diff options
Diffstat (limited to 'arch/s390/mm/pageattr.c')
| -rw-r--r-- | arch/s390/mm/pageattr.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c new file mode 100644 index 000000000..749c98407 --- /dev/null +++ b/arch/s390/mm/pageattr.c @@ -0,0 +1,170 @@ +/* + * Copyright IBM Corp. 2011 + * Author(s): Jan Glauber <jang@linux.vnet.ibm.com> + */ +#include <linux/hugetlb.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <asm/cacheflush.h> +#include <asm/facility.h> +#include <asm/pgtable.h> +#include <asm/page.h> + +#if PAGE_DEFAULT_KEY +static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) +{ + asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0" + : [addr] "+a" (addr) : [skey] "d" (skey)); + return addr; +} + +void __storage_key_init_range(unsigned long start, unsigned long end) +{ + unsigned long boundary, size; + + while (start < end) { + if (MACHINE_HAS_EDAT1) { + /* set storage keys for a 1MB frame */ + size = 1UL << 20; + boundary = (start + size) & ~(size - 1); + if (boundary <= end) { + do { + start = sske_frame(start, PAGE_DEFAULT_KEY); + } while (start < boundary); + continue; + } + } + page_set_storage_key(start, PAGE_DEFAULT_KEY, 0); + start += PAGE_SIZE; + } +} +#endif + +static pte_t *walk_page_table(unsigned long addr) +{ + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + pgdp = pgd_offset_k(addr); + if (pgd_none(*pgdp)) + return NULL; + pudp = pud_offset(pgdp, addr); + if (pud_none(*pudp) || pud_large(*pudp)) + return NULL; + pmdp = pmd_offset(pudp, addr); + if (pmd_none(*pmdp) || pmd_large(*pmdp)) + return NULL; + ptep = pte_offset_kernel(pmdp, addr); + if (pte_none(*ptep)) + return NULL; + return ptep; +} + +static void change_page_attr(unsigned long addr, int numpages, + pte_t (*set) (pte_t)) +{ + pte_t *ptep, pte; + int i; + + for (i = 0; i < numpages; i++) { + ptep = walk_page_table(addr); + if (WARN_ON_ONCE(!ptep)) + break; + pte = *ptep; + pte = set(pte); + __ptep_ipte(addr, ptep); + *ptep = pte; + addr += PAGE_SIZE; + } +} + +int set_memory_ro(unsigned long addr, int numpages) +{ + change_page_attr(addr, numpages, pte_wrprotect); + return 0; +} + +int set_memory_rw(unsigned long addr, int numpages) +{ + change_page_attr(addr, numpages, pte_mkwrite); + return 0; +} + +/* not possible */ +int set_memory_nx(unsigned long addr, int numpages) +{ + return 0; +} + +int set_memory_x(unsigned long addr, int numpages) +{ + return 0; +} + +#ifdef CONFIG_DEBUG_PAGEALLOC + +static void ipte_range(pte_t *pte, unsigned long address, int nr) +{ + int i; + + if (test_facility(13)) { + __ptep_ipte_range(address, nr - 1, pte); + return; + } + for (i = 0; i < nr; i++) { + __ptep_ipte(address, pte); + address += PAGE_SIZE; + pte++; + } +} + +void __kernel_map_pages(struct page *page, int numpages, int enable) +{ + unsigned long address; + int nr, i, j; + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + for (i = 0; i < numpages;) { + address = page_to_phys(page + i); + pgd = pgd_offset_k(address); + pud = pud_offset(pgd, address); + pmd = pmd_offset(pud, address); + pte = pte_offset_kernel(pmd, address); + nr = (unsigned long)pte >> ilog2(sizeof(long)); + nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); + nr = min(numpages - i, nr); + if (enable) { + for (j = 0; j < nr; j++) { + pte_val(*pte) = __pa(address); + address += PAGE_SIZE; + pte++; + } + } else { + ipte_range(pte, address, nr); + } + i += nr; + } +} + +#ifdef CONFIG_HIBERNATION +bool kernel_page_present(struct page *page) +{ + unsigned long addr; + int cc; + + addr = page_to_phys(page); + asm volatile( + " lra %1,0(%1)\n" + " ipm %0\n" + " srl %0,28" + : "=d" (cc), "+a" (addr) : : "cc"); + return cc == 0; +} +#endif /* CONFIG_HIBERNATION */ + +#endif /* CONFIG_DEBUG_PAGEALLOC */ |