* [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO
@ 2015-10-09 14:29 Andy Shevchenko
2015-10-09 14:35 ` Andy Shevchenko
2015-10-11 19:18 ` Thomas Gleixner
0 siblings, 2 replies; 5+ messages in thread
From: Andy Shevchenko @ 2015-10-09 14:29 UTC (permalink / raw)
To: linux-kernel, Thomas Gleixner, Ingo Molnar, H . Peter Anvin, x86
Cc: Andy Shevchenko
There are following warnings on unpatched code:
arch/x86/kernel/early_printk.c:198:32: warning: incorrect type in initializer (different address spaces)
arch/x86/kernel/early_printk.c:198:32: expected void [noderef] <asn:2>*vaddr
arch/x86/kernel/early_printk.c:198:32: got unsigned int [usertype] *<noident>
arch/x86/kernel/early_printk.c:205:32: warning: incorrect type in initializer (different address spaces)
arch/x86/kernel/early_printk.c:205:32: expected void [noderef] <asn:2>*vaddr
arch/x86/kernel/early_printk.c:205:32: got unsigned int [usertype] *<noident>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2:
- amend subject line
arch/x86/kernel/early_printk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c
index 076a4a7..77f2f5c 100644
--- a/arch/x86/kernel/early_printk.c
+++ b/arch/x86/kernel/early_printk.c
@@ -195,14 +195,14 @@ static __init void early_serial_init(char *s)
#ifdef CONFIG_PCI
static void mem32_serial_out(unsigned long addr, int offset, int value)
{
- u32 *vaddr = (u32 *)addr;
+ void __iomem *vaddr = (void __iomem *)addr;
/* shift implied by pointer type */
writel(value, vaddr + offset);
}
static unsigned int mem32_serial_in(unsigned long addr, int offset)
{
- u32 *vaddr = (u32 *)addr;
+ void __iomem *vaddr = (void __iomem *)addr;
/* shift implied by pointer type */
return readl(vaddr + offset);
}
--
2.5.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO
2015-10-09 14:29 [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO Andy Shevchenko
@ 2015-10-09 14:35 ` Andy Shevchenko
2015-10-11 19:18 ` Thomas Gleixner
1 sibling, 0 replies; 5+ messages in thread
From: Andy Shevchenko @ 2015-10-09 14:35 UTC (permalink / raw)
To: linux-kernel, Thomas Gleixner, Ingo Molnar, H . Peter Anvin, x86
On Fri, 2015-10-09 at 17:29 +0300, Andy Shevchenko wrote:
> There are following warnings on unpatched code:
>
> arch/x86/kernel/early_printk.c:198:32: warning: incorrect type in
> initializer (different address spaces)
> arch/x86/kernel/early_printk.c:198:32: expected void [noderef]
> <asn:2>*vaddr
> arch/x86/kernel/early_printk.c:198:32: got unsigned int [usertype]
> *<noident>
> arch/x86/kernel/early_printk.c:205:32: warning: incorrect type in
> initializer (different address spaces)
> arch/x86/kernel/early_printk.c:205:32: expected void [noderef]
> <asn:2>*vaddr
> arch/x86/kernel/early_printk.c:205:32: got unsigned int [usertype]
> *<noident>
This one is wrong, sorry for noise.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> v2:
> - amend subject line
> arch/x86/kernel/early_printk.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/early_printk.c
> b/arch/x86/kernel/early_printk.c
> index 076a4a7..77f2f5c 100644
> --- a/arch/x86/kernel/early_printk.c
> +++ b/arch/x86/kernel/early_printk.c
> @@ -195,14 +195,14 @@ static __init void early_serial_init(char *s)
> #ifdef CONFIG_PCI
> static void mem32_serial_out(unsigned long addr, int offset, int
> value)
> {
> - u32 *vaddr = (u32 *)addr;
> + void __iomem *vaddr = (void __iomem *)addr;
> /* shift implied by pointer type */
> writel(value, vaddr + offset);
> }
>
> static unsigned int mem32_serial_in(unsigned long addr, int offset)
> {
> - u32 *vaddr = (u32 *)addr;
> + void __iomem *vaddr = (void __iomem *)addr;
> /* shift implied by pointer type */
> return readl(vaddr + offset);
> }
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO
2015-10-09 14:29 [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO Andy Shevchenko
2015-10-09 14:35 ` Andy Shevchenko
@ 2015-10-11 19:18 ` Thomas Gleixner
2015-10-12 8:12 ` Andy Shevchenko
1 sibling, 1 reply; 5+ messages in thread
From: Thomas Gleixner @ 2015-10-11 19:18 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: linux-kernel, Ingo Molnar, H . Peter Anvin, x86
Andy,
On Fri, 9 Oct 2015, Andy Shevchenko wrote:
> #ifdef CONFIG_PCI
> static void mem32_serial_out(unsigned long addr, int offset, int value)
> {
> - u32 *vaddr = (u32 *)addr;
> + void __iomem *vaddr = (void __iomem *)addr;
> /* shift implied by pointer type */
> writel(value, vaddr + offset);
This is broken. Assume vaddr = 0x1000 and offset = 1
==> u32 *vaddr = 0x1000;
==> vaddr + offset = 0x1004
with your change
==> void __iomem *vaddr = 0x1000;
==> vaddr + offset = 0x1001
This comment is there for a reason:
> /* shift implied by pointer type */
Thanks,
tglx
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO
2015-10-11 19:18 ` Thomas Gleixner
@ 2015-10-12 8:12 ` Andy Shevchenko
2015-10-12 9:11 ` Thomas Gleixner
0 siblings, 1 reply; 5+ messages in thread
From: Andy Shevchenko @ 2015-10-12 8:12 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: linux-kernel, Ingo Molnar, H . Peter Anvin, x86
On Sun, 2015-10-11 at 21:18 +0200, Thomas Gleixner wrote:
> Andy,
>
> On Fri, 9 Oct 2015, Andy Shevchenko wrote:
> > #ifdef CONFIG_PCI
> > static void mem32_serial_out(unsigned long addr, int offset, int
> value)
> > {
> > - u32 *vaddr = (u32 *)addr;
> > + void __iomem *vaddr = (void __iomem *)addr;
> > /* shift implied by pointer type */
> > writel(value, vaddr + offset);
>
> This is broken. Assume vaddr = 0x1000 and offset = 1
Yes, I noticed in reply to myself
http://www.spinics.net/lists/kernel/msg2094143.html
Tests were okay because platform I have is using 8-bit I/O.
Does it make sense to use the following approach?
void __iomem *vaddr = (void __iomem *)addr;
writel(value, vaddr + offset << 2);
>
> ==> u32 *vaddr = 0x1000;
> ==> vaddr + offset = 0x1004
>
> with your change
>
> ==> void __iomem *vaddr = 0x1000;
>
> ==> vaddr + offset = 0x1001
>
> This comment is there for a reason:
> > /* shift implied by pointer type */
>
> Thanks,
>
> tglx
--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO
2015-10-12 8:12 ` Andy Shevchenko
@ 2015-10-12 9:11 ` Thomas Gleixner
0 siblings, 0 replies; 5+ messages in thread
From: Thomas Gleixner @ 2015-10-12 9:11 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: linux-kernel, Ingo Molnar, H . Peter Anvin, x86
On Mon, 12 Oct 2015, Andy Shevchenko wrote:
> On Sun, 2015-10-11 at 21:18 +0200, Thomas Gleixner wrote:
> > Andy,
> >
> > On Fri, 9 Oct 2015, Andy Shevchenko wrote:
> > > #ifdef CONFIG_PCI
> > > static void mem32_serial_out(unsigned long addr, int offset, int
> > value)
> > > {
> > > - u32 *vaddr = (u32 *)addr;
> > > + void __iomem *vaddr = (void __iomem *)addr;
> > > /* shift implied by pointer type */
> > > writel(value, vaddr + offset);
> >
> > This is broken. Assume vaddr = 0x1000 and offset = 1
>
> Yes, I noticed in reply to myself
> http://www.spinics.net/lists/kernel/msg2094143.html
>
> Tests were okay because platform I have is using 8-bit I/O.
>
> Does it make sense to use the following approach?
>
> void __iomem *vaddr = (void __iomem *)addr;
> writel(value, vaddr + offset << 2);
What's wrong with: u32 __iomem *vaddr ?
Thanks,
tglx
^ permalink raw reply [flat|nested] 5+ messages in thread
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2015-10-09 14:29 [PATCH v2 1/1] x86/early_printk: Use __iomem address space for IO Andy Shevchenko
2015-10-09 14:35 ` Andy Shevchenko
2015-10-11 19:18 ` Thomas Gleixner
2015-10-12 8:12 ` Andy Shevchenko
2015-10-12 9:11 ` Thomas Gleixner
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