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, end: start + size, nid,
83 prot: params->pgprot);
84 mutex_unlock(lock: &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, end: start + size);
102 mutex_unlock(lock: &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: start_pfn << PAGE_SHIFT,
139 size: 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_pfn: 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(enable: true);
293 swiotlb_init(addressing_limited: ppc_swiotlb_enable, flags: 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 */
451

source code of linux/arch/powerpc/mm/mem.c