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/abs_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_anchor.h>
51 #include <linux/virtio_config.h>
52
53 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
54 static pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
55
56 unsigned long s390_invalid_asce;
57
58 unsigned long empty_zero_page, zero_page_mask;
59 EXPORT_SYMBOL(empty_zero_page);
60 EXPORT_SYMBOL(zero_page_mask);
61
setup_zero_pages(void)62 static void __init setup_zero_pages(void)
63 {
64 unsigned int order;
65 struct page *page;
66 int i;
67
68 /* Latest machines require a mapping granularity of 512KB */
69 order = 7;
70
71 /* Limit number of empty zero pages for small memory sizes */
72 while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
73 order--;
74
75 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
76 if (!empty_zero_page)
77 panic("Out of memory in setup_zero_pages");
78
79 page = virt_to_page((void *) empty_zero_page);
80 split_page(page, order);
81 for (i = 1 << order; i > 0; i--) {
82 mark_page_reserved(page);
83 page++;
84 }
85
86 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
87 }
88
89 /*
90 * paging_init() sets up the page tables
91 */
paging_init(void)92 void __init paging_init(void)
93 {
94 unsigned long max_zone_pfns[MAX_NR_ZONES];
95 unsigned long pgd_type, asce_bits;
96 psw_t psw;
97
98 s390_invalid_asce = (unsigned long)invalid_pg_dir;
99 s390_invalid_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
100 crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY);
101 init_mm.pgd = swapper_pg_dir;
102 if (VMALLOC_END > _REGION2_SIZE) {
103 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
104 pgd_type = _REGION2_ENTRY_EMPTY;
105 } else {
106 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
107 pgd_type = _REGION3_ENTRY_EMPTY;
108 }
109 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
110 S390_lowcore.kernel_asce = init_mm.context.asce;
111 S390_lowcore.user_asce = s390_invalid_asce;
112 crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
113 vmem_map_init();
114 kasan_copy_shadow_mapping();
115
116 /* enable virtual mapping in kernel mode */
117 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
118 __ctl_load(S390_lowcore.user_asce, 7, 7);
119 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
120 psw.mask = __extract_psw();
121 psw_bits(psw).dat = 1;
122 psw_bits(psw).as = PSW_BITS_AS_HOME;
123 __load_psw_mask(psw.mask);
124 kasan_free_early_identity();
125
126 sparse_init();
127 zone_dma_bits = 31;
128 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
129 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
130 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
131 free_area_init(max_zone_pfns);
132 }
133
mark_rodata_ro(void)134 void mark_rodata_ro(void)
135 {
136 unsigned long size = __end_ro_after_init - __start_ro_after_init;
137
138 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
139 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
140 debug_checkwx();
141 }
142
set_memory_encrypted(unsigned long addr,int numpages)143 int set_memory_encrypted(unsigned long addr, int numpages)
144 {
145 int i;
146
147 /* make specified pages unshared, (swiotlb, dma_free) */
148 for (i = 0; i < numpages; ++i) {
149 uv_remove_shared(addr);
150 addr += PAGE_SIZE;
151 }
152 return 0;
153 }
154
set_memory_decrypted(unsigned long addr,int numpages)155 int set_memory_decrypted(unsigned long addr, int numpages)
156 {
157 int i;
158 /* make specified pages shared (swiotlb, dma_alloca) */
159 for (i = 0; i < numpages; ++i) {
160 uv_set_shared(addr);
161 addr += PAGE_SIZE;
162 }
163 return 0;
164 }
165
166 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)167 bool force_dma_unencrypted(struct device *dev)
168 {
169 return is_prot_virt_guest();
170 }
171
172 /* protected virtualization */
pv_init(void)173 static void pv_init(void)
174 {
175 if (!is_prot_virt_guest())
176 return;
177
178 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
179
180 /* make sure bounce buffers are shared */
181 swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
182 swiotlb_update_mem_attributes();
183 }
184
mem_init(void)185 void __init mem_init(void)
186 {
187 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
188 cpumask_set_cpu(0, mm_cpumask(&init_mm));
189
190 set_max_mapnr(max_low_pfn);
191 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
192
193 pv_init();
194 kfence_split_mapping();
195 /* Setup guest page hinting */
196 cmma_init();
197
198 /* this will put all low memory onto the freelists */
199 memblock_free_all();
200 setup_zero_pages(); /* Setup zeroed pages. */
201
202 cmma_init_nodat();
203 }
204
free_initmem(void)205 void free_initmem(void)
206 {
207 __set_memory((unsigned long)_sinittext,
208 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
209 SET_MEMORY_RW | SET_MEMORY_NX);
210 free_reserved_area(sclp_early_sccb,
211 sclp_early_sccb + EXT_SCCB_READ_SCP,
212 POISON_FREE_INITMEM, "unused early sccb");
213 free_initmem_default(POISON_FREE_INITMEM);
214 }
215
memory_block_size_bytes(void)216 unsigned long memory_block_size_bytes(void)
217 {
218 /*
219 * Make sure the memory block size is always greater
220 * or equal than the memory increment size.
221 */
222 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
223 }
224
225 #ifdef CONFIG_MEMORY_HOTPLUG
226
227 #ifdef CONFIG_CMA
228
229 /* Prevent memory blocks which contain cma regions from going offline */
230
231 struct s390_cma_mem_data {
232 unsigned long start;
233 unsigned long end;
234 };
235
s390_cma_check_range(struct cma * cma,void * data)236 static int s390_cma_check_range(struct cma *cma, void *data)
237 {
238 struct s390_cma_mem_data *mem_data;
239 unsigned long start, end;
240
241 mem_data = data;
242 start = cma_get_base(cma);
243 end = start + cma_get_size(cma);
244 if (end < mem_data->start)
245 return 0;
246 if (start >= mem_data->end)
247 return 0;
248 return -EBUSY;
249 }
250
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)251 static int s390_cma_mem_notifier(struct notifier_block *nb,
252 unsigned long action, void *data)
253 {
254 struct s390_cma_mem_data mem_data;
255 struct memory_notify *arg;
256 int rc = 0;
257
258 arg = data;
259 mem_data.start = arg->start_pfn << PAGE_SHIFT;
260 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
261 if (action == MEM_GOING_OFFLINE)
262 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
263 return notifier_from_errno(rc);
264 }
265
266 static struct notifier_block s390_cma_mem_nb = {
267 .notifier_call = s390_cma_mem_notifier,
268 };
269
s390_cma_mem_init(void)270 static int __init s390_cma_mem_init(void)
271 {
272 return register_memory_notifier(&s390_cma_mem_nb);
273 }
274 device_initcall(s390_cma_mem_init);
275
276 #endif /* CONFIG_CMA */
277
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)278 int arch_add_memory(int nid, u64 start, u64 size,
279 struct mhp_params *params)
280 {
281 unsigned long start_pfn = PFN_DOWN(start);
282 unsigned long size_pages = PFN_DOWN(size);
283 int rc;
284
285 if (WARN_ON_ONCE(params->altmap))
286 return -EINVAL;
287
288 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
289 return -EINVAL;
290
291 VM_BUG_ON(!mhp_range_allowed(start, size, true));
292 rc = vmem_add_mapping(start, size);
293 if (rc)
294 return rc;
295
296 rc = __add_pages(nid, start_pfn, size_pages, params);
297 if (rc)
298 vmem_remove_mapping(start, size);
299 return rc;
300 }
301
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)302 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
303 {
304 unsigned long start_pfn = start >> PAGE_SHIFT;
305 unsigned long nr_pages = size >> PAGE_SHIFT;
306
307 __remove_pages(start_pfn, nr_pages, altmap);
308 vmem_remove_mapping(start, size);
309 }
310 #endif /* CONFIG_MEMORY_HOTPLUG */
311
