[PATCH v2] mtd mxc_nand: use 32bit copy functions
From: Uwe Kleine-König <hidden>
Date: 2012-05-29 09:12:54
Hello, On Tue, May 29, 2012 at 10:16:09AM +0200, Sascha Hauer wrote:
The following commit changes the function used to copy from/to the hardware buffer to memcpy_[from|to]io. This does not work since the hardware cannot handle the byte accesses used by these functions. Instead of reverting this patch introduce 32bit correspondents of these functions.
Hmm, I didn't run an mtd test suite, but on mx27 it worked for me. IMHO it's surprising that memcpy used to work, but memcpy_fromio doesn't. I wouldn't expect a different semantic (apart from normal vs. __iomem memory). And I wonder what will break when ARM's memcpy_fromio et al. is optimized.
| commit 5775ba36ea9c760c2d7e697dac04f2f7fc95aa62 | Author: Uwe Kleine-K?nig [off-list ref] | Date: Tue Apr 24 10:05:22 2012 +0200 | | mtd: mxc_nand: fix several sparse warnings about incorrect address space | | Signed-off-by: Uwe Kleine-K?nig [off-list ref] | Signed-off-by: Artem Bityutskiy [off-list ref] Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Cc: Uwe Kleine-K?nig <redacted> --- v2: remove volatile, fix line over 80 characters
I'm not sure about the need for volatile. I don't have my C Reference handy, but maybe adding volatile prevents the compilier issuing code that e.g. uses a different word size?! Not sure if it matters for a static and so maybe inlined function. Still: Acked-by: Uwe Kleine-K?nig <redacted> Thanks Uwe
quoted hunk ↗ jump to hunk
drivers/mtd/nand/mxc_nand.c | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-)diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c index fd14966..17ddcf0 100644 --- a/drivers/mtd/nand/mxc_nand.c +++ b/drivers/mtd/nand/mxc_nand.c@@ -273,6 +273,26 @@ static struct nand_ecclayout nandv2_hw_eccoob_4k = { static const char *part_probes[] = { "RedBoot", "cmdlinepart", "ofpart", NULL }; +static void memcpy32_fromio(void *trg, const void __iomem *src, size_t size) +{ + int i; + u32 *t = trg; + const __iomem u32 *s = src; + + for (i = 0; i < (size >> 2); i++) + *t++ = __raw_readl(s++); +} + +static void memcpy32_toio(void __iomem *trg, const void *src, int size) +{ + int i; + u32 __iomem *t = trg; + const u32 *s = src; + + for (i = 0; i < (size >> 2); i++) + __raw_writel(*s++, t++); +} + static int check_int_v3(struct mxc_nand_host *host) { uint32_t tmp;@@ -519,7 +539,7 @@ static void send_read_id_v3(struct mxc_nand_host *host) wait_op_done(host, true); - memcpy_fromio(host->data_buf, host->main_area0, 16); + memcpy32_fromio(host->data_buf, host->main_area0, 16); } /* Request the NANDFC to perform a read of the NAND device ID. */@@ -535,7 +555,7 @@ static void send_read_id_v1_v2(struct mxc_nand_host *host) /* Wait for operation to complete */ wait_op_done(host, true); - memcpy_fromio(host->data_buf, host->main_area0, 16); + memcpy32_fromio(host->data_buf, host->main_area0, 16); if (this->options & NAND_BUSWIDTH_16) { /* compress the ID info */@@ -797,16 +817,16 @@ static void copy_spare(struct mtd_info *mtd, bool bfrom) if (bfrom) { for (i = 0; i < n - 1; i++) - memcpy_fromio(d + i * j, s + i * t, j); + memcpy32_fromio(d + i * j, s + i * t, j); /* the last section */ - memcpy_fromio(d + i * j, s + i * t, mtd->oobsize - i * j); + memcpy32_fromio(d + i * j, s + i * t, mtd->oobsize - i * j); } else { for (i = 0; i < n - 1; i++) - memcpy_toio(&s[i * t], &d[i * j], j); + memcpy32_toio(&s[i * t], &d[i * j], j); /* the last section */ - memcpy_toio(&s[i * t], &d[i * j], mtd->oobsize - i * j); + memcpy32_toio(&s[i * t], &d[i * j], mtd->oobsize - i * j); } }@@ -1070,7 +1090,8 @@ static void mxc_nand_command(struct mtd_info *mtd, unsigned command, host->devtype_data->send_page(mtd, NFC_OUTPUT); - memcpy_fromio(host->data_buf, host->main_area0, mtd->writesize); + memcpy32_fromio(host->data_buf, host->main_area0, + mtd->writesize); copy_spare(mtd, true); break;@@ -1086,7 +1107,7 @@ static void mxc_nand_command(struct mtd_info *mtd, unsigned command, break; case NAND_CMD_PAGEPROG: - memcpy_toio(host->main_area0, host->data_buf, mtd->writesize); + memcpy32_toio(host->main_area0, host->data_buf, mtd->writesize); copy_spare(mtd, false); host->devtype_data->send_page(mtd, NFC_INPUT); host->devtype_data->send_cmd(host, command, true);-- 1.7.10
-- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |