[PATCH v1 2/6] mtd: spi-nor: get rid of non-power-of-2 page size handling

[Michael Walle]

The Xilinx flashes were the only user of the page sized that were no
power of 2. Support for them were dropped, thus we can also get rid of
the special page size handling for it.

Signed-off-by: Michael Walle <mwalle at kernel.org>
---
 drivers/mtd/spi-nor/core.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index cbe5f92eb0af..fb76e0522665 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2098,7 +2098,7 @@ 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;
 
@@ -2111,21 +2111,9 @@ 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);
+		size_t page_remain = min_t(size_t, page_size - page_offset, len - i);
 
 		addr = spi_nor_convert_addr(nor, addr);
 
@@ -3054,7 +3042,14 @@ 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.
-- 
2.39.2