[mirror_ubuntu-jammy-kernel.git] / arch / powerpc / mm / pgtable_32.c

// 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>

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) {
		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);
		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);

	if (v_block_mapped((unsigned long)_sinittext)) {
		mmu_mark_initmem_nx();
	} else {
		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 (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 */
Commit	Line	Data
	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
	36	extern char etext[], _stext[], _sinittext[], _einittext[];
	37
	38	static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
	39
	40	notrace void __init early_ioremap_init(void)
	41	{
	42	unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
	43	pte_t ptep = (pte_t )early_fixmap_pagetable;
	44	pmd_t *pmdp = pmd_off_k(addr);
	45
	46	for (; (s32)(FIXADDR_TOP - addr) > 0;
	47	addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
	48	pmd_populate_kernel(&init_mm, pmdp, ptep);
	49
	50	early_ioremap_setup();
	51	}
	52
	53	static void __init *early_alloc_pgtable(unsigned long size)
	54	{
	55	void *ptr = memblock_alloc(size, size);
	56
	57	if (!ptr)
	58	panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
	59	__func__, size, size);
	60
	61	return ptr;
	62	}
	63
	64	pte_t __init early_pte_alloc_kernel(pmd_t pmdp, unsigned long va)
	65	{
	66	if (pmd_none(*pmdp)) {
	67	pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
	68
	69	pmd_populate_kernel(&init_mm, pmdp, ptep);
	70	}
	71	return pte_offset_kernel(pmdp, va);
	72	}
	73
	74
	75	int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
	76	{
	77	pmd_t *pd;
	78	pte_t *pg;
	79	int err = -ENOMEM;
	80
	81	/* Use upper 10 bits of VA to index the first level map */
	82	pd = pmd_off_k(va);
	83	/* Use middle 10 bits of VA to index the second-level map */
	84	if (likely(slab_is_available()))
	85	pg = pte_alloc_kernel(pd, va);
	86	else
	87	pg = early_pte_alloc_kernel(pd, va);
	88	if (pg) {
	89	err = 0;
	90	/* The PTE should never be already set nor present in the
	91	* hash table
	92	*/
	93	BUG_ON((pte_present(pg) \| pte_hashpte(pg)) && pgprot_val(prot));
	94	set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
	95	}
	96	smp_wmb();
	97	return err;
	98	}
	99
	100	/*
	101	* Map in a chunk of physical memory starting at start.
	102	*/
	103	static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
	104	{
	105	unsigned long v, s;
	106	phys_addr_t p;
	107	int ktext;
	108
	109	s = offset;
	110	v = PAGE_OFFSET + s;
	111	p = memstart_addr + s;
	112	for (; s < top; s += PAGE_SIZE) {
	113	ktext = ((char )v >= _stext && (char )v < etext) \|\|
	114	((char )v >= _sinittext && (char )v < _einittext);
	115	map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
	116	v += PAGE_SIZE;
	117	p += PAGE_SIZE;
	118	}
	119	}
	120
	121	void __init mapin_ram(void)
	122	{
	123	phys_addr_t base, end;
	124	u64 i;
	125
	126	for_each_mem_range(i, &base, &end) {
	127	phys_addr_t top = min(end, total_lowmem);
	128
	129	if (base >= top)
	130	continue;
	131	base = mmu_mapin_ram(base, top);
	132	__mapin_ram_chunk(base, top);
	133	}
	134	}
	135
	136	void mark_initmem_nx(void)
	137	{
	138	unsigned long numpages = PFN_UP((unsigned long)_einittext) -
	139	PFN_DOWN((unsigned long)_sinittext);
	140
	141	if (v_block_mapped((unsigned long)_sinittext)) {
	142	mmu_mark_initmem_nx();
	143	} else {
	144	set_memory_nx((unsigned long)_sinittext, numpages);
	145	set_memory_rw((unsigned long)_sinittext, numpages);
	146	}
	147	}
	148
	149	#ifdef CONFIG_STRICT_KERNEL_RWX
	150	void mark_rodata_ro(void)
	151	{
	152	unsigned long numpages;
	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)
	175	void __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 */