[PATCH 4.15 019/105] mmc: dw_mmc: Fix the DTO/CTO timeout overflow calculation for 32-bit systems

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Evgeniy Didin <Evgeniy.Didin@xxxxxxxxxxxx>

commit c7151602255a36ba07c84fe2baeef846fdb988b8 upstream.

The commit 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation")
and commit 4c2357f57dd5 ("mmc: dw_mmc: Fix the CTO timeout calculation")
made changes, which cause multiply overflow for 32-bit systems. The broken
timeout calculations leads to unexpected ETIMEDOUT errors and causes
stacktrace splat (such as below) during normal data exchange with SD-card.

| Running :  4M-check-reassembly-tcp-cmykw2-rotatew2.out -v0 -w1
| -  Info: Finished target initialization.
| mmcblk0: error -110 transferring data, sector 320544, nr 2048, cmd
| response 0x900, card status 0x0

DIV_ROUND_UP_ULL helps to escape usage of __udivdi3() from libgcc and so
code gets compiled on all 32-bit platforms as opposed to usage of
DIV_ROUND_UP when we may only compile stuff on a very few arches.

Lets cast this multiply to u64 type to prevent the overflow.

Fixes: 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation")
Fixes: 4c2357f57dd5 ("mmc: dw_mmc: Fix the CTO timeout calculation")
Tested-by: Vineet Gupta <Vineet.Gupta1@xxxxxxxxxxxx>
Reported-by: Vineet Gupta <Vineet.Gupta1@xxxxxxxxxxxx> # ARC STAR 9001306872 HSDK, sdio: board crashes when copying big files
Signed-off-by: Evgeniy Didin <Evgeniy.Didin@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 4.14
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Reviewed-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
Acked-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mmc/host/dw_mmc.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -413,7 +413,9 @@ static inline void dw_mci_set_cto(struct
 	cto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
 	if (cto_div == 0)
 		cto_div = 1;
-	cto_ms = DIV_ROUND_UP(MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz);
+
+	cto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * cto_clks * cto_div,
+				  host->bus_hz);
 
 	/* add a bit spare time */
 	cto_ms += 10;
@@ -1948,8 +1950,9 @@ static void dw_mci_set_drto(struct dw_mc
 	drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
 	if (drto_div == 0)
 		drto_div = 1;
-	drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div,
-			       host->bus_hz);
+
+	drto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * drto_clks * drto_div,
+				   host->bus_hz);
 
 	/* add a bit spare time */
 	drto_ms += 10;