/*
* IBM System z Huge TLB Page Support for Kernel.
*
* Copyright IBM Corp. 2008
* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
*/
#ifndef _ASM_S390_HUGETLB_H
#define _ASM_S390_HUGETLB_H
#include <asm/page.h>
#include <asm/pgtable.h>
#define is_hugepage_only_range(mm, addr, len) 0
#define hugetlb_free_pgd_range free_pgd_range
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte);
/*
* If the arch doesn't supply something else, assume that hugepage
* size aligned regions are ok without further preparation.
*/
static inline int prepare_hugepage_range(struct file *file,
unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
return -EINVAL;
return 0;
}
#define hugetlb_prefault_arch_hook(mm) do { } while (0)
int arch_prepare_hugepage(struct page *page);
void arch_release_hugepage(struct page *page);
static inline pte_t pte_mkhuge(pte_t pte)
{
/*
* PROT_NONE needs to be remapped from the pte type to the ste type.
* The HW invalid bit is also different for pte and ste. The pte
* invalid bit happens to be the same as the ste _SEGMENT_ENTRY_LARGE
* bit, so we don't have to clear it.
*/
if (pte_val(pte) & _PAGE_INVALID) {
if (pte_val(pte) & _PAGE_SWT)
pte_val(pte) |= _HPAGE_TYPE_NONE;
pte_val(pte) |= _SEGMENT_ENTRY_INV;
}
/*
* Clear SW pte bits SWT and SWX, there are no SW bits in a segment
* table entry.
*/
pte_val(pte) &= ~(_PAGE_SWT | _PAGE_SWX);
/*
* Also set the change-override bit because we don't need dirty bit
* tracking for hugetlbfs pages.
*/
pte_val(pte) |= (_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO);
return pte;
}
static inline pte_t huge_pte_wrprotect(pte_t pte)
{
pte_val(pte) |= _PAGE_RO;
return pte;
}
static inline int huge_pte_none(pte_t pte)
{
return (pte_val(pte) & _SEGMENT_ENTRY_INV) &&
!(pte_val(pte) & _SEGMENT_ENTRY_RO);
}
static inline pte_t huge_ptep_get(pte_t *ptep)
{
pte_t pte = *ptep;
unsigned long mask;
if (!MACHINE_HAS_HPAGE) {
ptep = (pte_t *) (pte_val(pte) & _SEGMENT_ENTRY_ORIGIN);
if (ptep) {
mask = pte_val(pte) &
(_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
pte = pte_mkhuge(*ptep);
pte_val(pte) |= mask;
}
}
return pte;
}
static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pte_t pte = huge_ptep_get(ptep);
pmd_clear((pmd_t *) ptep);
return pte;
}
static inline void __pmd_csp(pmd_t *pmdp)
{
register unsigned long reg2 asm("2") = pmd_val(*pmdp);
register unsigned long reg3 asm("3") = pmd_val(*pmdp) |
_SEGMENT_ENTRY_INV;
register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5;
asm volatile(
" csp %1,%3"
: "=m" (*pmdp)
: "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc");
pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
}
static inline void __pmd_idte(unsigned long address, pmd_t *pmdp)
{
unsigned long sto = (unsigned long) pmdp -
pmd_index(address) * sizeof(pmd_t);
if (!(pmd_val(*pmdp) & _SEGMENT_ENTRY_INV)) {
asm volatile(
" .insn rrf,0xb98e0000,%2,%3,0,0"
: "=m" (*pmdp)
: "m" (*pmdp), "a" (sto),
"a" ((address & HPAGE_MASK))
);
}
pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
}
static inline void huge_ptep_invalidate(struct mm_struct *mm,
unsigned long address, pte_t *ptep)
{
pmd_t *pmdp = (pmd_t *) ptep;
if (!MACHINE_HAS_IDTE) {
__pmd_csp(pmdp);
if (mm->context.noexec) {
pmdp = get_shadow_table(pmdp);
__pmd_csp(pmdp);
}
return;
}
__pmd_idte(address, pmdp);
if (mm->context.noexec) {
pmdp = get_shadow_table(pmdp);
__pmd_idte(address, pmdp);
}
return;
}
#define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \
({ \
int __changed = !pte_same(huge_ptep_get(__ptep), __entry); \
if (__changed) { \
huge_ptep_invalidate((__vma)->vm_mm, __addr, __ptep); \
set_huge_pte_at((__vma)->vm_mm, __addr, __ptep, __entry); \
} \
__changed; \
})
#define huge_ptep_set_wrprotect(__mm, __addr, __ptep) \
({ \
pte_t __pte = huge_ptep_get(__ptep); \
if (pte_write(__pte)) { \
if (atomic_read(&(__mm)->mm_users) > 1 || \
(__mm) != current->active_mm) \
huge_ptep_invalidate(__mm, __addr, __ptep); \
set_huge_pte_at(__mm, __addr, __ptep, \
huge_pte_wrprotect(__pte)); \
} \
})
static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
huge_ptep_invalidate(vma->vm_mm, address, ptep);
}
#endif /* _ASM_S390_HUGETLB_H */
