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
53pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
54pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
55
56struct ctlreg __bootdata_preserved(s390_invalid_asce);
57
58unsigned long empty_zero_page, zero_page_mask;
59EXPORT_SYMBOL(empty_zero_page);
60EXPORT_SYMBOL(zero_page_mask);
61
62static void __init setup_zero_pages(void)
63{
64	unsigned int order;
65	struct page *page;
66	int i;
67
68	/* Latest machines require a mapping granularity of 512KB */
69	order = 7;
70
71	/* Limit number of empty zero pages for small memory sizes */
72	while (order > 2 && (totalram_pages() >> 10) < (1UL << order))
73		order--;
74
75	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
76	if (!empty_zero_page)
77		panic("Out of memory in setup_zero_pages");
78
79	page = virt_to_page((void *) empty_zero_page);
80	split_page(page, order);
81	for (i = 1 << order; i > 0; i--) {
82		mark_page_reserved(page);
83		page++;
84	}
85
86	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
87}
88
89/*
90 * paging_init() sets up the page tables
91 */
92void __init paging_init(void)
93{
94	unsigned long max_zone_pfns[MAX_NR_ZONES];
95
96	vmem_map_init();
97	sparse_init();
98	zone_dma_bits = 31;
99	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
100	max_zone_pfns[ZONE_DMA] = virt_to_pfn(MAX_DMA_ADDRESS);
101	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
102	free_area_init(max_zone_pfns);
103}
104
105void mark_rodata_ro(void)
106{
107	unsigned long size = __end_ro_after_init - __start_ro_after_init;
108
109	__set_memory_ro(__start_ro_after_init, __end_ro_after_init);
110	pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
111}
112
113int set_memory_encrypted(unsigned long vaddr, int numpages)
114{
115	int i;
116
117	/* make specified pages unshared, (swiotlb, dma_free) */
118	for (i = 0; i < numpages; ++i) {
119		uv_remove_shared(virt_to_phys((void *)vaddr));
120		vaddr += PAGE_SIZE;
121	}
122	return 0;
123}
124
125int set_memory_decrypted(unsigned long vaddr, int numpages)
126{
127	int i;
128	/* make specified pages shared (swiotlb, dma_alloca) */
129	for (i = 0; i < numpages; ++i) {
130		uv_set_shared(virt_to_phys((void *)vaddr));
131		vaddr += PAGE_SIZE;
132	}
133	return 0;
134}
135
136/* are we a protected virtualization guest? */
137bool force_dma_unencrypted(struct device *dev)
138{
139	return is_prot_virt_guest();
140}
141
142/* protected virtualization */
143static void pv_init(void)
144{
145	if (!is_prot_virt_guest())
146		return;
147
148	virtio_set_mem_acc_cb(virtio_require_restricted_mem_acc);
149
150	/* make sure bounce buffers are shared */
151	swiotlb_init(true, SWIOTLB_FORCE | SWIOTLB_VERBOSE);
152	swiotlb_update_mem_attributes();
153}
154
155void __init mem_init(void)
156{
157	cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
158	cpumask_set_cpu(0, mm_cpumask(&init_mm));
159
160	set_max_mapnr(max_low_pfn);
161        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
162
163	pv_init();
164	kfence_split_mapping();
165
166	/* this will put all low memory onto the freelists */
167	memblock_free_all();
168	setup_zero_pages();	/* Setup zeroed pages. */
169}
170
171void free_initmem(void)
172{
173	set_memory_rwnx((unsigned long)_sinittext,
174			(unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT);
175	free_initmem_default(POISON_FREE_INITMEM);
176}
177
178unsigned long memory_block_size_bytes(void)
179{
180	/*
181	 * Make sure the memory block size is always greater
182	 * or equal than the memory increment size.
183	 */
184	return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
185}
186
187unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
188EXPORT_SYMBOL(__per_cpu_offset);
189
190static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
191{
192	return LOCAL_DISTANCE;
193}
194
195static int __init pcpu_cpu_to_node(int cpu)
196{
197	return 0;
198}
199
200void __init setup_per_cpu_areas(void)
201{
202	unsigned long delta;
203	unsigned int cpu;
204	int rc;
205
206	/*
207	 * Always reserve area for module percpu variables.  That's
208	 * what the legacy allocator did.
209	 */
210	rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
211				    PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
212				    pcpu_cpu_distance,
213				    pcpu_cpu_to_node);
214	if (rc < 0)
215		panic("Failed to initialize percpu areas.");
216
217	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
218	for_each_possible_cpu(cpu)
219		__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
220}
221
222#ifdef CONFIG_MEMORY_HOTPLUG
223
224#ifdef CONFIG_CMA
225
226/* Prevent memory blocks which contain cma regions from going offline */
227
228struct s390_cma_mem_data {
229	unsigned long start;
230	unsigned long end;
231};
232
233static int s390_cma_check_range(struct cma *cma, void *data)
234{
235	struct s390_cma_mem_data *mem_data;
236	unsigned long start, end;
237
238	mem_data = data;
239	start = cma_get_base(cma);
240	end = start + cma_get_size(cma);
241	if (end < mem_data->start)
242		return 0;
243	if (start >= mem_data->end)
244		return 0;
245	return -EBUSY;
246}
247
248static 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
263static struct notifier_block s390_cma_mem_nb = {
264	.notifier_call = s390_cma_mem_notifier,
265};
266
267static int __init s390_cma_mem_init(void)
268{
269	return register_memory_notifier(&s390_cma_mem_nb);
270}
271device_initcall(s390_cma_mem_init);
272
273#endif /* CONFIG_CMA */
274
275int 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(params->pgprot.pgprot != PAGE_KERNEL.pgprot))
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
296void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
297{
298	unsigned long start_pfn = start >> PAGE_SHIFT;
299	unsigned long nr_pages = size >> PAGE_SHIFT;
300
301	__remove_pages(start_pfn, nr_pages, altmap);
302	vmem_remove_mapping(start, size);
303}
304#endif /* CONFIG_MEMORY_HOTPLUG */
305