init.c

  1// SPDX-License-Identifier: GPL-2.0
  2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
  3
  4#include <linux/bug.h>
  5#include <linux/module.h>
  6#include <linux/init.h>
  7#include <linux/signal.h>
  8#include <linux/sched.h>
  9#include <linux/kernel.h>
 10#include <linux/errno.h>
 11#include <linux/string.h>
 12#include <linux/types.h>
 13#include <linux/pagemap.h>
 14#include <linux/ptrace.h>
 15#include <linux/mman.h>
 16#include <linux/mm.h>
 17#include <linux/highmem.h>
 18#include <linux/memblock.h>
 19#include <linux/swap.h>
 20#include <linux/proc_fs.h>
 21#include <linux/pfn.h>
 22#include <linux/initrd.h>
 23
 24#include <asm/setup.h>
 25#include <asm/cachectl.h>
 26#include <asm/dma.h>
 27#include <asm/pgalloc.h>
 28#include <asm/mmu_context.h>
 29#include <asm/sections.h>
 30#include <asm/tlb.h>
 31#include <asm/cacheflush.h>
 32
 33#define PTRS_KERN_TABLE \
 34		((PTRS_PER_PGD - USER_PTRS_PER_PGD) * PTRS_PER_PTE)
 35
 36pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 37pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
 38pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss;
 39
 40EXPORT_SYMBOL(invalid_pte_table);
 41unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
 42						__page_aligned_bss;
 43EXPORT_SYMBOL(empty_zero_page);
 44
 45void free_initmem(void)
 46{
 47	free_initmem_default(-1);
 48}
 49
 50void pgd_init(unsigned long *p)
 51{
 52	int i;
 53
 54	for (i = 0; i < PTRS_PER_PGD; i++)
 55		p[i] = __pa(invalid_pte_table);
 56
 57	flush_tlb_all();
 58	local_icache_inv_all(NULL);
 59}
 60
 61void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
 62{
 63	int i;
 64
 65	for (i = 0; i < USER_PTRS_PER_PGD; i++)
 66		swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
 67
 68	for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
 69		swapper_pg_dir[i].pgd =
 70			__pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
 71
 72	for (i = 0; i < PTRS_KERN_TABLE; i++)
 73		set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL));
 74
 75	for (i = min_pfn; i < max_pfn; i++)
 76		set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
 77
 78	flush_tlb_all();
 79	local_icache_inv_all(NULL);
 80
 81	/* Setup page mask to 4k */
 82	write_mmu_pagemask(0);
 83
 84	setup_pgd(swapper_pg_dir, 0);
 85}
 86
 87void __init fixrange_init(unsigned long start, unsigned long end,
 88			pgd_t *pgd_base)
 89{
 90	pgd_t *pgd;
 91	pud_t *pud;
 92	pmd_t *pmd;
 93	pte_t *pte;
 94	int i, j, k;
 95	unsigned long vaddr;
 96
 97	vaddr = start;
 98	i = pgd_index(vaddr);
 99	j = pud_index(vaddr);
100	k = pmd_index(vaddr);
101	pgd = pgd_base + i;
102
103	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
104		pud = (pud_t *)pgd;
105		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
106			pmd = (pmd_t *)pud;
107			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
108				if (pmd_none(*pmd)) {
109					pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
110					if (!pte)
111						panic("%s: Failed to allocate %lu bytes align=%lx\n",
112						      __func__, PAGE_SIZE,
113						      PAGE_SIZE);
114
115					set_pmd(pmd, __pmd(__pa(pte)));
116					BUG_ON(pte != pte_offset_kernel(pmd, 0));
117				}
118				vaddr += PMD_SIZE;
119			}
120			k = 0;
121		}
122		j = 0;
123	}
124}
125
126void __init fixaddr_init(void)
127{
128	unsigned long vaddr;
129
130	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
131	fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
132}
133
134static const pgprot_t protection_map[16] = {
135	[VM_NONE]					= PAGE_NONE,
136	[VM_READ]					= PAGE_READ,
137	[VM_WRITE]					= PAGE_READ,
138	[VM_WRITE | VM_READ]				= PAGE_READ,
139	[VM_EXEC]					= PAGE_READ,
140	[VM_EXEC | VM_READ]				= PAGE_READ,
141	[VM_EXEC | VM_WRITE]				= PAGE_READ,
142	[VM_EXEC | VM_WRITE | VM_READ]			= PAGE_READ,
143	[VM_SHARED]					= PAGE_NONE,
144	[VM_SHARED | VM_READ]				= PAGE_READ,
145	[VM_SHARED | VM_WRITE]				= PAGE_WRITE,
146	[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_WRITE,
147	[VM_SHARED | VM_EXEC]				= PAGE_READ,
148	[VM_SHARED | VM_EXEC | VM_READ]			= PAGE_READ,
149	[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_WRITE,
150	[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_WRITE
151};
152DECLARE_VM_GET_PAGE_PROT