cregit-Linux how code gets into the kernel

Release 4.14 arch/xtensa/include/asm/page.h

/*
 * 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>
#include <platform/hardware.h>
#include <asm/kmem_layout.h>

/*
 * 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))

#ifdef CONFIG_MMU

#define PAGE_OFFSET	XCHAL_KSEG_CACHED_VADDR

#define PHYS_OFFSET	XCHAL_KSEG_PADDR

#define MAX_LOW_PFN	(PHYS_PFN(XCHAL_KSEG_PADDR) + \
                         PHYS_PFN(XCHAL_KSEG_SIZE))
#else

#define PAGE_OFFSET	PLATFORM_DEFAULT_MEM_START

#define PHYS_OFFSET	PLATFORM_DEFAULT_MEM_START

#define MAX_LOW_PFN	PHYS_PFN(0xfffffffful)
#endif


#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

# define DCACHE_ALIAS(a)	((void)(a), 0)
#endif

#define DCACHE_N_COLORS		(1 << DCACHE_ALIAS_ORDER)

#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; }

Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel1990.48%266.67%
Adrian Bunk29.52%133.33%
Total21100.00%3100.00%

#else # include <asm-generic/getorder.h> #endif struct page; struct vm_area_struct; 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 defined(CONFIG_MMU) && DCACHE_WAY_SIZE > PAGE_SIZE extern void clear_page_alias(void *vaddr, unsigned long paddr); extern void copy_page_alias(void *to, void *from, unsigned long to_paddr, unsigned long from_paddr); #define clear_user_highpage clear_user_highpage void clear_user_highpage(struct page *page, unsigned long vaddr); #define __HAVE_ARCH_COPY_USER_HIGHPAGE void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma); #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 ARCH_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT) #ifdef CONFIG_MMU
static inline unsigned long ___pa(unsigned long va) { unsigned long off = va - PAGE_OFFSET; if (off >= XCHAL_KSEG_SIZE) off -= XCHAL_KSEG_SIZE; return off + PHYS_OFFSET; }

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Max Filippov35100.00%1100.00%
Total35100.00%1100.00%

#define __pa(x) ___pa((unsigned long)(x)) #else #define __pa(x) \ ((unsigned long) (x) - PAGE_OFFSET + PHYS_OFFSET) #endif #define __va(x) \ ((void *)((unsigned long) (x) - PHYS_OFFSET + PAGE_OFFSET)) #define pfn_valid(pfn) \ ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < 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) #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 */

Overall Contributors

PersonTokensPropCommitsCommitProp
Chris Zankel38068.84%628.57%
Max Filippov13925.18%838.10%
Johannes Weiner213.80%29.52%
Martin Schwidefsky61.09%14.76%
Adrian Bunk20.36%14.76%
Kamezawa Hiroyuki20.36%14.76%
Arnd Bergmann10.18%14.76%
Andrea Righi10.18%14.76%
Total552100.00%21100.00%
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