From fc8d782677f163dee76427fdd8a92bebd2b50b23 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Fri, 16 Nov 2012 13:57:13 -0800 Subject: 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 Link: http://lkml.kernel.org/r/20121116215640.8521.80483.stgit@ahduyck-cp1.jf.intel.com Signed-off-by: H. Peter Anvin --- arch/x86/mm/init_64.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) (limited to 'arch/x86/mm/init_64.c') diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 3baff255adac..0374a10f4fb7 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -770,12 +770,10 @@ void set_kernel_text_ro(void) 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 @@ void mark_rodata_ro(void) #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 -- cgit v1.2.3-55-g7522