mem.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  PowerPC version
  4 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  5 *
  6 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
  7 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
  8 *    Copyright (C) 1996 Paul Mackerras
  9 *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
 10 *
 11 *  Derived from "arch/i386/mm/init.c"
 12 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 13 */
 14
 15#include <linux/memblock.h>
 16#include <linux/highmem.h>
 17#include <linux/suspend.h>
 18#include <linux/dma-direct.h>
 19#include <linux/execmem.h>
 20#include <linux/vmalloc.h>
 21
 22#include <asm/swiotlb.h>
 23#include <asm/machdep.h>
 24#include <asm/rtas.h>
 25#include <asm/kasan.h>
 26#include <asm/svm.h>
 27#include <asm/mmzone.h>
 28#include <asm/ftrace.h>
 29#include <asm/text-patching.h>
 30#include <asm/setup.h>
 31#include <asm/fixmap.h>
 32
 33#include <mm/mmu_decl.h>
 34
 35unsigned long long memory_limit __initdata;
 36
 37unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
 38EXPORT_SYMBOL(empty_zero_page);
 39
 40pgprot_t __phys_mem_access_prot(unsigned long pfn, unsigned long size,
 41				pgprot_t vma_prot)
 42{
 43	if (ppc_md.phys_mem_access_prot)
 44		return ppc_md.phys_mem_access_prot(pfn, size, vma_prot);
 45
 46	if (!page_is_ram(pfn))
 47		vma_prot = pgprot_noncached(vma_prot);
 48
 49	return vma_prot;
 50}
 51EXPORT_SYMBOL(__phys_mem_access_prot);
 52
 53#ifdef CONFIG_MEMORY_HOTPLUG
 54static DEFINE_MUTEX(linear_mapping_mutex);
 55
 56#ifdef CONFIG_NUMA
 57int memory_add_physaddr_to_nid(u64 start)
 58{
 59	return hot_add_scn_to_nid(start);
 60}
 61EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 62#endif
 63
 64int __weak create_section_mapping(unsigned long start, unsigned long end,
 65				  int nid, pgprot_t prot)
 66{
 67	return -ENODEV;
 68}
 69
 70int __weak remove_section_mapping(unsigned long start, unsigned long end)
 71{
 72	return -ENODEV;
 73}
 74
 75int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
 76				     struct mhp_params *params)
 77{
 78	int rc;
 79
 80	start = (unsigned long)__va(start);
 81	mutex_lock(&linear_mapping_mutex);
 82	rc = create_section_mapping(start, start + size, nid,
 83				    params->pgprot);
 84	mutex_unlock(&linear_mapping_mutex);
 85	if (rc) {
 86		pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
 87			start, start + size, rc);
 88		return -EFAULT;
 89	}
 90	return 0;
 91}
 92
 93void __ref arch_remove_linear_mapping(u64 start, u64 size)
 94{
 95	int ret;
 96
 97	/* Remove htab bolted mappings for this section of memory */
 98	start = (unsigned long)__va(start);
 99
100	mutex_lock(&linear_mapping_mutex);
101	ret = remove_section_mapping(start, start + size);
102	mutex_unlock(&linear_mapping_mutex);
103	if (ret)
104		pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
105			start, start + size, ret);
106
107	/* Ensure all vmalloc mappings are flushed in case they also
108	 * hit that section of memory
109	 */
110	vm_unmap_aliases();
111}
112
113/*
114 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
115 * updating.
116 */
117static void update_end_of_memory_vars(u64 start, u64 size)
118{
119	unsigned long end_pfn = PFN_UP(start + size);
120
121	if (end_pfn > max_pfn) {
122		max_pfn = end_pfn;
123		max_low_pfn = end_pfn;
124		high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
125	}
126}
127
128int __ref add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
129		    struct mhp_params *params)
130{
131	int ret;
132
133	ret = __add_pages(nid, start_pfn, nr_pages, params);
134	if (ret)
135		return ret;
136
137	/* update max_pfn, max_low_pfn and high_memory */
138	update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
139				  nr_pages << PAGE_SHIFT);
140
141	return ret;
142}
143
144int __ref arch_add_memory(int nid, u64 start, u64 size,
145			  struct mhp_params *params)
146{
147	unsigned long start_pfn = start >> PAGE_SHIFT;
148	unsigned long nr_pages = size >> PAGE_SHIFT;
149	int rc;
150
151	rc = arch_create_linear_mapping(nid, start, size, params);
152	if (rc)
153		return rc;
154	rc = add_pages(nid, start_pfn, nr_pages, params);
155	if (rc)
156		arch_remove_linear_mapping(start, size);
157	return rc;
158}
159
160void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
161{
162	unsigned long start_pfn = start >> PAGE_SHIFT;
163	unsigned long nr_pages = size >> PAGE_SHIFT;
164
165	__remove_pages(start_pfn, nr_pages, altmap);
166	arch_remove_linear_mapping(start, size);
167}
168#endif
169
170#ifndef CONFIG_NUMA
171void __init mem_topology_setup(void)
172{
173	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
174	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
175#ifdef CONFIG_HIGHMEM
176	max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
177#endif
178
179	/* Place all memblock_regions in the same node and merge contiguous
180	 * memblock_regions
181	 */
182	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
183}
184
185void __init initmem_init(void)
186{
187	sparse_init();
188}
189
190/* mark pages that don't exist as nosave */
191static int __init mark_nonram_nosave(void)
192{
193	unsigned long spfn, epfn, prev = 0;
194	int i;
195
196	for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
197		if (prev && prev < spfn)
198			register_nosave_region(prev, spfn);
199
200		prev = epfn;
201	}
202
203	return 0;
204}
205#else /* CONFIG_NUMA */
206static int __init mark_nonram_nosave(void)
207{
208	return 0;
209}
210#endif
211
212/*
213 * Zones usage:
214 *
215 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
216 * everything else. GFP_DMA32 page allocations automatically fall back to
217 * ZONE_DMA.
218 *
219 * By using 31-bit unconditionally, we can exploit zone_dma_limit to inform the
220 * generic DMA mapping code.  32-bit only devices (if not handled by an IOMMU
221 * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
222 * ZONE_DMA.
223 */
224static unsigned long max_zone_pfns[MAX_NR_ZONES];
225
226/*
227 * paging_init() sets up the page tables - in fact we've already done this.
228 */
229void __init paging_init(void)
230{
231	unsigned long long total_ram = memblock_phys_mem_size();
232	phys_addr_t top_of_ram = memblock_end_of_DRAM();
233	int zone_dma_bits;
234
235#ifdef CONFIG_HIGHMEM
236	unsigned long v = __fix_to_virt(FIX_KMAP_END);
237	unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
238
239	for (; v < end; v += PAGE_SIZE)
240		map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
241
242	map_kernel_page(PKMAP_BASE, 0, __pgprot(0));	/* XXX gross */
243	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
244#endif /* CONFIG_HIGHMEM */
245
246	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
247	       (unsigned long long)top_of_ram, total_ram);
248	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
249	       (long int)((top_of_ram - total_ram) >> 20));
250
251	/*
252	 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
253	 * powerbooks.
254	 */
255	if (IS_ENABLED(CONFIG_PPC32))
256		zone_dma_bits = 30;
257	else
258		zone_dma_bits = 31;
259
260	zone_dma_limit = DMA_BIT_MASK(zone_dma_bits);
261
262#ifdef CONFIG_ZONE_DMA
263	max_zone_pfns[ZONE_DMA]	= min(max_low_pfn,
264				      1UL << (zone_dma_bits - PAGE_SHIFT));
265#endif
266	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
267#ifdef CONFIG_HIGHMEM
268	max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
269#endif
270
271	free_area_init(max_zone_pfns);
272
273	mark_nonram_nosave();
274}
275
276void __init arch_mm_preinit(void)
277{
278	/*
279	 * book3s is limited to 16 page sizes due to encoding this in
280	 * a 4-bit field for slices.
281	 */
282	BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
283
284#ifdef CONFIG_SWIOTLB
285	/*
286	 * Some platforms (e.g. 85xx) limit DMA-able memory way below
287	 * 4G. We force memblock to bottom-up mode to ensure that the
288	 * memory allocated in swiotlb_init() is DMA-able.
289	 * As it's the last memblock allocation, no need to reset it
290	 * back to to-down.
291	 */
292	memblock_set_bottom_up(true);
293	swiotlb_init(ppc_swiotlb_enable, ppc_swiotlb_flags);
294#endif
295
296	kasan_late_init();
297
298#if defined(CONFIG_PPC_E500) && !defined(CONFIG_SMP)
299	/*
300	 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
301	 * functions.... do it here for the non-smp case.
302	 */
303	per_cpu(next_tlbcam_idx, smp_processor_id()) =
304		(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
305#endif
306}
307
308void free_initmem(void)
309{
310	ppc_md.progress = ppc_printk_progress;
311	mark_initmem_nx();
312	free_initmem_default(POISON_FREE_INITMEM);
313	ftrace_free_init_tramp();
314}
315
316/*
317 * System memory should not be in /proc/iomem but various tools expect it
318 * (eg kdump).
319 */
320static int __init add_system_ram_resources(void)
321{
322	phys_addr_t start, end;
323	u64 i;
324
325	for_each_mem_range(i, &start, &end) {
326		struct resource *res;
327
328		res = kzalloc(sizeof(struct resource), GFP_KERNEL);
329		WARN_ON(!res);
330
331		if (res) {
332			res->name = "System RAM";
333			res->start = start;
334			/*
335			 * In memblock, end points to the first byte after
336			 * the range while in resourses, end points to the
337			 * last byte in the range.
338			 */
339			res->end = end - 1;
340			res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
341			WARN_ON(insert_resource(&iomem_resource, res) < 0);
342		}
343	}
344
345	return 0;
346}
347subsys_initcall(add_system_ram_resources);
348
349#ifdef CONFIG_STRICT_DEVMEM
350/*
351 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
352 * is valid. The argument is a physical page number.
353 *
354 * Access has to be given to non-kernel-ram areas as well, these contain the
355 * PCI mmio resources as well as potential bios/acpi data regions.
356 */
357int devmem_is_allowed(unsigned long pfn)
358{
359	if (page_is_rtas_user_buf(pfn))
360		return 1;
361	if (iomem_is_exclusive(PFN_PHYS(pfn)))
362		return 0;
363	if (!page_is_ram(pfn))
364		return 1;
365	return 0;
366}
367#endif /* CONFIG_STRICT_DEVMEM */
368
369/*
370 * This is defined in kernel/resource.c but only powerpc needs to export it, for
371 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
372 */
373EXPORT_SYMBOL_GPL(walk_system_ram_range);
374
375#ifdef CONFIG_EXECMEM
376static struct execmem_info execmem_info __ro_after_init;
377
378#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC_BOOK3S_603)
379static void prealloc_execmem_pgtable(void)
380{
381	unsigned long va;
382
383	for (va = ALIGN_DOWN(MODULES_VADDR, PGDIR_SIZE); va < MODULES_END; va += PGDIR_SIZE)
384		pte_alloc_kernel(pmd_off_k(va), va);
385}
386#else
387static void prealloc_execmem_pgtable(void) { }
388#endif
389
390struct execmem_info __init *execmem_arch_setup(void)
391{
392	pgprot_t kprobes_prot = strict_module_rwx_enabled() ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
393	pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
394	unsigned long fallback_start = 0, fallback_end = 0;
395	unsigned long start, end;
396
397	/*
398	 * BOOK3S_32 and 8xx define MODULES_VADDR for text allocations and
399	 * allow allocating data in the entire vmalloc space
400	 */
401#ifdef MODULES_VADDR
402	unsigned long limit = (unsigned long)_etext - SZ_32M;
403
404	BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
405
406	/* First try within 32M limit from _etext to avoid branch trampolines */
407	if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit) {
408		start = limit;
409		fallback_start = MODULES_VADDR;
410		fallback_end = MODULES_END;
411	} else {
412		start = MODULES_VADDR;
413	}
414
415	end = MODULES_END;
416#else
417	start = VMALLOC_START;
418	end = VMALLOC_END;
419#endif
420
421	prealloc_execmem_pgtable();
422
423	execmem_info = (struct execmem_info){
424		.ranges = {
425			[EXECMEM_DEFAULT] = {
426				.start	= start,
427				.end	= end,
428				.pgprot	= prot,
429				.alignment = 1,
430				.fallback_start	= fallback_start,
431				.fallback_end	= fallback_end,
432			},
433			[EXECMEM_KPROBES] = {
434				.start	= VMALLOC_START,
435				.end	= VMALLOC_END,
436				.pgprot	= kprobes_prot,
437				.alignment = 1,
438			},
439			[EXECMEM_MODULE_DATA] = {
440				.start	= VMALLOC_START,
441				.end	= VMALLOC_END,
442				.pgprot	= PAGE_KERNEL,
443				.alignment = 1,
444			},
445		},
446	};
447
448	return &execmem_info;
449}
450#endif /* CONFIG_EXECMEM */