init.c

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