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
20#include <asm/swiotlb.h>
21#include <asm/machdep.h>
22#include <asm/rtas.h>
23#include <asm/kasan.h>
24#include <asm/svm.h>
25#include <asm/mmzone.h>
26#include <asm/ftrace.h>
27#include <asm/code-patching.h>
28#include <asm/setup.h>
29#include <asm/fixmap.h>
30
31#include <mm/mmu_decl.h>
32
33unsigned long long memory_limit;
34
35unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
36EXPORT_SYMBOL(empty_zero_page);
37
38pgprot_t __phys_mem_access_prot(unsigned long pfn, unsigned long size,
39 pgprot_t vma_prot)
40{
41 if (ppc_md.phys_mem_access_prot)
42 return ppc_md.phys_mem_access_prot(pfn, size, vma_prot);
43
44 if (!page_is_ram(pfn))
45 vma_prot = pgprot_noncached(vma_prot);
46
47 return vma_prot;
48}
49EXPORT_SYMBOL(__phys_mem_access_prot);
50
51#ifdef CONFIG_MEMORY_HOTPLUG
52static DEFINE_MUTEX(linear_mapping_mutex);
53
54#ifdef CONFIG_NUMA
55int memory_add_physaddr_to_nid(u64 start)
56{
57 return hot_add_scn_to_nid(start);
58}
59EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
60#endif
61
62int __weak create_section_mapping(unsigned long start, unsigned long end,
63 int nid, pgprot_t prot)
64{
65 return -ENODEV;
66}
67
68int __weak remove_section_mapping(unsigned long start, unsigned long end)
69{
70 return -ENODEV;
71}
72
73int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
74 struct mhp_params *params)
75{
76 int rc;
77
78 start = (unsigned long)__va(start);
79 mutex_lock(&linear_mapping_mutex);
80 rc = create_section_mapping(start, end: start + size, nid,
81 prot: params->pgprot);
82 mutex_unlock(lock: &linear_mapping_mutex);
83 if (rc) {
84 pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
85 start, start + size, rc);
86 return -EFAULT;
87 }
88 return 0;
89}
90
91void __ref arch_remove_linear_mapping(u64 start, u64 size)
92{
93 int ret;
94
95 /* Remove htab bolted mappings for this section of memory */
96 start = (unsigned long)__va(start);
97
98 mutex_lock(&linear_mapping_mutex);
99 ret = remove_section_mapping(start, end: start + size);
100 mutex_unlock(lock: &linear_mapping_mutex);
101 if (ret)
102 pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
103 start, start + size, ret);
104
105 /* Ensure all vmalloc mappings are flushed in case they also
106 * hit that section of memory
107 */
108 vm_unmap_aliases();
109}
110
111/*
112 * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
113 * updating.
114 */
115static void update_end_of_memory_vars(u64 start, u64 size)
116{
117 unsigned long end_pfn = PFN_UP(start + size);
118
119 if (end_pfn > max_pfn) {
120 max_pfn = end_pfn;
121 max_low_pfn = end_pfn;
122 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
123 }
124}
125
126int __ref add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
127 struct mhp_params *params)
128{
129 int ret;
130
131 ret = __add_pages(nid, start_pfn, nr_pages, params);
132 if (ret)
133 return ret;
134
135 /* update max_pfn, max_low_pfn and high_memory */
136 update_end_of_memory_vars(start: start_pfn << PAGE_SHIFT,
137 size: nr_pages << PAGE_SHIFT);
138
139 return ret;
140}
141
142int __ref arch_add_memory(int nid, u64 start, u64 size,
143 struct mhp_params *params)
144{
145 unsigned long start_pfn = start >> PAGE_SHIFT;
146 unsigned long nr_pages = size >> PAGE_SHIFT;
147 int rc;
148
149 rc = arch_create_linear_mapping(nid, start, size, params);
150 if (rc)
151 return rc;
152 rc = add_pages(nid, start_pfn, nr_pages, params);
153 if (rc)
154 arch_remove_linear_mapping(start, size);
155 return rc;
156}
157
158void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
159{
160 unsigned long start_pfn = start >> PAGE_SHIFT;
161 unsigned long nr_pages = size >> PAGE_SHIFT;
162
163 __remove_pages(start_pfn, nr_pages, altmap);
164 arch_remove_linear_mapping(start, size);
165}
166#endif
167
168#ifndef CONFIG_NUMA
169void __init mem_topology_setup(void)
170{
171 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
172 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
173#ifdef CONFIG_HIGHMEM
174 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
175#endif
176
177 /* Place all memblock_regions in the same node and merge contiguous
178 * memblock_regions
179 */
180 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
181}
182
183void __init initmem_init(void)
184{
185 sparse_init();
186}
187
188/* mark pages that don't exist as nosave */
189static int __init mark_nonram_nosave(void)
190{
191 unsigned long spfn, epfn, prev = 0;
192 int i;
193
194 for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
195 if (prev && prev < spfn)
196 register_nosave_region(prev, spfn);
197
198 prev = epfn;
199 }
200
201 return 0;
202}
203#else /* CONFIG_NUMA */
204static int __init mark_nonram_nosave(void)
205{
206 return 0;
207}
208#endif
209
210/*
211 * Zones usage:
212 *
213 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
214 * everything else. GFP_DMA32 page allocations automatically fall back to
215 * ZONE_DMA.
216 *
217 * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
218 * generic DMA mapping code. 32-bit only devices (if not handled by an IOMMU
219 * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
220 * ZONE_DMA.
221 */
222static unsigned long max_zone_pfns[MAX_NR_ZONES];
223
224/*
225 * paging_init() sets up the page tables - in fact we've already done this.
226 */
227void __init paging_init(void)
228{
229 unsigned long long total_ram = memblock_phys_mem_size();
230 phys_addr_t top_of_ram = memblock_end_of_DRAM();
231
232#ifdef CONFIG_HIGHMEM
233 unsigned long v = __fix_to_virt(FIX_KMAP_END);
234 unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
235
236 for (; v < end; v += PAGE_SIZE)
237 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
238
239 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */
240 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
241#endif /* CONFIG_HIGHMEM */
242
243 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
244 (unsigned long long)top_of_ram, total_ram);
245 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
246 (long int)((top_of_ram - total_ram) >> 20));
247
248 /*
249 * Allow 30-bit DMA for very limited Broadcom wifi chips on many
250 * powerbooks.
251 */
252 if (IS_ENABLED(CONFIG_PPC32))
253 zone_dma_bits = 30;
254 else
255 zone_dma_bits = 31;
256
257#ifdef CONFIG_ZONE_DMA
258 max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
259 1UL << (zone_dma_bits - PAGE_SHIFT));
260#endif
261 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
262#ifdef CONFIG_HIGHMEM
263 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
264#endif
265
266 free_area_init(max_zone_pfn: max_zone_pfns);
267
268 mark_nonram_nosave();
269}
270
271void __init mem_init(void)
272{
273 /*
274 * book3s is limited to 16 page sizes due to encoding this in
275 * a 4-bit field for slices.
276 */
277 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
278
279#ifdef CONFIG_SWIOTLB
280 /*
281 * Some platforms (e.g. 85xx) limit DMA-able memory way below
282 * 4G. We force memblock to bottom-up mode to ensure that the
283 * memory allocated in swiotlb_init() is DMA-able.
284 * As it's the last memblock allocation, no need to reset it
285 * back to to-down.
286 */
287 memblock_set_bottom_up(enable: true);
288 swiotlb_init(addressing_limited: ppc_swiotlb_enable, flags: ppc_swiotlb_flags);
289#endif
290
291 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
292
293 kasan_late_init();
294
295 memblock_free_all();
296
297#ifdef CONFIG_HIGHMEM
298 {
299 unsigned long pfn, highmem_mapnr;
300
301 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
302 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
303 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
304 struct page *page = pfn_to_page(pfn);
305 if (memblock_is_memory(paddr) && !memblock_is_reserved(paddr))
306 free_highmem_page(page);
307 }
308 }
309#endif /* CONFIG_HIGHMEM */
310
311#if defined(CONFIG_PPC_E500) && !defined(CONFIG_SMP)
312 /*
313 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
314 * functions.... do it here for the non-smp case.
315 */
316 per_cpu(next_tlbcam_idx, smp_processor_id()) =
317 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
318#endif
319
320#ifdef CONFIG_PPC32
321 pr_info("Kernel virtual memory layout:\n");
322#ifdef CONFIG_KASAN
323 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
324 KASAN_SHADOW_START, KASAN_SHADOW_END);
325#endif
326 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
327#ifdef CONFIG_HIGHMEM
328 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
329 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
330#endif /* CONFIG_HIGHMEM */
331 if (ioremap_bot != IOREMAP_TOP)
332 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
333 ioremap_bot, IOREMAP_TOP);
334 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
335 VMALLOC_START, VMALLOC_END);
336#ifdef MODULES_VADDR
337 pr_info(" * 0x%08lx..0x%08lx : modules\n",
338 MODULES_VADDR, MODULES_END);
339#endif
340#endif /* CONFIG_PPC32 */
341}
342
343void free_initmem(void)
344{
345 ppc_md.progress = ppc_printk_progress;
346 mark_initmem_nx();
347 free_initmem_default(POISON_FREE_INITMEM);
348 ftrace_free_init_tramp();
349}
350
351/*
352 * System memory should not be in /proc/iomem but various tools expect it
353 * (eg kdump).
354 */
355static int __init add_system_ram_resources(void)
356{
357 phys_addr_t start, end;
358 u64 i;
359
360 for_each_mem_range(i, &start, &end) {
361 struct resource *res;
362
363 res = kzalloc(size: sizeof(struct resource), GFP_KERNEL);
364 WARN_ON(!res);
365
366 if (res) {
367 res->name = "System RAM";
368 res->start = start;
369 /*
370 * In memblock, end points to the first byte after
371 * the range while in resourses, end points to the
372 * last byte in the range.
373 */
374 res->end = end - 1;
375 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
376 WARN_ON(request_resource(&iomem_resource, res) < 0);
377 }
378 }
379
380 return 0;
381}
382subsys_initcall(add_system_ram_resources);
383
384#ifdef CONFIG_STRICT_DEVMEM
385/*
386 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
387 * is valid. The argument is a physical page number.
388 *
389 * Access has to be given to non-kernel-ram areas as well, these contain the
390 * PCI mmio resources as well as potential bios/acpi data regions.
391 */
392int devmem_is_allowed(unsigned long pfn)
393{
394 if (page_is_rtas_user_buf(pfn))
395 return 1;
396 if (iomem_is_exclusive(PFN_PHYS(pfn)))
397 return 0;
398 if (!page_is_ram(pfn))
399 return 1;
400 return 0;
401}
402#endif /* CONFIG_STRICT_DEVMEM */
403
404/*
405 * This is defined in kernel/resource.c but only powerpc needs to export it, for
406 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
407 */
408EXPORT_SYMBOL_GPL(walk_system_ram_range);
409

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