[PATCH 3.16 011/366] Revert "mtd: nand: omap2: Fix subpage write"

Ben Hutchings
2018-11-11T20:43:00Z

From: Ben Hutchings <ben@decadent.org.uk>

This reverts commit e7e13fa736726e9860a86e5e1ae19ce162e11b71, which
was commit 739c64414f01748a36e7d82c8e0611dea94412bd upstream. It
doesn't appear to fix a real bug in 3.16, and it results in build
breakage and/or compiler warnings depending on the kernel
configuration.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/mtd/nand/omap2.c | 340 +++++++++++++--------------------------
1 file changed, 115 insertions(+), 225 deletions(-)

--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1163,174 +1163,130 @@ static u8 bch8_polynomial[] = {0xef, 0x
0x97, 0x79, 0xe5, 0x24, 0xb5};

/**
- * _omap_calculate_ecc_bch - Generate ECC bytes for one sector
+ * omap_calculate_ecc_bch - Generate bytes of ECC bytes
* @mtd: MTD device structure
* @dat: The pointer to data on which ecc is computed
* @ecc_code: The ecc_code buffer
- * @i: The sector number (for a multi sector page)
*
- * Support calculating of BCH4/8/16 ECC vectors for one sector
- * within a page. Sector number is in @i.
+ * Support calculating of BCH4/8 ecc vectors for the page
*/
-static int _omap_calculate_ecc_bch(struct mtd_info *mtd,
- const u_char *dat, u_char *ecc_calc, int i)
+static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
+ const u_char *dat, u_char *ecc_calc)
{
struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
mtd);
int eccbytes = info->nand.ecc.bytes;
struct gpmc_nand_regs *gpmc_regs = &info->reg;
u8 *ecc_code;
- unsigned long bch_val1, bch_val2, bch_val3, bch_val4;
+ unsigned long nsectors, bch_val1, bch_val2, bch_val3, bch_val4;
u32 val;
- int j;
-
- ecc_code = ecc_calc;
- switch (info->ecc_opt) {
- case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
- case OMAP_ECC_BCH8_CODE_HW:
- bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
- bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
- bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
- bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
- *ecc_code++ = (bch_val4 & 0xFF);
- *ecc_code++ = ((bch_val3 >> 24) & 0xFF);
- *ecc_code++ = ((bch_val3 >> 16) & 0xFF);
- *ecc_code++ = ((bch_val3 >> 8) & 0xFF);
- *ecc_code++ = (bch_val3 & 0xFF);
- *ecc_code++ = ((bch_val2 >> 24) & 0xFF);
- *ecc_code++ = ((bch_val2 >> 16) & 0xFF);
- *ecc_code++ = ((bch_val2 >> 8) & 0xFF);
- *ecc_code++ = (bch_val2 & 0xFF);
- *ecc_code++ = ((bch_val1 >> 24) & 0xFF);
- *ecc_code++ = ((bch_val1 >> 16) & 0xFF);
- *ecc_code++ = ((bch_val1 >> 8) & 0xFF);
- *ecc_code++ = (bch_val1 & 0xFF);
- break;
- case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
- case OMAP_ECC_BCH4_CODE_HW:
- bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
- bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
- *ecc_code++ = ((bch_val2 >> 12) & 0xFF);
- *ecc_code++ = ((bch_val2 >> 4) & 0xFF);
- *ecc_code++ = ((bch_val2 & 0xF) << 4) |
- ((bch_val1 >> 28) & 0xF);
- *ecc_code++ = ((bch_val1 >> 20) & 0xFF);
- *ecc_code++ = ((bch_val1 >> 12) & 0xFF);
- *ecc_code++ = ((bch_val1 >> 4) & 0xFF);
- *ecc_code++ = ((bch_val1 & 0xF) << 4);
- break;
- case OMAP_ECC_BCH16_CODE_HW:
- val = readl(gpmc_regs->gpmc_bch_result6[i]);
- ecc_code[0] = ((val >> 8) & 0xFF);
- ecc_code[1] = ((val >> 0) & 0xFF);
- val = readl(gpmc_regs->gpmc_bch_result5[i]);
- ecc_code[2] = ((val >> 24) & 0xFF);
- ecc_code[3] = ((val >> 16) & 0xFF);
- ecc_code[4] = ((val >> 8) & 0xFF);
- ecc_code[5] = ((val >> 0) & 0xFF);
- val = readl(gpmc_regs->gpmc_bch_result4[i]);
- ecc_code[6] = ((val >> 24) & 0xFF);
- ecc_code[7] = ((val >> 16) & 0xFF);
- ecc_code[8] = ((val >> 8) & 0xFF);
- ecc_code[9] = ((val >> 0) & 0xFF);
- val = readl(gpmc_regs->gpmc_bch_result3[i]);
- ecc_code[10] = ((val >> 24) & 0xFF);
- ecc_code[11] = ((val >> 16) & 0xFF);
- ecc_code[12] = ((val >> 8) & 0xFF);
- ecc_code[13] = ((val >> 0) & 0xFF);
- val = readl(gpmc_regs->gpmc_bch_result2[i]);
- ecc_code[14] = ((val >> 24) & 0xFF);
- ecc_code[15] = ((val >> 16) & 0xFF);
- ecc_code[16] = ((val >> 8) & 0xFF);
- ecc_code[17] = ((val >> 0) & 0xFF);
- val = readl(gpmc_regs->gpmc_bch_result1[i]);
- ecc_code[18] = ((val >> 24) & 0xFF);
- ecc_code[19] = ((val >> 16) & 0xFF);
- ecc_code[20] = ((val >> 8) & 0xFF);
- ecc_code[21] = ((val >> 0) & 0xFF);
- val = readl(gpmc_regs->gpmc_bch_result0[i]);
- ecc_code[22] = ((val >> 24) & 0xFF);
- ecc_code[23] = ((val >> 16) & 0xFF);
- ecc_code[24] = ((val >> 8) & 0xFF);
- ecc_code[25] = ((val >> 0) & 0xFF);
- break;
- default:
- return -EINVAL;
- }
-
- /* ECC scheme specific syndrome customizations */
- switch (info->ecc_opt) {
- case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
- /* Add constant polynomial to remainder, so that
- * ECC of blank pages results in 0x0 on reading back
- */
- for (j = 0; j < eccbytes; j++)
- ecc_calc[j] ^= bch4_polynomial[j];
- break;
- case OMAP_ECC_BCH4_CODE_HW:
- /* Set 8th ECC byte as 0x0 for ROM compatibility */
- ecc_calc[eccbytes - 1] = 0x0;
- break;
- case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
- /* Add constant polynomial to remainder, so that
- * ECC of blank pages results in 0x0 on reading back
- */
- for (j = 0; j < eccbytes; j++)
- ecc_calc[j] ^= bch8_polynomial[j];
- break;
- case OMAP_ECC_BCH8_CODE_HW:
- /* Set 14th ECC byte as 0x0 for ROM compatibility */
- ecc_calc[eccbytes - 1] = 0x0;
- break;
- case OMAP_ECC_BCH16_CODE_HW:
- break;
- default:
- return -EINVAL;
- }
-
- return 0;
-}
-
-/**
- * omap_calculate_ecc_bch_sw - ECC generator for sector for SW based correction
- * @mtd: MTD device structure
- * @dat: The pointer to data on which ecc is computed
- * @ecc_code: The ecc_code buffer
- *
- * Support calculating of BCH4/8/16 ECC vectors for one sector. This is used
- * when SW based correction is required as ECC is required for one sector
- * at a time.
- */
-static int omap_calculate_ecc_bch_sw(struct mtd_info *mtd,
- const u_char *dat, u_char *ecc_calc)
-{
- return _omap_calculate_ecc_bch(mtd, dat, ecc_calc, 0);
-}
-
-/**
- * omap_calculate_ecc_bch_multi - Generate ECC for multiple sectors
- * @mtd: MTD device structure
- * @dat: The pointer to data on which ecc is computed
- * @ecc_code: The ecc_code buffer
- *
- * Support calculating of BCH4/8/16 ecc vectors for the entire page in one go.
- */
-static int omap_calculate_ecc_bch_multi(struct mtd_info *mtd,
- const u_char *dat, u_char *ecc_calc)
-{
- struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
- mtd);
- int eccbytes = info->nand.ecc.bytes;
- unsigned long nsectors;
- int i, ret;
+ int i, j;

nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
for (i = 0; i < nsectors; i++) {
- ret = _omap_calculate_ecc_bch(mtd, dat, ecc_calc, i);
- if (ret)
- return ret;
+ ecc_code = ecc_calc;
+ switch (info->ecc_opt) {
+ case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
+ case OMAP_ECC_BCH8_CODE_HW:
+ bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
+ bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
+ bch_val3 = readl(gpmc_regs->gpmc_bch_result2[i]);
+ bch_val4 = readl(gpmc_regs->gpmc_bch_result3[i]);
+ *ecc_code++ = (bch_val4 & 0xFF);
+ *ecc_code++ = ((bch_val3 >> 24) & 0xFF);
+ *ecc_code++ = ((bch_val3 >> 16) & 0xFF);
+ *ecc_code++ = ((bch_val3 >> 8) & 0xFF);
+ *ecc_code++ = (bch_val3 & 0xFF);
+ *ecc_code++ = ((bch_val2 >> 24) & 0xFF);
+ *ecc_code++ = ((bch_val2 >> 16) & 0xFF);
+ *ecc_code++ = ((bch_val2 >> 8) & 0xFF);
+ *ecc_code++ = (bch_val2 & 0xFF);
+ *ecc_code++ = ((bch_val1 >> 24) & 0xFF);
+ *ecc_code++ = ((bch_val1 >> 16) & 0xFF);
+ *ecc_code++ = ((bch_val1 >> 8) & 0xFF);
+ *ecc_code++ = (bch_val1 & 0xFF);
+ break;
+ case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
+ case OMAP_ECC_BCH4_CODE_HW:
+ bch_val1 = readl(gpmc_regs->gpmc_bch_result0[i]);
+ bch_val2 = readl(gpmc_regs->gpmc_bch_result1[i]);
+ *ecc_code++ = ((bch_val2 >> 12) & 0xFF);
+ *ecc_code++ = ((bch_val2 >> 4) & 0xFF);
+ *ecc_code++ = ((bch_val2 & 0xF) << 4) |
+ ((bch_val1 >> 28) & 0xF);
+ *ecc_code++ = ((bch_val1 >> 20) & 0xFF);
+ *ecc_code++ = ((bch_val1 >> 12) & 0xFF);
+ *ecc_code++ = ((bch_val1 >> 4) & 0xFF);
+ *ecc_code++ = ((bch_val1 & 0xF) << 4);
+ break;
+ case OMAP_ECC_BCH16_CODE_HW:
+ val = readl(gpmc_regs->gpmc_bch_result6[i]);
+ ecc_code[0] = ((val >> 8) & 0xFF);
+ ecc_code[1] = ((val >> 0) & 0xFF);
+ val = readl(gpmc_regs->gpmc_bch_result5[i]);
+ ecc_code[2] = ((val >> 24) & 0xFF);
+ ecc_code[3] = ((val >> 16) & 0xFF);
+ ecc_code[4] = ((val >> 8) & 0xFF);
+ ecc_code[5] = ((val >> 0) & 0xFF);
+ val = readl(gpmc_regs->gpmc_bch_result4[i]);
+ ecc_code[6] = ((val >> 24) & 0xFF);
+ ecc_code[7] = ((val >> 16) & 0xFF);
+ ecc_code[8] = ((val >> 8) & 0xFF);
+ ecc_code[9] = ((val >> 0) & 0xFF);
+ val = readl(gpmc_regs->gpmc_bch_result3[i]);
+ ecc_code[10] = ((val >> 24) & 0xFF);
+ ecc_code[11] = ((val >> 16) & 0xFF);
+ ecc_code[12] = ((val >> 8) & 0xFF);
+ ecc_code[13] = ((val >> 0) & 0xFF);
+ val = readl(gpmc_regs->gpmc_bch_result2[i]);
+ ecc_code[14] = ((val >> 24) & 0xFF);
+ ecc_code[15] = ((val >> 16) & 0xFF);
+ ecc_code[16] = ((val >> 8) & 0xFF);
+ ecc_code[17] = ((val >> 0) & 0xFF);
+ val = readl(gpmc_regs->gpmc_bch_result1[i]);
+ ecc_code[18] = ((val >> 24) & 0xFF);
+ ecc_code[19] = ((val >> 16) & 0xFF);
+ ecc_code[20] = ((val >> 8) & 0xFF);
+ ecc_code[21] = ((val >> 0) & 0xFF);
+ val = readl(gpmc_regs->gpmc_bch_result0[i]);
+ ecc_code[22] = ((val >> 24) & 0xFF);
+ ecc_code[23] = ((val >> 16) & 0xFF);
+ ecc_code[24] = ((val >> 8) & 0xFF);
+ ecc_code[25] = ((val >> 0) & 0xFF);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* ECC scheme specific syndrome customizations */
+ switch (info->ecc_opt) {
+ case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
+ /* Add constant polynomial to remainder, so that
+ * ECC of blank pages results in 0x0 on reading back */
+ for (j = 0; j < eccbytes; j++)
+ ecc_calc[j] ^= bch4_polynomial[j];
+ break;
+ case OMAP_ECC_BCH4_CODE_HW:
+ /* Set 8th ECC byte as 0x0 for ROM compatibility */
+ ecc_calc[eccbytes - 1] = 0x0;
+ break;
+ case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
+ /* Add constant polynomial to remainder, so that
+ * ECC of blank pages results in 0x0 on reading back */
+ for (j = 0; j < eccbytes; j++)
+ ecc_calc[j] ^= bch8_polynomial[j];
+ break;
+ case OMAP_ECC_BCH8_CODE_HW:
+ /* Set 14th ECC byte as 0x0 for ROM compatibility */
+ ecc_calc[eccbytes - 1] = 0x0;
+ break;
+ case OMAP_ECC_BCH16_CODE_HW:
+ break;
+ default:
+ return -EINVAL;
+ }

- ecc_calc += eccbytes;
+ ecc_calc += eccbytes;
}

return 0;
@@ -1571,7 +1527,7 @@ static int omap_write_page_bch(struct mt
chip->write_buf(mtd, buf, mtd->writesize);

/* Update ecc vector from GPMC result registers */
- omap_calculate_ecc_bch_multi(mtd, buf, &ecc_calc[0]);
+ chip->ecc.calculate(mtd, buf, &ecc_calc[0]);

for (i = 0; i < chip->ecc.total; i++)
chip->oob_poi[eccpos[i]] = ecc_calc[i];
@@ -1582,72 +1538,6 @@ static int omap_write_page_bch(struct mt
}

/**
- * omap_write_subpage_bch - BCH hardware ECC based subpage write
- * @mtd: mtd info structure
- * @chip: nand chip info structure
- * @offset: column address of subpage within the page
- * @data_len: data length
- * @buf: data buffer
- * @oob_required: must write chip->oob_poi to OOB
- * @page: page number to write
- *
- * OMAP optimized subpage write method.
- */
-static int omap_write_subpage_bch(struct mtd_info *mtd,
- struct nand_chip *chip, u32 offset,
- u32 data_len, const u8 *buf,
- int oob_required, int page)
-{
- u8 *ecc_calc = chip->buffers->ecccalc;
- int ecc_size = chip->ecc.size;
- int ecc_bytes = chip->ecc.bytes;
- int ecc_steps = chip->ecc.steps;
- u32 start_step = offset / ecc_size;
- u32 end_step = (offset + data_len - 1) / ecc_size;
- int step, ret = 0;
-
- /*
- * Write entire page at one go as it would be optimal
- * as ECC is calculated by hardware.
- * ECC is calculated for all subpages but we choose
- * only what we want.
- */
-
- /* Enable GPMC ECC engine */
- chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
-
- /* Write data */
- chip->write_buf(mtd, buf, mtd->writesize);
-
- for (step = 0; step < ecc_steps; step++) {
- /* mask ECC of un-touched subpages by padding 0xFF */
- if (step < start_step || step > end_step)
- memset(ecc_calc, 0xff, ecc_bytes);
- else
- ret = _omap_calculate_ecc_bch(mtd, buf, ecc_calc, step);
-
- if (ret)
- return ret;
-
- buf += ecc_size;
- ecc_calc += ecc_bytes;
- }
-
- /* copy calculated ECC for whole page to chip->buffer->oob */
- /* this include masked-value(0xFF) for unwritten subpages */
- ecc_calc = chip->buffers->ecccalc;
- ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi, 0,
- chip->ecc.total);
- if (ret)
- return ret;
-
- /* write OOB buffer to NAND device */
- chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
-
- return 0;
-}
-
-/**
* omap_read_page_bch - BCH ecc based page read function for entire page
* @mtd: mtd info structure
* @chip: nand chip info structure
@@ -1684,7 +1574,7 @@ static int omap_read_page_bch(struct mtd
chip->read_buf(mtd, oob, chip->ecc.total);

/* Calculate ecc bytes */
- omap_calculate_ecc_bch_multi(mtd, buf, ecc_calc);
+ chip->ecc.calculate(mtd, buf, ecc_calc);

memcpy(ecc_code, &chip->oob_poi[eccpos[0]], chip->ecc.total);

@@ -1933,7 +1823,7 @@ static int omap_nand_probe(struct platfo
nand_chip->ecc.strength = 4;
nand_chip->ecc.hwctl = omap_enable_hwecc_bch;
nand_chip->ecc.correct = nand_bch_correct_data;
- nand_chip->ecc.calculate = omap_calculate_ecc_bch_sw;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
/* define ECC layout */
ecclayout->eccbytes = nand_chip->ecc.bytes *
(mtd->writesize /
@@ -1973,9 +1863,9 @@ static int omap_nand_probe(struct platfo
nand_chip->ecc.strength = 4;
nand_chip->ecc.hwctl = omap_enable_hwecc_bch;
nand_chip->ecc.correct = omap_elm_correct_data;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
nand_chip->ecc.read_page = omap_read_page_bch;
nand_chip->ecc.write_page = omap_write_page_bch;
- nand_chip->ecc.write_subpage = omap_write_subpage_bch;
/* define ECC layout */
ecclayout->eccbytes = nand_chip->ecc.bytes *
(mtd->writesize /
@@ -2008,7 +1898,7 @@ static int omap_nand_probe(struct platfo
nand_chip->ecc.strength = 8;
nand_chip->ecc.hwctl = omap_enable_hwecc_bch;
nand_chip->ecc.correct = nand_bch_correct_data;
- nand_chip->ecc.calculate = omap_calculate_ecc_bch_sw;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
/* define ECC layout */
ecclayout->eccbytes = nand_chip->ecc.bytes *
(mtd->writesize /
@@ -2049,9 +1939,9 @@ static int omap_nand_probe(struct platfo
nand_chip->ecc.strength = 8;
nand_chip->ecc.hwctl = omap_enable_hwecc_bch;
nand_chip->ecc.correct = omap_elm_correct_data;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
nand_chip->ecc.read_page = omap_read_page_bch;
nand_chip->ecc.write_page = omap_write_page_bch;
- nand_chip->ecc.write_subpage = omap_write_subpage_bch;
/* This ECC scheme requires ELM H/W block */
err = is_elm_present(info, pdata->elm_of_node, BCH8_ECC);
if (err < 0) {
@@ -2084,9 +1974,9 @@ static int omap_nand_probe(struct platfo
nand_chip->ecc.strength = 16;
nand_chip->ecc.hwctl = omap_enable_hwecc_bch;
nand_chip->ecc.correct = omap_elm_correct_data;
+ nand_chip->ecc.calculate = omap_calculate_ecc_bch;
nand_chip->ecc.read_page = omap_read_page_bch;
nand_chip->ecc.write_page = omap_write_page_bch;
- nand_chip->ecc.write_subpage = omap_write_subpage_bch;
/* This ECC scheme requires ELM H/W block */
err = is_elm_present(info, pdata->elm_of_node, BCH16_ECC);
if (err < 0) {