1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * S390 version
4 * Copyright IBM Corp. 1999
5 * Author(s): Hartmut Penner (hp@de.ibm.com)
6 *
7 * Derived from "arch/i386/mm/init.c"
8 * Copyright (C) 1995 Linus Torvalds
9 */
10
11 #include <linux/signal.h>
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17 #include <linux/ptrace.h>
18 #include <linux/mman.h>
19 #include <linux/mm.h>
20 #include <linux/swap.h>
21 #include <linux/smp.h>
22 #include <linux/init.h>
23 #include <linux/pagemap.h>
24 #include <linux/bootmem.h>
25 #include <linux/memory.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/initrd.h>
29 #include <linux/export.h>
30 #include <linux/cma.h>
31 #include <linux/gfp.h>
32 #include <linux/memblock.h>
33 #include <asm/processor.h>
34 #include <linux/uaccess.h>
35 #include <asm/pgtable.h>
36 #include <asm/pgalloc.h>
37 #include <asm/dma.h>
38 #include <asm/lowcore.h>
39 #include <asm/tlb.h>
40 #include <asm/tlbflush.h>
41 #include <asm/sections.h>
42 #include <asm/ctl_reg.h>
43 #include <asm/sclp.h>
44 #include <asm/set_memory.h>
45
46 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
47
48 unsigned long empty_zero_page, zero_page_mask;
49 EXPORT_SYMBOL(empty_zero_page);
50 EXPORT_SYMBOL(zero_page_mask);
51
setup_zero_pages(void)52 static void __init setup_zero_pages(void)
53 {
54 unsigned int order;
55 struct page *page;
56 int i;
57
58 /* Latest machines require a mapping granularity of 512KB */
59 order = 7;
60
61 /* Limit number of empty zero pages for small memory sizes */
62 while (order > 2 && (totalram_pages >> 10) < (1UL << order))
63 order--;
64
65 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
66 if (!empty_zero_page)
67 panic("Out of memory in setup_zero_pages");
68
69 page = virt_to_page((void *) empty_zero_page);
70 split_page(page, order);
71 for (i = 1 << order; i > 0; i--) {
72 mark_page_reserved(page);
73 page++;
74 }
75
76 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
77 }
78
79 /*
80 * paging_init() sets up the page tables
81 */
paging_init(void)82 void __init paging_init(void)
83 {
84 unsigned long max_zone_pfns[MAX_NR_ZONES];
85 unsigned long pgd_type, asce_bits;
86 psw_t psw;
87
88 init_mm.pgd = swapper_pg_dir;
89 if (VMALLOC_END > _REGION2_SIZE) {
90 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
91 pgd_type = _REGION2_ENTRY_EMPTY;
92 } else {
93 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
94 pgd_type = _REGION3_ENTRY_EMPTY;
95 }
96 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
97 S390_lowcore.kernel_asce = init_mm.context.asce;
98 S390_lowcore.user_asce = S390_lowcore.kernel_asce;
99 crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
100 vmem_map_init();
101
102 /* enable virtual mapping in kernel mode */
103 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
104 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
105 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
106 psw.mask = __extract_psw();
107 psw_bits(psw).dat = 1;
108 psw_bits(psw).as = PSW_BITS_AS_HOME;
109 __load_psw_mask(psw.mask);
110
111 sparse_memory_present_with_active_regions(MAX_NUMNODES);
112 sparse_init();
113 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
114 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
115 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
116 free_area_init_nodes(max_zone_pfns);
117 }
118
mark_rodata_ro(void)119 void mark_rodata_ro(void)
120 {
121 unsigned long size = __end_ro_after_init - __start_ro_after_init;
122
123 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
124 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
125 }
126
mem_init(void)127 void __init mem_init(void)
128 {
129 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
130 cpumask_set_cpu(0, mm_cpumask(&init_mm));
131
132 set_max_mapnr(max_low_pfn);
133 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
134
135 /* Setup guest page hinting */
136 cmma_init();
137
138 /* this will put all low memory onto the freelists */
139 free_all_bootmem();
140 setup_zero_pages(); /* Setup zeroed pages. */
141
142 cmma_init_nodat();
143
144 mem_init_print_info(NULL);
145 }
146
free_initmem(void)147 void free_initmem(void)
148 {
149 __set_memory((unsigned long)_sinittext,
150 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
151 SET_MEMORY_RW | SET_MEMORY_NX);
152 free_initmem_default(POISON_FREE_INITMEM);
153 }
154
155 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)156 void __init free_initrd_mem(unsigned long start, unsigned long end)
157 {
158 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
159 "initrd");
160 }
161 #endif
162
memory_block_size_bytes(void)163 unsigned long memory_block_size_bytes(void)
164 {
165 /*
166 * Make sure the memory block size is always greater
167 * or equal than the memory increment size.
168 */
169 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
170 }
171
172 #ifdef CONFIG_MEMORY_HOTPLUG
173
174 #ifdef CONFIG_CMA
175
176 /* Prevent memory blocks which contain cma regions from going offline */
177
178 struct s390_cma_mem_data {
179 unsigned long start;
180 unsigned long end;
181 };
182
s390_cma_check_range(struct cma * cma,void * data)183 static int s390_cma_check_range(struct cma *cma, void *data)
184 {
185 struct s390_cma_mem_data *mem_data;
186 unsigned long start, end;
187
188 mem_data = data;
189 start = cma_get_base(cma);
190 end = start + cma_get_size(cma);
191 if (end < mem_data->start)
192 return 0;
193 if (start >= mem_data->end)
194 return 0;
195 return -EBUSY;
196 }
197
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)198 static int s390_cma_mem_notifier(struct notifier_block *nb,
199 unsigned long action, void *data)
200 {
201 struct s390_cma_mem_data mem_data;
202 struct memory_notify *arg;
203 int rc = 0;
204
205 arg = data;
206 mem_data.start = arg->start_pfn << PAGE_SHIFT;
207 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
208 if (action == MEM_GOING_OFFLINE)
209 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
210 return notifier_from_errno(rc);
211 }
212
213 static struct notifier_block s390_cma_mem_nb = {
214 .notifier_call = s390_cma_mem_notifier,
215 };
216
s390_cma_mem_init(void)217 static int __init s390_cma_mem_init(void)
218 {
219 return register_memory_notifier(&s390_cma_mem_nb);
220 }
221 device_initcall(s390_cma_mem_init);
222
223 #endif /* CONFIG_CMA */
224
arch_add_memory(int nid,u64 start,u64 size,struct vmem_altmap * altmap,bool want_memblock)225 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
226 bool want_memblock)
227 {
228 unsigned long start_pfn = PFN_DOWN(start);
229 unsigned long size_pages = PFN_DOWN(size);
230 int rc;
231
232 rc = vmem_add_mapping(start, size);
233 if (rc)
234 return rc;
235
236 rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
237 if (rc)
238 vmem_remove_mapping(start, size);
239 return rc;
240 }
241
242 #ifdef CONFIG_MEMORY_HOTREMOVE
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)243 int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
244 {
245 /*
246 * There is no hardware or firmware interface which could trigger a
247 * hot memory remove on s390. So there is nothing that needs to be
248 * implemented.
249 */
250 return -EBUSY;
251 }
252 #endif
253 #endif /* CONFIG_MEMORY_HOTPLUG */
254
