mtd: spi-nor: get rid of non-power-of-2 page size handling

The Xilinx flashes were the only users of page sizes that were not power
of 2. Support for them has been dropped, thus we can also get rid of the
special page size handling for it.
Signed-off-by: Michael Walle <mwalle@kernel.org>
Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
[pratyush@kernel.org: fixup minor typos and grammar in commit message]
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Link: https://lore.kernel.org/r/20240419141249.609534-3-mwalle@kernel.org

drivers/mtd/spi-nor/core.c

@@ -1463,14 +1463,6 @@ static void spi_nor_unlock_and_unprep_rd(struct spi_nor *nor, loff_t start, size
 	spi_nor_unprep(nor);
 }
 
-static u32 spi_nor_convert_addr(struct spi_nor *nor, loff_t addr)
-{
-	if (!nor->params->convert_addr)
-		return addr;
-
-	return nor->params->convert_addr(nor, addr);
-}
-
 /*
  * Initiate the erasure of a single sector
  */
@@ -1478,8 +1470,6 @@ int spi_nor_erase_sector(struct spi_nor *nor, u32 addr)
 {
 	int i;
 
-	addr = spi_nor_convert_addr(nor, addr);
-
 	if (nor->spimem) {
 		struct spi_mem_op op =
 			SPI_NOR_SECTOR_ERASE_OP(nor->erase_opcode,
@@ -2064,8 +2054,6 @@ static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
 	while (len) {
 		loff_t addr = from;
 
-		addr = spi_nor_convert_addr(nor, addr);
-
 		ret = spi_nor_read_data(nor, addr, len, buf);
 		if (ret == 0) {
 			/* We shouldn't see 0-length reads */
@@ -2098,7 +2086,7 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	size_t *retlen, const u_char *buf)
 {
 	struct spi_nor *nor = mtd_to_spi_nor(mtd);
-	size_t page_offset, page_remain, i;
+	size_t i;
 	ssize_t ret;
 	u32 page_size = nor->params->page_size;
 
@@ -2111,23 +2099,9 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 	for (i = 0; i < len; ) {
 		ssize_t written;
 		loff_t addr = to + i;
-
-		/*
-		 * If page_size is a power of two, the offset can be quickly
-		 * calculated with an AND operation. On the other cases we
-		 * need to do a modulus operation (more expensive).
-		 */
-		if (is_power_of_2(page_size)) {
-			page_offset = addr & (page_size - 1);
-		} else {
-			u64 aux = addr;
-
-			page_offset = do_div(aux, page_size);
-		}
+		size_t page_offset = addr & (page_size - 1);
 		/* the size of data remaining on the first page */
-		page_remain = min_t(size_t, page_size - page_offset, len - i);
-
-		addr = spi_nor_convert_addr(nor, addr);
+		size_t page_remain = min_t(size_t, page_size - page_offset, len - i);
 
 		ret = spi_nor_lock_device(nor);
 		if (ret)
@@ -3054,7 +3028,14 @@ static int spi_nor_init_params(struct spi_nor *nor)
 		spi_nor_init_params_deprecated(nor);
 	}
 
-	return spi_nor_late_init_params(nor);
+	ret = spi_nor_late_init_params(nor);
+	if (ret)
+		return ret;
+
+	if (WARN_ON(!is_power_of_2(nor->params->page_size)))
+		return -EINVAL;
+
+	return 0;
 }
 
 /** spi_nor_set_octal_dtr() - enable or disable Octal DTR I/O.

drivers/mtd/spi-nor/core.h

@@ -366,9 +366,6 @@ struct spi_nor_otp {
  * @set_octal_dtr:	enables or disables SPI NOR octal DTR mode.
  * @quad_enable:	enables SPI NOR quad mode.
  * @set_4byte_addr_mode: puts the SPI NOR in 4 byte addressing mode.
- * @convert_addr:	converts an absolute address into something the flash
- *                      will understand. Particularly useful when pagesize is
- *                      not a power-of-2.
  * @setup:		(optional) configures the SPI NOR memory. Useful for
  *			SPI NOR flashes that have peculiarities to the SPI NOR
  *			standard e.g. different opcodes, specific address
@@ -403,7 +400,6 @@ struct spi_nor_flash_parameter {
 	int (*set_octal_dtr)(struct spi_nor *nor, bool enable);
 	int (*quad_enable)(struct spi_nor *nor);
 	int (*set_4byte_addr_mode)(struct spi_nor *nor, bool enable);
-	u32 (*convert_addr)(struct spi_nor *nor, u32 addr);
 	int (*setup)(struct spi_nor *nor, const struct spi_nor_hwcaps *hwcaps);
 	int (*ready)(struct spi_nor *nor);