Re: [PATCH] Fix pointer cast for 32 bits arch

From: Dan Carpenter
Date: Mon Apr 13 2015 - 05:22:20 EST


On Mon, Apr 13, 2015 at 11:16:49AM +0200, Peter Senna Tschudin wrote:
> On Mon, Apr 13, 2015 at 11:10 AM, Dan Carpenter
> <dan.carpenter@xxxxxxxxxx> wrote:
> > On Sun, Apr 12, 2015 at 11:26:43AM +0200, Peter Senna Tschudin wrote:
> >> Sparse compalins about casting void * to u64 on i386.
> >> Change the cast to resource_size_t.
> >>
> >> Signed-off-by: Peter Senna Tschudin <peter.senna@xxxxxxxxx>
> >> ---
> >>
> >> Tested by compilation only. Tested for x86 and x86_64.
> >>
> >> drivers/staging/goldfish/goldfish_nand.c | 3 ++-
> >> include/linux/goldfish.h | 2 +-
> >> 2 files changed, 3 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/staging/goldfish/goldfish_nand.c b/drivers/staging/goldfish/goldfish_nand.c
> >> index d68f216..738fdc4 100644
> >> --- a/drivers/staging/goldfish/goldfish_nand.c
> >> +++ b/drivers/staging/goldfish/goldfish_nand.c
> >> @@ -87,7 +87,8 @@ static u32 goldfish_nand_cmd(struct mtd_info *mtd, enum nand_cmd cmd,
> >> writel((u32)(addr >> 32), base + NAND_ADDR_HIGH);
> >> writel((u32)addr, base + NAND_ADDR_LOW);
> >> writel(len, base + NAND_TRANSFER_SIZE);
> >> - gf_write64((u64)ptr, base + NAND_DATA, base + NAND_DATA_HIGH);
> >> + gf_write64((resource_size_t)ptr, base + NAND_DATA,
> >> + base + NAND_DATA_HIGH);
> >
> > write64 is a misleading name because it only writes 32 bits on 32 bit
> > systems.
> >
> > Are you sure it's a resource_size_t? If that's really true then this
> > code needs a lot more work. The ifdef in gf_write64() should be
> > CONFIG_PHYS_ADDR_T_64BIT and ops->datbuf needs to updated. It would be
> > a lot of changes...
> >
> > I *think* but I'm not positive that gf_write64 should just take a void
> > pointer like this:
> >
> > diff --git a/drivers/staging/goldfish/goldfish_nand.c b/drivers/staging/goldfish/goldfish_nand.c
> > index 213877a..92d6479 100644
> > --- a/drivers/staging/goldfish/goldfish_nand.c
> > +++ b/drivers/staging/goldfish/goldfish_nand.c
> > @@ -87,7 +87,7 @@ static u32 goldfish_nand_cmd(struct mtd_info *mtd, enum nand_cmd cmd,
> > writel((u32)(addr >> 32), base + NAND_ADDR_HIGH);
> > writel((u32)addr, base + NAND_ADDR_LOW);
> > writel(len, base + NAND_TRANSFER_SIZE);
> > - gf_write64((u64)ptr, base + NAND_DATA, base + NAND_DATA_HIGH);
> > + gf_write64(ptr, base + NAND_DATA, base + NAND_DATA_HIGH);
> > writel(cmd, base + NAND_COMMAND);
> > rv = readl(base + NAND_RESULT);
> > }
> > diff --git a/include/linux/goldfish.h b/include/linux/goldfish.h
> > index 569236e..4cdb913 100644
> > --- a/include/linux/goldfish.h
> > +++ b/include/linux/goldfish.h
> > @@ -3,12 +3,12 @@
> >
> > /* Helpers for Goldfish virtual platform */
> >
> > -static inline void gf_write64(unsigned long data,
> > +static inline void gf_write64(void *data,
> > void __iomem *portl, void __iomem *porth)
> > {
> > - writel((u32)data, portl);
> > + writel((u32)(unsigned long)data, portl);
> > #ifdef CONFIG_64BIT
> > - writel(data>>32, porth);
> > + writel((unsigned long)data >> 32, porth);
> > #endif
> > }
> >
>
> I like this solution. Should I send a single patch changing
> gf_write64() and removing all casts when calling the gf_write64(), or
> if to split, how to split the patch?

Single patch, please. Maybe rename the function to gf_write_ptr() or
something similar.

regards,
dan carpenter

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