1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * S390 version
4 * Copyright IBM Corp. 1999
5 * Author(s): Hartmut Penner ([email protected])
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 __bootdata_preserved(page_noexec_mask);
60 EXPORT_SYMBOL(page_noexec_mask);
61
62 unsigned long __bootdata_preserved(segment_noexec_mask);
63 EXPORT_SYMBOL(segment_noexec_mask);
64
65 unsigned long __bootdata_preserved(region_noexec_mask);
66 EXPORT_SYMBOL(region_noexec_mask);
67
68 unsigned long empty_zero_page, zero_page_mask;
69 EXPORT_SYMBOL(empty_zero_page);
70 EXPORT_SYMBOL(zero_page_mask);
71
setup_zero_pages(void)72 static void __init setup_zero_pages(void)
73 {
74 unsigned long total_pages = memblock_estimated_nr_free_pages();
75 unsigned int order;
76 struct page *page;
77 int i;
78
79 /* Latest machines require a mapping granularity of 512KB */
80 order = 7;
81
82 /* Limit number of empty zero pages for small memory sizes */
83 while (order > 2 && (total_pages >> 10) < (1UL << order))
84 order--;
85
86 empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
87 if (!empty_zero_page)
88 panic("Out of memory in setup_zero_pages");
89
90 page = virt_to_page((void *) empty_zero_page);
91 split_page(page, order);
92 for (i = 1 << order; i > 0; i--) {
93 mark_page_reserved(page);
94 page++;
95 }
96
97 zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
98 }
99
100 /*
101 * paging_init() sets up the page tables
102 */
paging_init(void)103 void __init paging_init(void)
104 {
105 unsigned long max_zone_pfns[MAX_NR_ZONES];
106
107 vmem_map_init();
108 sparse_init();
109 zone_dma_limit = DMA_BIT_MASK(31);
110 memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
111 max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
112 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
113 free_area_init(max_zone_pfns);
114 }
115
mark_rodata_ro(void)116 void mark_rodata_ro(void)
117 {
118 unsigned long size = __end_ro_after_init - __start_ro_after_init;
119
120 if (MACHINE_HAS_NX)
121 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
122 __set_memory_ro(__start_ro_after_init, __end_ro_after_init);
123 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
124 }
125
set_memory_encrypted(unsigned long vaddr,int numpages)126 int set_memory_encrypted(unsigned long vaddr, int numpages)
127 {
128 int i;
129
130 /* make specified pages unshared, (swiotlb, dma_free) */
131 for (i = 0; i < numpages; ++i) {
132 uv_remove_shared(virt_to_phys((void *)vaddr));
133 vaddr += PAGE_SIZE;
134 }
135 return 0;
136 }
137
set_memory_decrypted(unsigned long vaddr,int numpages)138 int set_memory_decrypted(unsigned long vaddr, int numpages)
139 {
140 int i;
141 /* make specified pages shared (swiotlb, dma_alloca) */
142 for (i = 0; i < numpages; ++i) {
143 uv_set_shared(virt_to_phys((void *)vaddr));
144 vaddr += PAGE_SIZE;
145 }
146 return 0;
147 }
148
149 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)150 bool force_dma_unencrypted(struct device *dev)
151 {
152 return is_prot_virt_guest();
153 }
154
155 /* protected virtualization */
pv_init(void)156 static void pv_init(void)
157 {
158 if (!is_prot_virt_guest())
159 return;
160
161 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
162
163 /* make sure bounce buffers are shared */
164 swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
165 swiotlb_update_mem_attributes();
166 }
167
mem_init(void)168 void __init mem_init(void)
169 {
170 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
171 cpumask_set_cpu(0, mm_cpumask(&init_mm));
172
173 set_max_mapnr(max_low_pfn);
174 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
175
176 pv_init();
177 kfence_split_mapping();
178
179 /* this will put all low memory onto the freelists */
180 memblock_free_all();
181 setup_zero_pages(); /* Setup zeroed pages. */
182 }
183
memory_block_size_bytes(void)184 unsigned long memory_block_size_bytes(void)
185 {
186 /*
187 * Make sure the memory block size is always greater
188 * or equal than the memory increment size.
189 */
190 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
191 }
192
193 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
194 EXPORT_SYMBOL(__per_cpu_offset);
195
pcpu_cpu_distance(unsigned int from,unsigned int to)196 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
197 {
198 return LOCAL_DISTANCE;
199 }
200
pcpu_cpu_to_node(int cpu)201 static int __init pcpu_cpu_to_node(int cpu)
202 {
203 return 0;
204 }
205
setup_per_cpu_areas(void)206 void __init setup_per_cpu_areas(void)
207 {
208 unsigned long delta;
209 unsigned int cpu;
210 int rc;
211
212 /*
213 * Always reserve area for module percpu variables. That's
214 * what the legacy allocator did.
215 */
216 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
217 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
218 pcpu_cpu_distance,
219 pcpu_cpu_to_node);
220 if (rc < 0)
221 panic("Failed to initialize percpu areas.");
222
223 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
224 for_each_possible_cpu(cpu)
225 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
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->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
312 #ifdef CONFIG_EXECMEM
313 static struct execmem_info execmem_info __ro_after_init;
314
execmem_arch_setup(void)315 struct execmem_info __init *execmem_arch_setup(void)
316 {
317 unsigned long module_load_offset = 0;
318 unsigned long start;
319
320 if (kaslr_enabled())
321 module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
322
323 start = MODULES_VADDR + module_load_offset;
324
325 execmem_info = (struct execmem_info){
326 .ranges = {
327 [EXECMEM_DEFAULT] = {
328 .flags = EXECMEM_KASAN_SHADOW,
329 .start = start,
330 .end = MODULES_END,
331 .pgprot = PAGE_KERNEL,
332 .alignment = MODULE_ALIGN,
333 },
334 },
335 };
336
337 return &execmem_info;
338 }
339 #endif /* CONFIG_EXECMEM */
340