1 /* 2 * Copyright IBM Corp. 2011 3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com> 4 */ 5 #include <linux/hugetlb.h> 6 #include <linux/module.h> 7 #include <linux/mm.h> 8 #include <asm/cacheflush.h> 9 #include <asm/facility.h> 10 #include <asm/pgtable.h> 11 #include <asm/page.h> 12 13 #if PAGE_DEFAULT_KEY 14 static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) 15 { 16 asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],9,0" 17 : [addr] "+a" (addr) : [skey] "d" (skey)); 18 return addr; 19 } 20 21 void __storage_key_init_range(unsigned long start, unsigned long end) 22 { 23 unsigned long boundary, size; 24 25 while (start < end) { 26 if (MACHINE_HAS_EDAT1) { 27 /* set storage keys for a 1MB frame */ 28 size = 1UL << 20; 29 boundary = (start + size) & ~(size - 1); 30 if (boundary <= end) { 31 do { 32 start = sske_frame(start, PAGE_DEFAULT_KEY); 33 } while (start < boundary); 34 continue; 35 } 36 } 37 page_set_storage_key(start, PAGE_DEFAULT_KEY, 0); 38 start += PAGE_SIZE; 39 } 40 } 41 #endif 42 43 static pte_t *walk_page_table(unsigned long addr) 44 { 45 pgd_t *pgdp; 46 pud_t *pudp; 47 pmd_t *pmdp; 48 pte_t *ptep; 49 50 pgdp = pgd_offset_k(addr); 51 if (pgd_none(*pgdp)) 52 return NULL; 53 pudp = pud_offset(pgdp, addr); 54 if (pud_none(*pudp) || pud_large(*pudp)) 55 return NULL; 56 pmdp = pmd_offset(pudp, addr); 57 if (pmd_none(*pmdp) || pmd_large(*pmdp)) 58 return NULL; 59 ptep = pte_offset_kernel(pmdp, addr); 60 if (pte_none(*ptep)) 61 return NULL; 62 return ptep; 63 } 64 65 static void change_page_attr(unsigned long addr, int numpages, 66 pte_t (*set) (pte_t)) 67 { 68 pte_t *ptep, pte; 69 int i; 70 71 for (i = 0; i < numpages; i++) { 72 ptep = walk_page_table(addr); 73 if (WARN_ON_ONCE(!ptep)) 74 break; 75 pte = *ptep; 76 pte = set(pte); 77 __ptep_ipte(addr, ptep); 78 *ptep = pte; 79 addr += PAGE_SIZE; 80 } 81 } 82 83 int set_memory_ro(unsigned long addr, int numpages) 84 { 85 change_page_attr(addr, numpages, pte_wrprotect); 86 return 0; 87 } 88 89 int set_memory_rw(unsigned long addr, int numpages) 90 { 91 change_page_attr(addr, numpages, pte_mkwrite); 92 return 0; 93 } 94 95 /* not possible */ 96 int set_memory_nx(unsigned long addr, int numpages) 97 { 98 return 0; 99 } 100 101 int set_memory_x(unsigned long addr, int numpages) 102 { 103 return 0; 104 } 105 106 #ifdef CONFIG_DEBUG_PAGEALLOC 107 108 static void ipte_range(pte_t *pte, unsigned long address, int nr) 109 { 110 int i; 111 112 if (test_facility(13)) { 113 __ptep_ipte_range(address, nr - 1, pte); 114 return; 115 } 116 for (i = 0; i < nr; i++) { 117 __ptep_ipte(address, pte); 118 address += PAGE_SIZE; 119 pte++; 120 } 121 } 122 123 void __kernel_map_pages(struct page *page, int numpages, int enable) 124 { 125 unsigned long address; 126 int nr, i, j; 127 pgd_t *pgd; 128 pud_t *pud; 129 pmd_t *pmd; 130 pte_t *pte; 131 132 for (i = 0; i < numpages;) { 133 address = page_to_phys(page + i); 134 pgd = pgd_offset_k(address); 135 pud = pud_offset(pgd, address); 136 pmd = pmd_offset(pud, address); 137 pte = pte_offset_kernel(pmd, address); 138 nr = (unsigned long)pte >> ilog2(sizeof(long)); 139 nr = PTRS_PER_PTE - (nr & (PTRS_PER_PTE - 1)); 140 nr = min(numpages - i, nr); 141 if (enable) { 142 for (j = 0; j < nr; j++) { 143 pte_val(*pte) = __pa(address); 144 address += PAGE_SIZE; 145 pte++; 146 } 147 } else { 148 ipte_range(pte, address, nr); 149 } 150 i += nr; 151 } 152 } 153 154 #ifdef CONFIG_HIBERNATION 155 bool kernel_page_present(struct page *page) 156 { 157 unsigned long addr; 158 int cc; 159 160 addr = page_to_phys(page); 161 asm volatile( 162 " lra %1,0(%1)\n" 163 " ipm %0\n" 164 " srl %0,28" 165 : "=d" (cc), "+a" (addr) : : "cc"); 166 return cc == 0; 167 } 168 #endif /* CONFIG_HIBERNATION */ 169 170 #endif /* CONFIG_DEBUG_PAGEALLOC */ 171