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>

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>
Alexander Duyck · H. Peter Anvin
1 parent 05a476b6e3
Showing 6 changed files with 27 additions and 29 deletions Side-by-side Diff
arch/x86/kernel/cpu/intel.c
arch/x86/kernel/setup.c
arch/x86/mm/init_64.c
arch/x86/mm/pageattr.c
arch/x86/platform/efi/efi.c
arch/x86/realmode/init.c
@@ -168,7 +168,7 @@
 #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
@@ -300,8 +300,8 @@
 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 @@
 	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
@@ -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
@@ -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)
@@ -410,8 +410,8 @@
 		 * - 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 */
@@ -62,9 +62,9 @@
 		__va(real_mode_header->trampoline_header);
  
 #ifdef CONFIG_X86_32
-	trampoline_header->start = __pa(startup_32_smp);
+	trampoline_header->start = __pa_symbol(startup_32_smp);
 	trampoline_header->gdt_limit = __BOOT_DS + 7;
-	trampoline_header->gdt_base = __pa(boot_gdt);
+	trampoline_header->gdt_base = __pa_symbol(boot_gdt);
 #else
 	/*
 	 * Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR
@@ -78,8 +78,8 @@
 	*trampoline_cr4_features = read_cr4();
  
 	trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
-	trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
-	trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
+	trampoline_pgd[0] = __pa_symbol(level3_ident_pgt) + _KERNPG_TABLE;
+	trampoline_pgd[511] = __pa_symbol(level3_kernel_pgt) + _KERNPG_TABLE;
 #endif
 }
...	...	@@ -168,7 +168,7 @@
168	168	#ifdef CONFIG_X86_F00F_BUG
169	169	static void __cpuinit trap_init_f00f_bug(void)
170	170	{
171		- __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
	171	+ __set_fixmap(FIX_F00F_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO);
172	172
173	173	/*
174	174	* Update the IDT descriptor and reload the IDT so that
...	...	@@ -300,8 +300,8 @@
300	300	static void __init reserve_brk(void)
301	301	{
302	302	if (_brk_end > _brk_start)
303		- memblock_reserve(__pa(_brk_start),
304		- __pa(_brk_end) - __pa(_brk_start));
	303	+ memblock_reserve(__pa_symbol(_brk_start),
	304	+ _brk_end - _brk_start);
305	305
306	306	/* Mark brk area as locked down and no longer taking any
307	307	new allocations */
...	...	@@ -761,12 +761,12 @@
761	761	init_mm.end_data = (unsigned long) _edata;
762	762	init_mm.brk = _brk_end;
763	763
764		- code_resource.start = virt_to_phys(_text);
765		- code_resource.end = virt_to_phys(_etext)-1;
766		- data_resource.start = virt_to_phys(_etext);
767		- data_resource.end = virt_to_phys(_edata)-1;
768		- bss_resource.start = virt_to_phys(&__bss_start);
769		- bss_resource.end = virt_to_phys(&__bss_stop)-1;
	764	+ code_resource.start = __pa_symbol(_text);
	765	+ code_resource.end = __pa_symbol(_etext)-1;
	766	+ data_resource.start = __pa_symbol(_etext);
	767	+ data_resource.end = __pa_symbol(_edata)-1;
	768	+ bss_resource.start = __pa_symbol(__bss_start);
	769	+ bss_resource.end = __pa_symbol(__bss_stop)-1;
770	770
771	771	#ifdef CONFIG_CMDLINE_BOOL
772	772	#ifdef CONFIG_CMDLINE_OVERRIDE
...	...	@@ -770,12 +770,10 @@
770	770	void mark_rodata_ro(void)
771	771	{
772	772	unsigned long start = PFN_ALIGN(_text);
773		- unsigned long rodata_start =
774		- ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
	773	+ unsigned long rodata_start = PFN_ALIGN(__start_rodata);
775	774	unsigned long end = (unsigned long) &__end_rodata_hpage_align;
776		- unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
777		- unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
778		- unsigned long data_start = (unsigned long) &_sdata;
	775	+ unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
	776	+ unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
779	777
780	778	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
781	779	(end - start) >> 10);
782	780
...	...	@@ -800,12 +798,12 @@
800	798	#endif
801	799
802	800	free_init_pages("unused kernel memory",
803		- (unsigned long) page_address(virt_to_page(text_end)),
804		- (unsigned long)
805		- page_address(virt_to_page(rodata_start)));
	801	+ (unsigned long) __va(__pa_symbol(text_end)),
	802	+ (unsigned long) __va(__pa_symbol(rodata_start)));
	803	+
806	804	free_init_pages("unused kernel memory",
807		- (unsigned long) page_address(virt_to_page(rodata_end)),
808		- (unsigned long) page_address(virt_to_page(data_start)));
	805	+ (unsigned long) __va(__pa_symbol(rodata_end)),
	806	+ (unsigned long) __va(__pa_symbol(_sdata)));
809	807	}
810	808
811	809	#endif
...	...	@@ -94,12 +94,12 @@
94	94
95	95	static inline unsigned long highmap_start_pfn(void)
96	96	{
97		- return __pa(_text) >> PAGE_SHIFT;
	97	+ return __pa_symbol(_text) >> PAGE_SHIFT;
98	98	}
99	99
100	100	static inline unsigned long highmap_end_pfn(void)
101	101	{
102		- return __pa(roundup(_brk_end, PMD_SIZE)) >> PAGE_SHIFT;
	102	+ return __pa_symbol(roundup(_brk_end, PMD_SIZE)) >> PAGE_SHIFT;
103	103	}
104	104
105	105	#endif
...	...	@@ -276,8 +276,8 @@
276	276	* The .rodata section needs to be read-only. Using the pfn
277	277	* catches all aliases.
278	278	*/
279		- if (within(pfn, __pa((unsigned long)__start_rodata) >> PAGE_SHIFT,
280		- __pa((unsigned long)__end_rodata) >> PAGE_SHIFT))
	279	+ if (within(pfn, __pa_symbol(__start_rodata) >> PAGE_SHIFT,
	280	+ __pa_symbol(__end_rodata) >> PAGE_SHIFT))
281	281	pgprot_val(forbidden) \|= _PAGE_RW;
282	282
283	283	#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA)
...	...	@@ -410,8 +410,8 @@
410	410	* - Not within any part of the kernel
411	411	* - Not the bios reserved area
412	412	*/
413		- if ((start+size >= virt_to_phys(_text)
414		- && start <= virt_to_phys(_end)) \|\|
	413	+ if ((start+size >= __pa_symbol(_text)
	414	+ && start <= __pa_symbol(_end)) \|\|
415	415	!e820_all_mapped(start, start+size, E820_RAM) \|\|
416	416	memblock_is_region_reserved(start, size)) {
417	417	/* Could not reserve, skip it */
...	...	@@ -62,9 +62,9 @@
62	62	__va(real_mode_header->trampoline_header);
63	63
64	64	#ifdef CONFIG_X86_32
65		- trampoline_header->start = __pa(startup_32_smp);
	65	+ trampoline_header->start = __pa_symbol(startup_32_smp);
66	66	trampoline_header->gdt_limit = __BOOT_DS + 7;
67		- trampoline_header->gdt_base = __pa(boot_gdt);
	67	+ trampoline_header->gdt_base = __pa_symbol(boot_gdt);
68	68	#else
69	69	/*
70	70	* Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR
...	...	@@ -78,8 +78,8 @@
78	78	*trampoline_cr4_features = read_cr4();
79	79
80	80	trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
81		- trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
82		- trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
	81	+ trampoline_pgd[0] = __pa_symbol(level3_ident_pgt) + _KERNPG_TABLE;
	82	+ trampoline_pgd[511] = __pa_symbol(level3_kernel_pgt) + _KERNPG_TABLE;
83	83	#endif
84	84	}
85	85