/*
* include/asm-xtensa/page.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version2 as
* published by the Free Software Foundation.
*
* Copyright (C) 2001 - 2007 Tensilica Inc.
*/
#ifndef _XTENSA_PAGE_H
#define _XTENSA_PAGE_H
#include <asm/processor.h>
#include <asm/types.h>
#include <asm/cache.h>
/*
* Fixed TLB translations in the processor.
*/
#define XCHAL_KSEG_CACHED_VADDR 0xd0000000
#define XCHAL_KSEG_BYPASS_VADDR 0xd8000000
#define XCHAL_KSEG_PADDR 0x00000000
#define XCHAL_KSEG_SIZE 0x08000000
/*
* PAGE_SHIFT determines the page size
*/
#define PAGE_SHIFT 12
#define PAGE_SIZE (__XTENSA_UL_CONST(1) << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#define PAGE_OFFSET XCHAL_KSEG_CACHED_VADDR
#define MAX_MEM_PFN XCHAL_KSEG_SIZE
#define PGTABLE_START 0x80000000
/*
* Cache aliasing:
*
* If the cache size for one way is greater than the page size, we have to
* deal with cache aliasing. The cache index is wider than the page size:
*
* | |cache| cache index
* | pfn |off| virtual address
* |xxxx:X|zzz|
* | : | |
* | \ / | |
* |trans.| |
* | / \ | |
* |yyyy:Y|zzz| physical address
*
* When the page number is translated to the physical page address, the lowest
* bit(s) (X) that are part of the cache index are also translated (Y).
* If this translation changes bit(s) (X), the cache index is also afected,
* thus resulting in a different cache line than before.
* The kernel does not provide a mechanism to ensure that the page color
* (represented by this bit) remains the same when allocated or when pages
* are remapped. When user pages are mapped into kernel space, the color of
* the page might also change.
*
* We use the address space VMALLOC_END ... VMALLOC_END + DCACHE_WAY_SIZE * 2
* to temporarily map a patch so we can match the color.
*/
#if DCACHE_WAY_SIZE > PAGE_SIZE
# define DCACHE_ALIAS_ORDER (DCACHE_WAY_SHIFT - PAGE_SHIFT)
# define DCACHE_ALIAS_MASK (PAGE_MASK & (DCACHE_WAY_SIZE - 1))
# define DCACHE_ALIAS(a) (((a) & DCACHE_ALIAS_MASK) >> PAGE_SHIFT)
# define DCACHE_ALIAS_EQ(a,b) ((((a) ^ (b)) & DCACHE_ALIAS_MASK) == 0)
#else
# define DCACHE_ALIAS_ORDER 0
#endif
#if ICACHE_WAY_SIZE > PAGE_SIZE
# define ICACHE_ALIAS_ORDER (ICACHE_WAY_SHIFT - PAGE_SHIFT)
# define ICACHE_ALIAS_MASK (PAGE_MASK & (ICACHE_WAY_SIZE - 1))
# define ICACHE_ALIAS(a) (((a) & ICACHE_ALIAS_MASK) >> PAGE_SHIFT)
# define ICACHE_ALIAS_EQ(a,b) ((((a) ^ (b)) & ICACHE_ALIAS_MASK) == 0)
#else
# define ICACHE_ALIAS_ORDER 0
#endif
#ifdef __ASSEMBLY__
#define __pgprot(x) (x)
#else
/*
* These are used to make use of C type-checking..
*/
typedef struct { unsigned long pte; } pte_t; /* page table entry */
typedef struct { unsigned long pgd; } pgd_t; /* PGD table entry */
typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct page *pgtable_t;
#define pte_val(x) ((x).pte)
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
/*
* Pure 2^n version of get_order
* Use 'nsau' instructions if supported by the processor or the generic version.
*/
#if XCHAL_HAVE_NSA
static inline __attribute_const__ int get_order(unsigned long size)
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" ((size - 1) >> PAGE_SHIFT));
return 32 - lz;
}
#else
# include <asm-generic/page.h>
#endif
struct page;
extern void clear_page(void *page);
extern void copy_page(void *to, void *from);
/*
* If we have cache aliasing and writeback caches, we might have to do
* some extra work
*/
#if DCACHE_WAY_SIZE > PAGE_SIZE
extern void clear_user_page(void*, unsigned long, struct page*);
extern void copy_user_page(void*, void*, unsigned long, struct page*);
#else
# define clear_user_page(page, vaddr, pg) clear_page(page)
# define copy_user_page(to, from, vaddr, pg) copy_page(to, from)
#endif
/*
* This handles the memory map. We handle pages at
* XCHAL_KSEG_CACHED_VADDR for kernels with 32 bit address space.
* These macros are for conversion of kernel address, not user
* addresses.
*/
#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET)
#define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET))
#define pfn_valid(pfn) ((unsigned long)pfn < max_mapnr)
#ifdef CONFIG_DISCONTIGMEM
# error CONFIG_DISCONTIGMEM not supported
#endif
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_virt(page) __va(page_to_pfn(page) << PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
#define WANT_PAGE_VIRTUAL
#endif /* __ASSEMBLY__ */
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#include <asm-generic/memory_model.h>
#endif /* _XTENSA_PAGE_H */
