xref: /linux/arch/microblaze/mm/init.c (revision 1c4b5ecb7ea190fa3e9f9d6891e6c90b60e04f24)
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/pagemap.h>
17 #include <linux/pfn.h>
18 #include <linux/slab.h>
19 #include <linux/swap.h>
20 #include <linux/export.h>
21 
22 #include <asm/page.h>
23 #include <asm/mmu_context.h>
24 #include <asm/pgalloc.h>
25 #include <asm/sections.h>
26 #include <asm/tlb.h>
27 #include <asm/fixmap.h>
28 
29 /* Use for MMU and noMMU because of PCI generic code */
30 int mem_init_done;
31 
32 char *klimit = _end;
33 
34 /*
35  * Initialize the bootmem system and give it all the memory we
36  * have available.
37  */
38 unsigned long memory_start;
39 EXPORT_SYMBOL(memory_start);
40 unsigned long memory_size;
41 EXPORT_SYMBOL(memory_size);
42 unsigned long lowmem_size;
43 
44 EXPORT_SYMBOL(min_low_pfn);
45 EXPORT_SYMBOL(max_low_pfn);
46 
47 #ifdef CONFIG_HIGHMEM
48 static void __init highmem_init(void)
49 {
50 	pr_debug("%x\n", (u32)PKMAP_BASE);
51 	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
52 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
53 }
54 
55 static void __meminit highmem_setup(void)
56 {
57 	unsigned long pfn;
58 
59 	for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
60 		struct page *page = pfn_to_page(pfn);
61 
62 		/* FIXME not sure about */
63 		if (!memblock_is_reserved(pfn << PAGE_SHIFT))
64 			free_highmem_page(page);
65 	}
66 }
67 #endif /* CONFIG_HIGHMEM */
68 
69 /*
70  * paging_init() sets up the page tables - in fact we've already done this.
71  */
72 static void __init paging_init(void)
73 {
74 	unsigned long zones_size[MAX_NR_ZONES];
75 	int idx;
76 
77 	/* Setup fixmaps */
78 	for (idx = 0; idx < __end_of_fixed_addresses; idx++)
79 		clear_fixmap(idx);
80 
81 	/* Clean every zones */
82 	memset(zones_size, 0, sizeof(zones_size));
83 
84 #ifdef CONFIG_HIGHMEM
85 	highmem_init();
86 
87 	zones_size[ZONE_DMA] = max_low_pfn;
88 	zones_size[ZONE_HIGHMEM] = max_pfn;
89 #else
90 	zones_size[ZONE_DMA] = max_pfn;
91 #endif
92 
93 	/* We don't have holes in memory map */
94 	free_area_init(zones_size);
95 }
96 
97 void __init setup_memory(void)
98 {
99 	/*
100 	 * Kernel:
101 	 * start: base phys address of kernel - page align
102 	 * end: base phys address of kernel - page align
103 	 *
104 	 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
105 	 * max_low_pfn
106 	 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
107 	 */
108 
109 	/* memory start is from the kernel end (aligned) to higher addr */
110 	min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
111 	/* RAM is assumed contiguous */
112 	max_mapnr = memory_size >> PAGE_SHIFT;
113 	max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
114 	max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
115 
116 	pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
117 	pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
118 	pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
119 	pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
120 
121 	paging_init();
122 }
123 
124 void __init mem_init(void)
125 {
126 	high_memory = (void *)__va(memory_start + lowmem_size - 1);
127 
128 	/* this will put all memory onto the freelists */
129 	memblock_free_all();
130 #ifdef CONFIG_HIGHMEM
131 	highmem_setup();
132 #endif
133 
134 	mem_init_done = 1;
135 }
136 
137 int page_is_ram(unsigned long pfn)
138 {
139 	return pfn < max_low_pfn;
140 }
141 
142 /*
143  * Check for command-line options that affect what MMU_init will do.
144  */
145 static void mm_cmdline_setup(void)
146 {
147 	unsigned long maxmem = 0;
148 	char *p = cmd_line;
149 
150 	/* Look for mem= option on command line */
151 	p = strstr(cmd_line, "mem=");
152 	if (p) {
153 		p += 4;
154 		maxmem = memparse(p, &p);
155 		if (maxmem && memory_size > maxmem) {
156 			memory_size = maxmem;
157 			memblock.memory.regions[0].size = memory_size;
158 		}
159 	}
160 }
161 
162 /*
163  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
164  */
165 static void __init mmu_init_hw(void)
166 {
167 	/*
168 	 * The Zone Protection Register (ZPR) defines how protection will
169 	 * be applied to every page which is a member of a given zone. At
170 	 * present, we utilize only two of the zones.
171 	 * The zone index bits (of ZSEL) in the PTE are used for software
172 	 * indicators, except the LSB.  For user access, zone 1 is used,
173 	 * for kernel access, zone 0 is used.  We set all but zone 1
174 	 * to zero, allowing only kernel access as indicated in the PTE.
175 	 * For zone 1, we set a 01 binary (a value of 10 will not work)
176 	 * to allow user access as indicated in the PTE.  This also allows
177 	 * kernel access as indicated in the PTE.
178 	 */
179 	__asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
180 			"mts rzpr, r11;"
181 			: : : "r11");
182 }
183 
184 /*
185  * MMU_init sets up the basic memory mappings for the kernel,
186  * including both RAM and possibly some I/O regions,
187  * and sets up the page tables and the MMU hardware ready to go.
188  */
189 
190 /* called from head.S */
191 asmlinkage void __init mmu_init(void)
192 {
193 	unsigned int kstart, ksize;
194 
195 	if (!memblock.reserved.cnt) {
196 		pr_emerg("Error memory count\n");
197 		machine_restart(NULL);
198 	}
199 
200 	if ((u32) memblock.memory.regions[0].size < 0x400000) {
201 		pr_emerg("Memory must be greater than 4MB\n");
202 		machine_restart(NULL);
203 	}
204 
205 	if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
206 		pr_emerg("Kernel size is greater than memory node\n");
207 		machine_restart(NULL);
208 	}
209 
210 	/* Find main memory where the kernel is */
211 	memory_start = (u32) memblock.memory.regions[0].base;
212 	lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
213 
214 	if (lowmem_size > CONFIG_LOWMEM_SIZE) {
215 		lowmem_size = CONFIG_LOWMEM_SIZE;
216 #ifndef CONFIG_HIGHMEM
217 		memory_size = lowmem_size;
218 #endif
219 	}
220 
221 	mm_cmdline_setup(); /* FIXME parse args from command line - not used */
222 
223 	/*
224 	 * Map out the kernel text/data/bss from the available physical
225 	 * memory.
226 	 */
227 	kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
228 	/* kernel size */
229 	ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
230 	memblock_reserve(kstart, ksize);
231 
232 #if defined(CONFIG_BLK_DEV_INITRD)
233 	/* Remove the init RAM disk from the available memory. */
234 	if (initrd_start) {
235 		unsigned long size;
236 		size = initrd_end - initrd_start;
237 		memblock_reserve(__virt_to_phys(initrd_start), size);
238 	}
239 #endif /* CONFIG_BLK_DEV_INITRD */
240 
241 	/* Initialize the MMU hardware */
242 	mmu_init_hw();
243 
244 	/* Map in all of RAM starting at CONFIG_KERNEL_START */
245 	mapin_ram();
246 
247 	/* Extend vmalloc and ioremap area as big as possible */
248 #ifdef CONFIG_HIGHMEM
249 	ioremap_base = ioremap_bot = PKMAP_BASE;
250 #else
251 	ioremap_base = ioremap_bot = FIXADDR_START;
252 #endif
253 
254 	/* Initialize the context management stuff */
255 	mmu_context_init();
256 
257 	/* Shortly after that, the entire linear mapping will be available */
258 	/* This will also cause that unflatten device tree will be allocated
259 	 * inside 768MB limit */
260 	memblock_set_current_limit(memory_start + lowmem_size - 1);
261 
262 	parse_early_param();
263 
264 	/* CMA initialization */
265 	dma_contiguous_reserve(memory_start + lowmem_size - 1);
266 }
267 
268 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
269 {
270 	void *p;
271 
272 	if (mem_init_done) {
273 		p = kzalloc(size, mask);
274 	} else {
275 		p = memblock_alloc(size, SMP_CACHE_BYTES);
276 		if (!p)
277 			panic("%s: Failed to allocate %zu bytes\n",
278 			      __func__, size);
279 	}
280 
281 	return p;
282 }
283