xref: /linux/arch/xtensa/mm/init.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 	} else {
79 		if (end < sysmem.bank[i].end)
80 			sysmem.bank[i].start = end;
81 		else {
82 			/* remove entry */
83 			sysmem.nr_banks--;
84 			sysmem.bank[i].start = sysmem.bank[sysmem.nr_banks].start;
85 			sysmem.bank[i].end   = sysmem.bank[sysmem.nr_banks].end;
86 		}
87 	}
88 	return -1;
89 }
90 
91 
92 /*
93  * Initialize the bootmem system and give it all the 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 		free_bootmem(sysmem.bank[i].start,
147 			     sysmem.bank[i].end - sysmem.bank[i].start);
148 
149 }
150 
151 
152 void __init zones_init(void)
153 {
154 	unsigned long zones_size[MAX_NR_ZONES];
155 	int i;
156 
157 	/* All pages are DMA-able, so we put them all in the DMA zone. */
158 
159 	zones_size[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET;
160 	for (i = 1; i < MAX_NR_ZONES; i++)
161 		zones_size[i] = 0;
162 
163 #ifdef CONFIG_HIGHMEM
164 	zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
165 #endif
166 
167 	free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
168 }
169 
170 /*
171  * Initialize memory pages.
172  */
173 
174 void __init mem_init(void)
175 {
176 	unsigned long codesize, reservedpages, datasize, initsize;
177 	unsigned long highmemsize, tmp, ram;
178 
179 	max_mapnr = num_physpages = max_low_pfn - ARCH_PFN_OFFSET;
180 	high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
181 	highmemsize = 0;
182 
183 #ifdef CONFIG_HIGHMEM
184 #error HIGHGMEM not implemented in init.c
185 #endif
186 
187 	totalram_pages += free_all_bootmem();
188 
189 	reservedpages = ram = 0;
190 	for (tmp = 0; tmp < max_mapnr; tmp++) {
191 		ram++;
192 		if (PageReserved(mem_map+tmp))
193 			reservedpages++;
194 	}
195 
196 	codesize =  (unsigned long) _etext - (unsigned long) _stext;
197 	datasize =  (unsigned long) _edata - (unsigned long) _sdata;
198 	initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
199 
200 	printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, "
201 	       "%ldk data, %ldk init %ldk highmem)\n",
202 	       nr_free_pages() << (PAGE_SHIFT-10),
203 	       ram << (PAGE_SHIFT-10),
204 	       codesize >> 10,
205 	       reservedpages << (PAGE_SHIFT-10),
206 	       datasize >> 10,
207 	       initsize >> 10,
208 	       highmemsize >> 10);
209 }
210 
211 void
212 free_reserved_mem(void *start, void *end)
213 {
214 	for (; start < end; start += PAGE_SIZE) {
215 		ClearPageReserved(virt_to_page(start));
216 		init_page_count(virt_to_page(start));
217 		free_page((unsigned long)start);
218 		totalram_pages++;
219 	}
220 }
221 
222 #ifdef CONFIG_BLK_DEV_INITRD
223 extern int initrd_is_mapped;
224 
225 void free_initrd_mem(unsigned long start, unsigned long end)
226 {
227 	if (initrd_is_mapped) {
228 		free_reserved_mem((void*)start, (void*)end);
229 		printk ("Freeing initrd memory: %ldk freed\n",(end-start)>>10);
230 	}
231 }
232 #endif
233 
234 void free_initmem(void)
235 {
236 	free_reserved_mem(__init_begin, __init_end);
237 	printk("Freeing unused kernel memory: %zuk freed\n",
238 	       (__init_end - __init_begin) >> 10);
239 }
240