| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * This file contains the routines setting up the linux page tables. |
| * -- paulus |
| * |
| * Derived from arch/ppc/mm/init.c: |
| * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) |
| * |
| * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) |
| * and Cort Dougan (PReP) (cort@cs.nmt.edu) |
| * Copyright (C) 1996 Paul Mackerras |
| * |
| * Derived from "arch/i386/mm/init.c" |
| * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/mm.h> |
| #include <linux/vmalloc.h> |
| #include <linux/init.h> |
| #include <linux/highmem.h> |
| #include <linux/memblock.h> |
| #include <linux/slab.h> |
| #include <linux/set_memory.h> |
| |
| #include <asm/pgalloc.h> |
| #include <asm/fixmap.h> |
| #include <asm/setup.h> |
| #include <asm/sections.h> |
| #include <asm/early_ioremap.h> |
| |
| #include <mm/mmu_decl.h> |
| |
| static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data; |
| |
| notrace void __init early_ioremap_init(void) |
| { |
| unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE); |
| pte_t *ptep = (pte_t *)early_fixmap_pagetable; |
| pmd_t *pmdp = pmd_off_k(addr); |
| |
| for (; (s32)(FIXADDR_TOP - addr) > 0; |
| addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++) |
| pmd_populate_kernel(&init_mm, pmdp, ptep); |
| |
| early_ioremap_setup(); |
| } |
| |
| static void __init *early_alloc_pgtable(unsigned long size) |
| { |
| void *ptr = memblock_alloc(size, size); |
| |
| if (!ptr) |
| panic("%s: Failed to allocate %lu bytes align=0x%lx\n", |
| __func__, size, size); |
| |
| return ptr; |
| } |
| |
| pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va) |
| { |
| if (pmd_none(*pmdp)) { |
| pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE); |
| |
| pmd_populate_kernel(&init_mm, pmdp, ptep); |
| } |
| return pte_offset_kernel(pmdp, va); |
| } |
| |
| |
| int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot) |
| { |
| pmd_t *pd; |
| pte_t *pg; |
| int err = -ENOMEM; |
| |
| /* Use upper 10 bits of VA to index the first level map */ |
| pd = pmd_off_k(va); |
| /* Use middle 10 bits of VA to index the second-level map */ |
| if (likely(slab_is_available())) |
| pg = pte_alloc_kernel(pd, va); |
| else |
| pg = early_pte_alloc_kernel(pd, va); |
| if (pg) { |
| err = 0; |
| /* The PTE should never be already set nor present in the |
| * hash table |
| */ |
| BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot)); |
| set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot)); |
| } |
| smp_wmb(); |
| return err; |
| } |
| |
| /* |
| * Map in a chunk of physical memory starting at start. |
| */ |
| static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) |
| { |
| unsigned long v, s; |
| phys_addr_t p; |
| bool ktext; |
| |
| s = offset; |
| v = PAGE_OFFSET + s; |
| p = memstart_addr + s; |
| for (; s < top; s += PAGE_SIZE) { |
| ktext = core_kernel_text(v); |
| map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL); |
| v += PAGE_SIZE; |
| p += PAGE_SIZE; |
| } |
| } |
| |
| void __init mapin_ram(void) |
| { |
| phys_addr_t base, end; |
| u64 i; |
| |
| for_each_mem_range(i, &base, &end) { |
| phys_addr_t top = min(end, total_lowmem); |
| |
| if (base >= top) |
| continue; |
| base = mmu_mapin_ram(base, top); |
| __mapin_ram_chunk(base, top); |
| } |
| } |
| |
| void mark_initmem_nx(void) |
| { |
| unsigned long numpages = PFN_UP((unsigned long)_einittext) - |
| PFN_DOWN((unsigned long)_sinittext); |
| |
| mmu_mark_initmem_nx(); |
| |
| if (!v_block_mapped((unsigned long)_sinittext)) { |
| set_memory_nx((unsigned long)_sinittext, numpages); |
| set_memory_rw((unsigned long)_sinittext, numpages); |
| } |
| } |
| |
| #ifdef CONFIG_STRICT_KERNEL_RWX |
| void mark_rodata_ro(void) |
| { |
| unsigned long numpages; |
| |
| if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE)) |
| pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n"); |
| |
| if (v_block_mapped((unsigned long)_stext + 1)) { |
| mmu_mark_rodata_ro(); |
| ptdump_check_wx(); |
| return; |
| } |
| |
| /* |
| * mark .text and .rodata as read only. Use __init_begin rather than |
| * __end_rodata to cover NOTES and EXCEPTION_TABLE. |
| */ |
| numpages = PFN_UP((unsigned long)__init_begin) - |
| PFN_DOWN((unsigned long)_stext); |
| |
| set_memory_ro((unsigned long)_stext, numpages); |
| |
| // mark_initmem_nx() should have already run by now |
| ptdump_check_wx(); |
| } |
| #endif |
| |
| #if defined(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && defined(CONFIG_DEBUG_PAGEALLOC) |
| void __kernel_map_pages(struct page *page, int numpages, int enable) |
| { |
| unsigned long addr = (unsigned long)page_address(page); |
| |
| if (PageHighMem(page)) |
| return; |
| |
| if (enable) |
| set_memory_p(addr, numpages); |
| else |
| set_memory_np(addr, numpages); |
| } |
| #endif /* CONFIG_DEBUG_PAGEALLOC */ |