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1/*
2 * Copyright (C) 2007-2008 Michal Simek <[email protected]>
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 */
31int mem_init_done;
32
33char *klimit = _end;
34
35/*
36 * Initialize the bootmem system and give it all the memory we
37 * have available.
38 */
39unsigned long memory_start;
40EXPORT_SYMBOL(memory_start);
41unsigned long memory_size;
42EXPORT_SYMBOL(memory_size);
43unsigned long lowmem_size;
44
45EXPORT_SYMBOL(min_low_pfn);
46EXPORT_SYMBOL(max_low_pfn);
47
48#ifdef CONFIG_HIGHMEM
49static 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#endif /* CONFIG_HIGHMEM */
56
57void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
58{
59#ifdef CONFIG_HIGHMEM
60 max_zone_pfns[ZONE_DMA] = max_low_pfn;
61 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
62#else
63 max_zone_pfns[ZONE_DMA] = max_pfn;
64#endif
65}
66
67/*
68 * paging_init() sets up the page tables - in fact we've already done this.
69 */
70static void __init paging_init(void)
71{
72 int idx;
73
74 /* Setup fixmaps */
75 for (idx = 0; idx < __end_of_fixed_addresses; idx++)
76 clear_fixmap(idx);
77
78#ifdef CONFIG_HIGHMEM
79 highmem_init();
80#endif
81}
82
83void __init setup_memory(void)
84{
85 /*
86 * Kernel:
87 * start: base phys address of kernel - page align
88 * end: base phys address of kernel - page align
89 *
90 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
91 * max_low_pfn
92 */
93
94 /* memory start is from the kernel end (aligned) to higher addr */
95 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
96 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
97 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
98
99 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
100 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
101 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
102
103 paging_init();
104}
105
106void __init mem_init(void)
107{
108 mem_init_done = 1;
109}
110
111int page_is_ram(unsigned long pfn)
112{
113 return pfn < max_low_pfn;
114}
115
116/*
117 * Check for command-line options that affect what MMU_init will do.
118 */
119static void __init mm_cmdline_setup(void)
120{
121 unsigned long maxmem = 0;
122 char *p = cmd_line;
123
124 /* Look for mem= option on command line */
125 p = strstr(cmd_line, "mem=");
126 if (p) {
127 p += 4;
128 maxmem = memparse(p, &p);
129 if (maxmem && memory_size > maxmem) {
130 memory_size = maxmem;
131 memblock.memory.regions[0].size = memory_size;
132 }
133 }
134}
135
136/*
137 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
138 */
139static void __init mmu_init_hw(void)
140{
141 /*
142 * The Zone Protection Register (ZPR) defines how protection will
143 * be applied to every page which is a member of a given zone. At
144 * present, we utilize only two of the zones.
145 * The zone index bits (of ZSEL) in the PTE are used for software
146 * indicators, except the LSB. For user access, zone 1 is used,
147 * for kernel access, zone 0 is used. We set all but zone 1
148 * to zero, allowing only kernel access as indicated in the PTE.
149 * For zone 1, we set a 01 binary (a value of 10 will not work)
150 * to allow user access as indicated in the PTE. This also allows
151 * kernel access as indicated in the PTE.
152 */
153 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
154 "mts rzpr, r11;"
155 : : : "r11");
156}
157
158/*
159 * MMU_init sets up the basic memory mappings for the kernel,
160 * including both RAM and possibly some I/O regions,
161 * and sets up the page tables and the MMU hardware ready to go.
162 */
163
164/* called from head.S */
165asmlinkage void __init mmu_init(void)
166{
167 unsigned int kstart, ksize;
168
169 if ((u32) memblock.memory.regions[0].size < 0x400000) {
170 pr_emerg("Memory must be greater than 4MB\n");
171 machine_restart(NULL);
172 }
173
174 if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
175 pr_emerg("Kernel size is greater than memory node\n");
176 machine_restart(NULL);
177 }
178
179 /* Find main memory where the kernel is */
180 memory_start = (u32) memblock.memory.regions[0].base;
181 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
182
183 if (lowmem_size > CONFIG_LOWMEM_SIZE) {
184 lowmem_size = CONFIG_LOWMEM_SIZE;
185#ifndef CONFIG_HIGHMEM
186 memory_size = lowmem_size;
187#endif
188 }
189
190 mm_cmdline_setup(); /* FIXME parse args from command line - not used */
191
192 /*
193 * Map out the kernel text/data/bss from the available physical
194 * memory.
195 */
196 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
197 /* kernel size */
198 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
199 memblock_reserve(kstart, ksize);
200
201#if defined(CONFIG_BLK_DEV_INITRD)
202 /* Remove the init RAM disk from the available memory. */
203 if (initrd_start) {
204 unsigned long size;
205 size = initrd_end - initrd_start;
206 memblock_reserve(__virt_to_phys(initrd_start), size);
207 }
208#endif /* CONFIG_BLK_DEV_INITRD */
209
210 /* Initialize the MMU hardware */
211 mmu_init_hw();
212
213 /* Map in all of RAM starting at CONFIG_KERNEL_START */
214 mapin_ram();
215
216 /* Extend vmalloc and ioremap area as big as possible */
217#ifdef CONFIG_HIGHMEM
218 ioremap_base = ioremap_bot = PKMAP_BASE;
219#else
220 ioremap_base = ioremap_bot = FIXADDR_START;
221#endif
222
223 /* Initialize the context management stuff */
224 mmu_context_init();
225
226 /* Shortly after that, the entire linear mapping will be available */
227 /* This will also cause that unflatten device tree will be allocated
228 * inside 768MB limit */
229 memblock_set_current_limit(memory_start + lowmem_size - 1);
230
231 parse_early_param();
232
233 early_init_fdt_scan_reserved_mem();
234
235 /* CMA initialization */
236 dma_contiguous_reserve(memory_start + lowmem_size - 1);
237
238 memblock_dump_all();
239}
240
241static const pgprot_t protection_map[16] = {
242 [VM_NONE] = PAGE_NONE,
243 [VM_READ] = PAGE_READONLY_X,
244 [VM_WRITE] = PAGE_COPY,
245 [VM_WRITE | VM_READ] = PAGE_COPY_X,
246 [VM_EXEC] = PAGE_READONLY,
247 [VM_EXEC | VM_READ] = PAGE_READONLY_X,
248 [VM_EXEC | VM_WRITE] = PAGE_COPY,
249 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X,
250 [VM_SHARED] = PAGE_NONE,
251 [VM_SHARED | VM_READ] = PAGE_READONLY_X,
252 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
253 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X,
254 [VM_SHARED | VM_EXEC] = PAGE_READONLY,
255 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X,
256 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
257 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X
258};
259DECLARE_VM_GET_PAGE_PROT