1 files changed, 99 insertions, 55 deletions

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 3b3ce2926f5d..53e16d39af4b 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -1093,28 +1093,32 @@ static int nand_fill_column_cycles(struct nand_chip *chip, u8 *addrs,
 				   unsigned int offset_in_page)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
+	bool ident_stage = !mtd->writesize;
 
-	/* Make sure the offset is less than the actual page size. */
-	if (offset_in_page > mtd->writesize + mtd->oobsize)
-		return -EINVAL;
+	/* Bypass all checks during NAND identification */
+	if (likely(!ident_stage)) {
+		/* Make sure the offset is less than the actual page size. */
+		if (offset_in_page > mtd->writesize + mtd->oobsize)
+			return -EINVAL;
 
-	/*
-	 * On small page NANDs, there's a dedicated command to access the OOB
-	 * area, and the column address is relative to the start of the OOB
-	 * area, not the start of the page. Asjust the address accordingly.
-	 */
-	if (mtd->writesize <= 512 && offset_in_page >= mtd->writesize)
-		offset_in_page -= mtd->writesize;
+		/*
+		 * On small page NANDs, there's a dedicated command to access the OOB
+		 * area, and the column address is relative to the start of the OOB
+		 * area, not the start of the page. Asjust the address accordingly.
+		 */
+		if (mtd->writesize <= 512 && offset_in_page >= mtd->writesize)
+			offset_in_page -= mtd->writesize;
 
-	/*
-	 * The offset in page is expressed in bytes, if the NAND bus is 16-bit
-	 * wide, then it must be divided by 2.
-	 */
-	if (chip->options & NAND_BUSWIDTH_16) {
-		if (WARN_ON(offset_in_page % 2))
-			return -EINVAL;
+		/*
+		 * The offset in page is expressed in bytes, if the NAND bus is 16-bit
+		 * wide, then it must be divided by 2.
+		 */
+		if (chip->options & NAND_BUSWIDTH_16) {
+			if (WARN_ON(offset_in_page % 2))
+				return -EINVAL;
 
-		offset_in_page /= 2;
+			offset_in_page /= 2;
+		}
 	}
 
 	addrs[0] = offset_in_page;
@@ -1123,7 +1127,7 @@ static int nand_fill_column_cycles(struct nand_chip *chip, u8 *addrs,
 	 * Small page NANDs use 1 cycle for the columns, while large page NANDs
 	 * need 2
 	 */
-	if (mtd->writesize <= 512)
+	if (!ident_stage && mtd->writesize <= 512)
 		return 1;
 
 	addrs[1] = offset_in_page >> 8;
@@ -1211,21 +1215,36 @@ static int nand_lp_exec_read_page_op(struct nand_chip *chip, unsigned int page,
 	return nand_exec_op(chip, &op);
 }
 
+static unsigned int rawnand_last_page_of_lun(unsigned int pages_per_lun, unsigned int lun)
+{
+	/* lun is expected to be very small */
+	return (lun * pages_per_lun) + pages_per_lun - 1;
+}
+
 static void rawnand_cap_cont_reads(struct nand_chip *chip)
 {
 	struct nand_memory_organization *memorg;
-	unsigned int pages_per_lun, first_lun, last_lun;
+	unsigned int ppl, first_lun, last_lun;
 
 	memorg = nanddev_get_memorg(&chip->base);
-	pages_per_lun = memorg->pages_per_eraseblock * memorg->eraseblocks_per_lun;
-	first_lun = chip->cont_read.first_page / pages_per_lun;
-	last_lun = chip->cont_read.last_page / pages_per_lun;
+	ppl = memorg->pages_per_eraseblock * memorg->eraseblocks_per_lun;
+	first_lun = chip->cont_read.first_page / ppl;
+	last_lun = chip->cont_read.last_page / ppl;
 
 	/* Prevent sequential cache reads across LUN boundaries */
 	if (first_lun != last_lun)
-		chip->cont_read.pause_page = first_lun * pages_per_lun + pages_per_lun - 1;
+		chip->cont_read.pause_page = rawnand_last_page_of_lun(ppl, first_lun);
 	else
 		chip->cont_read.pause_page = chip->cont_read.last_page;
+
+	if (chip->cont_read.first_page == chip->cont_read.pause_page) {
+		chip->cont_read.first_page++;
+		chip->cont_read.pause_page = min(chip->cont_read.last_page,
+						 rawnand_last_page_of_lun(ppl, first_lun + 1));
+	}
+
+	if (chip->cont_read.first_page >= chip->cont_read.last_page)
+		chip->cont_read.ongoing = false;
 }
 
 static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int page,
@@ -1292,12 +1311,11 @@ static int nand_lp_exec_cont_read_page_op(struct nand_chip *chip, unsigned int p
 	if (!chip->cont_read.ongoing)
 		return 0;
 
-	if (page == chip->cont_read.pause_page &&
-	    page != chip->cont_read.last_page) {
-		chip->cont_read.first_page = chip->cont_read.pause_page + 1;
-		rawnand_cap_cont_reads(chip);
-	} else if (page == chip->cont_read.last_page) {
+	if (page == chip->cont_read.last_page) {
 		chip->cont_read.ongoing = false;
+	} else if (page == chip->cont_read.pause_page) {
+		chip->cont_read.first_page++;
+		rawnand_cap_cont_reads(chip);
 	}
 
 	return 0;
@@ -1422,16 +1440,19 @@ int nand_change_read_column_op(struct nand_chip *chip,
 			       unsigned int len, bool force_8bit)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
+	bool ident_stage = !mtd->writesize;
 
 	if (len && !buf)
 		return -EINVAL;
 
-	if (offset_in_page + len > mtd->writesize + mtd->oobsize)
-		return -EINVAL;
+	if (!ident_stage) {
+		if (offset_in_page + len > mtd->writesize + mtd->oobsize)
+			return -EINVAL;
 
-	/* Small page NANDs do not support column change. */
-	if (mtd->writesize <= 512)
-		return -ENOTSUPP;
+		/* Small page NANDs do not support column change. */
+		if (mtd->writesize <= 512)
+			return -ENOTSUPP;
+	}
 
 	if (nand_has_exec_op(chip)) {
 		const struct nand_interface_config *conf =
@@ -2159,7 +2180,7 @@ EXPORT_SYMBOL_GPL(nand_reset_op);
 int nand_read_data_op(struct nand_chip *chip, void *buf, unsigned int len,
 		      bool force_8bit, bool check_only)
 {
-	if (!len || !buf)
+	if (!len || (!check_only && !buf))
 		return -EINVAL;
 
 	if (nand_has_exec_op(chip)) {
@@ -3466,30 +3487,36 @@ static void rawnand_enable_cont_reads(struct nand_chip *chip, unsigned int page,
 				      u32 readlen, int col)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
-	unsigned int end_page, end_col;
+	unsigned int first_page, last_page;
 
 	chip->cont_read.ongoing = false;
 
 	if (!chip->controller->supported_op.cont_read)
 		return;
 
-	end_page = DIV_ROUND_UP(col + readlen, mtd->writesize);
-	end_col = (col + readlen) % mtd->writesize;
+	/*
+	 * Don't bother making any calculations if the length is too small.
+	 * Side effect: avoids possible integer underflows below.
+	 */
+	if (readlen < (2 * mtd->writesize))
+		return;
 
+	/* Derive the page where continuous read should start (the first full page read) */
+	first_page = page;
 	if (col)
-		page++;
+		first_page++;
 
-	if (end_col && end_page)
-		end_page--;
+	/* Derive the page where continuous read should stop (the last full page read) */
+	last_page = page + ((col + readlen) / mtd->writesize) - 1;
 
-	if (page + 1 > end_page)
-		return;
-
-	chip->cont_read.first_page = page;
-	chip->cont_read.last_page = end_page;
-	chip->cont_read.ongoing = true;
-
-	rawnand_cap_cont_reads(chip);
+	/* Configure and enable continuous read when suitable */
+	if (first_page < last_page) {
+		chip->cont_read.first_page = first_page;
+		chip->cont_read.last_page = last_page;
+		chip->cont_read.ongoing = true;
+		/* May reset the ongoing flag */
+		rawnand_cap_cont_reads(chip);
+	}
 }
 
 static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned int page)
@@ -3498,10 +3525,7 @@ static void rawnand_cont_read_skip_first_page(struct nand_chip *chip, unsigned i
 		return;
 
 	chip->cont_read.first_page++;
-	if (chip->cont_read.first_page == chip->cont_read.pause_page)
-		chip->cont_read.first_page++;
-	if (chip->cont_read.first_page >= chip->cont_read.last_page)
-		chip->cont_read.ongoing = false;
+	rawnand_cap_cont_reads(chip);
 }
 
 /**
@@ -3577,7 +3601,8 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from,
 	oob = ops->oobbuf;
 	oob_required = oob ? 1 : 0;
 
-	rawnand_enable_cont_reads(chip, page, readlen, col);
+	if (likely(ops->mode != MTD_OPS_RAW))
+		rawnand_enable_cont_reads(chip, page, readlen, col);
 
 	while (1) {
 		struct mtd_ecc_stats ecc_stats = mtd->ecc_stats;
@@ -3710,6 +3735,9 @@ read_retry:
 	}
 	nand_deselect_target(chip);
 
+	if (WARN_ON_ONCE(chip->cont_read.ongoing))
+		chip->cont_read.ongoing = false;
+
 	ops->retlen = ops->len - (size_t) readlen;
 	if (oob)
 		ops->oobretlen = ops->ooblen - oobreadlen;
@@ -5195,6 +5223,15 @@ static void rawnand_late_check_supported_ops(struct nand_chip *chip)
 	if (!nand_has_exec_op(chip))
 		return;
 
+	/*
+	 * For now, continuous reads can only be used with the core page helpers.
+	 * This can be extended later.
+	 */
+	if (!(chip->ecc.read_page == nand_read_page_hwecc ||
+	      chip->ecc.read_page == nand_read_page_syndrome ||
+	      chip->ecc.read_page == nand_read_page_swecc))
+		return;
+
 	rawnand_check_cont_read_support(chip);
 }
 
@@ -6271,6 +6308,7 @@ static const struct nand_ops rawnand_ops = {
 static int nand_scan_tail(struct nand_chip *chip)
 {
 	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct nand_device *base = &chip->base;
 	struct nand_ecc_ctrl *ecc = &chip->ecc;
 	int ret, i;
 
@@ -6415,9 +6453,13 @@ static int nand_scan_tail(struct nand_chip *chip)
 	if (!ecc->write_oob_raw)
 		ecc->write_oob_raw = ecc->write_oob;
 
-	/* propagate ecc info to mtd_info */
+	/* Propagate ECC info to the generic NAND and MTD layers */
 	mtd->ecc_strength = ecc->strength;
+	if (!base->ecc.ctx.conf.strength)
+		base->ecc.ctx.conf.strength = ecc->strength;
 	mtd->ecc_step_size = ecc->size;
+	if (!base->ecc.ctx.conf.step_size)
+		base->ecc.ctx.conf.step_size = ecc->size;
 
 	/*
 	 * Set the number of read / write steps for one page depending on ECC
@@ -6425,6 +6467,8 @@ static int nand_scan_tail(struct nand_chip *chip)
 	 */
 	if (!ecc->steps)
 		ecc->steps = mtd->writesize / ecc->size;
+	if (!base->ecc.ctx.nsteps)
+		base->ecc.ctx.nsteps = ecc->steps;
 	if (ecc->steps * ecc->size != mtd->writesize) {
 		WARN(1, "Invalid ECC parameters\n");
 		ret = -EINVAL;