1 /*
2 * S390 version
3 * Copyright IBM Corp. 1999
4 * Author(s): Hartmut Penner (hp@de.ibm.com)
5 *
6 * Derived from "arch/i386/mm/init.c"
7 * Copyright (C) 1995 Linus Torvalds
8 */
9
10 #include <linux/signal.h>
11 #include <linux/sched.h>
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/string.h>
15 #include <linux/types.h>
16 #include <linux/ptrace.h>
17 #include <linux/mman.h>
18 #include <linux/mm.h>
19 #include <linux/swap.h>
20 #include <linux/smp.h>
21 #include <linux/init.h>
22 #include <linux/pagemap.h>
23 #include <linux/bootmem.h>
24 #include <linux/memory.h>
25 #include <linux/pfn.h>
26 #include <linux/poison.h>
27 #include <linux/initrd.h>
28 #include <linux/export.h>
29 #include <linux/gfp.h>
30 #include <linux/memblock.h>
31 #include <asm/processor.h>
32 #include <asm/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/pgalloc.h>
35 #include <asm/dma.h>
36 #include <asm/lowcore.h>
37 #include <asm/tlb.h>
38 #include <asm/tlbflush.h>
39 #include <asm/sections.h>
40 #include <asm/ctl_reg.h>
41 #include <asm/sclp.h>
42
43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
44
45 unsigned long empty_zero_page, zero_page_mask;
46 EXPORT_SYMBOL(empty_zero_page);
47 EXPORT_SYMBOL(zero_page_mask);
48
setup_zero_pages(void)49 static void __init setup_zero_pages(void)
50 {
51 unsigned int order;
52 struct page *page;
53 int i;
54
55 /* Latest machines require a mapping granularity of 512KB */
56 order = 7;
57
58 /* Limit number of empty zero pages for small memory sizes */
59 while (order > 2 && (totalram_pages >> 10) < (1UL << order))
60 order--;
61
62 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
63 if (!empty_zero_page)
64 panic("Out of memory in setup_zero_pages");
65
66 page = virt_to_page((void *) empty_zero_page);
67 split_page(page, order);
68 for (i = 1 << order; i > 0; i--) {
69 mark_page_reserved(page);
70 page++;
71 }
72
73 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
74 }
75
76 /*
77 * paging_init() sets up the page tables
78 */
paging_init(void)79 void __init paging_init(void)
80 {
81 unsigned long max_zone_pfns[MAX_NR_ZONES];
82 unsigned long pgd_type, asce_bits;
83
84 init_mm.pgd = swapper_pg_dir;
85 if (VMALLOC_END > (1UL << 42)) {
86 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
87 pgd_type = _REGION2_ENTRY_EMPTY;
88 } else {
89 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
90 pgd_type = _REGION3_ENTRY_EMPTY;
91 }
92 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
93 S390_lowcore.kernel_asce = init_mm.context.asce;
94 clear_table((unsigned long *) init_mm.pgd, pgd_type,
95 sizeof(unsigned long)*2048);
96 vmem_map_init();
97
98 /* enable virtual mapping in kernel mode */
99 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
100 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
101 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
102 arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
103
104 sparse_memory_present_with_active_regions(MAX_NUMNODES);
105 sparse_init();
106 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
107 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
108 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
109 free_area_init_nodes(max_zone_pfns);
110 }
111
mem_init(void)112 void __init mem_init(void)
113 {
114 if (MACHINE_HAS_TLB_LC)
115 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
116 cpumask_set_cpu(0, mm_cpumask(&init_mm));
117 atomic_set(&init_mm.context.attach_count, 1);
118
119 set_max_mapnr(max_low_pfn);
120 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
121
122 /* Setup guest page hinting */
123 cmma_init();
124
125 /* this will put all low memory onto the freelists */
126 free_all_bootmem();
127 setup_zero_pages(); /* Setup zeroed pages. */
128
129 mem_init_print_info(NULL);
130 printk("Write protected kernel read-only data: %#lx - %#lx\n",
131 (unsigned long)&_stext,
132 PFN_ALIGN((unsigned long)&_eshared) - 1);
133 }
134
free_initmem(void)135 void free_initmem(void)
136 {
137 free_initmem_default(POISON_FREE_INITMEM);
138 }
139
140 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)141 void __init free_initrd_mem(unsigned long start, unsigned long end)
142 {
143 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
144 "initrd");
145 }
146 #endif
147
148 #ifdef CONFIG_MEMORY_HOTPLUG
arch_add_memory(int nid,u64 start,u64 size,bool for_device)149 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
150 {
151 unsigned long normal_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
152 unsigned long dma_end_pfn = PFN_DOWN(MAX_DMA_ADDRESS);
153 unsigned long start_pfn = PFN_DOWN(start);
154 unsigned long size_pages = PFN_DOWN(size);
155 unsigned long nr_pages;
156 int rc, zone_enum;
157
158 rc = vmem_add_mapping(start, size);
159 if (rc)
160 return rc;
161
162 while (size_pages > 0) {
163 if (start_pfn < dma_end_pfn) {
164 nr_pages = (start_pfn + size_pages > dma_end_pfn) ?
165 dma_end_pfn - start_pfn : size_pages;
166 zone_enum = ZONE_DMA;
167 } else if (start_pfn < normal_end_pfn) {
168 nr_pages = (start_pfn + size_pages > normal_end_pfn) ?
169 normal_end_pfn - start_pfn : size_pages;
170 zone_enum = ZONE_NORMAL;
171 } else {
172 nr_pages = size_pages;
173 zone_enum = ZONE_MOVABLE;
174 }
175 rc = __add_pages(nid, NODE_DATA(nid)->node_zones + zone_enum,
176 start_pfn, size_pages);
177 if (rc)
178 break;
179 start_pfn += nr_pages;
180 size_pages -= nr_pages;
181 }
182 if (rc)
183 vmem_remove_mapping(start, size);
184 return rc;
185 }
186
memory_block_size_bytes(void)187 unsigned long memory_block_size_bytes(void)
188 {
189 /*
190 * Make sure the memory block size is always greater
191 * or equal than the memory increment size.
192 */
193 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
194 }
195
196 #ifdef CONFIG_MEMORY_HOTREMOVE
arch_remove_memory(u64 start,u64 size)197 int arch_remove_memory(u64 start, u64 size)
198 {
199 /*
200 * There is no hardware or firmware interface which could trigger a
201 * hot memory remove on s390. So there is nothing that needs to be
202 * implemented.
203 */
204 return -EBUSY;
205 }
206 #endif
207 #endif /* CONFIG_MEMORY_HOTPLUG */
208