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/cpufeature.h>
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/mman.h>
20 #include <linux/mm.h>
21 #include <linux/swap.h>
22 #include <linux/swiotlb.h>
23 #include <linux/smp.h>
24 #include <linux/init.h>
25 #include <linux/pagemap.h>
26 #include <linux/memblock.h>
27 #include <linux/memory.h>
28 #include <linux/pfn.h>
29 #include <linux/poison.h>
30 #include <linux/initrd.h>
31 #include <linux/export.h>
32 #include <linux/cma.h>
33 #include <linux/gfp.h>
34 #include <linux/dma-direct.h>
35 #include <linux/percpu.h>
36 #include <asm/processor.h>
37 #include <linux/uaccess.h>
38 #include <asm/pgalloc.h>
39 #include <asm/ctlreg.h>
40 #include <asm/kfence.h>
41 #include <asm/dma.h>
42 #include <asm/abs_lowcore.h>
43 #include <asm/tlb.h>
44 #include <asm/tlbflush.h>
45 #include <asm/sections.h>
46 #include <asm/sclp.h>
47 #include <asm/set_memory.h>
48 #include <asm/kasan.h>
49 #include <asm/dma-mapping.h>
50 #include <asm/uv.h>
51 #include <linux/virtio_anchor.h>
52 #include <linux/virtio_config.h>
53 #include <linux/execmem.h>
54
55 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
56 pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
57
58 struct ctlreg __bootdata_preserved(s390_invalid_asce);
59
60 unsigned long __bootdata_preserved(page_noexec_mask);
61 EXPORT_SYMBOL(page_noexec_mask);
62
63 unsigned long __bootdata_preserved(segment_noexec_mask);
64 EXPORT_SYMBOL(segment_noexec_mask);
65
66 unsigned long __bootdata_preserved(region_noexec_mask);
67 EXPORT_SYMBOL(region_noexec_mask);
68
69 unsigned long empty_zero_page, zero_page_mask;
70 EXPORT_SYMBOL(empty_zero_page);
71 EXPORT_SYMBOL(zero_page_mask);
72
setup_zero_pages(void)73 static void __init setup_zero_pages(void)
74 {
75 unsigned long total_pages = memblock_estimated_nr_free_pages();
76 unsigned int order;
77
78 /* Latest machines require a mapping granularity of 512KB */
79 order = 7;
80
81 /* Limit number of empty zero pages for small memory sizes */
82 while (order > 2 && (total_pages >> 10) < (1UL << order))
83 order--;
84
85 empty_zero_page = (unsigned long)memblock_alloc_or_panic(PAGE_SIZE << order, PAGE_SIZE);
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_limit = DMA_BIT_MASK(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 if (cpu_has_nx())
111 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
112 __set_memory_ro(__start_ro_after_init, __end_ro_after_init);
113 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
114 }
115
set_memory_encrypted(unsigned long vaddr,int numpages)116 int set_memory_encrypted(unsigned long vaddr, int numpages)
117 {
118 int i;
119
120 /* make specified pages unshared, (swiotlb, dma_free) */
121 for (i = 0; i < numpages; ++i) {
122 uv_remove_shared(virt_to_phys((void *)vaddr));
123 vaddr += PAGE_SIZE;
124 }
125 return 0;
126 }
127
set_memory_decrypted(unsigned long vaddr,int numpages)128 int set_memory_decrypted(unsigned long vaddr, int numpages)
129 {
130 int i;
131 /* make specified pages shared (swiotlb, dma_alloca) */
132 for (i = 0; i < numpages; ++i) {
133 uv_set_shared(virt_to_phys((void *)vaddr));
134 vaddr += PAGE_SIZE;
135 }
136 return 0;
137 }
138
139 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)140 bool force_dma_unencrypted(struct device *dev)
141 {
142 return is_prot_virt_guest();
143 }
144
145 /* protected virtualization */
pv_init(void)146 static void pv_init(void)
147 {
148 if (!is_prot_virt_guest())
149 return;
150
151 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
152
153 /* make sure bounce buffers are shared */
154 swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
155 swiotlb_update_mem_attributes();
156 }
157
arch_mm_preinit(void)158 void __init arch_mm_preinit(void)
159 {
160 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
161 cpumask_set_cpu(0, mm_cpumask(&init_mm));
162
163 pv_init();
164
165 setup_zero_pages(); /* Setup zeroed pages. */
166 }
167
memory_block_size_bytes(void)168 unsigned long memory_block_size_bytes(void)
169 {
170 /*
171 * Make sure the memory block size is always greater
172 * or equal than the memory increment size.
173 */
174 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
175 }
176
177 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
178 EXPORT_SYMBOL(__per_cpu_offset);
179
pcpu_cpu_distance(unsigned int from,unsigned int to)180 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
181 {
182 return LOCAL_DISTANCE;
183 }
184
pcpu_cpu_to_node(int cpu)185 static int __init pcpu_cpu_to_node(int cpu)
186 {
187 return 0;
188 }
189
setup_per_cpu_areas(void)190 void __init setup_per_cpu_areas(void)
191 {
192 unsigned long delta;
193 unsigned int cpu;
194 int rc;
195
196 /*
197 * Always reserve area for module percpu variables. That's
198 * what the legacy allocator did.
199 */
200 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
201 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
202 pcpu_cpu_distance,
203 pcpu_cpu_to_node);
204 if (rc < 0)
205 panic("Failed to initialize percpu areas.");
206
207 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
208 for_each_possible_cpu(cpu)
209 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
210 }
211
212 #ifdef CONFIG_MEMORY_HOTPLUG
213
214 #ifdef CONFIG_CMA
215
216 /* Prevent memory blocks which contain cma regions from going offline */
217
218 struct s390_cma_mem_data {
219 unsigned long start;
220 unsigned long end;
221 };
222
s390_cma_check_range(struct cma * cma,void * data)223 static int s390_cma_check_range(struct cma *cma, void *data)
224 {
225 struct s390_cma_mem_data *mem_data;
226
227 mem_data = data;
228
229 if (cma_intersects(cma, mem_data->start, mem_data->end))
230 return -EBUSY;
231
232 return 0;
233 }
234
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)235 static int s390_cma_mem_notifier(struct notifier_block *nb,
236 unsigned long action, void *data)
237 {
238 struct s390_cma_mem_data mem_data;
239 struct memory_notify *arg;
240 int rc = 0;
241
242 arg = data;
243 mem_data.start = arg->start_pfn << PAGE_SHIFT;
244 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
245 if (action == MEM_GOING_OFFLINE)
246 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
247 return notifier_from_errno(rc);
248 }
249
250 static struct notifier_block s390_cma_mem_nb = {
251 .notifier_call = s390_cma_mem_notifier,
252 };
253
s390_cma_mem_init(void)254 static int __init s390_cma_mem_init(void)
255 {
256 return register_memory_notifier(&s390_cma_mem_nb);
257 }
258 device_initcall(s390_cma_mem_init);
259
260 #endif /* CONFIG_CMA */
261
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)262 int arch_add_memory(int nid, u64 start, u64 size,
263 struct mhp_params *params)
264 {
265 unsigned long start_pfn = PFN_DOWN(start);
266 unsigned long size_pages = PFN_DOWN(size);
267 int rc;
268
269 if (WARN_ON_ONCE(pgprot_val(params->pgprot) != pgprot_val(PAGE_KERNEL)))
270 return -EINVAL;
271
272 VM_BUG_ON(!mhp_range_allowed(start, size, true));
273 rc = vmem_add_mapping(start, size);
274 if (rc)
275 return rc;
276
277 rc = __add_pages(nid, start_pfn, size_pages, params);
278 if (rc)
279 vmem_remove_mapping(start, size);
280 return rc;
281 }
282
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap)283 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
284 {
285 unsigned long start_pfn = start >> PAGE_SHIFT;
286 unsigned long nr_pages = size >> PAGE_SHIFT;
287
288 __remove_pages(start_pfn, nr_pages, altmap);
289 vmem_remove_mapping(start, size);
290 }
291 #endif /* CONFIG_MEMORY_HOTPLUG */
292
293 #ifdef CONFIG_EXECMEM
294 static struct execmem_info execmem_info __ro_after_init;
295
execmem_arch_setup(void)296 struct execmem_info __init *execmem_arch_setup(void)
297 {
298 unsigned long module_load_offset = 0;
299 unsigned long start;
300
301 if (kaslr_enabled())
302 module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
303
304 start = MODULES_VADDR + module_load_offset;
305
306 execmem_info = (struct execmem_info){
307 .ranges = {
308 [EXECMEM_DEFAULT] = {
309 .flags = EXECMEM_KASAN_SHADOW,
310 .start = start,
311 .end = MODULES_END,
312 .pgprot = PAGE_KERNEL,
313 .alignment = MODULE_ALIGN,
314 },
315 },
316 };
317
318 return &execmem_info;
319 }
320 #endif /* CONFIG_EXECMEM */
321