3 * Copyright IBM Corp. 1999
4 * Author(s): Hartmut Penner (hp@de.ibm.com)
6 * Derived from "arch/i386/mm/init.c"
7 * Copyright (C) 1995 Linus Torvalds
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>
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>
36 #include <asm/lowcore.h>
38 #include <asm/tlbflush.h>
39 #include <asm/sections.h>
40 #include <asm/ctl_reg.h>
43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
45 unsigned long empty_zero_page, zero_page_mask;
46 EXPORT_SYMBOL(empty_zero_page);
47 EXPORT_SYMBOL(zero_page_mask);
49 static void __init setup_zero_pages(void)
57 switch (cpu_id.machine) {
59 case 0x2064: /* z900 */
60 case 0x2066: /* z900 */
61 case 0x2084: /* z990 */
62 case 0x2086: /* z990 */
63 case 0x2094: /* z9-109 */
64 case 0x2096: /* z9-109 */
67 case 0x2097: /* z10 */
68 case 0x2098: /* z10 */
69 case 0x2817: /* z196 */
70 case 0x2818: /* z196 */
73 case 0x2827: /* zEC12 */
74 case 0x2828: /* zEC12 */
77 case 0x2964: /* z13 */
82 /* Limit number of empty zero pages for small memory sizes */
83 while (order > 2 && (totalram_pages >> 10) < (1UL << order))
86 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
88 panic("Out of memory in setup_zero_pages");
90 page = virt_to_page((void *) empty_zero_page);
91 split_page(page, order);
92 for (i = 1 << order; i > 0; i--) {
93 mark_page_reserved(page);
97 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
101 * paging_init() sets up the page tables
103 void __init paging_init(void)
105 unsigned long max_zone_pfns[MAX_NR_ZONES];
106 unsigned long pgd_type, asce_bits;
108 init_mm.pgd = swapper_pg_dir;
109 if (VMALLOC_END > (1UL << 42)) {
110 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
111 pgd_type = _REGION2_ENTRY_EMPTY;
113 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
114 pgd_type = _REGION3_ENTRY_EMPTY;
116 S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
117 clear_table((unsigned long *) init_mm.pgd, pgd_type,
118 sizeof(unsigned long)*2048);
121 /* enable virtual mapping in kernel mode */
122 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
123 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
124 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
125 arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
127 sparse_memory_present_with_active_regions(MAX_NUMNODES);
129 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
130 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
131 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
132 free_area_init_nodes(max_zone_pfns);
135 void __init mem_init(void)
137 if (MACHINE_HAS_TLB_LC)
138 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
139 cpumask_set_cpu(0, mm_cpumask(&init_mm));
140 atomic_set(&init_mm.context.attach_count, 1);
142 set_max_mapnr(max_low_pfn);
143 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
145 /* Setup guest page hinting */
148 /* this will put all low memory onto the freelists */
150 setup_zero_pages(); /* Setup zeroed pages. */
152 mem_init_print_info(NULL);
153 printk("Write protected kernel read-only data: %#lx - %#lx\n",
154 (unsigned long)&_stext,
155 PFN_ALIGN((unsigned long)&_eshared) - 1);
158 void free_initmem(void)
160 free_initmem_default(POISON_FREE_INITMEM);
163 #ifdef CONFIG_BLK_DEV_INITRD
164 void __init free_initrd_mem(unsigned long start, unsigned long end)
166 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
171 #ifdef CONFIG_MEMORY_HOTPLUG
172 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
174 unsigned long normal_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
175 unsigned long dma_end_pfn = PFN_DOWN(MAX_DMA_ADDRESS);
176 unsigned long start_pfn = PFN_DOWN(start);
177 unsigned long size_pages = PFN_DOWN(size);
178 unsigned long nr_pages;
181 rc = vmem_add_mapping(start, size);
185 while (size_pages > 0) {
186 if (start_pfn < dma_end_pfn) {
187 nr_pages = (start_pfn + size_pages > dma_end_pfn) ?
188 dma_end_pfn - start_pfn : size_pages;
189 zone_enum = ZONE_DMA;
190 } else if (start_pfn < normal_end_pfn) {
191 nr_pages = (start_pfn + size_pages > normal_end_pfn) ?
192 normal_end_pfn - start_pfn : size_pages;
193 zone_enum = ZONE_NORMAL;
195 nr_pages = size_pages;
196 zone_enum = ZONE_MOVABLE;
198 rc = __add_pages(nid, NODE_DATA(nid)->node_zones + zone_enum,
199 start_pfn, size_pages);
202 start_pfn += nr_pages;
203 size_pages -= nr_pages;
206 vmem_remove_mapping(start, size);
210 unsigned long memory_block_size_bytes(void)
213 * Make sure the memory block size is always greater
214 * or equal than the memory increment size.
216 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
219 #ifdef CONFIG_MEMORY_HOTREMOVE
220 int arch_remove_memory(u64 start, u64 size)
223 * There is no hardware or firmware interface which could trigger a
224 * hot memory remove on s390. So there is nothing that needs to be
230 #endif /* CONFIG_MEMORY_HOTPLUG */