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 <linux/percpu.h>
35 #include <asm/processor.h>
36 #include <linux/uaccess.h>
37 #include <asm/pgalloc.h>
38 #include <asm/ctlreg.h>
39 #include <asm/kfence.h>
40 #include <asm/dma.h>
41 #include <asm/abs_lowcore.h>
42 #include <asm/tlb.h>
43 #include <asm/tlbflush.h>
44 #include <asm/sections.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 #include <linux/execmem.h>
53
54 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
55 pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
56
57 struct ctlreg __bootdata_preserved(s390_invalid_asce);
58
59 unsigned long empty_zero_page, zero_page_mask;
60 EXPORT_SYMBOL(empty_zero_page);
61 EXPORT_SYMBOL(zero_page_mask);
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
97 vmem_map_init();
98 sparse_init();
99 zone_dma_bits = 31;
100 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
101 max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
102 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
103 free_area_init(max_zone_pfns);
104 }
105
mark_rodata_ro(void)106 void mark_rodata_ro(void)
107 {
108 unsigned long size = __end_ro_after_init - __start_ro_after_init;
109
110 __set_memory_ro(__start_ro_after_init, __end_ro_after_init);
111 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
112 }
113
set_memory_encrypted(unsigned long vaddr,int numpages)114 int set_memory_encrypted(unsigned long vaddr, int numpages)
115 {
116 int i;
117
118 /* make specified pages unshared, (swiotlb, dma_free) */
119 for (i = 0; i < numpages; ++i) {
120 uv_remove_shared(virt_to_phys((void *)vaddr));
121 vaddr += PAGE_SIZE;
122 }
123 return 0;
124 }
125
set_memory_decrypted(unsigned long vaddr,int numpages)126 int set_memory_decrypted(unsigned long vaddr, int numpages)
127 {
128 int i;
129 /* make specified pages shared (swiotlb, dma_alloca) */
130 for (i = 0; i < numpages; ++i) {
131 uv_set_shared(virt_to_phys((void *)vaddr));
132 vaddr += PAGE_SIZE;
133 }
134 return 0;
135 }
136
137 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)138 bool force_dma_unencrypted(struct device *dev)
139 {
140 return is_prot_virt_guest();
141 }
142
143 /* protected virtualization */
pv_init(void)144 static void pv_init(void)
145 {
146 if (!is_prot_virt_guest())
147 return;
148
149 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
150
151 /* make sure bounce buffers are shared */
152 swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
153 swiotlb_update_mem_attributes();
154 }
155
mem_init(void)156 void __init mem_init(void)
157 {
158 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
159 cpumask_set_cpu(0, mm_cpumask(&init_mm));
160
161 set_max_mapnr(max_low_pfn);
162 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
163
164 pv_init();
165 kfence_split_mapping();
166
167 /* this will put all low memory onto the freelists */
168 memblock_free_all();
169 setup_zero_pages(); /* Setup zeroed pages. */
170 }
171
free_initmem(void)172 void free_initmem(void)
173 {
174 set_memory_rwnx((unsigned long)_sinittext,
175 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT);
176 free_initmem_default(POISON_FREE_INITMEM);
177 }
178
memory_block_size_bytes(void)179 unsigned long memory_block_size_bytes(void)
180 {
181 /*
182 * Make sure the memory block size is always greater
183 * or equal than the memory increment size.
184 */
185 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
186 }
187
188 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
189 EXPORT_SYMBOL(__per_cpu_offset);
190
pcpu_cpu_distance(unsigned int from,unsigned int to)191 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
192 {
193 return LOCAL_DISTANCE;
194 }
195
pcpu_cpu_to_node(int cpu)196 static int __init pcpu_cpu_to_node(int cpu)
197 {
198 return 0;
199 }
200
setup_per_cpu_areas(void)201 void __init setup_per_cpu_areas(void)
202 {
203 unsigned long delta;
204 unsigned int cpu;
205 int rc;
206
207 /*
208 * Always reserve area for module percpu variables. That's
209 * what the legacy allocator did.
210 */
211 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
212 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
213 pcpu_cpu_distance,
214 pcpu_cpu_to_node);
215 if (rc < 0)
216 panic("Failed to initialize percpu areas.");
217
218 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
219 for_each_possible_cpu(cpu)
220 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
221 }
222
223 #ifdef CONFIG_MEMORY_HOTPLUG
224
225 #ifdef CONFIG_CMA
226
227 /* Prevent memory blocks which contain cma regions from going offline */
228
229 struct s390_cma_mem_data {
230 unsigned long start;
231 unsigned long end;
232 };
233
s390_cma_check_range(struct cma * cma,void * data)234 static int s390_cma_check_range(struct cma *cma, void *data)
235 {
236 struct s390_cma_mem_data *mem_data;
237 unsigned long start, end;
238
239 mem_data = data;
240 start = cma_get_base(cma);
241 end = start + cma_get_size(cma);
242 if (end < mem_data->start)
243 return 0;
244 if (start >= mem_data->end)
245 return 0;
246 return -EBUSY;
247 }
248
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)249 static int s390_cma_mem_notifier(struct notifier_block *nb,
250 unsigned long action, void *data)
251 {
252 struct s390_cma_mem_data mem_data;
253 struct memory_notify *arg;
254 int rc = 0;
255
256 arg = data;
257 mem_data.start = arg->start_pfn << PAGE_SHIFT;
258 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
259 if (action == MEM_GOING_OFFLINE)
260 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
261 return notifier_from_errno(rc);
262 }
263
264 static struct notifier_block s390_cma_mem_nb = {
265 .notifier_call = s390_cma_mem_notifier,
266 };
267
s390_cma_mem_init(void)268 static int __init s390_cma_mem_init(void)
269 {
270 return register_memory_notifier(&s390_cma_mem_nb);
271 }
272 device_initcall(s390_cma_mem_init);
273
274 #endif /* CONFIG_CMA */
275
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)276 int arch_add_memory(int nid, u64 start, u64 size,
277 struct mhp_params *params)
278 {
279 unsigned long start_pfn = PFN_DOWN(start);
280 unsigned long size_pages = PFN_DOWN(size);
281 int rc;
282
283 if (WARN_ON_ONCE(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
284 return -EINVAL;
285
286 VM_BUG_ON(!mhp_range_allowed(start, size, true));
287 rc = vmem_add_mapping(start, size);
288 if (rc)
289 return rc;
290
291 rc = __add_pages(nid, start_pfn, size_pages, params);
292 if (rc)
293 vmem_remove_mapping(start, size);
294 return rc;
295 }
296
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)297 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
298 {
299 unsigned long start_pfn = start >> PAGE_SHIFT;
300 unsigned long nr_pages = size >> PAGE_SHIFT;
301
302 __remove_pages(start_pfn, nr_pages, altmap);
303 vmem_remove_mapping(start, size);
304 }
305 #endif /* CONFIG_MEMORY_HOTPLUG */
306
307 #ifdef CONFIG_EXECMEM
308 static struct execmem_info execmem_info __ro_after_init;
309
execmem_arch_setup(void)310 struct execmem_info __init *execmem_arch_setup(void)
311 {
312 unsigned long module_load_offset = 0;
313 unsigned long start;
314
315 if (kaslr_enabled())
316 module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
317
318 start = MODULES_VADDR + module_load_offset;
319
320 execmem_info = (struct execmem_info){
321 .ranges = {
322 [EXECMEM_DEFAULT] = {
323 .flags = EXECMEM_KASAN_SHADOW,
324 .start = start,
325 .end = MODULES_END,
326 .pgprot = PAGE_KERNEL,
327 .alignment = MODULE_ALIGN,
328 },
329 },
330 };
331
332 return &execmem_info;
333 }
334 #endif /* CONFIG_EXECMEM */
335