1 /*
2 * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2006 Atmark Techno, Inc.
4 *
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
8 */
9
10 #include <linux/dma-map-ops.h>
11 #include <linux/memblock.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h> /* mem_init */
15 #include <linux/initrd.h>
16 #include <linux/of_fdt.h>
17 #include <linux/pagemap.h>
18 #include <linux/pfn.h>
19 #include <linux/slab.h>
20 #include <linux/swap.h>
21 #include <linux/export.h>
22
23 #include <asm/page.h>
24 #include <asm/mmu_context.h>
25 #include <asm/pgalloc.h>
26 #include <asm/sections.h>
27 #include <asm/tlb.h>
28 #include <asm/fixmap.h>
29
30 /* Use for MMU and noMMU because of PCI generic code */
31 int mem_init_done;
32
33 char *klimit = _end;
34
35 /*
36 * Initialize the bootmem system and give it all the memory we
37 * have available.
38 */
39 unsigned long memory_start;
40 EXPORT_SYMBOL(memory_start);
41 unsigned long memory_size;
42 EXPORT_SYMBOL(memory_size);
43 unsigned long lowmem_size;
44
45 EXPORT_SYMBOL(min_low_pfn);
46 EXPORT_SYMBOL(max_low_pfn);
47
48 #ifdef CONFIG_HIGHMEM
49 static void __init highmem_init(void)
50 {
51 pr_debug("%x\n", (u32)PKMAP_BASE);
52 map_page(PKMAP_BASE, 0, 0); /* XXX gross */
53 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
54 }
55
56 static void __meminit highmem_setup(void)
57 {
58 unsigned long pfn;
59
60 for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
61 struct page *page = pfn_to_page(pfn);
62
63 /* FIXME not sure about */
64 if (!memblock_is_reserved(pfn << PAGE_SHIFT))
65 free_highmem_page(page);
66 }
67 }
68 #endif /* CONFIG_HIGHMEM */
69
70 /*
71 * paging_init() sets up the page tables - in fact we've already done this.
72 */
73 static void __init paging_init(void)
74 {
75 unsigned long zones_size[MAX_NR_ZONES];
76 int idx;
77
78 /* Setup fixmaps */
79 for (idx = 0; idx < __end_of_fixed_addresses; idx++)
80 clear_fixmap(idx);
81
82 /* Clean every zones */
83 memset(zones_size, 0, sizeof(zones_size));
84
85 #ifdef CONFIG_HIGHMEM
86 highmem_init();
87
88 zones_size[ZONE_DMA] = max_low_pfn;
89 zones_size[ZONE_HIGHMEM] = max_pfn;
90 #else
91 zones_size[ZONE_DMA] = max_pfn;
92 #endif
93
94 /* We don't have holes in memory map */
95 free_area_init(zones_size);
96 }
97
98 void __init setup_memory(void)
99 {
100 /*
101 * Kernel:
102 * start: base phys address of kernel - page align
103 * end: base phys address of kernel - page align
104 *
105 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
106 * max_low_pfn
107 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
108 */
109
110 /* memory start is from the kernel end (aligned) to higher addr */
111 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
112 /* RAM is assumed contiguous */
113 max_mapnr = memory_size >> PAGE_SHIFT;
114 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
115 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
116
117 pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
118 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
119 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
120 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
121
122 paging_init();
123 }
124
125 void __init mem_init(void)
126 {
127 high_memory = (void *)__va(memory_start + lowmem_size - 1);
128
129 /* this will put all memory onto the freelists */
130 memblock_free_all();
131 #ifdef CONFIG_HIGHMEM
132 highmem_setup();
133 #endif
134
135 mem_init_done = 1;
136 }
137
138 int page_is_ram(unsigned long pfn)
139 {
140 return pfn < max_low_pfn;
141 }
142
143 /*
144 * Check for command-line options that affect what MMU_init will do.
145 */
146 static void mm_cmdline_setup(void)
147 {
148 unsigned long maxmem = 0;
149 char *p = cmd_line;
150
151 /* Look for mem= option on command line */
152 p = strstr(cmd_line, "mem=");
153 if (p) {
154 p += 4;
155 maxmem = memparse(p, &p);
156 if (maxmem && memory_size > maxmem) {
157 memory_size = maxmem;
158 memblock.memory.regions[0].size = memory_size;
159 }
160 }
161 }
162
163 /*
164 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
165 */
166 static void __init mmu_init_hw(void)
167 {
168 /*
169 * The Zone Protection Register (ZPR) defines how protection will
170 * be applied to every page which is a member of a given zone. At
171 * present, we utilize only two of the zones.
172 * The zone index bits (of ZSEL) in the PTE are used for software
173 * indicators, except the LSB. For user access, zone 1 is used,
174 * for kernel access, zone 0 is used. We set all but zone 1
175 * to zero, allowing only kernel access as indicated in the PTE.
176 * For zone 1, we set a 01 binary (a value of 10 will not work)
177 * to allow user access as indicated in the PTE. This also allows
178 * kernel access as indicated in the PTE.
179 */
180 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
181 "mts rzpr, r11;"
182 : : : "r11");
183 }
184
185 /*
186 * MMU_init sets up the basic memory mappings for the kernel,
187 * including both RAM and possibly some I/O regions,
188 * and sets up the page tables and the MMU hardware ready to go.
189 */
190
191 /* called from head.S */
192 asmlinkage void __init mmu_init(void)
193 {
194 unsigned int kstart, ksize;
195
196 if ((u32) memblock.memory.regions[0].size < 0x400000) {
197 pr_emerg("Memory must be greater than 4MB\n");
198 machine_restart(NULL);
199 }
200
201 if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
202 pr_emerg("Kernel size is greater than memory node\n");
203 machine_restart(NULL);
204 }
205
206 /* Find main memory where the kernel is */
207 memory_start = (u32) memblock.memory.regions[0].base;
208 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
209
210 if (lowmem_size > CONFIG_LOWMEM_SIZE) {
211 lowmem_size = CONFIG_LOWMEM_SIZE;
212 #ifndef CONFIG_HIGHMEM
213 memory_size = lowmem_size;
214 #endif
215 }
216
217 mm_cmdline_setup(); /* FIXME parse args from command line - not used */
218
219 /*
220 * Map out the kernel text/data/bss from the available physical
221 * memory.
222 */
223 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
224 /* kernel size */
225 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
226 memblock_reserve(kstart, ksize);
227
228 #if defined(CONFIG_BLK_DEV_INITRD)
229 /* Remove the init RAM disk from the available memory. */
230 if (initrd_start) {
231 unsigned long size;
232 size = initrd_end - initrd_start;
233 memblock_reserve(__virt_to_phys(initrd_start), size);
234 }
235 #endif /* CONFIG_BLK_DEV_INITRD */
236
237 /* Initialize the MMU hardware */
238 mmu_init_hw();
239
240 /* Map in all of RAM starting at CONFIG_KERNEL_START */
241 mapin_ram();
242
243 /* Extend vmalloc and ioremap area as big as possible */
244 #ifdef CONFIG_HIGHMEM
245 ioremap_base = ioremap_bot = PKMAP_BASE;
246 #else
247 ioremap_base = ioremap_bot = FIXADDR_START;
248 #endif
249
250 /* Initialize the context management stuff */
251 mmu_context_init();
252
253 /* Shortly after that, the entire linear mapping will be available */
254 /* This will also cause that unflatten device tree will be allocated
255 * inside 768MB limit */
256 memblock_set_current_limit(memory_start + lowmem_size - 1);
257
258 parse_early_param();
259
260 early_init_fdt_scan_reserved_mem();
261
262 /* CMA initialization */
263 dma_contiguous_reserve(memory_start + lowmem_size - 1);
264
265 memblock_dump_all();
266 }
267
268 static const pgprot_t protection_map[16] = {
269 [VM_NONE] = PAGE_NONE,
270 [VM_READ] = PAGE_READONLY_X,
271 [VM_WRITE] = PAGE_COPY,
272 [VM_WRITE | VM_READ] = PAGE_COPY_X,
273 [VM_EXEC] = PAGE_READONLY,
274 [VM_EXEC | VM_READ] = PAGE_READONLY_X,
275 [VM_EXEC | VM_WRITE] = PAGE_COPY,
276 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X,
277 [VM_SHARED] = PAGE_NONE,
278 [VM_SHARED | VM_READ] = PAGE_READONLY_X,
279 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
280 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X,
281 [VM_SHARED | VM_EXEC] = PAGE_READONLY,
282 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X,
283 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
284 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X
285 };
286 DECLARE_VM_GET_PAGE_PROT
287
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