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Commit fc8d7826 authored by Alexander Duyck's avatar Alexander Duyck Committed by H. Peter Anvin
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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: default avatarAlexander Duyck <alexander.h.duyck@intel.com>
Link: http://lkml.kernel.org/r/20121116215640.8521.80483.stgit@ahduyck-cp1.jf.intel.com


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 05a476b6

arch/x86/kernel/cpu/intel.c

+1 −1
Original line number Diff line number Diff line
@@ -168,7 +168,7 @@ int __cpuinit ppro_with_ram_bug(void) 
#ifdef CONFIG_X86_F00F_BUG

static void __cpuinit trap_init_f00f_bug(void)

{

	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);

	__set_fixmap(FIX_F00F_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO);



	/*

	 * Update the IDT descriptor and reload the IDT so that

arch/x86/kernel/setup.c

+8 −8
Original line number Diff line number Diff line
@@ -300,8 +300,8 @@ static void __init cleanup_highmap(void) 
static void __init reserve_brk(void)

{

	if (_brk_end > _brk_start)

		memblock_reserve(__pa(_brk_start),

				 __pa(_brk_end) - __pa(_brk_start));

		memblock_reserve(__pa_symbol(_brk_start),

				 _brk_end - _brk_start);



	/* Mark brk area as locked down and no longer taking any

	   new allocations */
@@ -761,12 +761,12 @@ void __init setup_arch(char **cmdline_p) 
	init_mm.end_data = (unsigned long) _edata;

	init_mm.brk = _brk_end;



	code_resource.start = virt_to_phys(_text);

	code_resource.end = virt_to_phys(_etext)-1;

	data_resource.start = virt_to_phys(_etext);

	data_resource.end = virt_to_phys(_edata)-1;

	bss_resource.start = virt_to_phys(&__bss_start);

	bss_resource.end = virt_to_phys(&__bss_stop)-1;

	code_resource.start = __pa_symbol(_text);

	code_resource.end = __pa_symbol(_etext)-1;

	data_resource.start = __pa_symbol(_etext);

	data_resource.end = __pa_symbol(_edata)-1;

	bss_resource.start = __pa_symbol(__bss_start);

	bss_resource.end = __pa_symbol(__bss_stop)-1;



#ifdef CONFIG_CMDLINE_BOOL

#ifdef CONFIG_CMDLINE_OVERRIDE

arch/x86/mm/init_64.c

+8 −10
Original line number Diff line number Diff line
@@ -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

arch/x86/mm/pageattr.c

+4 −4
Original line number Diff line number Diff line
@@ -94,12 +94,12 @@ static inline void split_page_count(int level) { } 


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 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, 
	 * 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)

arch/x86/platform/efi/efi.c

+2 −2
Original line number Diff line number Diff line
@@ -410,8 +410,8 @@ void __init efi_reserve_boot_services(void) 
		 * - Not within any part of the kernel

		 * - Not the bios reserved area

		*/

		if ((start+size >= virt_to_phys(_text)

				&& start <= virt_to_phys(_end)) ||

		if ((start+size >= __pa_symbol(_text)

				&& start <= __pa_symbol(_end)) ||

			!e820_all_mapped(start, start+size, E820_RAM) ||

			memblock_is_region_reserved(start, size)) {

			/* Could not reserve, skip it */