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linux/include/asm-s390/page.h
Heiko Carstens f4eb07c17d [S390] Virtual memmap for s390. 
Virtual memmap support for s390. Inspired by the ia64 implementation.

Unlike ia64 we need a mechanism which allows us to dynamically attach
shared memory regions.
These memory regions are accessed via the dcss device driver. dcss
implements the 'direct_access' operation, which requires struct pages
for every single shared page.
Therefore this implementation provides an interface to attach/detach
shared memory:

int add_shared_memory(unsigned long start, unsigned long size);
int remove_shared_memory(unsigned long start, unsigned long size);

The purpose of the add_shared_memory function is to add the given
memory range to the 1:1 mapping and to make sure that the
corresponding range in the vmemmap is backed with physical pages.
It also initialises the new struct pages.

remove_shared_memory in turn only invalidates the page table
entries in the 1:1 mapping. The page tables and the memory used for
struct pages in the vmemmap are currently not freed. They will be
reused when the next segment will be attached.
Given that the maximum size of a shared memory region is 2GB and
in addition all regions must reside below 2GB this is not too much of
a restriction, but there is room for improvement.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-12-08 15:56:07 +01:00

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/*
* include/asm-s390/page.h
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com)
*/
#ifndef _S390_PAGE_H
#define _S390_PAGE_H
#include <asm/types.h>
/* PAGE_SHIFT determines the page size */
#define PAGE_SHIFT 12
#define PAGE_SIZE (1UL << PAGE_SHIFT)
#define PAGE_MASK (~(PAGE_SIZE-1))
#define PAGE_DEFAULT_ACC 0
#define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4)
#ifdef __KERNEL__
#include <asm/setup.h>
#ifndef __ASSEMBLY__
static inline void clear_page(void *page)
{
register unsigned long reg1 asm ("1") = 0;
register void *reg2 asm ("2") = page;
register unsigned long reg3 asm ("3") = 4096;
asm volatile(
" mvcl 2,0"
: "+d" (reg2), "+d" (reg3) : "d" (reg1) : "memory", "cc");
}
static inline void copy_page(void *to, void *from)
{
if (MACHINE_HAS_MVPG) {
register unsigned long reg0 asm ("0") = 0;
asm volatile(
" mvpg %0,%1"
: : "a" (to), "a" (from), "d" (reg0)
: "memory", "cc");
} else
asm volatile(
" mvc 0(256,%0),0(%1)\n"
" mvc 256(256,%0),256(%1)\n"
" mvc 512(256,%0),512(%1)\n"
" mvc 768(256,%0),768(%1)\n"
" mvc 1024(256,%0),1024(%1)\n"
" mvc 1280(256,%0),1280(%1)\n"
" mvc 1536(256,%0),1536(%1)\n"
" mvc 1792(256,%0),1792(%1)\n"
" mvc 2048(256,%0),2048(%1)\n"
" mvc 2304(256,%0),2304(%1)\n"
" mvc 2560(256,%0),2560(%1)\n"
" mvc 2816(256,%0),2816(%1)\n"
" mvc 3072(256,%0),3072(%1)\n"
" mvc 3328(256,%0),3328(%1)\n"
" mvc 3584(256,%0),3584(%1)\n"
" mvc 3840(256,%0),3840(%1)\n"
: : "a" (to), "a" (from) : "memory");
}
#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 pgprot; } pgprot_t;
typedef struct { unsigned long pte; } pte_t;
#define pte_val(x) ((x).pte)
#define pgprot_val(x) ((x).pgprot)
#ifndef __s390x__
typedef struct { unsigned long pmd; } pmd_t;
typedef struct {
unsigned long pgd0;
unsigned long pgd1;
unsigned long pgd2;
unsigned long pgd3;
} pgd_t;
#define pmd_val(x) ((x).pmd)
#define pgd_val(x) ((x).pgd0)
#else /* __s390x__ */
typedef struct {
unsigned long pmd0;
unsigned long pmd1;
} pmd_t;
typedef struct { unsigned long pgd; } pgd_t;
#define pmd_val(x) ((x).pmd0)
#define pmd_val1(x) ((x).pmd1)
#define pgd_val(x) ((x).pgd)
#endif /* __s390x__ */
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
/* default storage key used for all pages */
extern unsigned int default_storage_key;
static inline void
page_set_storage_key(unsigned long addr, unsigned int skey)
{
asm volatile("sske %0,%1" : : "d" (skey), "a" (addr));
}
static inline unsigned int
page_get_storage_key(unsigned long addr)
{
unsigned int skey;
asm volatile("iske %0,%1" : "=d" (skey) : "a" (addr), "0" (0));
return skey;
}
extern unsigned long max_pfn;
static inline int pfn_valid(unsigned long pfn)
{
unsigned long dummy;
int ccode;
if (pfn >= max_pfn)
return 0;
asm volatile(
" lra %0,0(%2)\n"
" ipm %1\n"
" srl %1,28\n"
: "=d" (dummy), "=d" (ccode)
: "a" (pfn << PAGE_SHIFT)
: "cc");
return !ccode;
}
#endif /* !__ASSEMBLY__ */
/* to align the pointer to the (next) page boundary */
#define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK)
#define __PAGE_OFFSET 0x0UL
#define PAGE_OFFSET 0x0UL
#define __pa(x) (unsigned long)(x)
#define __va(x) (void *)(unsigned long)(x)
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#include <asm-generic/memory_model.h>
#include <asm-generic/page.h>
#endif /* __KERNEL__ */
#endif /* _S390_PAGE_H */
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