1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/mm.h>
  8#include <linux/memblock.h>
  9#ifdef CONFIG_BLK_DEV_INITRD
 10#include <linux/initrd.h>
 11#endif
 12#include <linux/of_fdt.h>
 13#include <linux/swap.h>
 14#include <linux/module.h>
 15#include <linux/highmem.h>
 16#include <asm/page.h>
 17#include <asm/sections.h>
 18#include <asm/arcregs.h>
 19
 20pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
 21char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 22EXPORT_SYMBOL(empty_zero_page);
 23
 24static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
 25static unsigned long low_mem_sz;
 26
 27#ifdef CONFIG_HIGHMEM
 28static unsigned long min_high_pfn, max_high_pfn;
 29static phys_addr_t high_mem_start;
 30static phys_addr_t high_mem_sz;
 31#endif
 32
 33#ifdef CONFIG_DISCONTIGMEM
 34struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
 35EXPORT_SYMBOL(node_data);
 36#endif
 37
 38long __init arc_get_mem_sz(void)
 39{
 40	return low_mem_sz;
 41}
 42
 43/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
 44static int __init setup_mem_sz(char *str)
 45{
 46	low_mem_sz = memparse(str, NULL) & PAGE_MASK;
 47
 48	/* early console might not be setup yet - it will show up later */
 49	pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
 50
 51	return 0;
 52}
 53early_param("mem", setup_mem_sz);
 54
 55void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 56{
 57	int in_use = 0;
 58
 59	if (!low_mem_sz) {
 60		if (base != low_mem_start)
 61			panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
 62
 63		low_mem_sz = size;
 64		in_use = 1;
 65		memblock_add_node(base, size, 0);
 66	} else {
 67#ifdef CONFIG_HIGHMEM
 68		high_mem_start = base;
 69		high_mem_sz = size;
 70		in_use = 1;
 71		memblock_add_node(base, size, 1);
 72		memblock_reserve(base, size);
 73#endif
 74	}
 75
 76	pr_info("Memory @ %llx [%lldM] %s\n",
 77		base, TO_MB(size), !in_use ? "Not used":"");
 78}
 79
 80bool arch_has_descending_max_zone_pfns(void)
 81{
 82	return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
 83}
 84
 85/*
 86 * First memory setup routine called from setup_arch()
 87 * 1. setup swapper's mm @init_mm
 88 * 2. Count the pages we have and setup bootmem allocator
 89 * 3. zone setup
 90 */
 91void __init setup_arch_memory(void)
 92{
 93	unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
 94
 95	init_mm.start_code = (unsigned long)_text;
 96	init_mm.end_code = (unsigned long)_etext;
 97	init_mm.end_data = (unsigned long)_edata;
 98	init_mm.brk = (unsigned long)_end;
 99
100	/* first page of system - kernel .vector starts here */
101	min_low_pfn = ARCH_PFN_OFFSET;
102
103	/* Last usable page of low mem */
104	max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
105
106#ifdef CONFIG_FLATMEM
107	/* pfn_valid() uses this */
108	max_mapnr = max_low_pfn - min_low_pfn;
109#endif
110
111	/*------------- bootmem allocator setup -----------------------*/
112
113	/*
114	 * seed the bootmem allocator after any DT memory node parsing or
115	 * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
116	 *
117	 * Only low mem is added, otherwise we have crashes when allocating
118	 * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
119	 * avail memory, ending in highmem with a > 32-bit address. However
120	 * it then tries to memset it with a truncaed 32-bit handle, causing
121	 * the crash
122	 */
123
124	memblock_reserve(CONFIG_LINUX_LINK_BASE,
125			 __pa(_end) - CONFIG_LINUX_LINK_BASE);
126
127#ifdef CONFIG_BLK_DEV_INITRD
128	if (phys_initrd_size) {
129		memblock_reserve(phys_initrd_start, phys_initrd_size);
130		initrd_start = (unsigned long)__va(phys_initrd_start);
131		initrd_end = initrd_start + phys_initrd_size;
132	}
133#endif
134
135	early_init_fdt_reserve_self();
136	early_init_fdt_scan_reserved_mem();
137
138	memblock_dump_all();
139
140	/*----------------- node/zones setup --------------------------*/
141	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
142
143#ifdef CONFIG_HIGHMEM
144	/*
145	 * Populate a new node with highmem
146	 *
147	 * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
148	 * than addresses in normal ala low memory (0x8000_0000 based).
149	 * Even with PAE, the huge peripheral space hole would waste a lot of
150	 * mem with single mem_map[]. This warrants a mem_map per region design.
151	 * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
152	 *
153	 * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
154	 * populated with normal memory zone while node 1 only has highmem
155	 */
156	node_set_online(1);
157
158	min_high_pfn = PFN_DOWN(high_mem_start);
159	max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
160
161	max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn;
162
163	high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
164	kmap_init();
165#endif
166
167	free_area_init(max_zone_pfn);
168}
169
170static void __init highmem_init(void)
171{
172#ifdef CONFIG_HIGHMEM
173	unsigned long tmp;
174
175	memblock_free(high_mem_start, high_mem_sz);
176	for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
177		free_highmem_page(pfn_to_page(tmp));
178#endif
179}
180
181/*
182 * mem_init - initializes memory
183 *
184 * Frees up bootmem
185 * Calculates and displays memory available/used
186 */
187void __init mem_init(void)
188{
189	memblock_free_all();
190	highmem_init();
191	mem_init_print_info(NULL);
192}