xref: /openbmc/linux/arch/xtensa/mm/init.c (revision afb46f79)
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  *
12  * Chris Zankel	<chris@zankel.net>
13  * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
14  * Marc Gauthier
15  * Kevin Chea
16  */
17 
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/bootmem.h>
21 #include <linux/gfp.h>
22 #include <linux/swap.h>
23 #include <linux/mman.h>
24 #include <linux/nodemask.h>
25 #include <linux/mm.h>
26 
27 #include <asm/bootparam.h>
28 #include <asm/page.h>
29 #include <asm/sections.h>
30 
31 /*
32  * mem_reserve(start, end, must_exist)
33  *
34  * Reserve some memory from the memory pool.
35  *
36  * Parameters:
37  *  start	Start of region,
38  *  end		End of region,
39  *  must_exist	Must exist in memory pool.
40  *
41  * Returns:
42  *  0 (memory area couldn't be mapped)
43  * -1 (success)
44  */
45 
46 int __init mem_reserve(unsigned long start, unsigned long end, int must_exist)
47 {
48 	int i;
49 
50 	if (start == end)
51 		return 0;
52 
53 	start = start & PAGE_MASK;
54 	end = PAGE_ALIGN(end);
55 
56 	for (i = 0; i < sysmem.nr_banks; i++)
57 		if (start < sysmem.bank[i].end
58 		    && end >= sysmem.bank[i].start)
59 			break;
60 
61 	if (i == sysmem.nr_banks) {
62 		if (must_exist)
63 			printk (KERN_WARNING "mem_reserve: [0x%0lx, 0x%0lx) "
64 				"not in any region!\n", start, end);
65 		return 0;
66 	}
67 
68 	if (start > sysmem.bank[i].start) {
69 		if (end < sysmem.bank[i].end) {
70 			/* split entry */
71 			if (sysmem.nr_banks >= SYSMEM_BANKS_MAX)
72 				panic("meminfo overflow\n");
73 			sysmem.bank[sysmem.nr_banks].start = end;
74 			sysmem.bank[sysmem.nr_banks].end = sysmem.bank[i].end;
75 			sysmem.nr_banks++;
76 		}
77 		sysmem.bank[i].end = start;
78 
79 	} else if (end < sysmem.bank[i].end) {
80 		sysmem.bank[i].start = end;
81 
82 	} else {
83 		/* remove entry */
84 		sysmem.nr_banks--;
85 		sysmem.bank[i].start = sysmem.bank[sysmem.nr_banks].start;
86 		sysmem.bank[i].end   = sysmem.bank[sysmem.nr_banks].end;
87 	}
88 	return -1;
89 }
90 
91 
92 /*
93  * Initialize the bootmem system and give it all low memory we have available.
94  */
95 
96 void __init bootmem_init(void)
97 {
98 	unsigned long pfn;
99 	unsigned long bootmap_start, bootmap_size;
100 	int i;
101 
102 	max_low_pfn = max_pfn = 0;
103 	min_low_pfn = ~0;
104 
105 	for (i=0; i < sysmem.nr_banks; i++) {
106 		pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT;
107 		if (pfn < min_low_pfn)
108 			min_low_pfn = pfn;
109 		pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT;
110 		if (pfn > max_pfn)
111 			max_pfn = pfn;
112 	}
113 
114 	if (min_low_pfn > max_pfn)
115 		panic("No memory found!\n");
116 
117 	max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ?
118 		max_pfn : MAX_MEM_PFN >> PAGE_SHIFT;
119 
120 	/* Find an area to use for the bootmem bitmap. */
121 
122 	bootmap_size = bootmem_bootmap_pages(max_low_pfn - min_low_pfn);
123 	bootmap_size <<= PAGE_SHIFT;
124 	bootmap_start = ~0;
125 
126 	for (i=0; i<sysmem.nr_banks; i++)
127 		if (sysmem.bank[i].end - sysmem.bank[i].start >= bootmap_size) {
128 			bootmap_start = sysmem.bank[i].start;
129 			break;
130 		}
131 
132 	if (bootmap_start == ~0UL)
133 		panic("Cannot find %ld bytes for bootmap\n", bootmap_size);
134 
135 	/* Reserve the bootmem bitmap area */
136 
137 	mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1);
138 	bootmap_size = init_bootmem_node(NODE_DATA(0),
139 					 bootmap_start >> PAGE_SHIFT,
140 					 min_low_pfn,
141 					 max_low_pfn);
142 
143 	/* Add all remaining memory pieces into the bootmem map */
144 
145 	for (i = 0; i < sysmem.nr_banks; i++) {
146 		if (sysmem.bank[i].start >> PAGE_SHIFT < max_low_pfn) {
147 			unsigned long end = min(max_low_pfn << PAGE_SHIFT,
148 						sysmem.bank[i].end);
149 			free_bootmem(sysmem.bank[i].start,
150 				     end - sysmem.bank[i].start);
151 		}
152 	}
153 
154 }
155 
156 
157 void __init zones_init(void)
158 {
159 	unsigned long zones_size[MAX_NR_ZONES];
160 	int i;
161 
162 	/* All pages are DMA-able, so we put them all in the DMA zone. */
163 
164 	zones_size[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET;
165 	for (i = 1; i < MAX_NR_ZONES; i++)
166 		zones_size[i] = 0;
167 
168 #ifdef CONFIG_HIGHMEM
169 	zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
170 #endif
171 
172 	free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
173 }
174 
175 /*
176  * Initialize memory pages.
177  */
178 
179 void __init mem_init(void)
180 {
181 	max_mapnr = max_low_pfn - ARCH_PFN_OFFSET;
182 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
183 
184 #ifdef CONFIG_HIGHMEM
185 #error HIGHGMEM not implemented in init.c
186 #endif
187 
188 	free_all_bootmem();
189 
190 	mem_init_print_info(NULL);
191 }
192 
193 #ifdef CONFIG_BLK_DEV_INITRD
194 extern int initrd_is_mapped;
195 
196 void free_initrd_mem(unsigned long start, unsigned long end)
197 {
198 	if (initrd_is_mapped)
199 		free_reserved_area((void *)start, (void *)end, -1, "initrd");
200 }
201 #endif
202 
203 void free_initmem(void)
204 {
205 	free_initmem_default(-1);
206 }
207