alistair23-linux/include/asm-x86_64/page.h
Vivek Goyal 0dbf7028c0 [PATCH] x86: __pa and __pa_symbol address space separation
Currently __pa_symbol is for use with symbols in the kernel address
map and __pa is for use with pointers into the physical memory map.
But the code is implemented so you can usually interchange the two.

__pa which is much more common can be implemented much more cheaply
if it is it doesn't have to worry about any other kernel address
spaces.  This is especially true with a relocatable kernel as
__pa_symbol needs to peform an extra variable read to resolve
the address.

There is a third macro that is added for the vsyscall data
__pa_vsymbol for finding the physical addesses of vsyscall pages.

Most of this patch is simply sorting through the references to
__pa or __pa_symbol and using the proper one.  A little of
it is continuing to use a physical address when we have it
instead of recalculating it several times.

swapper_pgd is now NULL.  leave_mm now uses init_mm.pgd
and init_mm.pgd is initialized at boot (instead of compile time)
to the physmem virtual mapping of init_level4_pgd.  The
physical address changed.

Except for the for EMPTY_ZERO page all of the remaining references
to __pa_symbol appear to be during kernel initialization.  So this
should reduce the cost of __pa in the common case, even on a relocated
kernel.

As this is technically a semantic change we need to be on the lookout
for anything I missed.  But it works for me (tm).

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
2007-05-02 19:27:07 +02:00

134 lines
4 KiB
C

#ifndef _X86_64_PAGE_H
#define _X86_64_PAGE_H
#include <asm/const.h>
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#define PHYSICAL_PAGE_MASK (~(PAGE_SIZE-1) & __PHYSICAL_MASK)
#define THREAD_ORDER 1
#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
#define CURRENT_MASK (~(THREAD_SIZE-1))
#define EXCEPTION_STACK_ORDER 0
#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
#define DEBUG_STACK_ORDER (EXCEPTION_STACK_ORDER + 1)
#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)
#define IRQSTACK_ORDER 2
#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)
#define STACKFAULT_STACK 1
#define DOUBLEFAULT_STACK 2
#define NMI_STACK 3
#define DEBUG_STACK 4
#define MCE_STACK 5
#define N_EXCEPTION_STACKS 5 /* hw limit: 7 */
#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
#define LARGE_PAGE_SIZE (_AC(1,UL) << PMD_SHIFT)
#define HPAGE_SHIFT PMD_SHIFT
#define HPAGE_SIZE (_AC(1,UL) << HPAGE_SHIFT)
#define HPAGE_MASK (~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
extern unsigned long end_pfn;
void clear_page(void *);
void copy_page(void *, void *);
#define clear_user_page(page, vaddr, pg) clear_page(page)
#define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
#define alloc_zeroed_user_highpage(vma, vaddr) alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO, vma, vaddr)
#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
/*
* These are used to make use of C type-checking..
*/
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pud; } pud_t;
typedef struct { unsigned long pgd; } pgd_t;
#define PTE_MASK PHYSICAL_PAGE_MASK
typedef struct { unsigned long pgprot; } pgprot_t;
#define pte_val(x) ((x).pte)
#define pmd_val(x) ((x).pmd)
#define pud_val(x) ((x).pud)
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pud(x) ((pud_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
#endif /* !__ASSEMBLY__ */
#define __PHYSICAL_START CONFIG_PHYSICAL_START
#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
#define __START_KERNEL_map 0xffffffff80000000
#define __PAGE_OFFSET 0xffff810000000000
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
/* See Documentation/x86_64/mm.txt for a description of the memory map. */
#define __PHYSICAL_MASK_SHIFT 46
#define __PHYSICAL_MASK ((_AC(1,UL) << __PHYSICAL_MASK_SHIFT) - 1)
#define __VIRTUAL_MASK_SHIFT 48
#define __VIRTUAL_MASK ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - 1)
#define KERNEL_TEXT_SIZE (40*1024*1024)
#define KERNEL_TEXT_START 0xffffffff80000000
#ifndef __ASSEMBLY__
#include <asm/bug.h>
#endif /* __ASSEMBLY__ */
#define PAGE_OFFSET __PAGE_OFFSET
/* Note: __pa(&symbol_visible_to_c) should be always replaced with __pa_symbol.
Otherwise you risk miscompilation. */
#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
/* __pa_symbol should be used for C visible symbols.
This seems to be the official gcc blessed way to do such arithmetic. */
#define __pa_symbol(x) \
({unsigned long v; \
asm("" : "=r" (v) : "0" (x)); \
(v - __START_KERNEL_map); })
#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
#ifdef CONFIG_FLATMEM
#define pfn_valid(pfn) ((pfn) < end_pfn)
#endif
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
#define VM_DATA_DEFAULT_FLAGS \
(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#define __HAVE_ARCH_GATE_AREA 1
#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>
#endif /* __KERNEL__ */
#endif /* _X86_64_PAGE_H */