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
56static 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 */
73static 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(max_zone_pfn: zones_size);
96}
97
98void __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
125void __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
138int 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 */
146static 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(ptr: p, retptr: &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 */
166static 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 */
192asmlinkage void __init mmu_init(void)
193{
194 unsigned int kstart, ksize;
195
196 if (!memblock.reserved.cnt) {
197 pr_emerg("Error memory count\n");
198 machine_restart(NULL);
199 }
200
201 if ((u32) memblock.memory.regions[0].size < 0x400000) {
202 pr_emerg("Memory must be greater than 4MB\n");
203 machine_restart(NULL);
204 }
205
206 if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
207 pr_emerg("Kernel size is greater than memory node\n");
208 machine_restart(NULL);
209 }
210
211 /* Find main memory where the kernel is */
212 memory_start = (u32) memblock.memory.regions[0].base;
213 lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
214
215 if (lowmem_size > CONFIG_LOWMEM_SIZE) {
216 lowmem_size = CONFIG_LOWMEM_SIZE;
217#ifndef CONFIG_HIGHMEM
218 memory_size = lowmem_size;
219#endif
220 }
221
222 mm_cmdline_setup(); /* FIXME parse args from command line - not used */
223
224 /*
225 * Map out the kernel text/data/bss from the available physical
226 * memory.
227 */
228 kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
229 /* kernel size */
230 ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
231 memblock_reserve(base: kstart, size: ksize);
232
233#if defined(CONFIG_BLK_DEV_INITRD)
234 /* Remove the init RAM disk from the available memory. */
235 if (initrd_start) {
236 unsigned long size;
237 size = initrd_end - initrd_start;
238 memblock_reserve(base: __virt_to_phys(initrd_start), size);
239 }
240#endif /* CONFIG_BLK_DEV_INITRD */
241
242 /* Initialize the MMU hardware */
243 mmu_init_hw();
244
245 /* Map in all of RAM starting at CONFIG_KERNEL_START */
246 mapin_ram();
247
248 /* Extend vmalloc and ioremap area as big as possible */
249#ifdef CONFIG_HIGHMEM
250 ioremap_base = ioremap_bot = PKMAP_BASE;
251#else
252 ioremap_base = ioremap_bot = FIXADDR_START;
253#endif
254
255 /* Initialize the context management stuff */
256 mmu_context_init();
257
258 /* Shortly after that, the entire linear mapping will be available */
259 /* This will also cause that unflatten device tree will be allocated
260 * inside 768MB limit */
261 memblock_set_current_limit(limit: memory_start + lowmem_size - 1);
262
263 parse_early_param();
264
265 early_init_fdt_scan_reserved_mem();
266
267 /* CMA initialization */
268 dma_contiguous_reserve(addr_limit: memory_start + lowmem_size - 1);
269
270 memblock_dump_all();
271}
272
273static const pgprot_t protection_map[16] = {
274 [VM_NONE] = PAGE_NONE,
275 [VM_READ] = PAGE_READONLY_X,
276 [VM_WRITE] = PAGE_COPY,
277 [VM_WRITE | VM_READ] = PAGE_COPY_X,
278 [VM_EXEC] = PAGE_READONLY,
279 [VM_EXEC | VM_READ] = PAGE_READONLY_X,
280 [VM_EXEC | VM_WRITE] = PAGE_COPY,
281 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_X,
282 [VM_SHARED] = PAGE_NONE,
283 [VM_SHARED | VM_READ] = PAGE_READONLY_X,
284 [VM_SHARED | VM_WRITE] = PAGE_SHARED,
285 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED_X,
286 [VM_SHARED | VM_EXEC] = PAGE_READONLY,
287 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_X,
288 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
289 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_X
290};
291DECLARE_VM_GET_PAGE_PROT
292

source code of linux/arch/microblaze/mm/init.c