linux/arch/s390/include/asm/page.h
Martin Schwidefsky 0944fe3f4a s390/mm: implement software referenced bits
The last remaining use for the storage key of the s390 architecture
is reference counting. The alternative is to make page table entries
invalid while they are old. On access the fault handler marks the
pte/pmd as young which makes the pte/pmd valid if the access rights
allow read access. The pte/pmd invalidations required for software
managed reference bits cost a bit of performance, on the other hand
the RRBE/RRBM instructions to read and reset the referenced bits are
quite expensive as well.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-08-29 13:20:11 +02:00

175 lines
4.7 KiB
C

/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Hartmut Penner (hp@de.ibm.com)
*/
#ifndef _S390_PAGE_H
#define _S390_PAGE_H
#include <linux/const.h>
#include <asm/types.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 PAGE_DEFAULT_ACC 0
#define PAGE_DEFAULT_KEY (PAGE_DEFAULT_ACC << 4)
#define HPAGE_SHIFT 20
#define HPAGE_SIZE (1UL << HPAGE_SHIFT)
#define HPAGE_MASK (~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
#define ARCH_HAS_SETCLEAR_HUGE_PTE
#define ARCH_HAS_HUGE_PTE_TYPE
#define ARCH_HAS_PREPARE_HUGEPAGE
#define ARCH_HAS_HUGEPAGE_CLEAR_FLUSH
#include <asm/setup.h>
#ifndef __ASSEMBLY__
void storage_key_init_range(unsigned long start, unsigned long end);
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(movableflags, vma, vaddr) \
alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, 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 pgste; } pgste_t;
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;
typedef pte_t *pgtable_t;
#define pgprot_val(x) ((x).pgprot)
#define pgste_val(x) ((x).pgste)
#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 __pgste(x) ((pgste_t) { (x) } )
#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) } )
static inline void page_set_storage_key(unsigned long addr,
unsigned char skey, int mapped)
{
if (!mapped)
asm volatile(".insn rrf,0xb22b0000,%0,%1,8,0"
: : "d" (skey), "a" (addr));
else
asm volatile("sske %0,%1" : : "d" (skey), "a" (addr));
}
static inline unsigned char page_get_storage_key(unsigned long addr)
{
unsigned char skey;
asm volatile("iske %0,%1" : "=d" (skey) : "a" (addr));
return skey;
}
static inline int page_reset_referenced(unsigned long addr)
{
unsigned int ipm;
asm volatile(
" rrbe 0,%1\n"
" ipm %0\n"
: "=d" (ipm) : "a" (addr) : "cc");
return !!(ipm & 0x20000000);
}
/* Bits int the storage key */
#define _PAGE_CHANGED 0x02 /* HW changed bit */
#define _PAGE_REFERENCED 0x04 /* HW referenced bit */
#define _PAGE_FP_BIT 0x08 /* HW fetch protection bit */
#define _PAGE_ACC_BITS 0xf0 /* HW access control bits */
struct page;
void arch_free_page(struct page *page, int order);
void arch_alloc_page(struct page *page, int order);
void arch_set_page_states(int make_stable);
static inline int devmem_is_allowed(unsigned long pfn)
{
return 0;
}
#define HAVE_ARCH_FREE_PAGE
#define HAVE_ARCH_ALLOC_PAGE
#endif /* !__ASSEMBLY__ */
#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_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
#include <asm-generic/memory_model.h>
#include <asm-generic/getorder.h>
#define __HAVE_ARCH_GATE_AREA 1
#endif /* _S390_PAGE_H */