x86: Use __pa_symbol instead of __pa on C visible symbols
When I made an attempt at separating __pa_symbol and __pa I found that there
were a number of cases where __pa was used on an obvious symbol.
I also caught one non-obvious case as _brk_start and _brk_end are based on the
address of __brk_base which is a C visible symbol.
In mark_rodata_ro I was able to reduce the overhead of kernel symbol to
virtual memory translation by using a combination of __va(__pa_symbol())
instead of page_address(virt_to_page()).
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Link: http://lkml.kernel.org/r/20121116215640.8521.80483.stgit@ahduyck-cp1.jf.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 3baff25..0374a10 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -770,12 +770,10 @@
void mark_rodata_ro(void)
{
unsigned long start = PFN_ALIGN(_text);
- unsigned long rodata_start =
- ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
+ unsigned long rodata_start = PFN_ALIGN(__start_rodata);
unsigned long end = (unsigned long) &__end_rodata_hpage_align;
- unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
- unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
- unsigned long data_start = (unsigned long) &_sdata;
+ unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
+ unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
(end - start) >> 10);
@@ -800,12 +798,12 @@
#endif
free_init_pages("unused kernel memory",
- (unsigned long) page_address(virt_to_page(text_end)),
- (unsigned long)
- page_address(virt_to_page(rodata_start)));
+ (unsigned long) __va(__pa_symbol(text_end)),
+ (unsigned long) __va(__pa_symbol(rodata_start)));
+
free_init_pages("unused kernel memory",
- (unsigned long) page_address(virt_to_page(rodata_end)),
- (unsigned long) page_address(virt_to_page(data_start)));
+ (unsigned long) __va(__pa_symbol(rodata_end)),
+ (unsigned long) __va(__pa_symbol(_sdata)));
}
#endif
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index a718e0d..40f92f3 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -94,12 +94,12 @@
static inline unsigned long highmap_start_pfn(void)
{
- return __pa(_text) >> PAGE_SHIFT;
+ return __pa_symbol(_text) >> PAGE_SHIFT;
}
static inline unsigned long highmap_end_pfn(void)
{
- return __pa(roundup(_brk_end, PMD_SIZE)) >> PAGE_SHIFT;
+ return __pa_symbol(roundup(_brk_end, PMD_SIZE)) >> PAGE_SHIFT;
}
#endif
@@ -276,8 +276,8 @@
* The .rodata section needs to be read-only. Using the pfn
* catches all aliases.
*/
- if (within(pfn, __pa((unsigned long)__start_rodata) >> PAGE_SHIFT,
- __pa((unsigned long)__end_rodata) >> PAGE_SHIFT))
+ if (within(pfn, __pa_symbol(__start_rodata) >> PAGE_SHIFT,
+ __pa_symbol(__end_rodata) >> PAGE_SHIFT))
pgprot_val(forbidden) |= _PAGE_RW;
#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)