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-rw-r--r--arch/s390/mm/pageattr.c452
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 0000000000..b87e96c64b
--- /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 */