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Diffstat (limited to 'arch/powerpc/mm/pgtable_32.c')
| -rw-r--r-- | arch/powerpc/mm/pgtable_32.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c new file mode 100644 index 000000000..079159e97 --- /dev/null +++ b/arch/powerpc/mm/pgtable_32.c @@ -0,0 +1,233 @@ +// 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 <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> + +extern char etext[], _stext[], _sinittext[], _einittext[]; + +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 != 0) { + 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; + int ktext; + + s = offset; + v = PAGE_OFFSET + s; + p = memstart_addr + s; + for (; s < top; s += PAGE_SIZE) { + ktext = ((char *)v >= _stext && (char *)v < etext) || + ((char *)v >= _sinittext && (char *)v < _einittext); + map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL); +#ifdef CONFIG_PPC_BOOK3S_32 + if (ktext) + hash_preload(&init_mm, v); +#endif + 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); + } +} + +static int __change_page_attr_noflush(struct page *page, pgprot_t prot) +{ + pte_t *kpte; + unsigned long address; + + BUG_ON(PageHighMem(page)); + address = (unsigned long)page_address(page); + + if (v_block_mapped(address)) + return 0; + kpte = virt_to_kpte(address); + if (!kpte) + return -EINVAL; + __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); + + return 0; +} + +/* + * Change the page attributes of an page in the linear mapping. + * + * THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY + */ +static int change_page_attr(struct page *page, int numpages, pgprot_t prot) +{ + int i, err = 0; + unsigned long flags; + struct page *start = page; + + local_irq_save(flags); + for (i = 0; i < numpages; i++, page++) { + err = __change_page_attr_noflush(page, prot); + if (err) + break; + } + wmb(); + local_irq_restore(flags); + flush_tlb_kernel_range((unsigned long)page_address(start), + (unsigned long)page_address(page)); + return err; +} + +void mark_initmem_nx(void) +{ + struct page *page = virt_to_page(_sinittext); + unsigned long numpages = PFN_UP((unsigned long)_einittext) - + PFN_DOWN((unsigned long)_sinittext); + + if (v_block_mapped((unsigned long)_sinittext)) + mmu_mark_initmem_nx(); + else + change_page_attr(page, numpages, PAGE_KERNEL); +} + +#ifdef CONFIG_STRICT_KERNEL_RWX +void mark_rodata_ro(void) +{ + struct page *page; + unsigned long numpages; + + if (v_block_mapped((unsigned long)_stext + 1)) { + mmu_mark_rodata_ro(); + ptdump_check_wx(); + return; + } + + page = virt_to_page(_stext); + numpages = PFN_UP((unsigned long)_etext) - + PFN_DOWN((unsigned long)_stext); + + change_page_attr(page, numpages, PAGE_KERNEL_ROX); + /* + * mark .rodata as read only. Use __init_begin rather than __end_rodata + * to cover NOTES and EXCEPTION_TABLE. + */ + page = virt_to_page(__start_rodata); + numpages = PFN_UP((unsigned long)__init_begin) - + PFN_DOWN((unsigned long)__start_rodata); + + change_page_attr(page, numpages, PAGE_KERNEL_RO); + + // mark_initmem_nx() should have already run by now + ptdump_check_wx(); +} +#endif + +#ifdef CONFIG_DEBUG_PAGEALLOC +void __kernel_map_pages(struct page *page, int numpages, int enable) +{ + if (PageHighMem(page)) + return; + + change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); +} +#endif /* CONFIG_DEBUG_PAGEALLOC */ |