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/bootmem.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/memblock.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 */
30int mem_init_done;
31
32#ifndef CONFIG_MMU
33unsigned int __page_offset;
34EXPORT_SYMBOL(__page_offset);
35
36#else
37static int init_bootmem_done;
38#endif /* CONFIG_MMU */
39
40char *klimit = _end;
41
42/*
43 * Initialize the bootmem system and give it all the memory we
44 * have available.
45 */
46unsigned long memory_start;
47EXPORT_SYMBOL(memory_start);
48unsigned long memory_size;
49EXPORT_SYMBOL(memory_size);
50unsigned long lowmem_size;
51
52#ifdef CONFIG_HIGHMEM
53pte_t *kmap_pte;
54EXPORT_SYMBOL(kmap_pte);
55pgprot_t kmap_prot;
56EXPORT_SYMBOL(kmap_prot);
57
58static inline pte_t *virt_to_kpte(unsigned long vaddr)
59{
60	return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
61			vaddr), vaddr);
62}
63
64static void __init highmem_init(void)
65{
66	pr_debug("%x\n", (u32)PKMAP_BASE);
67	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
68	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
69
70	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
71	kmap_prot = PAGE_KERNEL;
72}
73
74static void highmem_setup(void)
75{
76	unsigned long pfn;
77
78	for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
79		struct page *page = pfn_to_page(pfn);
80
81		/* FIXME not sure about */
82		if (!memblock_is_reserved(pfn << PAGE_SHIFT))
83			free_highmem_page(page);
84	}
85}
86#endif /* CONFIG_HIGHMEM */
87
88/*
89 * paging_init() sets up the page tables - in fact we've already done this.
90 */
91static void __init paging_init(void)
92{
93	unsigned long zones_size[MAX_NR_ZONES];
94#ifdef CONFIG_MMU
95	int idx;
96
97	/* Setup fixmaps */
98	for (idx = 0; idx < __end_of_fixed_addresses; idx++)
99		clear_fixmap(idx);
100#endif
101
102	/* Clean every zones */
103	memset(zones_size, 0, sizeof(zones_size));
104
105#ifdef CONFIG_HIGHMEM
106	highmem_init();
107
108	zones_size[ZONE_DMA] = max_low_pfn;
109	zones_size[ZONE_HIGHMEM] = max_pfn;
110#else
111	zones_size[ZONE_DMA] = max_pfn;
112#endif
113
114	/* We don't have holes in memory map */
115	free_area_init_nodes(zones_size);
116}
117
118void __init setup_memory(void)
119{
120	unsigned long map_size;
121	struct memblock_region *reg;
122
123#ifndef CONFIG_MMU
124	u32 kernel_align_start, kernel_align_size;
125
126	/* Find main memory where is the kernel */
127	for_each_memblock(memory, reg) {
128		memory_start = (u32)reg->base;
129		lowmem_size = reg->size;
130		if ((memory_start <= (u32)_text) &&
131			((u32)_text <= (memory_start + lowmem_size - 1))) {
132			memory_size = lowmem_size;
133			PAGE_OFFSET = memory_start;
134			pr_info("%s: Main mem: 0x%x, size 0x%08x\n",
135				__func__, (u32) memory_start,
136					(u32) memory_size);
137			break;
138		}
139	}
140
141	if (!memory_start || !memory_size) {
142		panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
143			__func__, (u32) memory_start, (u32) memory_size);
144	}
145
146	/* reservation of region where is the kernel */
147	kernel_align_start = PAGE_DOWN((u32)_text);
148	/* ALIGN can be remove because _end in vmlinux.lds.S is align */
149	kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
150	pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
151		__func__, kernel_align_start, kernel_align_start
152			+ kernel_align_size, kernel_align_size);
153	memblock_reserve(kernel_align_start, kernel_align_size);
154#endif
155	/*
156	 * Kernel:
157	 * start: base phys address of kernel - page align
158	 * end: base phys address of kernel - page align
159	 *
160	 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
161	 * max_low_pfn
162	 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
163	 */
164
165	/* memory start is from the kernel end (aligned) to higher addr */
166	min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
167	/* RAM is assumed contiguous */
168	max_mapnr = memory_size >> PAGE_SHIFT;
169	max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
170	max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
171
172	pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
173	pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
174	pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
175	pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
176
177	/*
178	 * Find an area to use for the bootmem bitmap.
179	 * We look for the first area which is at least
180	 * 128kB in length (128kB is enough for a bitmap
181	 * for 4GB of memory, using 4kB pages), plus 1 page
182	 * (in case the address isn't page-aligned).
183	 */
184	map_size = init_bootmem_node(NODE_DATA(0),
185		PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn);
186	memblock_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size);
187
188	/* Add active regions with valid PFNs */
189	for_each_memblock(memory, reg) {
190		unsigned long start_pfn, end_pfn;
191
192		start_pfn = memblock_region_memory_base_pfn(reg);
193		end_pfn = memblock_region_memory_end_pfn(reg);
194		memblock_set_node(start_pfn << PAGE_SHIFT,
195				  (end_pfn - start_pfn) << PAGE_SHIFT,
196				  &memblock.memory, 0);
197	}
198
199	/* free bootmem is whole main memory */
200	free_bootmem_with_active_regions(0, max_low_pfn);
201
202	/* reserve allocate blocks */
203	for_each_memblock(reserved, reg) {
204		unsigned long top = reg->base + reg->size - 1;
205
206		pr_debug("reserved - 0x%08x-0x%08x, %lx, %lx\n",
207			 (u32) reg->base, (u32) reg->size, top,
208						memory_start + lowmem_size - 1);
209
210		if (top <= (memory_start + lowmem_size - 1)) {
211			reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
212		} else if (reg->base < (memory_start + lowmem_size - 1)) {
213			unsigned long trunc_size = memory_start + lowmem_size -
214								reg->base;
215			reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
216		}
217	}
218
219	/* XXX need to clip this if using highmem? */
220	sparse_memory_present_with_active_regions(0);
221
222#ifdef CONFIG_MMU
223	init_bootmem_done = 1;
224#endif
225	paging_init();
226}
227
228#ifdef CONFIG_BLK_DEV_INITRD
229void free_initrd_mem(unsigned long start, unsigned long end)
230{
231	free_reserved_area((void *)start, (void *)end, -1, "initrd");
232}
233#endif
234
235void free_initmem(void)
236{
237	free_initmem_default(-1);
238}
239
240void __init mem_init(void)
241{
242	high_memory = (void *)__va(memory_start + lowmem_size - 1);
243
244	/* this will put all memory onto the freelists */
245	free_all_bootmem();
246#ifdef CONFIG_HIGHMEM
247	highmem_setup();
248#endif
249
250	mem_init_print_info(NULL);
251#ifdef CONFIG_MMU
252	pr_info("Kernel virtual memory layout:\n");
253	pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
254#ifdef CONFIG_HIGHMEM
255	pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
256		PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
257#endif /* CONFIG_HIGHMEM */
258	pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
259		ioremap_bot, ioremap_base);
260	pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
261		(unsigned long)VMALLOC_START, VMALLOC_END);
262#endif
263	mem_init_done = 1;
264}
265
266#ifndef CONFIG_MMU
267int page_is_ram(unsigned long pfn)
268{
269	return __range_ok(pfn, 0);
270}
271#else
272int page_is_ram(unsigned long pfn)
273{
274	return pfn < max_low_pfn;
275}
276
277/*
278 * Check for command-line options that affect what MMU_init will do.
279 */
280static void mm_cmdline_setup(void)
281{
282	unsigned long maxmem = 0;
283	char *p = cmd_line;
284
285	/* Look for mem= option on command line */
286	p = strstr(cmd_line, "mem=");
287	if (p) {
288		p += 4;
289		maxmem = memparse(p, &p);
290		if (maxmem && memory_size > maxmem) {
291			memory_size = maxmem;
292			memblock.memory.regions[0].size = memory_size;
293		}
294	}
295}
296
297/*
298 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
299 */
300static void __init mmu_init_hw(void)
301{
302	/*
303	 * The Zone Protection Register (ZPR) defines how protection will
304	 * be applied to every page which is a member of a given zone. At
305	 * present, we utilize only two of the zones.
306	 * The zone index bits (of ZSEL) in the PTE are used for software
307	 * indicators, except the LSB.  For user access, zone 1 is used,
308	 * for kernel access, zone 0 is used.  We set all but zone 1
309	 * to zero, allowing only kernel access as indicated in the PTE.
310	 * For zone 1, we set a 01 binary (a value of 10 will not work)
311	 * to allow user access as indicated in the PTE.  This also allows
312	 * kernel access as indicated in the PTE.
313	 */
314	__asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
315			"mts rzpr, r11;"
316			: : : "r11");
317}
318
319/*
320 * MMU_init sets up the basic memory mappings for the kernel,
321 * including both RAM and possibly some I/O regions,
322 * and sets up the page tables and the MMU hardware ready to go.
323 */
324
325/* called from head.S */
326asmlinkage void __init mmu_init(void)
327{
328	unsigned int kstart, ksize;
329
330	if (!memblock.reserved.cnt) {
331		pr_emerg("Error memory count\n");
332		machine_restart(NULL);
333	}
334
335	if ((u32) memblock.memory.regions[0].size < 0x400000) {
336		pr_emerg("Memory must be greater than 4MB\n");
337		machine_restart(NULL);
338	}
339
340	if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
341		pr_emerg("Kernel size is greater than memory node\n");
342		machine_restart(NULL);
343	}
344
345	/* Find main memory where the kernel is */
346	memory_start = (u32) memblock.memory.regions[0].base;
347	lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
348
349	if (lowmem_size > CONFIG_LOWMEM_SIZE) {
350		lowmem_size = CONFIG_LOWMEM_SIZE;
351#ifndef CONFIG_HIGHMEM
352		memory_size = lowmem_size;
353#endif
354	}
355
356	mm_cmdline_setup(); /* FIXME parse args from command line - not used */
357
358	/*
359	 * Map out the kernel text/data/bss from the available physical
360	 * memory.
361	 */
362	kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
363	/* kernel size */
364	ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
365	memblock_reserve(kstart, ksize);
366
367#if defined(CONFIG_BLK_DEV_INITRD)
368	/* Remove the init RAM disk from the available memory. */
369	if (initrd_start) {
370		unsigned long size;
371		size = initrd_end - initrd_start;
372		memblock_reserve(__virt_to_phys(initrd_start), size);
373	}
374#endif /* CONFIG_BLK_DEV_INITRD */
375
376	/* Initialize the MMU hardware */
377	mmu_init_hw();
378
379	/* Map in all of RAM starting at CONFIG_KERNEL_START */
380	mapin_ram();
381
382	/* Extend vmalloc and ioremap area as big as possible */
383#ifdef CONFIG_HIGHMEM
384	ioremap_base = ioremap_bot = PKMAP_BASE;
385#else
386	ioremap_base = ioremap_bot = FIXADDR_START;
387#endif
388
389	/* Initialize the context management stuff */
390	mmu_context_init();
391
392	/* Shortly after that, the entire linear mapping will be available */
393	/* This will also cause that unflatten device tree will be allocated
394	 * inside 768MB limit */
395	memblock_set_current_limit(memory_start + lowmem_size - 1);
396}
397
398/* This is only called until mem_init is done. */
399void __init *early_get_page(void)
400{
401	void *p;
402	if (init_bootmem_done) {
403		p = alloc_bootmem_pages(PAGE_SIZE);
404	} else {
405		/*
406		 * Mem start + kernel_tlb -> here is limit
407		 * because of mem mapping from head.S
408		 */
409		p = __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
410					memory_start + kernel_tlb));
411	}
412	return p;
413}
414
415#endif /* CONFIG_MMU */
416
417void * __init_refok alloc_maybe_bootmem(size_t size, gfp_t mask)
418{
419	if (mem_init_done)
420		return kmalloc(size, mask);
421	else
422		return alloc_bootmem(size);
423}
424
425void * __init_refok zalloc_maybe_bootmem(size_t size, gfp_t mask)
426{
427	void *p;
428
429	if (mem_init_done)
430		p = kzalloc(size, mask);
431	else {
432		p = alloc_bootmem(size);
433		if (p)
434			memset(p, 0, size);
435	}
436	return p;
437}
438