cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

pgtable_32.c (4530B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * This file contains the routines setting up the linux page tables.
      4 *  -- paulus
      5 *
      6 *  Derived from arch/ppc/mm/init.c:
      7 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
      8 *
      9 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
     10 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
     11 *    Copyright (C) 1996 Paul Mackerras
     12 *
     13 *  Derived from "arch/i386/mm/init.c"
     14 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
     15 */
     16
     17#include <linux/kernel.h>
     18#include <linux/module.h>
     19#include <linux/types.h>
     20#include <linux/mm.h>
     21#include <linux/vmalloc.h>
     22#include <linux/init.h>
     23#include <linux/highmem.h>
     24#include <linux/memblock.h>
     25#include <linux/slab.h>
     26#include <linux/set_memory.h>
     27
     28#include <asm/pgalloc.h>
     29#include <asm/fixmap.h>
     30#include <asm/setup.h>
     31#include <asm/sections.h>
     32#include <asm/early_ioremap.h>
     33
     34#include <mm/mmu_decl.h>
     35
     36static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
     37
     38notrace void __init early_ioremap_init(void)
     39{
     40	unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
     41	pte_t *ptep = (pte_t *)early_fixmap_pagetable;
     42	pmd_t *pmdp = pmd_off_k(addr);
     43
     44	for (; (s32)(FIXADDR_TOP - addr) > 0;
     45	     addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
     46		pmd_populate_kernel(&init_mm, pmdp, ptep);
     47
     48	early_ioremap_setup();
     49}
     50
     51static void __init *early_alloc_pgtable(unsigned long size)
     52{
     53	void *ptr = memblock_alloc(size, size);
     54
     55	if (!ptr)
     56		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
     57		      __func__, size, size);
     58
     59	return ptr;
     60}
     61
     62pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
     63{
     64	if (pmd_none(*pmdp)) {
     65		pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
     66
     67		pmd_populate_kernel(&init_mm, pmdp, ptep);
     68	}
     69	return pte_offset_kernel(pmdp, va);
     70}
     71
     72
     73int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
     74{
     75	pmd_t *pd;
     76	pte_t *pg;
     77	int err = -ENOMEM;
     78
     79	/* Use upper 10 bits of VA to index the first level map */
     80	pd = pmd_off_k(va);
     81	/* Use middle 10 bits of VA to index the second-level map */
     82	if (likely(slab_is_available()))
     83		pg = pte_alloc_kernel(pd, va);
     84	else
     85		pg = early_pte_alloc_kernel(pd, va);
     86	if (pg) {
     87		err = 0;
     88		/* The PTE should never be already set nor present in the
     89		 * hash table
     90		 */
     91		BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
     92		set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
     93	}
     94	smp_wmb();
     95	return err;
     96}
     97
     98/*
     99 * Map in a chunk of physical memory starting at start.
    100 */
    101static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
    102{
    103	unsigned long v, s;
    104	phys_addr_t p;
    105	bool ktext;
    106
    107	s = offset;
    108	v = PAGE_OFFSET + s;
    109	p = memstart_addr + s;
    110	for (; s < top; s += PAGE_SIZE) {
    111		ktext = core_kernel_text(v);
    112		map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
    113		v += PAGE_SIZE;
    114		p += PAGE_SIZE;
    115	}
    116}
    117
    118void __init mapin_ram(void)
    119{
    120	phys_addr_t base, end;
    121	u64 i;
    122
    123	for_each_mem_range(i, &base, &end) {
    124		phys_addr_t top = min(end, total_lowmem);
    125
    126		if (base >= top)
    127			continue;
    128		base = mmu_mapin_ram(base, top);
    129		__mapin_ram_chunk(base, top);
    130	}
    131}
    132
    133void mark_initmem_nx(void)
    134{
    135	unsigned long numpages = PFN_UP((unsigned long)_einittext) -
    136				 PFN_DOWN((unsigned long)_sinittext);
    137
    138	if (v_block_mapped((unsigned long)_sinittext)) {
    139		mmu_mark_initmem_nx();
    140	} else {
    141		set_memory_nx((unsigned long)_sinittext, numpages);
    142		set_memory_rw((unsigned long)_sinittext, numpages);
    143	}
    144}
    145
    146#ifdef CONFIG_STRICT_KERNEL_RWX
    147void mark_rodata_ro(void)
    148{
    149	unsigned long numpages;
    150
    151	if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE))
    152		pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n");
    153
    154	if (v_block_mapped((unsigned long)_stext + 1)) {
    155		mmu_mark_rodata_ro();
    156		ptdump_check_wx();
    157		return;
    158	}
    159
    160	/*
    161	 * mark .text and .rodata as read only. Use __init_begin rather than
    162	 * __end_rodata to cover NOTES and EXCEPTION_TABLE.
    163	 */
    164	numpages = PFN_UP((unsigned long)__init_begin) -
    165		   PFN_DOWN((unsigned long)_stext);
    166
    167	set_memory_ro((unsigned long)_stext, numpages);
    168
    169	// mark_initmem_nx() should have already run by now
    170	ptdump_check_wx();
    171}
    172#endif
    173
    174#if defined(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && defined(CONFIG_DEBUG_PAGEALLOC)
    175void __kernel_map_pages(struct page *page, int numpages, int enable)
    176{
    177	unsigned long addr = (unsigned long)page_address(page);
    178
    179	if (PageHighMem(page))
    180		return;
    181
    182	if (enable)
    183		set_memory_p(addr, numpages);
    184	else
    185		set_memory_np(addr, numpages);
    186}
    187#endif /* CONFIG_DEBUG_PAGEALLOC */