn)
38 			*pfn = page_to_pfn_t(page);
39 		pr_debug_ratelimited("%s: pmem: %p pgoff: %#lx pfn: %#lx\n",
40 				__func__, pmem, pgoff, page_to_pfn(page));
41 
42 		return 1;
43 	}
44 
45 	if (kaddr)
46 		*kaddr = pmem->virt_addr + offset;
47 	if (pfn)
48 		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
49 
50 	/*
51 	 * If badblocks are present, limit known good range to the
52 	 * requested range.
53 	 */
54 	if (unlikely(pmem->bb.count))
55 		return nr_pages;
56 	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
57 }
58