[PATCH 1/2] mtd: st_spi_fsm: correct type issues

[PATCH 1/2] mtd: st_spi_fsm: correct type issues

[Brian Norris]

Compile-testing for a 64-bit arch uncovers several bad casts:

    In file included from include/linux/linkage.h:4:0,
                     from include/linux/kernel.h:6,
                     from drivers/mtd/devices/st_spi_fsm.c:15:
    drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_read_fifo’:
    drivers/mtd/devices/st_spi_fsm.c:758:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
    ...

Use uintptr_t instead of uint32_t, since it's guaranteed to be
pointer-sized.

We also see this warning, if size_t is not 32 bits wide:

    In file included from drivers/mtd/devices/st_spi_fsm.c:15:0:
    drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_mtd_write’:
    include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
      (void) (&_min1 == &_min2);  \
                     ^
    drivers/mtd/devices/st_spi_fsm.c:1704:11: note: in expansion of macro ‘min’
       bytes = min(FLASH_PAGESIZE - page_offs, len);
               ^

Just use min_t() to force the type conversion, since we don't really
want to upgrade 'page_offs' and 'bytes' to size_t; they only should be
handling <= 256 byte offsets.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
---
 drivers/mtd/devices/st_spi_fsm.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/devices/st_spi_fsm.c b/drivers/mtd/devices/st_spi_fsm.c
index 7cc49ba78f68..f97fe144077d 100644
--- a/drivers/mtd/devices/st_spi_fsm.c
+++ b/drivers/mtd/devices/st_spi_fsm.c
@@ -755,7 +755,7 @@ static void stfsm_read_fifo(struct stfsm *fsm, uint32_t *buf, uint32_t size)
 
 	dev_dbg(fsm->dev, "Reading %d bytes from FIFO\n", size);
 
-	BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
+	BUG_ON((((uintptr_t)buf) & 0x3) || (size & 0x3));
 
 	while (remaining) {
 		for (;;) {
@@ -779,7 +779,7 @@ static int stfsm_write_fifo(struct stfsm *fsm, const uint32_t *buf,
 
 	dev_dbg(fsm->dev, "writing %d bytes to FIFO\n", size);
 
-	BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
+	BUG_ON((((uintptr_t)buf) & 0x3) || (size & 0x3));
 
 	writesl(fsm->base + SPI_FAST_SEQ_DATA_REG, buf, words);
 
@@ -1474,7 +1474,7 @@ static int stfsm_read(struct stfsm *fsm, uint8_t *buf, uint32_t size,
 	read_mask = (data_pads << 2) - 1;
 
 	/* Handle non-aligned buf */
-	p = ((uint32_t)buf & 0x3) ? (uint8_t *)page_buf : buf;
+	p = ((uintptr_t)buf & 0x3) ? (uint8_t *)page_buf : buf;
 
 	/* Handle non-aligned size */
 	size_ub = (size + read_mask) & ~read_mask;
@@ -1496,7 +1496,7 @@ static int stfsm_read(struct stfsm *fsm, uint8_t *buf, uint32_t size,
 	}
 
 	/* Handle non-aligned buf */
-	if ((uint32_t)buf & 0x3)
+	if ((uintptr_t)buf & 0x3)
 		memcpy(buf, page_buf, size);
 
 	/* Wait for sequence to finish */
@@ -1538,7 +1538,7 @@ static int stfsm_write(struct stfsm *fsm, const uint8_t *buf,
 	write_mask = (data_pads << 2) - 1;
 
 	/* Handle non-aligned buf */
-	if ((uint32_t)buf & 0x3) {
+	if ((uintptr_t)buf & 0x3) {
 		memcpy(page_buf, buf, size);
 		p = (uint8_t *)page_buf;
 	} else {
@@ -1701,7 +1701,7 @@ static int stfsm_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	while (len) {
 		/* Write up to page boundary */
-		bytes = min(FLASH_PAGESIZE - page_offs, len);
+		bytes = min_t(size_t, FLASH_PAGESIZE - page_offs, len);
 
 		ret = stfsm_write(fsm, b, bytes, to);
 		if (ret)
-- 
1.8.3.2

[PATCH 2/2] mtd: st_spi_fsm: only build for ARM

[Brian Norris]

COMPILE_TEST allows us to build this driver on other arch'es. But not
all arch'es have the right I/O accessors -- particularly, x86 is missing
readsl() and writesl().

So just restrict this driver to ARCH_STI. It's still buildable for a
multiplatform ARM kernel, so it can get decent compile coverage.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
---
 drivers/mtd/devices/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 9aae1042c14f..c49d0b127fef 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -212,7 +212,7 @@ config MTD_DOCG3
 
 config MTD_ST_SPI_FSM
 	tristate "ST Microelectronics SPI FSM Serial Flash Controller"
-	depends on ARCH_STI || COMPILE_TEST
+	depends on ARCH_STI
 	help
 	  This provides an MTD device driver for the ST Microelectronics
 	  SPI Fast Sequence Mode (FSM) Serial Flash Controller and support
-- 
1.8.3.2

Re: [PATCH 1/2] mtd: st_spi_fsm: correct type issues

[Lee Jones]

> Compile-testing for a 64-bit arch uncovers several bad casts:
> 
>     In file included from include/linux/linkage.h:4:0,
>                      from include/linux/kernel.h:6,
>                      from drivers/mtd/devices/st_spi_fsm.c:15:
>     drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_read_fifo’:
>     drivers/mtd/devices/st_spi_fsm.c:758:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
>       BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
>     ...
> 
> Use uintptr_t instead of uint32_t, since it's guaranteed to be
> pointer-sized.
> 
> We also see this warning, if size_t is not 32 bits wide:
> 
>     In file included from drivers/mtd/devices/st_spi_fsm.c:15:0:
>     drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_mtd_write’:
>     include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
>       (void) (&_min1 == &_min2);  \
>                      ^
>     drivers/mtd/devices/st_spi_fsm.c:1704:11: note: in expansion of macro ‘min’
>        bytes = min(FLASH_PAGESIZE - page_offs, len);
>                ^
> 
> Just use min_t() to force the type conversion, since we don't really
> want to upgrade 'page_offs' and 'bytes' to size_t; they only should be
> handling <= 256 byte offsets.
> 
> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
> Cc: Lee Jones <lee.jones@linaro.org>
> ---
>  drivers/mtd/devices/st_spi_fsm.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

Thanks for fixing Brian. Fixes look good.

Acked-by: Lee Jones <lee.jones@linaro.org>

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH 1/2] mtd: st_spi_fsm: correct type issues

[Brian Norris]

On Wed, Apr 16, 2014 at 11:46:11AM +0100, Lee Jones wrote:
> > Compile-testing for a 64-bit arch uncovers several bad casts:
> > 
> >     In file included from include/linux/linkage.h:4:0,
> >                      from include/linux/kernel.h:6,
> >                      from drivers/mtd/devices/st_spi_fsm.c:15:
> >     drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_read_fifo’:
> >     drivers/mtd/devices/st_spi_fsm.c:758:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> >       BUG_ON((((uint32_t)buf) & 0x3) || (size & 0x3));
> >     ...
> > 
> > Use uintptr_t instead of uint32_t, since it's guaranteed to be
> > pointer-sized.
> > 
> > We also see this warning, if size_t is not 32 bits wide:
> > 
> >     In file included from drivers/mtd/devices/st_spi_fsm.c:15:0:
> >     drivers/mtd/devices/st_spi_fsm.c: In function ‘stfsm_mtd_write’:
> >     include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default]
> >       (void) (&_min1 == &_min2);  \
> >                      ^
> >     drivers/mtd/devices/st_spi_fsm.c:1704:11: note: in expansion of macro ‘min’
> >        bytes = min(FLASH_PAGESIZE - page_offs, len);
> >                ^
> > 
> > Just use min_t() to force the type conversion, since we don't really
> > want to upgrade 'page_offs' and 'bytes' to size_t; they only should be
> > handling <= 256 byte offsets.
> > 
> > Signed-off-by: Brian Norris <computersforpeace@gmail.com>
> > Cc: Lee Jones <lee.jones@linaro.org>
> > ---
> >  drivers/mtd/devices/st_spi_fsm.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> Thanks for fixing Brian. Fixes look good.
> 
> Acked-by: Lee Jones <lee.jones@linaro.org>

Pushed both to l2-mtd.git/spinor.

Brian