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/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/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 #include <linux/cc_platform.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
arch_setup_zero_pages(void)73 void __init arch_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 set_memory_ro(empty_zero_page, 1UL << order);
90 }
91
arch_zone_limits_init(unsigned long * max_zone_pfns)92 void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
93 {
94 max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
95 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
96 }
97
98 /*
99 * paging_init() sets up the page tables
100 */
paging_init(void)101 void __init paging_init(void)
102 {
103 vmem_map_init();
104 zone_dma_limit = DMA_BIT_MASK(31);
105 }
106
mark_rodata_ro(void)107 void mark_rodata_ro(void)
108 {
109 unsigned long size = __end_ro_after_init - __start_ro_after_init;
110
111 if (cpu_has_nx())
112 system_ctl_set_bit(0, CR0_INSTRUCTION_EXEC_PROTECTION_BIT);
113 __set_memory_ro(__start_ro_after_init, __end_ro_after_init);
114 pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
115 }
116
set_memory_encrypted(unsigned long vaddr,int numpages)117 int set_memory_encrypted(unsigned long vaddr, int numpages)
118 {
119 int i;
120
121 /* make specified pages unshared, (swiotlb, dma_free) */
122 for (i = 0; i < numpages; ++i) {
123 uv_remove_shared(virt_to_phys((void *)vaddr));
124 vaddr += PAGE_SIZE;
125 }
126 return 0;
127 }
128
set_memory_decrypted(unsigned long vaddr,int numpages)129 int set_memory_decrypted(unsigned long vaddr, int numpages)
130 {
131 int i;
132 /* make specified pages shared (swiotlb, dma_alloca) */
133 for (i = 0; i < numpages; ++i) {
134 uv_set_shared(virt_to_phys((void *)vaddr));
135 vaddr += PAGE_SIZE;
136 }
137 return 0;
138 }
139
140 /* are we a protected virtualization guest? */
force_dma_unencrypted(struct device * dev)141 bool force_dma_unencrypted(struct device *dev)
142 {
143 return is_prot_virt_guest();
144 }
145
146
cc_platform_has(enum cc_attr attr)147 bool cc_platform_has(enum cc_attr attr)
148 {
149 switch (attr) {
150 case CC_ATTR_MEM_ENCRYPT:
151 case CC_ATTR_GUEST_MEM_ENCRYPT:
152 return is_prot_virt_guest();
153
154 default:
155 return false;
156 }
157 }
158 EXPORT_SYMBOL_GPL(cc_platform_has);
159
160 /* protected virtualization */
pv_init(void)161 static void __init pv_init(void)
162 {
163 if (!is_prot_virt_guest())
164 return;
165
166 virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
167
168 /* make sure bounce buffers are shared */
169 swiotlb_init(true, SWIOTLB_VERBOSE | SWIOTLB_ANY);
170 swiotlb_update_mem_attributes();
171 }
172
arch_mm_preinit(void)173 void __init arch_mm_preinit(void)
174 {
175 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
176 cpumask_set_cpu(0, mm_cpumask(&init_mm));
177
178 pv_init();
179 }
180
memory_block_size_bytes(void)181 unsigned long memory_block_size_bytes(void)
182 {
183 /*
184 * Make sure the memory block size is always greater
185 * or equal than the memory increment size.
186 */
187 return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
188 }
189
190 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
191 EXPORT_SYMBOL(__per_cpu_offset);
192
pcpu_cpu_distance(unsigned int from,unsigned int to)193 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
194 {
195 return LOCAL_DISTANCE;
196 }
197
pcpu_cpu_to_node(int cpu)198 static int __init pcpu_cpu_to_node(int cpu)
199 {
200 return 0;
201 }
202
setup_per_cpu_areas(void)203 void __init setup_per_cpu_areas(void)
204 {
205 unsigned long delta;
206 unsigned int cpu;
207 int rc;
208
209 /*
210 * Always reserve area for module percpu variables. That's
211 * what the legacy allocator did.
212 */
213 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
214 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
215 pcpu_cpu_distance,
216 pcpu_cpu_to_node);
217 if (rc < 0)
218 panic("Failed to initialize percpu areas.");
219
220 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
221 for_each_possible_cpu(cpu)
222 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
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
240 mem_data = data;
241
242 if (cma_intersects(cma, mem_data->start, mem_data->end))
243 return -EBUSY;
244
245 return 0;
246 }
247
s390_cma_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)248 static int s390_cma_mem_notifier(struct notifier_block *nb,
249 unsigned long action, void *data)
250 {
251 struct s390_cma_mem_data mem_data;
252 struct memory_notify *arg;
253 int rc = 0;
254
255 arg = data;
256 mem_data.start = arg->start_pfn << PAGE_SHIFT;
257 mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
258 if (action == MEM_GOING_OFFLINE)
259 rc = cma_for_each_area(s390_cma_check_range, &mem_data);
260 return notifier_from_errno(rc);
261 }
262
263 static struct notifier_block s390_cma_mem_nb = {
264 .notifier_call = s390_cma_mem_notifier,
265 };
266
s390_cma_mem_init(void)267 static int __init s390_cma_mem_init(void)
268 {
269 return register_memory_notifier(&s390_cma_mem_nb);
270 }
271 device_initcall(s390_cma_mem_init);
272
273 #endif /* CONFIG_CMA */
274
arch_add_memory(int nid,u64 start,u64 size,struct mhp_params * params)275 int arch_add_memory(int nid, u64 start, u64 size,
276 struct mhp_params *params)
277 {
278 unsigned long start_pfn = PFN_DOWN(start);
279 unsigned long size_pages = PFN_DOWN(size);
280 int rc;
281
282 if (WARN_ON_ONCE(pgprot_val(params->pgprot) != pgprot_val(PAGE_KERNEL)))
283 return -EINVAL;
284
285 VM_BUG_ON(!mhp_range_allowed(start, size, true));
286 rc = vmem_add_mapping(start, size);
287 if (rc)
288 return rc;
289
290 rc = __add_pages(nid, start_pfn, size_pages, params);
291 if (rc)
292 vmem_remove_mapping(start, size);
293 return rc;
294 }
295
arch_remove_memory(u64 start,u64 size,struct vmem_altmap * altmap,struct dev_pagemap * pgmap)296 void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap,
297 struct dev_pagemap *pgmap)
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, pgmap);
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