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/swiotlb.h>
22 #include <linux/smp.h>
23 #include <linux/init.h>
24 #include <linux/pagemap.h>
25 #include <linux/memblock.h>
26 #include <linux/memory.h>
27 #include <linux/pfn.h>
28 #include <linux/poison.h>
29 #include <linux/initrd.h>
30 #include <linux/export.h>
31 #include <linux/cma.h>
32 #include <linux/gfp.h>
33 #include <linux/dma-direct.h>
34 #include <asm/processor.h>
35 #include <linux/uaccess.h>
36 #include <asm/pgtable.h>
37 #include <asm/pgalloc.h>
38 #include <asm/dma.h>
39 #include <asm/lowcore.h>
40 #include <asm/tlb.h>
41 #include <asm/tlbflush.h>
42 #include <asm/sections.h>
43 #include <asm/ctl_reg.h>
44 #include <asm/sclp.h>
45 #include <asm/set_memory.h>
46 #include <asm/kasan.h>
47 #include <asm/dma-mapping.h>
48 #include <asm/uv.h>
49
50 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
51
52 unsigned long empty_zero_page, zero_page_mask;
53 EXPORT_SYMBOL(empty_zero_page);
54 EXPORT_SYMBOL(zero_page_mask);
55
56 bool initmem_freed;
57
setup_zero_pages(void)58 static void __init setup_zero_pages(void)
59 {
60 unsigned int order;
61 struct page *page;
62 int i;
63
64 /* Latest machines require a mapping granularity of 512KB */
65 order = 7;
66
67 /* Limit number of empty zero pages for small memory sizes */
68 while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
69 order--;
70
71 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
72 if (!empty_zero_page)
73 panic("Out of memory in setup_zero_pages");
74
75 page = virt_to_page((void *) empty_zero_page);
76 split_page(page, order);
77 for (i = 1 << order; i > 0; i--) {
78 mark_page_reserved(page);
79 page++;
80 }
81
82 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
83 }
84
85 /*
86 * paging_init() sets up the page tables
87 */
paging_init(void)88 void __init paging_init(void)
89 {
90 unsigned long max_zone_pfns[MAX_NR_ZONES];
91 unsigned long pgd_type, asce_bits;
92 psw_t psw;
93
94 init_mm.pgd = swapper_pg_dir;
95 if (VMALLOC_END > _REGION2_SIZE) {
96 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
97 pgd_type = _REGION2_ENTRY_EMPTY;
98 } else {
99 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
100 pgd_type = _REGION3_ENTRY_EMPTY;
101 }
102 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
103 S390_lowcore.kernel_asce = init_mm.context.asce;
104 S390_lowcore.user_asce = S390_lowcore.kernel_asce;
105 crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
106 vmem_map_init();
107 kasan_copy_shadow(init_mm.pgd);
108
109 /* enable virtual mapping in kernel mode */
110 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
111 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
112 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
113 psw.mask = __extract_psw();
114 psw_bits(psw).dat = 1;
115 psw_bits(psw).as = PSW_BITS_AS_HOME;
116 __load_psw_mask(psw.mask);
117 kasan_free_early_identity();
118
119 sparse_memory_present_with_active_regions(MAX_NUMNODES);
120 sparse_init();
121 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
122 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
123 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
124 free_area_init_nodes(max_zone_pfns);
125 }
126
mark_rodata_ro(void)127 void mark_rodata_ro(void)
128 {
129 unsigned long size = __end_ro_after_init - __start_ro_after_init;
130
131 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
132 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
133 }
134
set_memory_encrypted(unsigned long addr,int numpages)135 int set_memory_encrypted(unsigned long addr, int numpages)
136 {
137 int i;
138
139 /* make specified pages unshared, (swiotlb, dma_free) */
140 for (i = 0; i < numpages; ++i) {
141 uv_remove_shared(addr);
142 addr += PAGE_SIZE;
143 }
144 return 0;
145 }
146
set_memory_decrypted(unsigned long addr,int numpages)147 int set_memory_decrypted(unsigned long addr, int numpages)
148 {
149 int i;
150 /* make specified pages shared (swiotlb, dma_alloca) */
151 for (i = 0; i < numpages; ++i) {
152 uv_set_shared(addr);
153 addr += PAGE_SIZE;
154 }
155 return 0;
156 }
157
158 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)159 bool force_dma_unencrypted(struct device *dev)
160 {
161 return is_prot_virt_guest();
162 }
163
164 /* protected virtualization */
pv_init(void)165 static void pv_init(void)
166 {
167 if (!is_prot_virt_guest())
168 return;
169
170 /* make sure bounce buffers are shared */
171 swiotlb_init(1);
172 swiotlb_update_mem_attributes();
173 swiotlb_force = SWIOTLB_FORCE;
174 }
175
mem_init(void)176 void __init mem_init(void)
177 {
178 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
179 cpumask_set_cpu(0, mm_cpumask(&init_mm));
180
181 set_max_mapnr(max_low_pfn);
182 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
183
184 pv_init();
185
186 /* Setup guest page hinting */
187 cmma_init();
188
189 /* this will put all low memory onto the freelists */
190 memblock_free_all();
191 setup_zero_pages(); /* Setup zeroed pages. */
192
193 cmma_init_nodat();
194
195 mem_init_print_info(NULL);
196 }
197
free_initmem(void)198 void free_initmem(void)
199 {
200 initmem_freed = true;
201 __set_memory((unsigned long)_sinittext,
202 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
203 SET_MEMORY_RW | SET_MEMORY_NX);
204 free_initmem_default(POISON_FREE_INITMEM);
205 }
206
memory_block_size_bytes(void)207 unsigned long memory_block_size_bytes(void)
208 {
209 /*
210 * Make sure the memory block size is always greater
211 * or equal than the memory increment size.
212 */
213 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
214 }
215
216 #ifdef CONFIG_MEMORY_HOTPLUG
217
218 #ifdef CONFIG_CMA
219
220 /* Prevent memory blocks which contain cma regions from going offline */
221
222 struct s390_cma_mem_data {
223 unsigned long start;
224 unsigned long end;
225 };
226
s390_cma_check_range(struct cma * cma,void * data)227 static int s390_cma_check_range(struct cma *cma, void *data)
228 {
229 struct s390_cma_mem_data *mem_data;
230 unsigned long start, end;
231
232 mem_data = data;
233 start = cma_get_base(cma);
234 end = start + cma_get_size(cma);
235 if (end < mem_data->start)
236 return 0;
237 if (start >= mem_data->end)
238 return 0;
239 return -EBUSY;
240 }
241
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)242 static int s390_cma_mem_notifier(struct notifier_block *nb,
243 unsigned long action, void *data)
244 {
245 struct s390_cma_mem_data mem_data;
246 struct memory_notify *arg;
247 int rc = 0;
248
249 arg = data;
250 mem_data.start = arg->start_pfn << PAGE_SHIFT;
251 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
252 if (action == MEM_GOING_OFFLINE)
253 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
254 return notifier_from_errno(rc);
255 }
256
257 static struct notifier_block s390_cma_mem_nb = {
258 .notifier_call = s390_cma_mem_notifier,
259 };
260
s390_cma_mem_init(void)261 static int __init s390_cma_mem_init(void)
262 {
263 return register_memory_notifier(&s390_cma_mem_nb);
264 }
265 device_initcall(s390_cma_mem_init);
266
267 #endif /* CONFIG_CMA */
268
arch_add_memory(int nid,u64 start,u64 size,struct mhp_restrictions * restrictions)269 int arch_add_memory(int nid, u64 start, u64 size,
270 struct mhp_restrictions *restrictions)
271 {
272 unsigned long start_pfn = PFN_DOWN(start);
273 unsigned long size_pages = PFN_DOWN(size);
274 int rc;
275
276 if (WARN_ON_ONCE(restrictions->altmap))
277 return -EINVAL;
278
279 rc = vmem_add_mapping(start, size);
280 if (rc)
281 return rc;
282
283 rc = __add_pages(nid, start_pfn, size_pages, restrictions);
284 if (rc)
285 vmem_remove_mapping(start, size);
286 return rc;
287 }
288
arch_remove_memory(int nid,u64 start,u64 size,struct vmem_altmap * altmap)289 void arch_remove_memory(int nid, u64 start, u64 size,
290 struct vmem_altmap *altmap)
291 {
292 unsigned long start_pfn = start >> PAGE_SHIFT;
293 unsigned long nr_pages = size >> PAGE_SHIFT;
294 struct zone *zone;
295
296 zone = page_zone(pfn_to_page(start_pfn));
297 __remove_pages(zone, start_pfn, nr_pages, altmap);
298 vmem_remove_mapping(start, size);
299 }
300 #endif /* CONFIG_MEMORY_HOTPLUG */
301
