[mirror_ubuntu-eoan-kernel.git] / arch / microblaze / mm / init.c

/*
 * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/memblock.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h> /* mem_init */
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/pfn.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/export.h>

#include <asm/page.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>

/* Use for MMU and noMMU because of PCI generic code */
int mem_init_done;

#ifndef CONFIG_MMU
unsigned int __page_offset;
EXPORT_SYMBOL(__page_offset);
#endif /* CONFIG_MMU */

char *klimit = _end;

/*
 * Initialize the bootmem system and give it all the memory we
 * have available.
 */
unsigned long memory_start;
EXPORT_SYMBOL(memory_start);
unsigned long memory_size;
EXPORT_SYMBOL(memory_size);
unsigned long lowmem_size;

#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);

static inline pte_t *virt_to_kpte(unsigned long vaddr)
{
	return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
			vaddr), vaddr);
}

static void __init highmem_init(void)
{
	pr_debug("%x\n", (u32)PKMAP_BASE);
	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
	pkmap_page_table = virt_to_kpte(PKMAP_BASE);

	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
	kmap_prot = PAGE_KERNEL;
}

static void highmem_setup(void)
{
	unsigned long pfn;

	for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
		struct page *page = pfn_to_page(pfn);

		/* FIXME not sure about */
		if (!memblock_is_reserved(pfn << PAGE_SHIFT))
			free_highmem_page(page);
	}
}
#endif /* CONFIG_HIGHMEM */

/*
 * paging_init() sets up the page tables - in fact we've already done this.
 */
static void __init paging_init(void)
{
	unsigned long zones_size[MAX_NR_ZONES];
#ifdef CONFIG_MMU
	int idx;

	/* Setup fixmaps */
	for (idx = 0; idx < __end_of_fixed_addresses; idx++)
		clear_fixmap(idx);
#endif

	/* Clean every zones */
	memset(zones_size, 0, sizeof(zones_size));

#ifdef CONFIG_HIGHMEM
	highmem_init();

	zones_size[ZONE_DMA] = max_low_pfn;
	zones_size[ZONE_HIGHMEM] = max_pfn;
#else
	zones_size[ZONE_DMA] = max_pfn;
#endif

	/* We don't have holes in memory map */
	free_area_init_nodes(zones_size);
}

void __init setup_memory(void)
{
	struct memblock_region *reg;

#ifndef CONFIG_MMU
	u32 kernel_align_start, kernel_align_size;

	/* Find main memory where is the kernel */
	for_each_memblock(memory, reg) {
		memory_start = (u32)reg->base;
		lowmem_size = reg->size;
		if ((memory_start <= (u32)_text) &&
			((u32)_text <= (memory_start + lowmem_size - 1))) {
			memory_size = lowmem_size;
			PAGE_OFFSET = memory_start;
			pr_info("%s: Main mem: 0x%x, size 0x%08x\n",
				__func__, (u32) memory_start,
					(u32) memory_size);
			break;
		}
	}

	if (!memory_start || !memory_size) {
		panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
			__func__, (u32) memory_start, (u32) memory_size);
	}

	/* reservation of region where is the kernel */
	kernel_align_start = PAGE_DOWN((u32)_text);
	/* ALIGN can be remove because _end in vmlinux.lds.S is align */
	kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
	pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
		__func__, kernel_align_start, kernel_align_start
			+ kernel_align_size, kernel_align_size);
	memblock_reserve(kernel_align_start, kernel_align_size);
#endif
	/*
	 * Kernel:
	 * start: base phys address of kernel - page align
	 * end: base phys address of kernel - page align
	 *
	 * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
	 * max_low_pfn
	 * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
	 */

	/* memory start is from the kernel end (aligned) to higher addr */
	min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
	/* RAM is assumed contiguous */
	max_mapnr = memory_size >> PAGE_SHIFT;
	max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
	max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;

	pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
	pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
	pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
	pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);

	/* Add active regions with valid PFNs */
	for_each_memblock(memory, reg) {
		unsigned long start_pfn, end_pfn;

		start_pfn = memblock_region_memory_base_pfn(reg);
		end_pfn = memblock_region_memory_end_pfn(reg);
		memblock_set_node(start_pfn << PAGE_SHIFT,
				  (end_pfn - start_pfn) << PAGE_SHIFT,
				  &memblock.memory, 0);
	}

	/* XXX need to clip this if using highmem? */
	sparse_memory_present_with_active_regions(0);

	paging_init();
}

void __init mem_init(void)
{
	high_memory = (void *)__va(memory_start + lowmem_size - 1);

	/* this will put all memory onto the freelists */
	memblock_free_all();
#ifdef CONFIG_HIGHMEM
	highmem_setup();
#endif

	mem_init_print_info(NULL);
#ifdef CONFIG_MMU
	pr_info("Kernel virtual memory layout:\n");
	pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
#ifdef CONFIG_HIGHMEM
	pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
		PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
#endif /* CONFIG_HIGHMEM */
	pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
		ioremap_bot, ioremap_base);
	pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
		(unsigned long)VMALLOC_START, VMALLOC_END);
#endif
	mem_init_done = 1;
}

#ifndef CONFIG_MMU
int page_is_ram(unsigned long pfn)
{
	return __range_ok(pfn, 0);
}
#else
int page_is_ram(unsigned long pfn)
{
	return pfn < max_low_pfn;
}

/*
 * Check for command-line options that affect what MMU_init will do.
 */
static void mm_cmdline_setup(void)
{
	unsigned long maxmem = 0;
	char *p = cmd_line;

	/* Look for mem= option on command line */
	p = strstr(cmd_line, "mem=");
	if (p) {
		p += 4;
		maxmem = memparse(p, &p);
		if (maxmem && memory_size > maxmem) {
			memory_size = maxmem;
			memblock.memory.regions[0].size = memory_size;
		}
	}
}

/*
 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 */
static void __init mmu_init_hw(void)
{
	/*
	 * The Zone Protection Register (ZPR) defines how protection will
	 * be applied to every page which is a member of a given zone. At
	 * present, we utilize only two of the zones.
	 * The zone index bits (of ZSEL) in the PTE are used for software
	 * indicators, except the LSB.  For user access, zone 1 is used,
	 * for kernel access, zone 0 is used.  We set all but zone 1
	 * to zero, allowing only kernel access as indicated in the PTE.
	 * For zone 1, we set a 01 binary (a value of 10 will not work)
	 * to allow user access as indicated in the PTE.  This also allows
	 * kernel access as indicated in the PTE.
	 */
	__asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
			"mts rzpr, r11;"
			: : : "r11");
}

/*
 * MMU_init sets up the basic memory mappings for the kernel,
 * including both RAM and possibly some I/O regions,
 * and sets up the page tables and the MMU hardware ready to go.
 */

/* called from head.S */
asmlinkage void __init mmu_init(void)
{
	unsigned int kstart, ksize;

	if (!memblock.reserved.cnt) {
		pr_emerg("Error memory count\n");
		machine_restart(NULL);
	}

	if ((u32) memblock.memory.regions[0].size < 0x400000) {
		pr_emerg("Memory must be greater than 4MB\n");
		machine_restart(NULL);
	}

	if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
		pr_emerg("Kernel size is greater than memory node\n");
		machine_restart(NULL);
	}

	/* Find main memory where the kernel is */
	memory_start = (u32) memblock.memory.regions[0].base;
	lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;

	if (lowmem_size > CONFIG_LOWMEM_SIZE) {
		lowmem_size = CONFIG_LOWMEM_SIZE;
#ifndef CONFIG_HIGHMEM
		memory_size = lowmem_size;
#endif
	}

	mm_cmdline_setup(); /* FIXME parse args from command line - not used */

	/*
	 * Map out the kernel text/data/bss from the available physical
	 * memory.
	 */
	kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
	/* kernel size */
	ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
	memblock_reserve(kstart, ksize);

#if defined(CONFIG_BLK_DEV_INITRD)
	/* Remove the init RAM disk from the available memory. */
	if (initrd_start) {
		unsigned long size;
		size = initrd_end - initrd_start;
		memblock_reserve(__virt_to_phys(initrd_start), size);
	}
#endif /* CONFIG_BLK_DEV_INITRD */

	/* Initialize the MMU hardware */
	mmu_init_hw();

	/* Map in all of RAM starting at CONFIG_KERNEL_START */
	mapin_ram();

	/* Extend vmalloc and ioremap area as big as possible */
#ifdef CONFIG_HIGHMEM
	ioremap_base = ioremap_bot = PKMAP_BASE;
#else
	ioremap_base = ioremap_bot = FIXADDR_START;
#endif

	/* Initialize the context management stuff */
	mmu_context_init();

	/* Shortly after that, the entire linear mapping will be available */
	/* This will also cause that unflatten device tree will be allocated
	 * inside 768MB limit */
	memblock_set_current_limit(memory_start + lowmem_size - 1);
}

/* This is only called until mem_init is done. */
void __init *early_get_page(void)
{
	/*
	 * Mem start + kernel_tlb -> here is limit
	 * because of mem mapping from head.S
	 */
	return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
				MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
				NUMA_NO_NODE);
}

#endif /* CONFIG_MMU */

void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
{
	void *p;

	if (mem_init_done) {
		p = kzalloc(size, mask);
	} else {
		p = memblock_alloc(size, SMP_CACHE_BYTES);
		if (!p)
			panic("%s: Failed to allocate %zu bytes\n",
			      __func__, size);
	}

	return p;
}
Commit	Line	Data
a95d0e16 MS	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
57c8a661	10	#include <linux/memblock.h>
a95d0e16 MS	11	#include <linux/init.h>
a95d0e16 MS	12	#include <linux/kernel.h>
a95d0e16 MS	13	#include <linux/mm.h> /* mem_init */
	14	#include <linux/initrd.h>
	15	#include <linux/pagemap.h>
	16	#include <linux/pfn.h>
5a0e3ad6	17	#include <linux/slab.h>
a95d0e16	18	#include <linux/swap.h>
66421a64	19	#include <linux/export.h>
a95d0e16 MS	20
	21	#include <asm/page.h>
	22	#include <asm/mmu_context.h>
	23	#include <asm/pgalloc.h>
	24	#include <asm/sections.h>
	25	#include <asm/tlb.h>
41938761	26	#include <asm/fixmap.h>
a95d0e16	27
79bf3a13 MS	28	/* Use for MMU and noMMU because of PCI generic code */
	29	int mem_init_done;
	30
4dc60832	31	#ifndef CONFIG_MMU
a95d0e16	32	unsigned int __page_offset;
5af7fa68	33	EXPORT_SYMBOL(__page_offset);
4dc60832 MS	34	#endif /* CONFIG_MMU */
4dc60832 MS	35
a95d0e16 MS	36	char *klimit = _end;
	37
	38	/*
	39	* Initialize the bootmem system and give it all the memory we
	40	* have available.
	41	*/
4dc60832	42	unsigned long memory_start;
fd6ed51f	43	EXPORT_SYMBOL(memory_start);
4dc60832	44	unsigned long memory_size;
ee4bcdf1	45	EXPORT_SYMBOL(memory_size);
83a92529	46	unsigned long lowmem_size;
a95d0e16	47
2f2f371f MS	48	#ifdef CONFIG_HIGHMEM
	49	pte_t *kmap_pte;
	50	EXPORT_SYMBOL(kmap_pte);
	51	pgprot_t kmap_prot;
	52	EXPORT_SYMBOL(kmap_prot);
	53
	54	static inline pte_t *virt_to_kpte(unsigned long vaddr)
	55	{
	56	return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
	57	vaddr), vaddr);
	58	}
	59
	60	static void __init highmem_init(void)
	61	{
	62	pr_debug("%x\n", (u32)PKMAP_BASE);
	63	map_page(PKMAP_BASE, 0, 0); /* XXX gross */
	64	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
	65
	66	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
	67	kmap_prot = PAGE_KERNEL;
	68	}
	69
6879ea83	70	static void highmem_setup(void)
2f2f371f MS	71	{
2f2f371f MS	72	unsigned long pfn;
2f2f371f MS	73
	74	for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
	75	struct page *page = pfn_to_page(pfn);
	76
	77	/* FIXME not sure about */
6879ea83 JL	78	if (!memblock_is_reserved(pfn << PAGE_SHIFT))
6879ea83 JL	79	free_highmem_page(page);
2f2f371f	80	}
2f2f371f MS	81	}
	82	#endif /* CONFIG_HIGHMEM */
	83
a95d0e16 MS	84	/*
	85	* paging_init() sets up the page tables - in fact we've already done this.
	86	*/
	87	static void __init paging_init(void)
	88	{
a95d0e16	89	unsigned long zones_size[MAX_NR_ZONES];
41938761 MS	90	#ifdef CONFIG_MMU
	91	int idx;
	92
	93	/* Setup fixmaps */
	94	for (idx = 0; idx < __end_of_fixed_addresses; idx++)
	95	clear_fixmap(idx);
	96	#endif
a95d0e16	97
5af90438 SM	98	/* Clean every zones */
	99	memset(zones_size, 0, sizeof(zones_size));
	100
2f2f371f MS	101	#ifdef CONFIG_HIGHMEM
	102	highmem_init();
	103
	104	zones_size[ZONE_DMA] = max_low_pfn;
	105	zones_size[ZONE_HIGHMEM] = max_pfn;
	106	#else
83a92529	107	zones_size[ZONE_DMA] = max_pfn;
2f2f371f	108	#endif
a95d0e16	109
baab8a82 MS	110	/* We don't have holes in memory map */
baab8a82 MS	111	free_area_init_nodes(zones_size);
a95d0e16 MS	112	}
	113
	114	void __init setup_memory(void)
	115	{
76bfcc81 BH	116	struct memblock_region *reg;
76bfcc81 BH	117
4dc60832	118	#ifndef CONFIG_MMU
a95d0e16 MS	119	u32 kernel_align_start, kernel_align_size;
	120
	121	/* Find main memory where is the kernel */
76bfcc81 BH	122	for_each_memblock(memory, reg) {
76bfcc81 BH	123	memory_start = (u32)reg->base;
83a92529	124	lowmem_size = reg->size;
a95d0e16	125	if ((memory_start <= (u32)_text) &&
83a92529 MS	126	((u32)_text <= (memory_start + lowmem_size - 1))) {
83a92529 MS	127	memory_size = lowmem_size;
a95d0e16	128	PAGE_OFFSET = memory_start;
6bd55f0b MS	129	pr_info("%s: Main mem: 0x%x, size 0x%08x\n",
6bd55f0b MS	130	__func__, (u32) memory_start,
83a92529	131	(u32) memory_size);
a95d0e16 MS	132	break;
	133	}
	134	}
	135
83a92529 MS	136	if (!memory_start \|\| !memory_size) {
	137	panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
	138	__func__, (u32) memory_start, (u32) memory_size);
a95d0e16 MS	139	}
	140
	141	/* reservation of region where is the kernel */
	142	kernel_align_start = PAGE_DOWN((u32)_text);
	143	/* ALIGN can be remove because _end in vmlinux.lds.S is align */
	144	kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
6bd55f0b	145	pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
a95d0e16 MS	146	__func__, kernel_align_start, kernel_align_start
a95d0e16 MS	147	+ kernel_align_size, kernel_align_size);
83a92529	148	memblock_reserve(kernel_align_start, kernel_align_size);
4dc60832	149	#endif
a95d0e16 MS	150	/*
	151	* Kernel:
	152	* start: base phys address of kernel - page align
	153	* end: base phys address of kernel - page align
	154	*
	155	* min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
	156	* max_low_pfn
	157	* max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
a95d0e16 MS	158	*/
	159
	160	/* memory start is from the kernel end (aligned) to higher addr */
	161	min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
	162	/* RAM is assumed contiguous */
6879ea83	163	max_mapnr = memory_size >> PAGE_SHIFT;
83a92529 MS	164	max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
83a92529 MS	165	max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
a95d0e16	166
6bd55f0b MS	167	pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
	168	pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
	169	pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
	170	pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
a95d0e16	171
baab8a82 MS	172	/* Add active regions with valid PFNs */
	173	for_each_memblock(memory, reg) {
	174	unsigned long start_pfn, end_pfn;
	175
	176	start_pfn = memblock_region_memory_base_pfn(reg);
	177	end_pfn = memblock_region_memory_end_pfn(reg);
	178	memblock_set_node(start_pfn << PAGE_SHIFT,
e7e8de59 TC	179	(end_pfn - start_pfn) << PAGE_SHIFT,
e7e8de59 TC	180	&memblock.memory, 0);
baab8a82 MS	181	}
baab8a82 MS	182
baab8a82 MS	183	/* XXX need to clip this if using highmem? */
	184	sparse_memory_present_with_active_regions(0);
	185
a95d0e16 MS	186	paging_init();
	187	}
	188
a95d0e16 MS	189	void __init mem_init(void)
a95d0e16 MS	190	{
83a92529 MS	191	high_memory = (void *)__va(memory_start + lowmem_size - 1);
83a92529 MS	192
a95d0e16	193	/* this will put all memory onto the freelists */
c6ffc5ca	194	memblock_free_all();
2f2f371f	195	#ifdef CONFIG_HIGHMEM
6879ea83	196	highmem_setup();
2f2f371f MS	197	#endif
2f2f371f MS	198
6879ea83	199	mem_init_print_info(NULL);
83299799 MS	200	#ifdef CONFIG_MMU
	201	pr_info("Kernel virtual memory layout:\n");
	202	pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
2f2f371f MS	203	#ifdef CONFIG_HIGHMEM
	204	pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
	205	PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
	206	#endif /* CONFIG_HIGHMEM */
83299799 MS	207	pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
	208	ioremap_bot, ioremap_base);
	209	pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
	210	(unsigned long)VMALLOC_START, VMALLOC_END);
	211	#endif
4dc60832	212	mem_init_done = 1;
a95d0e16 MS	213	}
a95d0e16 MS	214
4dc60832	215	#ifndef CONFIG_MMU
79bf3a13 MS	216	int page_is_ram(unsigned long pfn)
	217	{
	218	return __range_ok(pfn, 0);
	219	}
4dc60832 MS	220	#else
	221	int page_is_ram(unsigned long pfn)
	222	{
	223	return pfn < max_low_pfn;
	224	}
	225
	226	/*
	227	* Check for command-line options that affect what MMU_init will do.
	228	*/
	229	static void mm_cmdline_setup(void)
	230	{
	231	unsigned long maxmem = 0;
	232	char *p = cmd_line;
	233
	234	/* Look for mem= option on command line */
	235	p = strstr(cmd_line, "mem=");
	236	if (p) {
	237	p += 4;
	238	maxmem = memparse(p, &p);
	239	if (maxmem && memory_size > maxmem) {
	240	memory_size = maxmem;
da5ab11c	241	memblock.memory.regions[0].size = memory_size;
4dc60832 MS	242	}
	243	}
	244	}
	245
	246	/*
	247	* MMU_init_hw does the chip-specific initialization of the MMU hardware.
	248	*/
	249	static void __init mmu_init_hw(void)
	250	{
	251	/*
	252	* The Zone Protection Register (ZPR) defines how protection will
	253	* be applied to every page which is a member of a given zone. At
	254	* present, we utilize only two of the zones.
	255	* The zone index bits (of ZSEL) in the PTE are used for software
	256	* indicators, except the LSB. For user access, zone 1 is used,
	257	* for kernel access, zone 0 is used. We set all but zone 1
	258	* to zero, allowing only kernel access as indicated in the PTE.
	259	* For zone 1, we set a 01 binary (a value of 10 will not work)
	260	* to allow user access as indicated in the PTE. This also allows
	261	* kernel access as indicated in the PTE.
	262	*/
	263	__asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
	264	"mts rzpr, r11;"
	265	: : : "r11");
	266	}
	267
	268	/*
	269	* MMU_init sets up the basic memory mappings for the kernel,
	270	* including both RAM and possibly some I/O regions,
	271	* and sets up the page tables and the MMU hardware ready to go.
	272	*/
	273
	274	/* called from head.S */
	275	asmlinkage void __init mmu_init(void)
	276	{
	277	unsigned int kstart, ksize;
	278
95f72d1e	279	if (!memblock.reserved.cnt) {
6bd55f0b	280	pr_emerg("Error memory count\n");
4dc60832 MS	281	machine_restart(NULL);
	282	}
	283
95b0f9ea	284	if ((u32) memblock.memory.regions[0].size < 0x400000) {
6bd55f0b	285	pr_emerg("Memory must be greater than 4MB\n");
4dc60832 MS	286	machine_restart(NULL);
4dc60832 MS	287	}
95b0f9ea MS	288
95b0f9ea MS	289	if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
6bd55f0b	290	pr_emerg("Kernel size is greater than memory node\n");
95b0f9ea MS	291	machine_restart(NULL);
	292	}
	293
4dc60832	294	/* Find main memory where the kernel is */
da5ab11c	295	memory_start = (u32) memblock.memory.regions[0].base;
83a92529 MS	296	lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
	297
	298	if (lowmem_size > CONFIG_LOWMEM_SIZE) {
	299	lowmem_size = CONFIG_LOWMEM_SIZE;
2f2f371f	300	#ifndef CONFIG_HIGHMEM
83a92529	301	memory_size = lowmem_size;
2f2f371f	302	#endif
83a92529	303	}
4dc60832 MS	304
	305	mm_cmdline_setup(); /* FIXME parse args from command line - not used */
	306
	307	/*
	308	* Map out the kernel text/data/bss from the available physical
	309	* memory.
	310	*/
	311	kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
	312	/* kernel size */
	313	ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
95f72d1e	314	memblock_reserve(kstart, ksize);
4dc60832 MS	315
	316	#if defined(CONFIG_BLK_DEV_INITRD)
	317	/* Remove the init RAM disk from the available memory. */
5eec2f02 MS	318	if (initrd_start) {
	319	unsigned long size;
	320	size = initrd_end - initrd_start;
a66a6265	321	memblock_reserve(__virt_to_phys(initrd_start), size);
5eec2f02	322	}
4dc60832 MS	323	#endif /* CONFIG_BLK_DEV_INITRD */
	324
	325	/* Initialize the MMU hardware */
	326	mmu_init_hw();
	327
	328	/* Map in all of RAM starting at CONFIG_KERNEL_START */
	329	mapin_ram();
	330
41938761	331	/* Extend vmalloc and ioremap area as big as possible */
2f2f371f MS	332	#ifdef CONFIG_HIGHMEM
	333	ioremap_base = ioremap_bot = PKMAP_BASE;
	334	#else
41938761	335	ioremap_base = ioremap_bot = FIXADDR_START;
2f2f371f	336	#endif
41938761	337
4dc60832 MS	338	/* Initialize the context management stuff */
4dc60832 MS	339	mmu_context_init();
83a92529 MS	340
	341	/* Shortly after that, the entire linear mapping will be available */
	342	/* This will also cause that unflatten device tree will be allocated
	343	* inside 768MB limit */
	344	memblock_set_current_limit(memory_start + lowmem_size - 1);
4dc60832 MS	345	}
	346
	347	/* This is only called until mem_init is done. */
	348	void __init *early_get_page(void)
	349	{
101646a2 RH	350	/*
	351	* Mem start + kernel_tlb -> here is limit
	352	* because of mem mapping from head.S
	353	*/
3e5e79f2 MR	354	return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
	355	MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
	356	NUMA_NO_NODE);
4dc60832	357	}
a84642a3	358
79bf3a13 MS	359	#endif /* CONFIG_MMU */
79bf3a13 MS	360
bd721ea7	361	void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
a84642a3 MS	362	{
	363	void *p;
	364
8a7f97b9	365	if (mem_init_done) {
a84642a3	366	p = kzalloc(size, mask);
8a7f97b9	367	} else {
7e1c4e27	368	p = memblock_alloc(size, SMP_CACHE_BYTES);
8a7f97b9 MR	369	if (!p)
	370	panic("%s: Failed to allocate %zu bytes\n",
	371	__func__, size);
	372	}
0240dfd5	373
a84642a3 MS	374	return p;
a84642a3 MS	375	}