Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 */
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
57/*
58 * paging_init() sets up the page tables - in fact we've already done this.
59 */
60static void __init paging_init(void)
61{
62 unsigned long zones_size[MAX_NR_ZONES];
63 int idx;
64
65 /* Setup fixmaps */
66 for (idx = 0; idx < __end_of_fixed_addresses; idx++)
67 clear_fixmap(idx);
68
69 /* Clean every zones */
70 memset(zones_size, 0, sizeof(zones_size));
71
72#ifdef CONFIG_HIGHMEM
73 highmem_init();
74
75 zones_size[ZONE_DMA] = max_low_pfn;
76 zones_size[ZONE_HIGHMEM] = max_pfn;
77#else
78 zones_size[ZONE_DMA] = max_pfn;
79#endif
80
81 /* We don't have holes in memory map */
82 free_area_init(zones_size);
83}
84
85void __init setup_memory(void)
86{
87 /*
88 * Kernel:
89 * start: base phys address of kernel - page align
90 * end: base phys address of kernel - page align
91 *
92 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
93 * max_low_pfn
94 */
95
96 /* memory start is from the kernel end (aligned) to higher addr */
97 min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
98 max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
99 max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
100
101 pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
102 pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
103 pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
104
105 paging_init();
106}
107
108void __init mem_init(void)
109{
110 mem_init_done = 1;
111}
112
113int page_is_ram(unsigned long pfn)
114{
115 return pfn < max_low_pfn;
116}
117
118/*
119 * Check for command-line options that affect what MMU_init will do.
120 */
121static void __init mm_cmdline_setup(void)
122{
123 unsigned long maxmem = 0;
124 char *p = cmd_line;
125
126 /* Look for mem= option on command line */
127 p = strstr(cmd_line, "mem=");
128 if (p) {
129 p += 4;
130 maxmem = memparse(p, &p);
131 if (maxmem && memory_size > maxmem) {
132 memory_size = maxmem;
133 memblock.memory.regions[0].size = memory_size;
134 }
135 }
136}
137
138/*
139 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
140 */
141static void __init mmu_init_hw(void)
142{
143 /*
144 * The Zone Protection Register (ZPR) defines how protection will
145 * be applied to every page which is a member of a given zone. At
146 * present, we utilize only two of the zones.
147 * The zone index bits (of ZSEL) in the PTE are used for software
148 * indicators, except the LSB. For user access, zone 1 is used,
149 * for kernel access, zone 0 is used. We set all but zone 1
150 * to zero, allowing only kernel access as indicated in the PTE.
151 * For zone 1, we set a 01 binary (a value of 10 will not work)
152 * to allow user access as indicated in the PTE. This also allows
153 * kernel access as indicated in the PTE.
154 */
155 __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
156 "mts rzpr, r11;"
157 : : : "r11");
158}
159
160/*
161 * MMU_init sets up the basic memory mappings for the kernel,
162 * including both RAM and possibly some I/O regions,
163 * and sets up the page tables and the MMU hardware ready to go.
164 */
165
166/* called from head.S */
167asmlinkage void __init mmu_init(void)
168{
169 unsigned int kstart, ksize;
170
171 if ((u32) memblock.memory.regions[0].size < 0x400000) {
172 pr_emerg("Memory must be greater than 4MB\n");
173 machine_restart(NULL);
174 }
175
176 if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
177 pr_emerg("Kernel size is greater than memory node\n");
178 machine_restart(NULL);
179 }
180
181 /* Find main memory where the kernel is */
182 memory_start = (u32) memblock.memory.regions[0].base;
183 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
184
185 if (lowmem_size > CONFIG_LOWMEM_SIZE) {
186 lowmem_size = CONFIG_LOWMEM_SIZE;
187#ifndef CONFIG_HIGHMEM
188 memory_size = lowmem_size;
189#endif
190 }
191
192 mm_cmdline_setup(); /* FIXME parse args from command line - not used */
193
194 /*
195 * Map out the kernel text/data/bss from the available physical
196 * memory.
197 */
198 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
199 /* kernel size */
200 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
201 memblock_reserve(kstart, ksize);
202
203#if defined(CONFIG_BLK_DEV_INITRD)
204 /* Remove the init RAM disk from the available memory. */
205 if (initrd_start) {
206 unsigned long size;
207 size = initrd_end - initrd_start;
208 memblock_reserve(__virt_to_phys(initrd_start), size);
209 }
210#endif /* CONFIG_BLK_DEV_INITRD */
211
212 /* Initialize the MMU hardware */
213 mmu_init_hw();
214
215 /* Map in all of RAM starting at CONFIG_KERNEL_START */
216 mapin_ram();
217
218 /* Extend vmalloc and ioremap area as big as possible */
219#ifdef CONFIG_HIGHMEM
220 ioremap_base = ioremap_bot = PKMAP_BASE;
221#else
222 ioremap_base = ioremap_bot = FIXADDR_START;
223#endif
224
225 /* Initialize the context management stuff */
226 mmu_context_init();
227
228 /* Shortly after that, the entire linear mapping will be available */
229 /* This will also cause that unflatten device tree will be allocated
230 * inside 768MB limit */
231 memblock_set_current_limit(memory_start + lowmem_size - 1);
232
233 parse_early_param();
234
235 early_init_fdt_scan_reserved_mem();
236
237 /* CMA initialization */
238 dma_contiguous_reserve(memory_start + lowmem_size - 1);
239
240 memblock_dump_all();
241}
242
243static const pgprot_t protection_map[16] = {
244 [VM_NONE] = PAGE_NONE,
245 [VM_READ] = PAGE_READONLY_X,
246 [VM_WRITE] = PAGE_COPY,
247 [VM_WRITE | VM_READ] = PAGE_COPY_X,
248 [VM_EXEC] = PAGE_READONLY,
249 [VM_EXEC | VM_READ] = PAGE_READONLY_X,
250 [VM_EXEC | VM_WRITE] = PAGE_COPY,
251 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X,
252 [VM_SHARED] = PAGE_NONE,
253 [VM_SHARED | VM_READ] = PAGE_READONLY_X,
254 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
255 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X,
256 [VM_SHARED | VM_EXEC] = PAGE_READONLY,
257 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X,
258 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
259 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X
260};
261DECLARE_VM_GET_PAGE_PROT