2f569afd9c
Background: I've implemented 1K/2K page tables for s390. These sub-page page tables are required to properly support the s390 virtualization instruction with KVM. The SIE instruction requires that the page tables have 256 page table entries (pte) followed by 256 page status table entries (pgste). The pgstes are only required if the process is using the SIE instruction. The pgstes are updated by the hardware and by the hypervisor for a number of reasons, one of them is dirty and reference bit tracking. To avoid wasting memory the standard pte table allocation should return 1K/2K (31/64 bit) and 2K/4K if the process is using SIE. Problem: Page size on s390 is 4K, page table size is 1K or 2K. That means the s390 version for pte_alloc_one cannot return a pointer to a struct page. Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one cannot return a pointer to a pte either, since that would require more than 32 bit for the return value of pte_alloc_one (and the pte * would not be accessible since its not kmapped). Solution: The only solution I found to this dilemma is a new typedef: a pgtable_t. For s390 pgtable_t will be a (pte *) - to be introduced with a later patch. For everybody else it will be a (struct page *). The additional problem with the initialization of the ptl lock and the NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and a destructor pgtable_page_dtor. The page table allocation and free functions need to call these two whenever a page table page is allocated or freed. pmd_populate will get a pgtable_t instead of a struct page pointer. To get the pgtable_t back from a pmd entry that has been installed with pmd_populate a new function pmd_pgtable is added. It replaces the pmd_page call in free_pte_range and apply_to_pte_range. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
177 lines
4.4 KiB
C
177 lines
4.4 KiB
C
/*
|
|
* 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 <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)
|
|
|
|
#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(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 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 pud; } pud_t;
|
|
typedef struct {
|
|
unsigned long pgd0;
|
|
unsigned long pgd1;
|
|
unsigned long pgd2;
|
|
unsigned long pgd3;
|
|
} pgd_t;
|
|
|
|
#define pmd_val(x) ((x).pmd)
|
|
#define pud_val(x) ((x).pud)
|
|
#define pgd_val(x) ((x).pgd0)
|
|
|
|
#else /* __s390x__ */
|
|
|
|
typedef struct {
|
|
unsigned long pmd0;
|
|
unsigned long pmd1;
|
|
} pmd_t;
|
|
typedef struct { unsigned long pud; } pud_t;
|
|
typedef struct { unsigned long pgd; } pgd_t;
|
|
|
|
#define pmd_val(x) ((x).pmd0)
|
|
#define pmd_val1(x) ((x).pmd1)
|
|
#define pud_val(x) ((x).pud)
|
|
#define pgd_val(x) ((x).pgd)
|
|
|
|
#endif /* __s390x__ */
|
|
|
|
typedef struct page *pgtable_t;
|
|
|
|
#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 /* _S390_PAGE_H */
|