1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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)
11 * Derived from "arch/i386/mm/init.c"
12 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 #include <linux/export.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/gfp.h>
21 #include <linux/types.h>
23 #include <linux/stddef.h>
24 #include <linux/init.h>
25 #include <linux/memblock.h>
26 #include <linux/highmem.h>
27 #include <linux/initrd.h>
28 #include <linux/pagemap.h>
29 #include <linux/suspend.h>
30 #include <linux/hugetlb.h>
31 #include <linux/slab.h>
32 #include <linux/vmalloc.h>
33 #include <linux/memremap.h>
35 #include <asm/pgalloc.h>
38 #include <asm/mmu_context.h>
39 #include <asm/pgtable.h>
42 #include <asm/machdep.h>
43 #include <asm/btext.h>
45 #include <asm/sections.h>
46 #include <asm/sparsemem.h>
48 #include <asm/fixmap.h>
49 #include <asm/swiotlb.h>
52 #include <mm/mmu_decl.h>
54 #ifndef CPU_FTR_COHERENT_ICACHE
55 #define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
56 #define CPU_FTR_NOEXECUTE 0
59 unsigned long long memory_limit;
60 bool init_mem_is_free;
64 EXPORT_SYMBOL(kmap_pte);
66 EXPORT_SYMBOL(kmap_prot);
68 static inline pte_t *virt_to_kpte(unsigned long vaddr)
70 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
71 vaddr), vaddr), vaddr);
75 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
76 unsigned long size, pgprot_t vma_prot)
78 if (ppc_md.phys_mem_access_prot)
79 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
81 if (!page_is_ram(pfn))
82 vma_prot = pgprot_noncached(vma_prot);
86 EXPORT_SYMBOL(phys_mem_access_prot);
88 #ifdef CONFIG_MEMORY_HOTPLUG
91 int memory_add_physaddr_to_nid(u64 start)
93 return hot_add_scn_to_nid(start);
97 int __weak create_section_mapping(unsigned long start, unsigned long end, int nid)
102 int __weak remove_section_mapping(unsigned long start, unsigned long end)
107 int __ref arch_add_memory(int nid, u64 start, u64 size,
108 struct mhp_restrictions *restrictions)
110 unsigned long start_pfn = start >> PAGE_SHIFT;
111 unsigned long nr_pages = size >> PAGE_SHIFT;
114 resize_hpt_for_hotplug(memblock_phys_mem_size());
116 start = (unsigned long)__va(start);
117 rc = create_section_mapping(start, start + size, nid);
119 pr_warn("Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
120 start, start + size, rc);
123 flush_dcache_range(start, start + size);
125 return __add_pages(nid, start_pfn, nr_pages, restrictions);
128 void __ref arch_remove_memory(int nid, u64 start, u64 size,
129 struct vmem_altmap *altmap)
131 unsigned long start_pfn = start >> PAGE_SHIFT;
132 unsigned long nr_pages = size >> PAGE_SHIFT;
133 struct page *page = pfn_to_page(start_pfn) + vmem_altmap_offset(altmap);
136 __remove_pages(page_zone(page), start_pfn, nr_pages, altmap);
138 /* Remove htab bolted mappings for this section of memory */
139 start = (unsigned long)__va(start);
140 flush_dcache_range(start, start + size);
141 ret = remove_section_mapping(start, start + size);
144 /* Ensure all vmalloc mappings are flushed in case they also
145 * hit that section of memory
149 if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
150 pr_warn("Hash collision while resizing HPT\n");
154 #ifndef CONFIG_NEED_MULTIPLE_NODES
155 void __init mem_topology_setup(void)
157 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
158 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
159 #ifdef CONFIG_HIGHMEM
160 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
163 /* Place all memblock_regions in the same node and merge contiguous
166 memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
169 void __init initmem_init(void)
171 /* XXX need to clip this if using highmem? */
172 sparse_memory_present_with_active_regions(0);
176 /* mark pages that don't exist as nosave */
177 static int __init mark_nonram_nosave(void)
179 struct memblock_region *reg, *prev = NULL;
181 for_each_memblock(memory, reg) {
183 memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
184 register_nosave_region(memblock_region_memory_end_pfn(prev),
185 memblock_region_memory_base_pfn(reg));
190 #else /* CONFIG_NEED_MULTIPLE_NODES */
191 static int __init mark_nonram_nosave(void)
200 * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
201 * everything else. GFP_DMA32 page allocations automatically fall back to
204 * By using 31-bit unconditionally, we can exploit ARCH_ZONE_DMA_BITS to
205 * inform the generic DMA mapping code. 32-bit only devices (if not handled
206 * by an IOMMU anyway) will take a first dip into ZONE_NORMAL and get
207 * otherwise served by ZONE_DMA.
209 static unsigned long max_zone_pfns[MAX_NR_ZONES];
212 * paging_init() sets up the page tables - in fact we've already done this.
214 void __init paging_init(void)
216 unsigned long long total_ram = memblock_phys_mem_size();
217 phys_addr_t top_of_ram = memblock_end_of_DRAM();
220 unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
221 unsigned long end = __fix_to_virt(FIX_HOLE);
223 for (; v < end; v += PAGE_SIZE)
224 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
227 #ifdef CONFIG_HIGHMEM
228 map_kernel_page(PKMAP_BASE, 0, __pgprot(0)); /* XXX gross */
229 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
231 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
232 kmap_prot = PAGE_KERNEL;
233 #endif /* CONFIG_HIGHMEM */
235 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
236 (unsigned long long)top_of_ram, total_ram);
237 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
238 (long int)((top_of_ram - total_ram) >> 20));
240 #ifdef CONFIG_ZONE_DMA
241 max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
242 1UL << (ARCH_ZONE_DMA_BITS - PAGE_SHIFT));
244 max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
245 #ifdef CONFIG_HIGHMEM
246 max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
249 free_area_init_nodes(max_zone_pfns);
251 mark_nonram_nosave();
254 void __init mem_init(void)
257 * book3s is limited to 16 page sizes due to encoding this in
258 * a 4-bit field for slices.
260 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
262 #ifdef CONFIG_SWIOTLB
266 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
267 set_max_mapnr(max_pfn);
270 #ifdef CONFIG_HIGHMEM
272 unsigned long pfn, highmem_mapnr;
274 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
275 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
276 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
277 struct page *page = pfn_to_page(pfn);
278 if (!memblock_is_reserved(paddr))
279 free_highmem_page(page);
282 #endif /* CONFIG_HIGHMEM */
284 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
286 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
287 * functions.... do it here for the non-smp case.
289 per_cpu(next_tlbcam_idx, smp_processor_id()) =
290 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
293 mem_init_print_info(NULL);
295 pr_info("Kernel virtual memory layout:\n");
297 pr_info(" * 0x%08lx..0x%08lx : kasan shadow mem\n",
298 KASAN_SHADOW_START, KASAN_SHADOW_END);
300 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
301 #ifdef CONFIG_HIGHMEM
302 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
303 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
304 #endif /* CONFIG_HIGHMEM */
305 #ifdef CONFIG_NOT_COHERENT_CACHE
306 pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
307 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
308 #endif /* CONFIG_NOT_COHERENT_CACHE */
309 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
310 ioremap_bot, IOREMAP_TOP);
311 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
312 VMALLOC_START, VMALLOC_END);
313 #endif /* CONFIG_PPC32 */
316 void free_initmem(void)
318 ppc_md.progress = ppc_printk_progress;
320 init_mem_is_free = true;
321 free_initmem_default(POISON_FREE_INITMEM);
325 * This is called when a page has been modified by the kernel.
326 * It just marks the page as not i-cache clean. We do the i-cache
327 * flush later when the page is given to a user process, if necessary.
329 void flush_dcache_page(struct page *page)
331 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
333 /* avoid an atomic op if possible */
334 if (test_bit(PG_arch_1, &page->flags))
335 clear_bit(PG_arch_1, &page->flags);
337 EXPORT_SYMBOL(flush_dcache_page);
339 void flush_dcache_icache_page(struct page *page)
341 #ifdef CONFIG_HUGETLB_PAGE
342 if (PageCompound(page)) {
343 flush_dcache_icache_hugepage(page);
347 #if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC64)
348 /* On 8xx there is no need to kmap since highmem is not supported */
349 __flush_dcache_icache(page_address(page));
351 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
352 void *start = kmap_atomic(page);
353 __flush_dcache_icache(start);
354 kunmap_atomic(start);
356 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
360 EXPORT_SYMBOL(flush_dcache_icache_page);
362 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
367 * We shouldn't have to do this, but some versions of glibc
368 * require it (ld.so assumes zero filled pages are icache clean)
371 flush_dcache_page(pg);
373 EXPORT_SYMBOL(clear_user_page);
375 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
378 copy_page(vto, vfrom);
381 * We should be able to use the following optimisation, however
382 * there are two problems.
383 * Firstly a bug in some versions of binutils meant PLT sections
384 * were not marked executable.
385 * Secondly the first word in the GOT section is blrl, used
386 * to establish the GOT address. Until recently the GOT was
387 * not marked executable.
391 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
395 flush_dcache_page(pg);
398 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
399 unsigned long addr, int len)
403 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
404 flush_icache_range(maddr, maddr + len);
407 EXPORT_SYMBOL(flush_icache_user_range);
410 * This is called at the end of handling a user page fault, when the
411 * fault has been handled by updating a PTE in the linux page tables.
412 * We use it to preload an HPTE into the hash table corresponding to
413 * the updated linux PTE.
415 * This must always be called with the pte lock held.
417 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
420 #ifdef CONFIG_PPC_BOOK3S
422 * We don't need to worry about _PAGE_PRESENT here because we are
423 * called with either mm->page_table_lock held or ptl lock held
428 if (radix_enabled()) {
429 prefetch((void *)address);
433 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
434 if (!pte_young(*ptep) || address >= TASK_SIZE)
437 /* We try to figure out if we are coming from an instruction
438 * access fault and pass that down to __hash_page so we avoid
439 * double-faulting on execution of fresh text. We have to test
440 * for regs NULL since init will get here first thing at boot
442 * We also avoid filling the hash if not coming from a fault
445 trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
457 hash_preload(vma->vm_mm, address, is_exec, trap);
458 #endif /* CONFIG_PPC_BOOK3S */
459 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
460 && defined(CONFIG_HUGETLB_PAGE)
461 if (is_vm_hugetlb_page(vma))
462 book3e_hugetlb_preload(vma, address, *ptep);
467 * System memory should not be in /proc/iomem but various tools expect it
470 static int __init add_system_ram_resources(void)
472 struct memblock_region *reg;
474 for_each_memblock(memory, reg) {
475 struct resource *res;
476 unsigned long base = reg->base;
477 unsigned long size = reg->size;
479 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
483 res->name = "System RAM";
485 res->end = base + size - 1;
486 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
487 WARN_ON(request_resource(&iomem_resource, res) < 0);
493 subsys_initcall(add_system_ram_resources);
495 #ifdef CONFIG_STRICT_DEVMEM
497 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
498 * is valid. The argument is a physical page number.
500 * Access has to be given to non-kernel-ram areas as well, these contain the
501 * PCI mmio resources as well as potential bios/acpi data regions.
503 int devmem_is_allowed(unsigned long pfn)
505 if (page_is_rtas_user_buf(pfn))
507 if (iomem_is_exclusive(PFN_PHYS(pfn)))
509 if (!page_is_ram(pfn))
513 #endif /* CONFIG_STRICT_DEVMEM */
516 * This is defined in kernel/resource.c but only powerpc needs to export it, for
517 * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
519 EXPORT_SYMBOL_GPL(walk_system_ram_range);