1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * asynchronous raid6 recovery self test
4 * Copyright (c) 2009, Intel Corporation.
5 *
6 * based on drivers/md/raid6test/test.c:
7 * 	Copyright 2002-2007 H. Peter Anvin
8 */
9#include <linux/async_tx.h>
10#include <linux/gfp.h>
11#include <linux/mm.h>
12#include <linux/random.h>
13#include <linux/module.h>
14
15#undef pr
16#define pr(fmt, args...) pr_info("raid6test: " fmt, ##args)
17
18#define NDISKS 64 /* Including P and Q */
19
20static struct page *dataptrs[NDISKS];
21unsigned int dataoffs[NDISKS];
22static addr_conv_t addr_conv[NDISKS];
23static struct page *data[NDISKS+3];
24static struct page *spare;
25static struct page *recovi;
26static struct page *recovj;
27
28static void callback(void *param)
29{
30	struct completion *cmp = param;
31
32	complete(cmp);
33}
34
35static void makedata(int disks)
36{
37	int i;
38
39	for (i = 0; i < disks; i++) {
40		get_random_bytes(page_address(data[i]), PAGE_SIZE);
41		dataptrs[i] = data[i];
42		dataoffs[i] = 0;
43	}
44}
45
46static char disk_type(int d, int disks)
47{
48	if (d == disks - 2)
49		return 'P';
50	else if (d == disks - 1)
51		return 'Q';
52	else
53		return 'D';
54}
55
56/* Recover two failed blocks. */
57static void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,
58		struct page **ptrs, unsigned int *offs)
59{
60	struct async_submit_ctl submit;
61	struct completion cmp;
62	struct dma_async_tx_descriptor *tx = NULL;
63	enum sum_check_flags result = ~0;
64
65	if (faila > failb)
66		swap(faila, failb);
67
68	if (failb == disks-1) {
69		if (faila == disks-2) {
70			/* P+Q failure.  Just rebuild the syndrome. */
71			init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);
72			tx = async_gen_syndrome(ptrs, offs,
73					disks, bytes, &submit);
74		} else {
75			struct page *blocks[NDISKS];
76			struct page *dest;
77			int count = 0;
78			int i;
79
80			BUG_ON(disks > NDISKS);
81
82			/* data+Q failure.  Reconstruct data from P,
83			 * then rebuild syndrome
84			 */
85			for (i = disks; i-- ; ) {
86				if (i == faila || i == failb)
87					continue;
88				blocks[count++] = ptrs[i];
89			}
90			dest = ptrs[faila];
91			init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL,
92					  NULL, NULL, addr_conv);
93			tx = async_xor(dest, blocks, 0, count, bytes, &submit);
94
95			init_async_submit(&submit, 0, tx, NULL, NULL, addr_conv);
96			tx = async_gen_syndrome(ptrs, offs,
97					disks, bytes, &submit);
98		}
99	} else {
100		if (failb == disks-2) {
101			/* data+P failure. */
102			init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);
103			tx = async_raid6_datap_recov(disks, bytes,
104					faila, ptrs, offs, &submit);
105		} else {
106			/* data+data failure. */
107			init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);
108			tx = async_raid6_2data_recov(disks, bytes,
109					faila, failb, ptrs, offs, &submit);
110		}
111	}
112	init_completion(&cmp);
113	init_async_submit(&submit, ASYNC_TX_ACK, tx, callback, &cmp, addr_conv);
114	tx = async_syndrome_val(ptrs, offs,
115			disks, bytes, &result, spare, 0, &submit);
116	async_tx_issue_pending(tx);
117
118	if (wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000)) == 0)
119		pr("%s: timeout! (faila: %d failb: %d disks: %d)\n",
120		   __func__, faila, failb, disks);
121
122	if (result != 0)
123		pr("%s: validation failure! faila: %d failb: %d sum_check_flags: %x\n",
124		   __func__, faila, failb, result);
125}
126
127static int test_disks(int i, int j, int disks)
128{
129	int erra, errb;
130
131	memset(page_address(recovi), 0xf0, PAGE_SIZE);
132	memset(page_address(recovj), 0xba, PAGE_SIZE);
133
134	dataptrs[i] = recovi;
135	dataptrs[j] = recovj;
136
137	raid6_dual_recov(disks, PAGE_SIZE, i, j, dataptrs, dataoffs);
138
139	erra = memcmp(page_address(data[i]), page_address(recovi), PAGE_SIZE);
140	errb = memcmp(page_address(data[j]), page_address(recovj), PAGE_SIZE);
141
142	pr("%s(%d, %d): faila=%3d(%c)  failb=%3d(%c)  %s\n",
143	   __func__, i, j, i, disk_type(i, disks), j, disk_type(j, disks),
144	   (!erra && !errb) ? "OK" : !erra ? "ERRB" : !errb ? "ERRA" : "ERRAB");
145
146	dataptrs[i] = data[i];
147	dataptrs[j] = data[j];
148
149	return erra || errb;
150}
151
152static int test(int disks, int *tests)
153{
154	struct dma_async_tx_descriptor *tx;
155	struct async_submit_ctl submit;
156	struct completion cmp;
157	int err = 0;
158	int i, j;
159
160	recovi = data[disks];
161	recovj = data[disks+1];
162	spare  = data[disks+2];
163
164	makedata(disks);
165
166	/* Nuke syndromes */
167	memset(page_address(data[disks-2]), 0xee, PAGE_SIZE);
168	memset(page_address(data[disks-1]), 0xee, PAGE_SIZE);
169
170	/* Generate assumed good syndrome */
171	init_completion(&cmp);
172	init_async_submit(&submit, ASYNC_TX_ACK, NULL, callback, &cmp, addr_conv);
173	tx = async_gen_syndrome(dataptrs, dataoffs, disks, PAGE_SIZE, &submit);
174	async_tx_issue_pending(tx);
175
176	if (wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000)) == 0) {
177		pr("error: initial gen_syndrome(%d) timed out\n", disks);
178		return 1;
179	}
180
181	pr("testing the %d-disk case...\n", disks);
182	for (i = 0; i < disks-1; i++)
183		for (j = i+1; j < disks; j++) {
184			(*tests)++;
185			err += test_disks(i, j, disks);
186		}
187
188	return err;
189}
190
191
192static int __init raid6_test(void)
193{
194	int err = 0;
195	int tests = 0;
196	int i;
197
198	for (i = 0; i < NDISKS+3; i++) {
199		data[i] = alloc_page(GFP_KERNEL);
200		if (!data[i]) {
201			while (i--)
202				put_page(data[i]);
203			return -ENOMEM;
204		}
205	}
206
207	/* the 4-disk and 5-disk cases are special for the recovery code */
208	if (NDISKS > 4)
209		err += test(4, &tests);
210	if (NDISKS > 5)
211		err += test(5, &tests);
212	/* the 11 and 12 disk cases are special for ioatdma (p-disabled
213	 * q-continuation without extended descriptor)
214	 */
215	if (NDISKS > 12) {
216		err += test(11, &tests);
217		err += test(12, &tests);
218	}
219
220	/* the 24 disk case is special for ioatdma as it is the boundary point
221	 * at which it needs to switch from 8-source ops to 16-source
222	 * ops for continuation (assumes DMA_HAS_PQ_CONTINUE is not set)
223	 */
224	if (NDISKS > 24)
225		err += test(24, &tests);
226
227	err += test(NDISKS, &tests);
228
229	pr("\n");
230	pr("complete (%d tests, %d failure%s)\n",
231	   tests, err, err == 1 ? "" : "s");
232
233	for (i = 0; i < NDISKS+3; i++)
234		put_page(data[i]);
235
236	return 0;
237}
238
239static void __exit raid6_test_exit(void)
240{
241}
242
243/* when compiled-in wait for drivers to load first (assumes dma drivers
244 * are also compiled-in)
245 */
246late_initcall(raid6_test);
247module_exit(raid6_test_exit);
248MODULE_AUTHOR("Dan Williams <dan.j.williams@intel.com>");
249MODULE_DESCRIPTION("asynchronous RAID-6 recovery self tests");
250MODULE_LICENSE("GPL");
251