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/ptdump.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 #include <linux/virtio_config.h>
50
51 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
52
53 unsigned long empty_zero_page, zero_page_mask;
54 EXPORT_SYMBOL(empty_zero_page);
55 EXPORT_SYMBOL(zero_page_mask);
56
57 bool initmem_freed;
58
setup_zero_pages(void)59 static void __init setup_zero_pages(void)
60 {
61 unsigned int order;
62 struct page *page;
63 int i;
64
65 /* Latest machines require a mapping granularity of 512KB */
66 order = 7;
67
68 /* Limit number of empty zero pages for small memory sizes */
69 while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
70 order--;
71
72 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
73 if (!empty_zero_page)
74 panic("Out of memory in setup_zero_pages");
75
76 page = virt_to_page((void *) empty_zero_page);
77 split_page(page, order);
78 for (i = 1 << order; i > 0; i--) {
79 mark_page_reserved(page);
80 page++;
81 }
82
83 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
84 }
85
86 /*
87 * paging_init() sets up the page tables
88 */
paging_init(void)89 void __init paging_init(void)
90 {
91 unsigned long max_zone_pfns[MAX_NR_ZONES];
92 unsigned long pgd_type, asce_bits;
93 psw_t psw;
94
95 init_mm.pgd = swapper_pg_dir;
96 if (VMALLOC_END > _REGION2_SIZE) {
97 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
98 pgd_type = _REGION2_ENTRY_EMPTY;
99 } else {
100 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
101 pgd_type = _REGION3_ENTRY_EMPTY;
102 }
103 init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
104 S390_lowcore.kernel_asce = init_mm.context.asce;
105 S390_lowcore.user_asce = S390_lowcore.kernel_asce;
106 crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
107 vmem_map_init();
108 kasan_copy_shadow(init_mm.pgd);
109
110 /* enable virtual mapping in kernel mode */
111 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
112 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
113 __ctl_load(S390_lowcore.kernel_asce, 13, 13);
114 psw.mask = __extract_psw();
115 psw_bits(psw).dat = 1;
116 psw_bits(psw).as = PSW_BITS_AS_HOME;
117 __load_psw_mask(psw.mask);
118 kasan_free_early_identity();
119
120 sparse_init();
121 zone_dma_bits = 31;
122 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
123 max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
124 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
125 free_area_init(max_zone_pfns);
126 }
127
mark_rodata_ro(void)128 void mark_rodata_ro(void)
129 {
130 unsigned long size = __end_ro_after_init - __start_ro_after_init;
131
132 set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
133 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
134 debug_checkwx();
135 }
136
set_memory_encrypted(unsigned long addr,int numpages)137 int set_memory_encrypted(unsigned long addr, int numpages)
138 {
139 int i;
140
141 /* make specified pages unshared, (swiotlb, dma_free) */
142 for (i = 0; i < numpages; ++i) {
143 uv_remove_shared(addr);
144 addr += PAGE_SIZE;
145 }
146 return 0;
147 }
148
set_memory_decrypted(unsigned long addr,int numpages)149 int set_memory_decrypted(unsigned long addr, int numpages)
150 {
151 int i;
152 /* make specified pages shared (swiotlb, dma_alloca) */
153 for (i = 0; i < numpages; ++i) {
154 uv_set_shared(addr);
155 addr += PAGE_SIZE;
156 }
157 return 0;
158 }
159
160 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)161 bool force_dma_unencrypted(struct device *dev)
162 {
163 return is_prot_virt_guest();
164 }
165
166 #ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
167
arch_has_restricted_virtio_memory_access(void)168 int arch_has_restricted_virtio_memory_access(void)
169 {
170 return is_prot_virt_guest();
171 }
172 EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
173
174 #endif
175
176 /* protected virtualization */
pv_init(void)177 static void pv_init(void)
178 {
179 if (!is_prot_virt_guest())
180 return;
181
182 /* make sure bounce buffers are shared */
183 swiotlb_force = SWIOTLB_FORCE;
184 swiotlb_init(1);
185 swiotlb_update_mem_attributes();
186 }
187
mem_init(void)188 void __init mem_init(void)
189 {
190 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
191 cpumask_set_cpu(0, mm_cpumask(&init_mm));
192
193 set_max_mapnr(max_low_pfn);
194 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
195
196 pv_init();
197
198 /* Setup guest page hinting */
199 cmma_init();
200
201 /* this will put all low memory onto the freelists */
202 memblock_free_all();
203 setup_zero_pages(); /* Setup zeroed pages. */
204
205 cmma_init_nodat();
206
207 mem_init_print_info(NULL);
208 }
209
free_initmem(void)210 void free_initmem(void)
211 {
212 initmem_freed = true;
213 __set_memory((unsigned long)_sinittext,
214 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
215 SET_MEMORY_RW | SET_MEMORY_NX);
216 free_initmem_default(POISON_FREE_INITMEM);
217 }
218
memory_block_size_bytes(void)219 unsigned long memory_block_size_bytes(void)
220 {
221 /*
222 * Make sure the memory block size is always greater
223 * or equal than the memory increment size.
224 */
225 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
226 }
227
228 #ifdef CONFIG_MEMORY_HOTPLUG
229
230 #ifdef CONFIG_CMA
231
232 /* Prevent memory blocks which contain cma regions from going offline */
233
234 struct s390_cma_mem_data {
235 unsigned long start;
236 unsigned long end;
237 };
238
s390_cma_check_range(struct cma * cma,void * data)239 static int s390_cma_check_range(struct cma *cma, void *data)
240 {
241 struct s390_cma_mem_data *mem_data;
242 unsigned long start, end;
243
244 mem_data = data;
245 start = cma_get_base(cma);
246 end = start + cma_get_size(cma);
247 if (end < mem_data->start)
248 return 0;
249 if (start >= mem_data->end)
250 return 0;
251 return -EBUSY;
252 }
253
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)254 static int s390_cma_mem_notifier(struct notifier_block *nb,
255 unsigned long action, void *data)
256 {
257 struct s390_cma_mem_data mem_data;
258 struct memory_notify *arg;
259 int rc = 0;
260
261 arg = data;
262 mem_data.start = arg->start_pfn << PAGE_SHIFT;
263 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
264 if (action == MEM_GOING_OFFLINE)
265 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
266 return notifier_from_errno(rc);
267 }
268
269 static struct notifier_block s390_cma_mem_nb = {
270 .notifier_call = s390_cma_mem_notifier,
271 };
272
s390_cma_mem_init(void)273 static int __init s390_cma_mem_init(void)
274 {
275 return register_memory_notifier(&s390_cma_mem_nb);
276 }
277 device_initcall(s390_cma_mem_init);
278
279 #endif /* CONFIG_CMA */
280
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)281 int arch_add_memory(int nid, u64 start, u64 size,
282 struct mhp_params *params)
283 {
284 unsigned long start_pfn = PFN_DOWN(start);
285 unsigned long size_pages = PFN_DOWN(size);
286 int rc;
287
288 if (WARN_ON_ONCE(params->altmap))
289 return -EINVAL;
290
291 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
292 return -EINVAL;
293
294 rc = vmem_add_mapping(start, size);
295 if (rc)
296 return rc;
297
298 rc = __add_pages(nid, start_pfn, size_pages, params);
299 if (rc)
300 vmem_remove_mapping(start, size);
301 return rc;
302 }
303
arch_remove_memory(int nid,u64 start,u64 size,struct vmem_altmap * altmap)304 void arch_remove_memory(int nid, u64 start, u64 size,
305 struct vmem_altmap *altmap)
306 {
307 unsigned long start_pfn = start >> PAGE_SHIFT;
308 unsigned long nr_pages = size >> PAGE_SHIFT;
309
310 __remove_pages(start_pfn, nr_pages, altmap);
311 vmem_remove_mapping(start, size);
312 }
313 #endif /* CONFIG_MEMORY_HOTPLUG */
314