xref: /linux/arch/csky/mm/init.c (revision 2209fda323e2fd2a2d0885595fd5097717f8d2aa)
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/bootmem.h>
18 #include <linux/highmem.h>
19 #include <linux/memblock.h>
20 #include <linux/swap.h>
21 #include <linux/proc_fs.h>
22 #include <linux/pfn.h>
23 
24 #include <asm/setup.h>
25 #include <asm/cachectl.h>
26 #include <asm/dma.h>
27 #include <asm/pgtable.h>
28 #include <asm/pgalloc.h>
29 #include <asm/mmu_context.h>
30 #include <asm/sections.h>
31 #include <asm/tlb.h>
32 
33 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
34 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
35 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
36 						__page_aligned_bss;
37 EXPORT_SYMBOL(empty_zero_page);
38 
39 void __init mem_init(void)
40 {
41 #ifdef CONFIG_HIGHMEM
42 	unsigned long tmp;
43 
44 	max_mapnr = highend_pfn;
45 #else
46 	max_mapnr = max_low_pfn;
47 #endif
48 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
49 
50 	free_all_bootmem();
51 
52 #ifdef CONFIG_HIGHMEM
53 	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
54 		struct page *page = pfn_to_page(tmp);
55 
56 		/* FIXME not sure about */
57 		if (!memblock_is_reserved(tmp << PAGE_SHIFT))
58 			free_highmem_page(page);
59 	}
60 #endif
61 	mem_init_print_info(NULL);
62 }
63 
64 #ifdef CONFIG_BLK_DEV_INITRD
65 void free_initrd_mem(unsigned long start, unsigned long end)
66 {
67 	if (start < end)
68 		pr_info("Freeing initrd memory: %ldk freed\n",
69 			(end - start) >> 10);
70 
71 	for (; start < end; start += PAGE_SIZE) {
72 		ClearPageReserved(virt_to_page(start));
73 		init_page_count(virt_to_page(start));
74 		free_page(start);
75 		totalram_pages++;
76 	}
77 }
78 #endif
79 
80 extern char __init_begin[], __init_end[];
81 
82 void free_initmem(void)
83 {
84 	unsigned long addr;
85 
86 	addr = (unsigned long) &__init_begin;
87 
88 	while (addr < (unsigned long) &__init_end) {
89 		ClearPageReserved(virt_to_page(addr));
90 		init_page_count(virt_to_page(addr));
91 		free_page(addr);
92 		totalram_pages++;
93 		addr += PAGE_SIZE;
94 	}
95 
96 	pr_info("Freeing unused kernel memory: %dk freed\n",
97 	((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
98 }
99 
100 void pgd_init(unsigned long *p)
101 {
102 	int i;
103 
104 	for (i = 0; i < PTRS_PER_PGD; i++)
105 		p[i] = __pa(invalid_pte_table);
106 }
107 
108 void __init pre_mmu_init(void)
109 {
110 	/*
111 	 * Setup page-table and enable TLB-hardrefill
112 	 */
113 	flush_tlb_all();
114 	pgd_init((unsigned long *)swapper_pg_dir);
115 	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
116 	TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
117 
118 	asid_cache(smp_processor_id()) = ASID_FIRST_VERSION;
119 
120 	/* Setup page mask to 4k */
121 	write_mmu_pagemask(0);
122 }
123