1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * This file provides ECC correction for more than 1 bit per block of data,
15 #include <linux/mtd/nand-ecc-sw-bch.h>
18  * nand_ecc_sw_bch_calculate - Calculate the ECC corresponding to a data block
26 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_calculate()
29 	memset(code, 0, engine_conf->code_size);  in nand_ecc_sw_bch_calculate()
30 	bch_encode(engine_conf->bch, buf, nand->ecc.ctx.conf.step_size, code);  in nand_ecc_sw_bch_calculate()
33 	for (i = 0; i < engine_conf->code_size; i++)  in nand_ecc_sw_bch_calculate()
34 		code[i] ^= engine_conf->eccmask[i];  in nand_ecc_sw_bch_calculate()
41  * nand_ecc_sw_bch_correct - Detect, correct and report bit error(s)
52 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_correct()
53 	unsigned int step_size = nand->ecc.ctx.conf.step_size;  in nand_ecc_sw_bch_correct()
54 	unsigned int *errloc = engine_conf->errloc;  in nand_ecc_sw_bch_correct()
57 	count = bch_decode(engine_conf->bch, NULL, step_size, read_ecc,  in nand_ecc_sw_bch_correct()
62 				/* The error is in the data area: correct it */  in nand_ecc_sw_bch_correct()
65 			/* Otherwise the error is in the ECC area: nothing to do */  in nand_ecc_sw_bch_correct()
70 		pr_err("ECC unrecoverable error\n");  in nand_ecc_sw_bch_correct()
71 		count = -EBADMSG;  in nand_ecc_sw_bch_correct()
79  * nand_ecc_sw_bch_cleanup - Cleanup software BCH ECC resources
84 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_cleanup()
86 	bch_free(engine_conf->bch);  in nand_ecc_sw_bch_cleanup()
87 	kfree(engine_conf->errloc);  in nand_ecc_sw_bch_cleanup()
88 	kfree(engine_conf->eccmask);  in nand_ecc_sw_bch_cleanup()
92  * nand_ecc_sw_bch_init - Initialize software BCH ECC engine
97  * Initialize NAND BCH error correction. @nand.ecc parameters 'step_size' and
100  *     t, the error correction capability
102  * bits, where m is such that 2^m - 1 > step_size * 8.
104  * Example: to configure 4 bit correction per 512 bytes, you should pass
105  * step_size = 512 (thus, m = 13 is the smallest integer such that 2^m - 1 > 512 * 8)
110 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_init()
111 	unsigned int eccsize = nand->ecc.ctx.conf.step_size;  in nand_ecc_sw_bch_init()
112 	unsigned int eccbytes = engine_conf->code_size;  in nand_ecc_sw_bch_init()
120 	engine_conf->bch = bch_init(m, t, 0, false);  in nand_ecc_sw_bch_init()
121 	if (!engine_conf->bch)  in nand_ecc_sw_bch_init()
122 		return -EINVAL;  in nand_ecc_sw_bch_init()
124 	engine_conf->eccmask = kzalloc(eccbytes, GFP_KERNEL);  in nand_ecc_sw_bch_init()
125 	engine_conf->errloc = kmalloc_array(t, sizeof(*engine_conf->errloc),  in nand_ecc_sw_bch_init()
127 	if (!engine_conf->eccmask || !engine_conf->errloc) {  in nand_ecc_sw_bch_init()
128 		ret = -ENOMEM;  in nand_ecc_sw_bch_init()
135 		ret = -ENOMEM;  in nand_ecc_sw_bch_init()
140 	bch_encode(engine_conf->bch, erased_page, eccsize,  in nand_ecc_sw_bch_init()
141 		   engine_conf->eccmask);  in nand_ecc_sw_bch_init()
145 		engine_conf->eccmask[i] ^= 0xff;  in nand_ecc_sw_bch_init()
148 	if (engine_conf->bch->ecc_bytes != eccbytes) {  in nand_ecc_sw_bch_init()
150 		       eccbytes, engine_conf->bch->ecc_bytes);  in nand_ecc_sw_bch_init()
151 		ret = -EINVAL;  in nand_ecc_sw_bch_init()
158 		ret = -EINVAL;  in nand_ecc_sw_bch_init()
172 	struct nand_ecc_props *conf = &nand->ecc.ctx.conf;  in nand_ecc_sw_bch_init_ctx()
179 	if (mtd->oobsize < 64) {  in nand_ecc_sw_bch_init_ctx()
181 		return -EINVAL;  in nand_ecc_sw_bch_init_ctx()
184 	if (!mtd->ooblayout)  in nand_ecc_sw_bch_init_ctx()
187 	conf->engine_type = NAND_ECC_ENGINE_TYPE_SOFT;  in nand_ecc_sw_bch_init_ctx()
188 	conf->algo = NAND_ECC_ALGO_BCH;  in nand_ecc_sw_bch_init_ctx()
189 	conf->step_size = nand->ecc.user_conf.step_size;  in nand_ecc_sw_bch_init_ctx()
190 	conf->strength = nand->ecc.user_conf.strength;  in nand_ecc_sw_bch_init_ctx()
198 	if (!conf->step_size) {  in nand_ecc_sw_bch_init_ctx()
199 		if (mtd->oobsize >= 64)  in nand_ecc_sw_bch_init_ctx()
200 			conf->step_size = 512;  in nand_ecc_sw_bch_init_ctx()
202 			conf->step_size = 256;  in nand_ecc_sw_bch_init_ctx()
204 		conf->strength = 4;  in nand_ecc_sw_bch_init_ctx()
207 	nsteps = mtd->writesize / conf->step_size;  in nand_ecc_sw_bch_init_ctx()
210 	if (nand->ecc.user_conf.flags & NAND_ECC_MAXIMIZE_STRENGTH) {  in nand_ecc_sw_bch_init_ctx()
211 		conf->step_size = 1024;  in nand_ecc_sw_bch_init_ctx()
212 		nsteps = mtd->writesize / conf->step_size;  in nand_ecc_sw_bch_init_ctx()
214 		code_size = (mtd->oobsize - 2) / nsteps;  in nand_ecc_sw_bch_init_ctx()
215 		conf->strength = code_size * 8 / fls(8 * conf->step_size);  in nand_ecc_sw_bch_init_ctx()
219 		code_size = DIV_ROUND_UP(conf->strength *  in nand_ecc_sw_bch_init_ctx()
220 					 fls(8 * conf->step_size), 8);  in nand_ecc_sw_bch_init_ctx()
222 	if (!conf->strength)  in nand_ecc_sw_bch_init_ctx()
223 		conf->strength = (code_size * 8) / fls(8 * conf->step_size);  in nand_ecc_sw_bch_init_ctx()
225 	if (!code_size && !conf->strength) {  in nand_ecc_sw_bch_init_ctx()
227 		return -EINVAL;  in nand_ecc_sw_bch_init_ctx()
232 		return -ENOMEM;  in nand_ecc_sw_bch_init_ctx()
234 	ret = nand_ecc_init_req_tweaking(&engine_conf->req_ctx, nand);  in nand_ecc_sw_bch_init_ctx()
238 	engine_conf->code_size = code_size;  in nand_ecc_sw_bch_init_ctx()
239 	engine_conf->calc_buf = kzalloc(mtd->oobsize, GFP_KERNEL);  in nand_ecc_sw_bch_init_ctx()
240 	engine_conf->code_buf = kzalloc(mtd->oobsize, GFP_KERNEL);  in nand_ecc_sw_bch_init_ctx()
241 	if (!engine_conf->calc_buf || !engine_conf->code_buf) {  in nand_ecc_sw_bch_init_ctx()
242 		ret = -ENOMEM;  in nand_ecc_sw_bch_init_ctx()
246 	nand->ecc.ctx.priv = engine_conf;  in nand_ecc_sw_bch_init_ctx()
247 	nand->ecc.ctx.nsteps = nsteps;  in nand_ecc_sw_bch_init_ctx()
248 	nand->ecc.ctx.total = nsteps * code_size;  in nand_ecc_sw_bch_init_ctx()
256 	    nand->ecc.ctx.nsteps * engine_conf->code_size) {  in nand_ecc_sw_bch_init_ctx()
258 		ret = -EINVAL;  in nand_ecc_sw_bch_init_ctx()
267 	nand_ecc_cleanup_req_tweaking(&engine_conf->req_ctx);  in nand_ecc_sw_bch_init_ctx()
268 	kfree(engine_conf->calc_buf);  in nand_ecc_sw_bch_init_ctx()
269 	kfree(engine_conf->code_buf);  in nand_ecc_sw_bch_init_ctx()
279 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_cleanup_ctx()
283 		nand_ecc_cleanup_req_tweaking(&engine_conf->req_ctx);  in nand_ecc_sw_bch_cleanup_ctx()
284 		kfree(engine_conf->calc_buf);  in nand_ecc_sw_bch_cleanup_ctx()
285 		kfree(engine_conf->code_buf);  in nand_ecc_sw_bch_cleanup_ctx()
294 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_prepare_io_req()
296 	int eccsize = nand->ecc.ctx.conf.step_size;  in nand_ecc_sw_bch_prepare_io_req()
297 	int eccbytes = engine_conf->code_size;  in nand_ecc_sw_bch_prepare_io_req()
298 	int eccsteps = nand->ecc.ctx.nsteps;  in nand_ecc_sw_bch_prepare_io_req()
299 	int total = nand->ecc.ctx.total;  in nand_ecc_sw_bch_prepare_io_req()
300 	u8 *ecccalc = engine_conf->calc_buf;  in nand_ecc_sw_bch_prepare_io_req()
305 	if (req->mode == MTD_OPS_RAW)  in nand_ecc_sw_bch_prepare_io_req()
309 	if (!req->datalen)  in nand_ecc_sw_bch_prepare_io_req()
312 	nand_ecc_tweak_req(&engine_conf->req_ctx, req);  in nand_ecc_sw_bch_prepare_io_req()
315 	if (req->type == NAND_PAGE_READ)  in nand_ecc_sw_bch_prepare_io_req()
319 	for (i = 0, data = req->databuf.out;  in nand_ecc_sw_bch_prepare_io_req()
321 	     eccsteps--, i += eccbytes, data += eccsize)  in nand_ecc_sw_bch_prepare_io_req()
324 	return mtd_ooblayout_set_eccbytes(mtd, ecccalc, (void *)req->oobbuf.out,  in nand_ecc_sw_bch_prepare_io_req()
331 	struct nand_ecc_sw_bch_conf *engine_conf = nand->ecc.ctx.priv;  in nand_ecc_sw_bch_finish_io_req()
333 	int eccsize = nand->ecc.ctx.conf.step_size;  in nand_ecc_sw_bch_finish_io_req()
334 	int total = nand->ecc.ctx.total;  in nand_ecc_sw_bch_finish_io_req()
335 	int eccbytes = engine_conf->code_size;  in nand_ecc_sw_bch_finish_io_req()
336 	int eccsteps = nand->ecc.ctx.nsteps;  in nand_ecc_sw_bch_finish_io_req()
337 	u8 *ecccalc = engine_conf->calc_buf;  in nand_ecc_sw_bch_finish_io_req()
338 	u8 *ecccode = engine_conf->code_buf;  in nand_ecc_sw_bch_finish_io_req()
340 	u8 *data = req->databuf.in;  in nand_ecc_sw_bch_finish_io_req()
344 	if (req->mode == MTD_OPS_RAW)  in nand_ecc_sw_bch_finish_io_req()
348 	if (!req->datalen)  in nand_ecc_sw_bch_finish_io_req()
352 	if (req->type == NAND_PAGE_WRITE) {  in nand_ecc_sw_bch_finish_io_req()
353 		nand_ecc_restore_req(&engine_conf->req_ctx, req);  in nand_ecc_sw_bch_finish_io_req()
358 	ret = mtd_ooblayout_get_eccbytes(mtd, ecccode, req->oobbuf.in, 0,  in nand_ecc_sw_bch_finish_io_req()
364 	for (i = 0; eccsteps; eccsteps--, i += eccbytes, data += eccsize)  in nand_ecc_sw_bch_finish_io_req()
368 	for (eccsteps = nand->ecc.ctx.nsteps, i = 0, data = req->databuf.in;  in nand_ecc_sw_bch_finish_io_req()
370 	     eccsteps--, i += eccbytes, data += eccsize) {  in nand_ecc_sw_bch_finish_io_req()
375 			mtd->ecc_stats.failed++;  in nand_ecc_sw_bch_finish_io_req()
377 			mtd->ecc_stats.corrected += stat;  in nand_ecc_sw_bch_finish_io_req()
382 	nand_ecc_restore_req(&engine_conf->req_ctx, req);  in nand_ecc_sw_bch_finish_io_req()