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/pgalloc.h>
37 #include <asm/kfence.h>
38 #include <asm/ptdump.h>
39 #include <asm/dma.h>
40 #include <asm/lowcore.h>
41 #include <asm/tlb.h>
42 #include <asm/tlbflush.h>
43 #include <asm/sections.h>
44 #include <asm/ctl_reg.h>
45 #include <asm/sclp.h>
46 #include <asm/set_memory.h>
47 #include <asm/kasan.h>
48 #include <asm/dma-mapping.h>
49 #include <asm/uv.h>
50 #include <linux/virtio_config.h>
51
52 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
53 static pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
54
55 unsigned long s390_invalid_asce;
56
57 unsigned long empty_zero_page, zero_page_mask;
58 EXPORT_SYMBOL(empty_zero_page);
59 EXPORT_SYMBOL(zero_page_mask);
60
61 bool initmem_freed;
62
setup_zero_pages(void)63 static void __init setup_zero_pages(void)
64 {
65 unsigned int order;
66 struct page *page;
67 int i;
68
69 /* Latest machines require a mapping granularity of 512KB */
70 order = 7;
71
72 /* Limit number of empty zero pages for small memory sizes */
73 while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
74 order--;
75
76 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
77 if (!empty_zero_page)
78 panic("Out of memory in setup_zero_pages");
79
80 page = virt_to_page((void *) empty_zero_page);
81 split_page(page, order);
82 for (i = 1 << order; i > 0; i--) {
83 mark_page_reserved(page);
84 page++;
85 }
86
87 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
88 }
89
90 /*
91 * paging_init() sets up the page tables
92 */
paging_init(void)93 void __init paging_init(void)
94 {
95 unsigned long max_zone_pfns[MAX_NR_ZONES];
96 unsigned long pgd_type, asce_bits;
97 psw_t psw;
98
99 s390_invalid_asce = (unsigned long)invalid_pg_dir;
100 s390_invalid_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
101 crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY);
102 init_mm.pgd = swapper_pg_dir;
103 if (VMALLOC_END > _REGION2_SIZE) {
104 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
105 pgd_type = _REGION2_ENTRY_EMPTY;
106 } else {
107 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
108 pgd_type = _REGION3_ENTRY_EMPTY;
109 }
110 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
111 S390_lowcore.kernel_asce = init_mm.context.asce;
112 S390_lowcore.user_asce = s390_invalid_asce;
113 crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
114 vmem_map_init();
115 kasan_copy_shadow_mapping();
116
117 /* enable virtual mapping in kernel mode */
118 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
119 __ctl_load(S390_lowcore.user_asce, 7, 7);
120 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
121 psw.mask = __extract_psw();
122 psw_bits(psw).dat = 1;
123 psw_bits(psw).as = PSW_BITS_AS_HOME;
124 __load_psw_mask(psw.mask);
125 kasan_free_early_identity();
126
127 sparse_init();
128 zone_dma_bits = 31;
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(max_zone_pfns);
133 }
134
mark_rodata_ro(void)135 void mark_rodata_ro(void)
136 {
137 unsigned long size = __end_ro_after_init - __start_ro_after_init;
138
139 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
140 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
141 debug_checkwx();
142 }
143
set_memory_encrypted(unsigned long addr,int numpages)144 int set_memory_encrypted(unsigned long addr, int numpages)
145 {
146 int i;
147
148 /* make specified pages unshared, (swiotlb, dma_free) */
149 for (i = 0; i < numpages; ++i) {
150 uv_remove_shared(addr);
151 addr += PAGE_SIZE;
152 }
153 return 0;
154 }
155
set_memory_decrypted(unsigned long addr,int numpages)156 int set_memory_decrypted(unsigned long addr, int numpages)
157 {
158 int i;
159 /* make specified pages shared (swiotlb, dma_alloca) */
160 for (i = 0; i < numpages; ++i) {
161 uv_set_shared(addr);
162 addr += PAGE_SIZE;
163 }
164 return 0;
165 }
166
167 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)168 bool force_dma_unencrypted(struct device *dev)
169 {
170 return is_prot_virt_guest();
171 }
172
173 #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
174
arch_has_restricted_virtio_memory_access(void)175 int arch_has_restricted_virtio_memory_access(void)
176 {
177 return is_prot_virt_guest();
178 }
179 EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
180
181 #endif
182
183 /* protected virtualization */
pv_init(void)184 static void pv_init(void)
185 {
186 if (!is_prot_virt_guest())
187 return;
188
189 /* make sure bounce buffers are shared */
190 swiotlb_force = SWIOTLB_FORCE;
191 swiotlb_init(1);
192 swiotlb_update_mem_attributes();
193 }
194
mem_init(void)195 void __init mem_init(void)
196 {
197 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
198 cpumask_set_cpu(0, mm_cpumask(&init_mm));
199
200 set_max_mapnr(max_low_pfn);
201 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
202
203 pv_init();
204 kfence_split_mapping();
205 /* Setup guest page hinting */
206 cmma_init();
207
208 /* this will put all low memory onto the freelists */
209 memblock_free_all();
210 setup_zero_pages(); /* Setup zeroed pages. */
211
212 cmma_init_nodat();
213 }
214
free_initmem(void)215 void free_initmem(void)
216 {
217 initmem_freed = true;
218 __set_memory((unsigned long)_sinittext,
219 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
220 SET_MEMORY_RW | SET_MEMORY_NX);
221 free_initmem_default(POISON_FREE_INITMEM);
222 }
223
memory_block_size_bytes(void)224 unsigned long memory_block_size_bytes(void)
225 {
226 /*
227 * Make sure the memory block size is always greater
228 * or equal than the memory increment size.
229 */
230 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
231 }
232
233 #ifdef CONFIG_MEMORY_HOTPLUG
234
235 #ifdef CONFIG_CMA
236
237 /* Prevent memory blocks which contain cma regions from going offline */
238
239 struct s390_cma_mem_data {
240 unsigned long start;
241 unsigned long end;
242 };
243
s390_cma_check_range(struct cma * cma,void * data)244 static int s390_cma_check_range(struct cma *cma, void *data)
245 {
246 struct s390_cma_mem_data *mem_data;
247 unsigned long start, end;
248
249 mem_data = data;
250 start = cma_get_base(cma);
251 end = start + cma_get_size(cma);
252 if (end < mem_data->start)
253 return 0;
254 if (start >= mem_data->end)
255 return 0;
256 return -EBUSY;
257 }
258
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)259 static int s390_cma_mem_notifier(struct notifier_block *nb,
260 unsigned long action, void *data)
261 {
262 struct s390_cma_mem_data mem_data;
263 struct memory_notify *arg;
264 int rc = 0;
265
266 arg = data;
267 mem_data.start = arg->start_pfn << PAGE_SHIFT;
268 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
269 if (action == MEM_GOING_OFFLINE)
270 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
271 return notifier_from_errno(rc);
272 }
273
274 static struct notifier_block s390_cma_mem_nb = {
275 .notifier_call = s390_cma_mem_notifier,
276 };
277
s390_cma_mem_init(void)278 static int __init s390_cma_mem_init(void)
279 {
280 return register_memory_notifier(&s390_cma_mem_nb);
281 }
282 device_initcall(s390_cma_mem_init);
283
284 #endif /* CONFIG_CMA */
285
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)286 int arch_add_memory(int nid, u64 start, u64 size,
287 struct mhp_params *params)
288 {
289 unsigned long start_pfn = PFN_DOWN(start);
290 unsigned long size_pages = PFN_DOWN(size);
291 int rc;
292
293 if (WARN_ON_ONCE(params->altmap))
294 return -EINVAL;
295
296 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
297 return -EINVAL;
298
299 VM_BUG_ON(!mhp_range_allowed(start, size, true));
300 rc = vmem_add_mapping(start, size);
301 if (rc)
302 return rc;
303
304 rc = __add_pages(nid, start_pfn, size_pages, params);
305 if (rc)
306 vmem_remove_mapping(start, size);
307 return rc;
308 }
309
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)310 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
311 {
312 unsigned long start_pfn = start >> PAGE_SHIFT;
313 unsigned long nr_pages = size >> PAGE_SHIFT;
314
315 __remove_pages(start_pfn, nr_pages, altmap);
316 vmem_remove_mapping(start, size);
317 }
318 #endif /* CONFIG_MEMORY_HOTPLUG */
319