xref: /openbmc/linux/arch/xtensa/mm/init.c (revision 020c5260)
1 /*
2  * arch/xtensa/mm/init.c
3  *
4  * Derived from MIPS, PPC.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  *
10  * Copyright (C) 2001 - 2005 Tensilica Inc.
11  * Copyright (C) 2014 - 2016 Cadence Design Systems Inc.
12  *
13  * Chris Zankel	<chris@zankel.net>
14  * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
15  * Marc Gauthier
16  * Kevin Chea
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/bootmem.h>
22 #include <linux/gfp.h>
23 #include <linux/highmem.h>
24 #include <linux/swap.h>
25 #include <linux/mman.h>
26 #include <linux/nodemask.h>
27 #include <linux/mm.h>
28 #include <linux/of_fdt.h>
29 #include <linux/dma-contiguous.h>
30 
31 #include <asm/bootparam.h>
32 #include <asm/page.h>
33 #include <asm/sections.h>
34 #include <asm/sysmem.h>
35 
36 /*
37  * Initialize the bootmem system and give it all low memory we have available.
38  */
39 
40 void __init bootmem_init(void)
41 {
42 	/* Reserve all memory below PHYS_OFFSET, as memory
43 	 * accounting doesn't work for pages below that address.
44 	 *
45 	 * If PHYS_OFFSET is zero reserve page at address 0:
46 	 * successfull allocations should never return NULL.
47 	 */
48 	if (PHYS_OFFSET)
49 		memblock_reserve(0, PHYS_OFFSET);
50 	else
51 		memblock_reserve(0, 1);
52 
53 	early_init_fdt_scan_reserved_mem();
54 
55 	if (!memblock_phys_mem_size())
56 		panic("No memory found!\n");
57 
58 	min_low_pfn = PFN_UP(memblock_start_of_DRAM());
59 	min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET));
60 	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
61 	max_low_pfn = min(max_pfn, MAX_LOW_PFN);
62 
63 	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
64 	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
65 
66 	memblock_dump_all();
67 }
68 
69 
70 void __init zones_init(void)
71 {
72 	/* All pages are DMA-able, so we put them all in the DMA zone. */
73 	unsigned long zones_size[MAX_NR_ZONES] = {
74 		[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET,
75 #ifdef CONFIG_HIGHMEM
76 		[ZONE_HIGHMEM] = max_pfn - max_low_pfn,
77 #endif
78 	};
79 	free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
80 }
81 
82 /*
83  * Initialize memory pages.
84  */
85 
86 void __init mem_init(void)
87 {
88 #ifdef CONFIG_HIGHMEM
89 	unsigned long tmp;
90 
91 	reset_all_zones_managed_pages();
92 	for (tmp = max_low_pfn; tmp < max_pfn; tmp++)
93 		free_highmem_page(pfn_to_page(tmp));
94 #endif
95 
96 	max_mapnr = max_pfn - ARCH_PFN_OFFSET;
97 	high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
98 
99 	free_all_bootmem();
100 
101 	mem_init_print_info(NULL);
102 	pr_info("virtual kernel memory layout:\n"
103 #ifdef CONFIG_HIGHMEM
104 		"    pkmap   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
105 		"    fixmap  : 0x%08lx - 0x%08lx  (%5lu kB)\n"
106 #endif
107 #ifdef CONFIG_MMU
108 		"    vmalloc : 0x%08lx - 0x%08lx  (%5lu MB)\n"
109 #endif
110 		"    lowmem  : 0x%08lx - 0x%08lx  (%5lu MB)\n",
111 #ifdef CONFIG_HIGHMEM
112 		PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
113 		(LAST_PKMAP*PAGE_SIZE) >> 10,
114 		FIXADDR_START, FIXADDR_TOP,
115 		(FIXADDR_TOP - FIXADDR_START) >> 10,
116 #endif
117 #ifdef CONFIG_MMU
118 		VMALLOC_START, VMALLOC_END,
119 		(VMALLOC_END - VMALLOC_START) >> 20,
120 		PAGE_OFFSET, PAGE_OFFSET +
121 		(max_low_pfn - min_low_pfn) * PAGE_SIZE,
122 #else
123 		min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
124 #endif
125 		((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20);
126 }
127 
128 #ifdef CONFIG_BLK_DEV_INITRD
129 extern int initrd_is_mapped;
130 
131 void free_initrd_mem(unsigned long start, unsigned long end)
132 {
133 	if (initrd_is_mapped)
134 		free_reserved_area((void *)start, (void *)end, -1, "initrd");
135 }
136 #endif
137 
138 void free_initmem(void)
139 {
140 	free_initmem_default(-1);
141 }
142 
143 static void __init parse_memmap_one(char *p)
144 {
145 	char *oldp;
146 	unsigned long start_at, mem_size;
147 
148 	if (!p)
149 		return;
150 
151 	oldp = p;
152 	mem_size = memparse(p, &p);
153 	if (p == oldp)
154 		return;
155 
156 	switch (*p) {
157 	case '@':
158 		start_at = memparse(p + 1, &p);
159 		memblock_add(start_at, mem_size);
160 		break;
161 
162 	case '$':
163 		start_at = memparse(p + 1, &p);
164 		memblock_reserve(start_at, mem_size);
165 		break;
166 
167 	case 0:
168 		memblock_reserve(mem_size, -mem_size);
169 		break;
170 
171 	default:
172 		pr_warn("Unrecognized memmap syntax: %s\n", p);
173 		break;
174 	}
175 }
176 
177 static int __init parse_memmap_opt(char *str)
178 {
179 	while (str) {
180 		char *k = strchr(str, ',');
181 
182 		if (k)
183 			*k++ = 0;
184 
185 		parse_memmap_one(str);
186 		str = k;
187 	}
188 
189 	return 0;
190 }
191 early_param("memmap", parse_memmap_opt);
192