1/*
  2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License version 2 as
  6 * published by the Free Software Foundation.
  7 */
  8
  9#include <linux/kernel.h>
 10#include <linux/mm.h>
 11#include <linux/bootmem.h>
 12#include <linux/memblock.h>
 13#ifdef CONFIG_BLK_DEV_INITRD
 14#include <linux/initrd.h>
 15#endif
 16#include <linux/swap.h>
 17#include <linux/module.h>
 18#include <asm/page.h>
 19#include <asm/pgalloc.h>
 20#include <asm/sections.h>
 21#include <asm/arcregs.h>
 22
 23pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
 24char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 25EXPORT_SYMBOL(empty_zero_page);
 26
 27/* Default tot mem from .config */
 28static unsigned long arc_mem_sz = 0x20000000;  /* some default */
 29
 30/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
 31static int __init setup_mem_sz(char *str)
 32{
 33	arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
 34
 35	/* early console might not be setup yet - it will show up later */
 36	pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
 37
 38	return 0;
 39}
 40early_param("mem", setup_mem_sz);
 41
 42void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 43{
 44	arc_mem_sz = size & PAGE_MASK;
 45	pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz));
 46}
 47
 48#ifdef CONFIG_BLK_DEV_INITRD
 49static int __init early_initrd(char *p)
 50{
 51	unsigned long start, size;
 52	char *endp;
 53
 54	start = memparse(p, &endp);
 55	if (*endp == ',') {
 56		size = memparse(endp + 1, NULL);
 57
 58		initrd_start = (unsigned long)__va(start);
 59		initrd_end = (unsigned long)__va(start + size);
 60	}
 61	return 0;
 62}
 63early_param("initrd", early_initrd);
 64#endif
 65
 66/*
 67 * First memory setup routine called from setup_arch()
 68 * 1. setup swapper's mm @init_mm
 69 * 2. Count the pages we have and setup bootmem allocator
 70 * 3. zone setup
 71 */
 72void __init setup_arch_memory(void)
 73{
 74	unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 };
 75	unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
 76
 77	init_mm.start_code = (unsigned long)_text;
 78	init_mm.end_code = (unsigned long)_etext;
 79	init_mm.end_data = (unsigned long)_edata;
 80	init_mm.brk = (unsigned long)_end;
 81
 82	/*
 83	 * We do it here, so that memory is correctly instantiated
 84	 * even if "mem=xxx" cmline over-ride is given and/or
 85	 * DT has memory node. Each causes an update to @arc_mem_sz
 86	 * and we finally add memory one here
 87	 */
 88	memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
 89
 90	/*------------- externs in mm need setting up ---------------*/
 91
 92	/* first page of system - kernel .vector starts here */
 93	min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE);
 94
 95	/* Last usable page of low mem (no HIGHMEM yet for ARC port) */
 96	max_low_pfn = max_pfn = PFN_DOWN(end_mem);
 97
 98	max_mapnr = max_low_pfn - min_low_pfn;
 99
100	/*------------- reserve kernel image -----------------------*/
101	memblock_reserve(CONFIG_LINUX_LINK_BASE,
102			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
103
104#ifdef CONFIG_BLK_DEV_INITRD
105	/*------------- reserve initrd image -----------------------*/
106	if (initrd_start)
107		memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
108#endif
109
110	memblock_dump_all();
111
112	/*-------------- node setup --------------------------------*/
113	memset(zones_size, 0, sizeof(zones_size));
114	zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
115
116	/*
117	 * We can't use the helper free_area_init(zones[]) because it uses
118	 * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
119	 * when our kernel doesn't start at PAGE_OFFSET, i.e.
120	 * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
121	 */
122	free_area_init_node(0,			/* node-id */
123			    zones_size,		/* num pages per zone */
124			    min_low_pfn,	/* first pfn of node */
125			    NULL);		/* NO holes */
126}
127
128/*
129 * mem_init - initializes memory
130 *
131 * Frees up bootmem
132 * Calculates and displays memory available/used
133 */
134void __init mem_init(void)
135{
136	high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz);
137	free_all_bootmem();
138	mem_init_print_info(NULL);
139}
140
141/*
142 * free_initmem: Free all the __init memory.
143 */
144void __init_refok free_initmem(void)
145{
146	free_initmem_default(-1);
147}
148
149#ifdef CONFIG_BLK_DEV_INITRD
150void __init free_initrd_mem(unsigned long start, unsigned long end)
151{
152	free_reserved_area((void *)start, (void *)end, -1, "initrd");
153}
154#endif