diff options
Diffstat (limited to 'arch/s390/mm/pgtable.c')
| -rw-r--r-- | arch/s390/mm/pgtable.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 463e5ef02304..947b66a5cdba 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -23,6 +23,7 @@ #include <asm/tlb.h> #include <asm/tlbflush.h> #include <asm/mmu_context.h> +#include <asm/page-states.h> static inline pte_t ptep_flush_direct(struct mm_struct *mm, unsigned long addr, pte_t *ptep) @@ -787,4 +788,156 @@ int get_guest_storage_key(struct mm_struct *mm, unsigned long addr, return 0; } EXPORT_SYMBOL(get_guest_storage_key); + +/** + * pgste_perform_essa - perform ESSA actions on the PGSTE. + * @mm: the memory context. It must have PGSTEs, no check is performed here! + * @hva: the host virtual address of the page whose PGSTE is to be processed + * @orc: the specific action to perform, see the ESSA_SET_* macros. + * @oldpte: the PTE will be saved there if the pointer is not NULL. + * @oldpgste: the old PGSTE will be saved there if the pointer is not NULL. + * + * Return: 1 if the page is to be added to the CBRL, otherwise 0, + * or < 0 in case of error. -EINVAL is returned for invalid values + * of orc, -EFAULT for invalid addresses. + */ +int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc, + unsigned long *oldpte, unsigned long *oldpgste) +{ + unsigned long pgstev; + spinlock_t *ptl; + pgste_t pgste; + pte_t *ptep; + int res = 0; + + WARN_ON_ONCE(orc > ESSA_MAX); + if (unlikely(orc > ESSA_MAX)) + return -EINVAL; + ptep = get_locked_pte(mm, hva, &ptl); + if (unlikely(!ptep)) + return -EFAULT; + pgste = pgste_get_lock(ptep); + pgstev = pgste_val(pgste); + if (oldpte) + *oldpte = pte_val(*ptep); + if (oldpgste) + *oldpgste = pgstev; + + switch (orc) { + case ESSA_GET_STATE: + break; + case ESSA_SET_STABLE: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_STABLE; + break; + case ESSA_SET_UNUSED: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_UNUSED; + if (pte_val(*ptep) & _PAGE_INVALID) + res = 1; + break; + case ESSA_SET_VOLATILE: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_VOLATILE; + if (pte_val(*ptep) & _PAGE_INVALID) + res = 1; + break; + case ESSA_SET_POT_VOLATILE: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + pgstev |= _PGSTE_GPS_USAGE_POT_VOLATILE; + break; + } + if (pgstev & _PGSTE_GPS_ZERO) { + pgstev |= _PGSTE_GPS_USAGE_VOLATILE; + break; + } + if (!(pgstev & PGSTE_GC_BIT)) { + pgstev |= _PGSTE_GPS_USAGE_VOLATILE; + res = 1; + break; + } + break; + case ESSA_SET_STABLE_RESIDENT: + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_STABLE; + /* + * Since the resident state can go away any time after this + * call, we will not make this page resident. We can revisit + * this decision if a guest will ever start using this. + */ + break; + case ESSA_SET_STABLE_IF_RESIDENT: + if (!(pte_val(*ptep) & _PAGE_INVALID)) { + pgstev &= ~_PGSTE_GPS_USAGE_MASK; + pgstev |= _PGSTE_GPS_USAGE_STABLE; + } + break; + default: + /* we should never get here! */ + break; + } + /* If we are discarding a page, set it to logical zero */ + if (res) + pgstev |= _PGSTE_GPS_ZERO; + + pgste_val(pgste) = pgstev; + pgste_set_unlock(ptep, pgste); + pte_unmap_unlock(ptep, ptl); + return res; +} +EXPORT_SYMBOL(pgste_perform_essa); + +/** + * set_pgste_bits - set specific PGSTE bits. + * @mm: the memory context. It must have PGSTEs, no check is performed here! + * @hva: the host virtual address of the page whose PGSTE is to be processed + * @bits: a bitmask representing the bits that will be touched + * @value: the values of the bits to be written. Only the bits in the mask + * will be written. + * + * Return: 0 on success, < 0 in case of error. + */ +int set_pgste_bits(struct mm_struct *mm, unsigned long hva, + unsigned long bits, unsigned long value) +{ + spinlock_t *ptl; + pgste_t new; + pte_t *ptep; + + ptep = get_locked_pte(mm, hva, &ptl); + if (unlikely(!ptep)) + return -EFAULT; + new = pgste_get_lock(ptep); + + pgste_val(new) &= ~bits; + pgste_val(new) |= value & bits; + + pgste_set_unlock(ptep, new); + pte_unmap_unlock(ptep, ptl); + return 0; +} +EXPORT_SYMBOL(set_pgste_bits); + +/** + * get_pgste - get the current PGSTE for the given address. + * @mm: the memory context. It must have PGSTEs, no check is performed here! + * @hva: the host virtual address of the page whose PGSTE is to be processed + * @pgstep: will be written with the current PGSTE for the given address. + * + * Return: 0 on success, < 0 in case of error. + */ +int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep) +{ + spinlock_t *ptl; + pte_t *ptep; + + ptep = get_locked_pte(mm, hva, &ptl); + if (unlikely(!ptep)) + return -EFAULT; + *pgstep = pgste_val(pgste_get(ptep)); + pte_unmap_unlock(ptep, ptl); + return 0; +} +EXPORT_SYMBOL(get_pgste); #endif |