mtd: nand: Update to Linux-5.9

This updates the barebox NAND layer and parts of the mtd layer to
Linux-5.9.

This patch is huge, but the barebox NAND layer is so far away from the
Linux NAND layer that a step by step update would have taken ages.

Unlike Linux barebox has functions to mark a block as good. This feature
has been preserved. Also barebox used to make NAND write support
optional, this feature is lost during the update for the sake of better
compatibility to the Linux NAND layer.

This patch has been tested:

- GPMI aka nand_mxs on i.MX6
- nand_imx on i.MX25
- nand_omap_gpmc on AM335x
- atmel_nand on Atmel sama5d3
- nand_denali on SoCFPGA

Currently untested:

- nand_orion
- nand_mrvl_nfc
- nand_s3c24xx

The nand_denali driver is tested with the update of that driver to
Linux-5.9 following in the next patch.

I could only test the drivers with the NAND chips found on my boards, so
there's still enough room for regressions, especially given that the
NAND drivers themselves are mostly not updated. With the NAND layer
being up-to-date with Linux it should hopefully be easy to update
drivers to their Linux counterpart as well if necessary.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 132 insertions, 0 deletions

diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c
new file mode 100644
index 0000000000..172ab5ffbc
--- /dev/null
+++ b/drivers/mtd/nand/bbt.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2017 Free Electrons
+ *
+ * Authors:
+ *	Boris Brezillon <boris.brezillon@free-electrons.com>
+ *	Peter Pan <peterpandong@micron.com>
+ */
+
+#define pr_fmt(fmt)	"nand-bbt: " fmt
+
+#include <common.h>
+#include <linux/mtd/nand.h>
+#include <linux/slab.h>
+
+/**
+ * nanddev_bbt_init() - Initialize the BBT (Bad Block Table)
+ * @nand: NAND device
+ *
+ * Initialize the in-memory BBT.
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int nanddev_bbt_init(struct nand_device *nand)
+{
+	unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
+	unsigned int nblocks = nanddev_neraseblocks(nand);
+	unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block,
+					   BITS_PER_LONG);
+
+	nand->bbt.cache = kcalloc(nwords, sizeof(*nand->bbt.cache),
+				  GFP_KERNEL);
+	if (!nand->bbt.cache)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nanddev_bbt_init);
+
+/**
+ * nanddev_bbt_cleanup() - Cleanup the BBT (Bad Block Table)
+ * @nand: NAND device
+ *
+ * Undoes what has been done in nanddev_bbt_init()
+ */
+void nanddev_bbt_cleanup(struct nand_device *nand)
+{
+	kfree(nand->bbt.cache);
+}
+EXPORT_SYMBOL_GPL(nanddev_bbt_cleanup);
+
+/**
+ * nanddev_bbt_update() - Update a BBT
+ * @nand: nand device
+ *
+ * Update the BBT. Currently a NOP function since on-flash bbt is not yet
+ * supported.
+ *
+ * Return: 0 in case of success, a negative error code otherwise.
+ */
+int nanddev_bbt_update(struct nand_device *nand)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nanddev_bbt_update);
+
+/**
+ * nanddev_bbt_get_block_status() - Return the status of an eraseblock
+ * @nand: nand device
+ * @entry: the BBT entry
+ *
+ * Return: a positive number nand_bbt_block_status status or -%ERANGE if @entry
+ *	   is bigger than the BBT size.
+ */
+int nanddev_bbt_get_block_status(const struct nand_device *nand,
+				 unsigned int entry)
+{
+	unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
+	unsigned long *pos = nand->bbt.cache +
+			     ((entry * bits_per_block) / BITS_PER_LONG);
+	unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
+	unsigned long status;
+
+	if (entry >= nanddev_neraseblocks(nand))
+		return -ERANGE;
+
+	status = pos[0] >> offs;
+	if (bits_per_block + offs > BITS_PER_LONG)
+		status |= pos[1] << (BITS_PER_LONG - offs);
+
+	return status & GENMASK(bits_per_block - 1, 0);
+}
+EXPORT_SYMBOL_GPL(nanddev_bbt_get_block_status);
+
+/**
+ * nanddev_bbt_set_block_status() - Update the status of an eraseblock in the
+ *				    in-memory BBT
+ * @nand: nand device
+ * @entry: the BBT entry to update
+ * @status: the new status
+ *
+ * Update an entry of the in-memory BBT. If you want to push the updated BBT
+ * the NAND you should call nanddev_bbt_update().
+ *
+ * Return: 0 in case of success or -%ERANGE if @entry is bigger than the BBT
+ *	   size.
+ */
+int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
+				 enum nand_bbt_block_status status)
+{
+	unsigned int bits_per_block = fls(NAND_BBT_BLOCK_NUM_STATUS);
+	unsigned long *pos = nand->bbt.cache +
+			     ((entry * bits_per_block) / BITS_PER_LONG);
+	unsigned int offs = (entry * bits_per_block) % BITS_PER_LONG;
+	unsigned long val = status & GENMASK(bits_per_block - 1, 0);
+
+	if (entry >= nanddev_neraseblocks(nand))
+		return -ERANGE;
+
+	pos[0] &= ~GENMASK(offs + bits_per_block - 1, offs);
+	pos[0] |= val << offs;
+
+	if (bits_per_block + offs > BITS_PER_LONG) {
+		unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;
+
+		pos[1] &= ~GENMASK(rbits - 1, 0);
+		pos[1] |= val >> rbits;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nanddev_bbt_set_block_status);