* [PATCH] archs: add ioremap_change_write_prot
@ 2010-10-24 8:41 Marco Stornelli
2010-10-26 10:56 ` Marco Stornelli
2010-10-26 16:24 ` Thomas Gleixner
0 siblings, 2 replies; 6+ messages in thread
From: Marco Stornelli @ 2010-10-24 8:41 UTC (permalink / raw)
To: Linux Kernel; +Cc: x86, Tim Bird, andi
From: Marco Stornelli <marco.stornelli@gmail.com>
This patch adds a new function called ioremap_change_write_prot.
Goal of this patch is to create a general function for all archs to be
able to change a write protection of a memory mapped area. x86
has already got a similar framework, so this function is only
a wrapper. Next target will be arm and powerpc. This function
will be used by Pramfs (see its latest review).
Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
---
diff -Nurp linux-2.6.36-orig/arch/x86/mm/ioremap.c linux-2.6.36/arch/x86/mm/ioremap.c
--- linux-2.6.36-orig/arch/x86/mm/ioremap.c 2010-09-13 01:07:37.000000000 +0200
+++ linux-2.6.36/arch/x86/mm/ioremap.c 2010-10-24 10:03:36.000000000 +0200
@@ -50,6 +50,27 @@ int ioremap_change_attr(unsigned long va
return err;
}
+int ioremap_change_write_prot(unsigned long vaddr, unsigned long size,
+ unsigned int rw)
+{
+ unsigned long nrpages = size >> PAGE_SHIFT;
+ int ret;
+
+ /* Page aligned */
+ vaddr &= PAGE_MASK;
+
+ if (size & (PAGE_SIZE - 1))
+ nrpages++;
+
+ if (rw)
+ ret = set_memory_rw(vaddr, nrpages);
+ else
+ ret = set_memory_ro(vaddr, nrpages);
+
+ return ret;
+}
+EXPORT_SYMBOL(ioremap_change_write_prot);
+
/*
* Remap an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access high addresses
--- linux-2.6.36-orig/arch/Kconfig 2010-09-13 01:07:37.000000000 +0200
+++ linux-2.6.36/arch/Kconfig 2010-10-23 09:29:56.000000000 +0200
@@ -83,6 +83,9 @@ config USER_RETURN_NOTIFIER
config HAVE_IOREMAP_PROT
bool
+config HAVE_IOREMAP_CHANGE_WRITE_PROT
+ bool
+
config HAVE_KPROBES
bool
--- linux-2.6.36-orig/arch/x86/Kconfig 2010-09-13 01:07:37.000000000 +0200
+++ linux-2.6.36/arch/x86/Kconfig 2010-10-23 09:09:06.000000000 +0200
@@ -26,6 +26,7 @@ config X86
select HAVE_OPROFILE
select HAVE_PERF_EVENTS if (!M386 && !M486)
select HAVE_IOREMAP_PROT
+ select HAVE_IOREMAP_CHANGE_WRITE_PROT
select HAVE_KPROBES
select ARCH_WANT_OPTIONAL_GPIOLIB
select ARCH_WANT_FRAME_POINTERS
diff -Nurp linux-2.6.36-orig/arch/x86/include/asm/io.h linux-2.6.36/arch/x86/include/asm/io.h
--- linux-2.6.36-orig/arch/x86/include/asm/io.h 2010-09-13 01:07:37.000000000 +0200
+++ linux-2.6.36/arch/x86/include/asm/io.h 2010-10-23 09:11:37.000000000 +0200
@@ -333,6 +333,8 @@ extern void unxlate_dev_mem_ptr(unsigned
extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
unsigned long prot_val);
+extern int ioremap_change_write_prot(unsigned long vaddr, unsigned long size,
+ unsigned int rw);
extern void __iomem *ioremap_wc(resource_size_t offset, unsigned long size);
/*
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] archs: add ioremap_change_write_prot
2010-10-24 8:41 [PATCH] archs: add ioremap_change_write_prot Marco Stornelli
@ 2010-10-26 10:56 ` Marco Stornelli
2010-10-26 13:14 ` Andi Kleen
2010-10-26 16:24 ` Thomas Gleixner
1 sibling, 1 reply; 6+ messages in thread
From: Marco Stornelli @ 2010-10-26 10:56 UTC (permalink / raw)
To: Linux Kernel; +Cc: x86, Tim Bird, andi, Andrew Morton
2010/10/24 Marco Stornelli <marco.stornelli@gmail.com>:
> From: Marco Stornelli <marco.stornelli@gmail.com>
>
> This patch adds a new function called ioremap_change_write_prot.
> Goal of this patch is to create a general function for all archs to be
> able to change a write protection of a memory mapped area. x86
> has already got a similar framework, so this function is only
> a wrapper. Next target will be arm and powerpc. This function
> will be used by Pramfs (see its latest review).
>
> Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
Sorry to re-open the topic, but I'd like to receive any
comments/feedback about this patch.
Marco
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] archs: add ioremap_change_write_prot
2010-10-26 10:56 ` Marco Stornelli
@ 2010-10-26 13:14 ` Andi Kleen
0 siblings, 0 replies; 6+ messages in thread
From: Andi Kleen @ 2010-10-26 13:14 UTC (permalink / raw)
To: Marco Stornelli; +Cc: Linux Kernel, x86, Tim Bird, andi, Andrew Morton
> Sorry to re-open the topic, but I'd like to receive any
> comments/feedback about this patch.
The name of the wrapper seems wrong -- this has nothing to do with IO.
I must admit I'm also not a fan of wrappers, why not call the set_memory_*
functions directly and implement them for the other archs too?
Other than that it seems reasonable.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] archs: add ioremap_change_write_prot
2010-10-24 8:41 [PATCH] archs: add ioremap_change_write_prot Marco Stornelli
2010-10-26 10:56 ` Marco Stornelli
@ 2010-10-26 16:24 ` Thomas Gleixner
2010-10-27 6:55 ` Marco Stornelli
1 sibling, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2010-10-26 16:24 UTC (permalink / raw)
To: Marco Stornelli; +Cc: Linux Kernel, x86, Tim Bird, andi
On Sun, 24 Oct 2010, Marco Stornelli wrote:
> From: Marco Stornelli <marco.stornelli@gmail.com>
>
> This patch adds a new function called ioremap_change_write_prot.
> Goal of this patch is to create a general function for all archs to be
> able to change a write protection of a memory mapped area. x86
> has already got a similar framework, so this function is only
> a wrapper. Next target will be arm and powerpc. This function
> will be used by Pramfs (see its latest review).
Sorry for the delay. I'm traveling.
> Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com>
> ---
>
> diff -Nurp linux-2.6.36-orig/arch/x86/mm/ioremap.c linux-2.6.36/arch/x86/mm/ioremap.c
> --- linux-2.6.36-orig/arch/x86/mm/ioremap.c 2010-09-13 01:07:37.000000000 +0200
> +++ linux-2.6.36/arch/x86/mm/ioremap.c 2010-10-24 10:03:36.000000000 +0200
> @@ -50,6 +50,27 @@ int ioremap_change_attr(unsigned long va
> return err;
> }
> +int ioremap_change_write_prot(unsigned long vaddr, unsigned long size,
> + unsigned int rw)
> +{
> + unsigned long nrpages = size >> PAGE_SHIFT;
> + int ret;
> +
> + /* Page aligned */
> + vaddr &= PAGE_MASK;
> +
> + if (size & (PAGE_SIZE - 1))
> + nrpages++;
> +
> + if (rw)
> + ret = set_memory_rw(vaddr, nrpages);
> + else
> + ret = set_memory_ro(vaddr, nrpages);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(ioremap_change_write_prot);
Why inventing a new interface if we have one already ?
set_memory_* which has a few more variants than ro/rw
Also this is not related to ioremap, these are functions which works on
almost anything when there are other restrictions in place.
So implementing set_memory_ro(), set_memory_rw() for those archs which
you need it for makes more sense than creating a misnomed and
misplaced wrapper.
Thanks,
tglx
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] archs: add ioremap_change_write_prot
2010-10-26 16:24 ` Thomas Gleixner
@ 2010-10-27 6:55 ` Marco Stornelli
2010-10-27 7:59 ` Andi Kleen
0 siblings, 1 reply; 6+ messages in thread
From: Marco Stornelli @ 2010-10-27 6:55 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: Linux Kernel, x86, Tim Bird, andi
2010/10/26 Thomas Gleixner <tglx@linutronix.de>:
>
> Why inventing a new interface if we have one already ?
>
> set_memory_* which has a few more variants than ro/rw
>
> Also this is not related to ioremap, these are functions which works on
> almost anything when there are other restrictions in place.
>
> So implementing set_memory_ro(), set_memory_rw() for those archs which
> you need it for makes more sense than creating a misnomed and
> misplaced wrapper.
>
> Thanks,
>
> tglx
>
Andi and Thomas, thanks for your response. I was trying to use an
homogeneous interface, I see that only x86 has got set_memory_*, but
ok I can use these ones. About the name I used, I was trying to use a
way to change the protection after an ioremap, so for x86 means a call
to these functions, but other archs could mean other checks.
However it needs to adds a define or something similar to know if the
archs implements or not this interface. Suggestions about this point?
Thanks.
Marco
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] archs: add ioremap_change_write_prot
2010-10-27 6:55 ` Marco Stornelli
@ 2010-10-27 7:59 ` Andi Kleen
0 siblings, 0 replies; 6+ messages in thread
From: Andi Kleen @ 2010-10-27 7:59 UTC (permalink / raw)
To: Marco Stornelli; +Cc: Thomas Gleixner, Linux Kernel, x86, Tim Bird, andi
> However it needs to adds a define or something similar to know if the
> archs implements or not this interface. Suggestions about this point?
That's fine, you can do that in Kconfig. I think you already had that
in the earlier patch: just give it a better name.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2010-10-27 7:59 UTC | newest]
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2010-10-24 8:41 [PATCH] archs: add ioremap_change_write_prot Marco Stornelli
2010-10-26 10:56 ` Marco Stornelli
2010-10-26 13:14 ` Andi Kleen
2010-10-26 16:24 ` Thomas Gleixner
2010-10-27 6:55 ` Marco Stornelli
2010-10-27 7:59 ` Andi Kleen
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