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);
/*
--
