xref: /openbmc/linux/arch/s390/mm/init.c (revision 82e6fdd6)
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/smp.h>
22 #include <linux/init.h>
23 #include <linux/pagemap.h>
24 #include <linux/bootmem.h>
25 #include <linux/memory.h>
26 #include <linux/pfn.h>
27 #include <linux/poison.h>
28 #include <linux/initrd.h>
29 #include <linux/export.h>
30 #include <linux/cma.h>
31 #include <linux/gfp.h>
32 #include <linux/memblock.h>
33 #include <asm/processor.h>
34 #include <linux/uaccess.h>
35 #include <asm/pgtable.h>
36 #include <asm/pgalloc.h>
37 #include <asm/dma.h>
38 #include <asm/lowcore.h>
39 #include <asm/tlb.h>
40 #include <asm/tlbflush.h>
41 #include <asm/sections.h>
42 #include <asm/ctl_reg.h>
43 #include <asm/sclp.h>
44 #include <asm/set_memory.h>
45 
46 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
47 
48 unsigned long empty_zero_page, zero_page_mask;
49 EXPORT_SYMBOL(empty_zero_page);
50 EXPORT_SYMBOL(zero_page_mask);
51 
52 static void __init setup_zero_pages(void)
53 {
54 	unsigned int order;
55 	struct page *page;
56 	int i;
57 
58 	/* Latest machines require a mapping granularity of 512KB */
59 	order = 7;
60 
61 	/* Limit number of empty zero pages for small memory sizes */
62 	while (order > 2 && (totalram_pages >> 10) < (1UL << order))
63 		order--;
64 
65 	empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
66 	if (!empty_zero_page)
67 		panic("Out of memory in setup_zero_pages");
68 
69 	page = virt_to_page((void *) empty_zero_page);
70 	split_page(page, order);
71 	for (i = 1 << order; i > 0; i--) {
72 		mark_page_reserved(page);
73 		page++;
74 	}
75 
76 	zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
77 }
78 
79 /*
80  * paging_init() sets up the page tables
81  */
82 void __init paging_init(void)
83 {
84 	unsigned long max_zone_pfns[MAX_NR_ZONES];
85 	unsigned long pgd_type, asce_bits;
86 	psw_t psw;
87 
88 	init_mm.pgd = swapper_pg_dir;
89 	if (VMALLOC_END > _REGION2_SIZE) {
90 		asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
91 		pgd_type = _REGION2_ENTRY_EMPTY;
92 	} else {
93 		asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
94 		pgd_type = _REGION3_ENTRY_EMPTY;
95 	}
96 	init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
97 	S390_lowcore.kernel_asce = init_mm.context.asce;
98 	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
99 	crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
100 	vmem_map_init();
101 
102         /* enable virtual mapping in kernel mode */
103 	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
104 	__ctl_load(S390_lowcore.kernel_asce, 7, 7);
105 	__ctl_load(S390_lowcore.kernel_asce, 13, 13);
106 	psw.mask = __extract_psw();
107 	psw_bits(psw).dat = 1;
108 	psw_bits(psw).as = PSW_BITS_AS_HOME;
109 	__load_psw_mask(psw.mask);
110 
111 	sparse_memory_present_with_active_regions(MAX_NUMNODES);
112 	sparse_init();
113 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
114 	max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
115 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
116 	free_area_init_nodes(max_zone_pfns);
117 }
118 
119 void mark_rodata_ro(void)
120 {
121 	unsigned long size = __end_ro_after_init - __start_ro_after_init;
122 
123 	set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
124 	pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
125 }
126 
127 void __init mem_init(void)
128 {
129 	cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
130 	cpumask_set_cpu(0, mm_cpumask(&init_mm));
131 
132 	set_max_mapnr(max_low_pfn);
133         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
134 
135 	/* Setup guest page hinting */
136 	cmma_init();
137 
138 	/* this will put all low memory onto the freelists */
139 	free_all_bootmem();
140 	setup_zero_pages();	/* Setup zeroed pages. */
141 
142 	cmma_init_nodat();
143 
144 	mem_init_print_info(NULL);
145 }
146 
147 void free_initmem(void)
148 {
149 	__set_memory((unsigned long)_sinittext,
150 		     (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT,
151 		     SET_MEMORY_RW | SET_MEMORY_NX);
152 	free_initmem_default(POISON_FREE_INITMEM);
153 }
154 
155 #ifdef CONFIG_BLK_DEV_INITRD
156 void __init free_initrd_mem(unsigned long start, unsigned long end)
157 {
158 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
159 			   "initrd");
160 }
161 #endif
162 
163 unsigned long memory_block_size_bytes(void)
164 {
165 	/*
166 	 * Make sure the memory block size is always greater
167 	 * or equal than the memory increment size.
168 	 */
169 	return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
170 }
171 
172 #ifdef CONFIG_MEMORY_HOTPLUG
173 
174 #ifdef CONFIG_CMA
175 
176 /* Prevent memory blocks which contain cma regions from going offline */
177 
178 struct s390_cma_mem_data {
179 	unsigned long start;
180 	unsigned long end;
181 };
182 
183 static int s390_cma_check_range(struct cma *cma, void *data)
184 {
185 	struct s390_cma_mem_data *mem_data;
186 	unsigned long start, end;
187 
188 	mem_data = data;
189 	start = cma_get_base(cma);
190 	end = start + cma_get_size(cma);
191 	if (end < mem_data->start)
192 		return 0;
193 	if (start >= mem_data->end)
194 		return 0;
195 	return -EBUSY;
196 }
197 
198 static int s390_cma_mem_notifier(struct notifier_block *nb,
199 				 unsigned long action, void *data)
200 {
201 	struct s390_cma_mem_data mem_data;
202 	struct memory_notify *arg;
203 	int rc = 0;
204 
205 	arg = data;
206 	mem_data.start = arg->start_pfn << PAGE_SHIFT;
207 	mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
208 	if (action == MEM_GOING_OFFLINE)
209 		rc = cma_for_each_area(s390_cma_check_range, &mem_data);
210 	return notifier_from_errno(rc);
211 }
212 
213 static struct notifier_block s390_cma_mem_nb = {
214 	.notifier_call = s390_cma_mem_notifier,
215 };
216 
217 static int __init s390_cma_mem_init(void)
218 {
219 	return register_memory_notifier(&s390_cma_mem_nb);
220 }
221 device_initcall(s390_cma_mem_init);
222 
223 #endif /* CONFIG_CMA */
224 
225 int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
226 		bool want_memblock)
227 {
228 	unsigned long start_pfn = PFN_DOWN(start);
229 	unsigned long size_pages = PFN_DOWN(size);
230 	int rc;
231 
232 	rc = vmem_add_mapping(start, size);
233 	if (rc)
234 		return rc;
235 
236 	rc = __add_pages(nid, start_pfn, size_pages, altmap, want_memblock);
237 	if (rc)
238 		vmem_remove_mapping(start, size);
239 	return rc;
240 }
241 
242 #ifdef CONFIG_MEMORY_HOTREMOVE
243 int arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
244 {
245 	/*
246 	 * There is no hardware or firmware interface which could trigger a
247 	 * hot memory remove on s390. So there is nothing that needs to be
248 	 * implemented.
249 	 */
250 	return -EBUSY;
251 }
252 #endif
253 #endif /* CONFIG_MEMORY_HOTPLUG */
254