diff options
Diffstat (limited to 'arch/s390/mm/pageattr.c')
| -rw-r--r-- | arch/s390/mm/pageattr.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c new file mode 100644 index 000000000..b87e96c64 --- /dev/null +++ b/arch/s390/mm/pageattr.c @@ -0,0 +1,452 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright IBM Corp. 2011 + * Author(s): Jan Glauber <jang@linux.vnet.ibm.com> + */ +#include <linux/hugetlb.h> +#include <linux/proc_fs.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <asm/cacheflush.h> +#include <asm/facility.h> +#include <asm/pgalloc.h> +#include <asm/kfence.h> +#include <asm/page.h> +#include <asm/set_memory.h> + +static inline unsigned long sske_frame(unsigned long addr, unsigned char skey) +{ + asm volatile(".insn rrf,0xb22b0000,%[skey],%[addr],1,0" + : [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, 1); + start += PAGE_SIZE; + } +} + +#ifdef CONFIG_PROC_FS +atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]); + +void arch_report_meminfo(struct seq_file *m) +{ + seq_printf(m, "DirectMap4k: %8lu kB\n", + atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_4K]) << 2); + seq_printf(m, "DirectMap1M: %8lu kB\n", + atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_1M]) << 10); + seq_printf(m, "DirectMap2G: %8lu kB\n", + atomic_long_read(&direct_pages_count[PG_DIRECT_MAP_2G]) << 21); +} +#endif /* CONFIG_PROC_FS */ + +static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr, + unsigned long dtt) +{ + unsigned long *table, mask; + + mask = 0; + if (MACHINE_HAS_EDAT2) { + switch (dtt) { + case CRDTE_DTT_REGION3: + mask = ~(PTRS_PER_PUD * sizeof(pud_t) - 1); + break; + case CRDTE_DTT_SEGMENT: + mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); + break; + case CRDTE_DTT_PAGE: + mask = ~(PTRS_PER_PTE * sizeof(pte_t) - 1); + break; + } + table = (unsigned long *)((unsigned long)old & mask); + crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce); + } else if (MACHINE_HAS_IDTE) { + cspg(old, *old, new); + } else { + csp((unsigned int *)old + 1, *old, new); + } +} + +static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end, + unsigned long flags) +{ + pte_t *ptep, new; + + if (flags == SET_MEMORY_4K) + return 0; + ptep = pte_offset_kernel(pmdp, addr); + do { + new = *ptep; + if (pte_none(new)) + return -EINVAL; + if (flags & SET_MEMORY_RO) + new = pte_wrprotect(new); + else if (flags & SET_MEMORY_RW) + new = pte_mkwrite_novma(pte_mkdirty(new)); + if (flags & SET_MEMORY_NX) + new = set_pte_bit(new, __pgprot(_PAGE_NOEXEC)); + else if (flags & SET_MEMORY_X) + new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC)); + if (flags & SET_MEMORY_INV) { + new = set_pte_bit(new, __pgprot(_PAGE_INVALID)); + } else if (flags & SET_MEMORY_DEF) { + new = __pte(pte_val(new) & PAGE_MASK); + new = set_pte_bit(new, PAGE_KERNEL); + if (!MACHINE_HAS_NX) + new = clear_pte_bit(new, __pgprot(_PAGE_NOEXEC)); + } + pgt_set((unsigned long *)ptep, pte_val(new), addr, CRDTE_DTT_PAGE); + ptep++; + addr += PAGE_SIZE; + cond_resched(); + } while (addr < end); + return 0; +} + +static int split_pmd_page(pmd_t *pmdp, unsigned long addr) +{ + unsigned long pte_addr, prot; + pte_t *pt_dir, *ptep; + pmd_t new; + int i, ro, nx; + + pt_dir = vmem_pte_alloc(); + if (!pt_dir) + return -ENOMEM; + pte_addr = pmd_pfn(*pmdp) << PAGE_SHIFT; + ro = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT); + nx = !!(pmd_val(*pmdp) & _SEGMENT_ENTRY_NOEXEC); + prot = pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL); + if (!nx) + prot &= ~_PAGE_NOEXEC; + ptep = pt_dir; + for (i = 0; i < PTRS_PER_PTE; i++) { + set_pte(ptep, __pte(pte_addr | prot)); + pte_addr += PAGE_SIZE; + ptep++; + } + new = __pmd(__pa(pt_dir) | _SEGMENT_ENTRY); + pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); + update_page_count(PG_DIRECT_MAP_4K, PTRS_PER_PTE); + update_page_count(PG_DIRECT_MAP_1M, -1); + return 0; +} + +static void modify_pmd_page(pmd_t *pmdp, unsigned long addr, + unsigned long flags) +{ + pmd_t new = *pmdp; + + if (flags & SET_MEMORY_RO) + new = pmd_wrprotect(new); + else if (flags & SET_MEMORY_RW) + new = pmd_mkwrite_novma(pmd_mkdirty(new)); + if (flags & SET_MEMORY_NX) + new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); + else if (flags & SET_MEMORY_X) + new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); + if (flags & SET_MEMORY_INV) { + new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID)); + } else if (flags & SET_MEMORY_DEF) { + new = __pmd(pmd_val(new) & PMD_MASK); + new = set_pmd_bit(new, SEGMENT_KERNEL); + if (!MACHINE_HAS_NX) + new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_NOEXEC)); + } + pgt_set((unsigned long *)pmdp, pmd_val(new), addr, CRDTE_DTT_SEGMENT); +} + +static int walk_pmd_level(pud_t *pudp, unsigned long addr, unsigned long end, + unsigned long flags) +{ + unsigned long next; + int need_split; + pmd_t *pmdp; + int rc = 0; + + pmdp = pmd_offset(pudp, addr); + do { + if (pmd_none(*pmdp)) + return -EINVAL; + next = pmd_addr_end(addr, end); + if (pmd_large(*pmdp)) { + need_split = !!(flags & SET_MEMORY_4K); + need_split |= !!(addr & ~PMD_MASK); + need_split |= !!(addr + PMD_SIZE > next); + if (need_split) { + rc = split_pmd_page(pmdp, addr); + if (rc) + return rc; + continue; + } + modify_pmd_page(pmdp, addr, flags); + } else { + rc = walk_pte_level(pmdp, addr, next, flags); + if (rc) + return rc; + } + pmdp++; + addr = next; + cond_resched(); + } while (addr < end); + return rc; +} + +static int split_pud_page(pud_t *pudp, unsigned long addr) +{ + unsigned long pmd_addr, prot; + pmd_t *pm_dir, *pmdp; + pud_t new; + int i, ro, nx; + + pm_dir = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); + if (!pm_dir) + return -ENOMEM; + pmd_addr = pud_pfn(*pudp) << PAGE_SHIFT; + ro = !!(pud_val(*pudp) & _REGION_ENTRY_PROTECT); + nx = !!(pud_val(*pudp) & _REGION_ENTRY_NOEXEC); + prot = pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL); + if (!nx) + prot &= ~_SEGMENT_ENTRY_NOEXEC; + pmdp = pm_dir; + for (i = 0; i < PTRS_PER_PMD; i++) { + set_pmd(pmdp, __pmd(pmd_addr | prot)); + pmd_addr += PMD_SIZE; + pmdp++; + } + new = __pud(__pa(pm_dir) | _REGION3_ENTRY); + pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); + update_page_count(PG_DIRECT_MAP_1M, PTRS_PER_PMD); + update_page_count(PG_DIRECT_MAP_2G, -1); + return 0; +} + +static void modify_pud_page(pud_t *pudp, unsigned long addr, + unsigned long flags) +{ + pud_t new = *pudp; + + if (flags & SET_MEMORY_RO) + new = pud_wrprotect(new); + else if (flags & SET_MEMORY_RW) + new = pud_mkwrite(pud_mkdirty(new)); + if (flags & SET_MEMORY_NX) + new = set_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); + else if (flags & SET_MEMORY_X) + new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); + if (flags & SET_MEMORY_INV) { + new = set_pud_bit(new, __pgprot(_REGION_ENTRY_INVALID)); + } else if (flags & SET_MEMORY_DEF) { + new = __pud(pud_val(new) & PUD_MASK); + new = set_pud_bit(new, REGION3_KERNEL); + if (!MACHINE_HAS_NX) + new = clear_pud_bit(new, __pgprot(_REGION_ENTRY_NOEXEC)); + } + pgt_set((unsigned long *)pudp, pud_val(new), addr, CRDTE_DTT_REGION3); +} + +static int walk_pud_level(p4d_t *p4d, unsigned long addr, unsigned long end, + unsigned long flags) +{ + unsigned long next; + int need_split; + pud_t *pudp; + int rc = 0; + + pudp = pud_offset(p4d, addr); + do { + if (pud_none(*pudp)) + return -EINVAL; + next = pud_addr_end(addr, end); + if (pud_large(*pudp)) { + need_split = !!(flags & SET_MEMORY_4K); + need_split |= !!(addr & ~PUD_MASK); + need_split |= !!(addr + PUD_SIZE > next); + if (need_split) { + rc = split_pud_page(pudp, addr); + if (rc) + break; + continue; + } + modify_pud_page(pudp, addr, flags); + } else { + rc = walk_pmd_level(pudp, addr, next, flags); + } + pudp++; + addr = next; + cond_resched(); + } while (addr < end && !rc); + return rc; +} + +static int walk_p4d_level(pgd_t *pgd, unsigned long addr, unsigned long end, + unsigned long flags) +{ + unsigned long next; + p4d_t *p4dp; + int rc = 0; + + p4dp = p4d_offset(pgd, addr); + do { + if (p4d_none(*p4dp)) + return -EINVAL; + next = p4d_addr_end(addr, end); + rc = walk_pud_level(p4dp, addr, next, flags); + p4dp++; + addr = next; + cond_resched(); + } while (addr < end && !rc); + return rc; +} + +DEFINE_MUTEX(cpa_mutex); + +static int change_page_attr(unsigned long addr, unsigned long end, + unsigned long flags) +{ + unsigned long next; + int rc = -EINVAL; + pgd_t *pgdp; + + pgdp = pgd_offset_k(addr); + do { + if (pgd_none(*pgdp)) + break; + next = pgd_addr_end(addr, end); + rc = walk_p4d_level(pgdp, addr, next, flags); + if (rc) + break; + cond_resched(); + } while (pgdp++, addr = next, addr < end && !rc); + return rc; +} + +static int change_page_attr_alias(unsigned long addr, unsigned long end, + unsigned long flags) +{ + unsigned long alias, offset, va_start, va_end; + struct vm_struct *area; + int rc = 0; + + /* + * Changes to read-only permissions on kernel VA mappings are also + * applied to the kernel direct mapping. Execute permissions are + * intentionally not transferred to keep all allocated pages within + * the direct mapping non-executable. + */ + flags &= SET_MEMORY_RO | SET_MEMORY_RW; + if (!flags) + return 0; + area = NULL; + while (addr < end) { + if (!area) + area = find_vm_area((void *)addr); + if (!area || !(area->flags & VM_ALLOC)) + return 0; + va_start = (unsigned long)area->addr; + va_end = va_start + area->nr_pages * PAGE_SIZE; + offset = (addr - va_start) >> PAGE_SHIFT; + alias = (unsigned long)page_address(area->pages[offset]); + rc = change_page_attr(alias, alias + PAGE_SIZE, flags); + if (rc) + break; + addr += PAGE_SIZE; + if (addr >= va_end) + area = NULL; + } + return rc; +} + +int __set_memory(unsigned long addr, unsigned long numpages, unsigned long flags) +{ + unsigned long end; + int rc; + + if (!MACHINE_HAS_NX) + flags &= ~(SET_MEMORY_NX | SET_MEMORY_X); + if (!flags) + return 0; + if (!numpages) + return 0; + addr &= PAGE_MASK; + end = addr + numpages * PAGE_SIZE; + mutex_lock(&cpa_mutex); + rc = change_page_attr(addr, end, flags); + if (rc) + goto out; + rc = change_page_attr_alias(addr, end, flags); +out: + mutex_unlock(&cpa_mutex); + return rc; +} + +int set_direct_map_invalid_noflush(struct page *page) +{ + return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_INV); +} + +int set_direct_map_default_noflush(struct page *page) +{ + return __set_memory((unsigned long)page_to_virt(page), 1, SET_MEMORY_DEF); +} + +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) + +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, IPTE_GLOBAL); + return; + } + for (i = 0; i < nr; i++) { + __ptep_ipte(address, pte, 0, 0, IPTE_GLOBAL); + address += PAGE_SIZE; + pte++; + } +} + +void __kernel_map_pages(struct page *page, int numpages, int enable) +{ + unsigned long address; + pte_t *ptep, pte; + int nr, i, j; + + for (i = 0; i < numpages;) { + address = (unsigned long)page_to_virt(page + i); + ptep = virt_to_kpte(address); + nr = (unsigned long)ptep >> 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 = clear_pte_bit(*ptep, __pgprot(_PAGE_INVALID)); + set_pte(ptep, pte); + address += PAGE_SIZE; + ptep++; + } + } else { + ipte_range(ptep, address, nr); + } + i += nr; + } +} + +#endif /* CONFIG_DEBUG_PAGEALLOC */ |