/* * Copyright (C) 2017 Free Electrons * Copyright (C) 2017 NextThing Co * * Author: Boris Brezillon * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include /* * Special Micron status bit 3 indicates that the block has been * corrected by on-die ECC and should be rewritten. */ #define NAND_ECC_STATUS_WRITE_RECOMMENDED BIT(3) /* * On chips with 8-bit ECC and additional bit can be used to distinguish * cases where a errors were corrected without needing a rewrite * * Bit 4 Bit 3 Bit 0 Description * ----- ----- ----- ----------- * 0 0 0 No Errors * 0 0 1 Multiple uncorrected errors * 0 1 0 4 - 6 errors corrected, recommend rewrite * 0 1 1 Reserved * 1 0 0 1 - 3 errors corrected * 1 0 1 Reserved * 1 1 0 7 - 8 errors corrected, recommend rewrite */ #define NAND_ECC_STATUS_MASK (BIT(4) | BIT(3) | BIT(0)) #define NAND_ECC_STATUS_UNCORRECTABLE BIT(0) #define NAND_ECC_STATUS_4_6_CORRECTED BIT(3) #define NAND_ECC_STATUS_1_3_CORRECTED BIT(4) #define NAND_ECC_STATUS_7_8_CORRECTED (BIT(4) | BIT(3)) struct nand_onfi_vendor_micron { u8 two_plane_read; u8 read_cache; u8 read_unique_id; u8 dq_imped; u8 dq_imped_num_settings; u8 dq_imped_feat_addr; u8 rb_pulldown_strength; u8 rb_pulldown_strength_feat_addr; u8 rb_pulldown_strength_num_settings; u8 otp_mode; u8 otp_page_start; u8 otp_data_prot_addr; u8 otp_num_pages; u8 otp_feat_addr; u8 read_retry_options; u8 reserved[72]; u8 param_revision; } __packed; struct micron_on_die_ecc { bool forced; bool enabled; void *rawbuf; }; struct micron_nand { struct micron_on_die_ecc ecc; }; static int micron_nand_setup_read_retry(struct mtd_info *mtd, int retry_mode) { struct nand_chip *chip = mtd_to_nand(mtd); u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = {retry_mode}; return nand_set_features(chip, ONFI_FEATURE_ADDR_READ_RETRY, feature); } /* * Configure chip properties from Micron vendor-specific ONFI table */ static int micron_nand_onfi_init(struct nand_chip *chip) { struct nand_parameters *p = &chip->parameters; if (p->onfi) { struct nand_onfi_vendor_micron *micron = (void *)p->onfi->vendor; chip->read_retries = micron->read_retry_options; chip->setup_read_retry = micron_nand_setup_read_retry; } if (p->supports_set_get_features) { set_bit(ONFI_FEATURE_ADDR_READ_RETRY, p->set_feature_list); set_bit(ONFI_FEATURE_ON_DIE_ECC, p->set_feature_list); set_bit(ONFI_FEATURE_ADDR_READ_RETRY, p->get_feature_list); set_bit(ONFI_FEATURE_ON_DIE_ECC, p->get_feature_list); } return 0; } static int micron_nand_on_die_4_ooblayout_ecc(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { if (section >= 4) return -ERANGE; oobregion->offset = (section * 16) + 8; oobregion->length = 8; return 0; } static int micron_nand_on_die_4_ooblayout_free(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { if (section >= 4) return -ERANGE; oobregion->offset = (section * 16) + 2; oobregion->length = 6; return 0; } static const struct mtd_ooblayout_ops micron_nand_on_die_4_ooblayout_ops = { .ecc = micron_nand_on_die_4_ooblayout_ecc, .free = micron_nand_on_die_4_ooblayout_free, }; static int micron_nand_on_die_8_ooblayout_ecc(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { struct nand_chip *chip = mtd_to_nand(mtd); if (section) return -ERANGE; oobregion->offset = mtd->oobsize - chip->ecc.total; oobregion->length = chip->ecc.total; return 0; } static int micron_nand_on_die_8_ooblayout_free(struct mtd_info *mtd, int section, struct mtd_oob_region *oobregion) { struct nand_chip *chip = mtd_to_nand(mtd); if (section) return -ERANGE; oobregion->offset = 2; oobregion->length = mtd->oobsize - chip->ecc.total - 2; return 0; } static const struct mtd_ooblayout_ops micron_nand_on_die_8_ooblayout_ops = { .ecc = micron_nand_on_die_8_ooblayout_ecc, .free = micron_nand_on_die_8_ooblayout_free, }; static int micron_nand_on_die_ecc_setup(struct nand_chip *chip, bool enable) { struct micron_nand *micron = nand_get_manufacturer_data(chip); u8 feature[ONFI_SUBFEATURE_PARAM_LEN] = { 0, }; int ret; if (micron->ecc.forced) return 0; if (micron->ecc.enabled == enable) return 0; if (enable) feature[0] |= ONFI_FEATURE_ON_DIE_ECC_EN; ret = nand_set_features(chip, ONFI_FEATURE_ON_DIE_ECC, feature); if (!ret) micron->ecc.enabled = enable; return ret; } static int micron_nand_on_die_ecc_status_4(struct nand_chip *chip, u8 status, void *buf, int page, int oob_required) { struct micron_nand *micron = nand_get_manufacturer_data(chip); struct mtd_info *mtd = nand_to_mtd(chip); unsigned int step, max_bitflips = 0; int ret; if (!(status & NAND_ECC_STATUS_WRITE_RECOMMENDED)) { if (status & NAND_STATUS_FAIL) mtd->ecc_stats.failed++; return 0; } /* * The internal ECC doesn't tell us the number of bitflips that have * been corrected, but tells us if it recommends to rewrite the block. * If it's the case, we need to read the page in raw mode and compare * its content to the corrected version to extract the actual number of * bitflips. * But before we do that, we must make sure we have all OOB bytes read * in non-raw mode, even if the user did not request those bytes. */ if (!oob_required) { ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize, false); if (ret) return ret; } micron_nand_on_die_ecc_setup(chip, false); ret = nand_read_page_op(chip, page, 0, micron->ecc.rawbuf, mtd->writesize + mtd->oobsize); if (ret) return ret; for (step = 0; step < chip->ecc.steps; step++) { unsigned int offs, i, nbitflips = 0; u8 *rawbuf, *corrbuf; offs = step * chip->ecc.size; rawbuf = micron->ecc.rawbuf + offs; corrbuf = buf + offs; for (i = 0; i < chip->ecc.size; i++) nbitflips += hweight8(corrbuf[i] ^ rawbuf[i]); offs = (step * 16) + 4; rawbuf = micron->ecc.rawbuf + mtd->writesize + offs; corrbuf = chip->oob_poi + offs; for (i = 0; i < chip->ecc.bytes + 4; i++) nbitflips += hweight8(corrbuf[i] ^ rawbuf[i]); if (WARN_ON(nbitflips > chip->ecc.strength)) return -EINVAL; max_bitflips = max(nbitflips, max_bitflips); mtd->ecc_stats.corrected += nbitflips; } return max_bitflips; } static int micron_nand_on_die_ecc_status_8(struct nand_chip *chip, u8 status) { struct mtd_info *mtd = nand_to_mtd(chip); /* * With 8/512 we have more information but still don't know precisely * how many bit-flips were seen. */ switch (status & NAND_ECC_STATUS_MASK) { case NAND_ECC_STATUS_UNCORRECTABLE: mtd->ecc_stats.failed++; return 0; case NAND_ECC_STATUS_1_3_CORRECTED: mtd->ecc_stats.corrected += 3; return 3; case NAND_ECC_STATUS_4_6_CORRECTED: mtd->ecc_stats.corrected += 6; /* rewrite recommended */ return 6; case NAND_ECC_STATUS_7_8_CORRECTED: mtd->ecc_stats.corrected += 8; /* rewrite recommended */ return 8; default: return 0; } } static int micron_nand_read_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip, uint8_t *buf, int oob_required, int page) { u8 status; int ret, max_bitflips = 0; ret = micron_nand_on_die_ecc_setup(chip, true); if (ret) return ret; ret = nand_read_page_op(chip, page, 0, NULL, 0); if (ret) goto out; ret = nand_status_op(chip, &status); if (ret) goto out; ret = nand_exit_status_op(chip); if (ret) goto out; ret = nand_read_data_op(chip, buf, mtd->writesize, false); if (!ret && oob_required) ret = nand_read_data_op(chip, chip->oob_poi, mtd->oobsize, false); if (chip->ecc.strength == 4) max_bitflips = micron_nand_on_die_ecc_status_4(chip, status, buf, page, oob_required); else max_bitflips = micron_nand_on_die_ecc_status_8(chip, status); out: micron_nand_on_die_ecc_setup(chip, false); return ret ? ret : max_bitflips; } static int micron_nand_write_page_on_die_ecc(struct mtd_info *mtd, struct nand_chip *chip, const uint8_t *buf, int oob_required, int page) { int ret; ret = micron_nand_on_die_ecc_setup(chip, true); if (ret) return ret; ret = nand_write_page_raw(mtd, chip, buf, oob_required, page); micron_nand_on_die_ecc_setup(chip, false); return ret; } enum { /* The NAND flash doesn't support on-die ECC */ MICRON_ON_DIE_UNSUPPORTED, /* * The NAND flash supports on-die ECC and it can be * enabled/disabled by a set features command. */ MICRON_ON_DIE_SUPPORTED, /* * The NAND flash supports on-die ECC, and it cannot be * disabled. */ MICRON_ON_DIE_MANDATORY, }; #define MICRON_ID_INTERNAL_ECC_MASK GENMASK(1, 0) #define MICRON_ID_ECC_ENABLED BIT(7) /* * Try to detect if the NAND support on-die ECC. To do this, we enable * the feature, and read back if it has been enabled as expected. We * also check if it can be disabled, because some Micron NANDs do not * allow disabling the on-die ECC and we don't support such NANDs for * now. * * This function also has the side effect of disabling on-die ECC if * it had been left enabled by the firmware/bootloader. */ static int micron_supports_on_die_ecc(struct nand_chip *chip) { u8 id[5]; int ret; if (!chip->parameters.onfi) return MICRON_ON_DIE_UNSUPPORTED; if (chip->bits_per_cell != 1) return MICRON_ON_DIE_UNSUPPORTED; /* * We only support on-die ECC of 4/512 or 8/512 */ if (chip->ecc_strength_ds != 4 && chip->ecc_strength_ds != 8) return MICRON_ON_DIE_UNSUPPORTED; /* 0x2 means on-die ECC is available. */ if (chip->id.len != 5 || (chip->id.data[4] & MICRON_ID_INTERNAL_ECC_MASK) != 0x2) return MICRON_ON_DIE_UNSUPPORTED; /* * It seems that there are devices which do not support ECC officially. * At least the MT29F2G08ABAGA / MT29F2G08ABBGA devices supports * enabling the ECC feature but don't reflect that to the READ_ID table. * So we have to guarantee that we disable the ECC feature directly * after we did the READ_ID table command. Later we can evaluate the * ECC_ENABLE support. */ ret = micron_nand_on_die_ecc_setup(chip, true); if (ret) return MICRON_ON_DIE_UNSUPPORTED; ret = nand_readid_op(chip, 0, id, sizeof(id)); if (ret) return MICRON_ON_DIE_UNSUPPORTED; ret = micron_nand_on_die_ecc_setup(chip, false); if (ret) return MICRON_ON_DIE_UNSUPPORTED; if (!(id[4] & MICRON_ID_ECC_ENABLED)) return MICRON_ON_DIE_UNSUPPORTED; ret = nand_readid_op(chip, 0, id, sizeof(id)); if (ret) return MICRON_ON_DIE_UNSUPPORTED; if (id[4] & MICRON_ID_ECC_ENABLED) return MICRON_ON_DIE_MANDATORY; /* * We only support on-die ECC of 4/512 or 8/512 */ if (chip->ecc_strength_ds != 4 && chip->ecc_strength_ds != 8) return MICRON_ON_DIE_UNSUPPORTED; return MICRON_ON_DIE_SUPPORTED; } static int micron_nand_init(struct nand_chip *chip) { struct mtd_info *mtd = nand_to_mtd(chip); struct micron_nand *micron; int ondie; int ret; micron = kzalloc(sizeof(*micron), GFP_KERNEL); if (!micron) return -ENOMEM; nand_set_manufacturer_data(chip, micron); ret = micron_nand_onfi_init(chip); if (ret) goto err_free_manuf_data; if (mtd->writesize == 2048) chip->bbt_options |= NAND_BBT_SCAN2NDPAGE; ondie = micron_supports_on_die_ecc(chip); if (ondie == MICRON_ON_DIE_MANDATORY && chip->ecc.mode != NAND_ECC_ON_DIE) { pr_err("On-die ECC forcefully enabled, not supported\n"); ret = -EINVAL; goto err_free_manuf_data; } if (chip->ecc.mode == NAND_ECC_ON_DIE) { if (ondie == MICRON_ON_DIE_UNSUPPORTED) { pr_err("On-die ECC selected but not supported\n"); ret = -EINVAL; goto err_free_manuf_data; } if (ondie == MICRON_ON_DIE_MANDATORY) { micron->ecc.forced = true; micron->ecc.enabled = true; } /* * In case of 4bit on-die ECC, we need a buffer to store a * page dumped in raw mode so that we can compare its content * to the same page after ECC correction happened and extract * the real number of bitflips from this comparison. * That's not needed for 8-bit ECC, because the status expose * a better approximation of the number of bitflips in a page. */ if (chip->ecc_strength_ds == 4) { micron->ecc.rawbuf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL); if (!micron->ecc.rawbuf) { ret = -ENOMEM; goto err_free_manuf_data; } } if (chip->ecc_strength_ds == 4) mtd_set_ooblayout(mtd, µn_nand_on_die_4_ooblayout_ops); else mtd_set_ooblayout(mtd, µn_nand_on_die_8_ooblayout_ops); chip->ecc.bytes = chip->ecc_strength_ds * 2; chip->ecc.size = 512; chip->ecc.strength = chip->ecc_strength_ds; chip->ecc.algo = NAND_ECC_BCH; chip->ecc.read_page = micron_nand_read_page_on_die_ecc; chip->ecc.write_page = micron_nand_write_page_on_die_ecc; if (ondie == MICRON_ON_DIE_MANDATORY) { chip->ecc.read_page_raw = nand_read_page_raw_notsupp; chip->ecc.write_page_raw = nand_write_page_raw_notsupp; } else { chip->ecc.read_page_raw = nand_read_page_raw; chip->ecc.write_page_raw = nand_write_page_raw; } } return 0; err_free_manuf_data: kfree(micron->ecc.rawbuf); kfree(micron); return ret; } static void micron_nand_cleanup(struct nand_chip *chip) { struct micron_nand *micron = nand_get_manufacturer_data(chip); kfree(micron->ecc.rawbuf); kfree(micron); } static void micron_fixup_onfi_param_page(struct nand_chip *chip, struct nand_onfi_params *p) { /* * MT29F1G08ABAFAWP-ITE:F and possibly others report 00 00 for the * revision number field of the ONFI parameter page. Assume ONFI * version 1.0 if the revision number is 00 00. */ if (le16_to_cpu(p->revision) == 0) p->revision = cpu_to_le16(ONFI_VERSION_1_0); } const struct nand_manufacturer_ops micron_nand_manuf_ops = { .init = micron_nand_init, .cleanup = micron_nand_cleanup, .fixup_onfi_param_page = micron_fixup_onfi_param_page, };