3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
6 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
7 * Copyright (C) 1996 Paul Mackerras
8 * PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
10 * Derived from "arch/i386/mm/init.c"
11 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
20 #include <linux/export.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/errno.h>
24 #include <linux/string.h>
25 #include <linux/gfp.h>
26 #include <linux/types.h>
28 #include <linux/stddef.h>
29 #include <linux/init.h>
30 #include <linux/bootmem.h>
31 #include <linux/highmem.h>
32 #include <linux/initrd.h>
33 #include <linux/pagemap.h>
34 #include <linux/suspend.h>
35 #include <linux/memblock.h>
36 #include <linux/hugetlb.h>
37 #include <linux/slab.h>
38 #include <linux/vmalloc.h>
40 #include <asm/pgalloc.h>
43 #include <asm/mmu_context.h>
44 #include <asm/pgtable.h>
47 #include <asm/machdep.h>
48 #include <asm/btext.h>
50 #include <asm/sections.h>
51 #include <asm/sparsemem.h>
53 #include <asm/fixmap.h>
54 #include <asm/swiotlb.h>
59 #ifndef CPU_FTR_COHERENT_ICACHE
60 #define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
61 #define CPU_FTR_NOEXECUTE 0
64 unsigned long long memory_limit;
68 EXPORT_SYMBOL(kmap_pte);
70 EXPORT_SYMBOL(kmap_prot);
71 #define TOP_ZONE ZONE_HIGHMEM
73 static inline pte_t *virt_to_kpte(unsigned long vaddr)
75 return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
76 vaddr), vaddr), vaddr);
79 #define TOP_ZONE ZONE_NORMAL
82 int page_is_ram(unsigned long pfn)
84 #ifndef CONFIG_PPC64 /* XXX for now */
87 unsigned long paddr = (pfn << PAGE_SHIFT);
88 struct memblock_region *reg;
90 for_each_memblock(memory, reg)
91 if (paddr >= reg->base && paddr < (reg->base + reg->size))
97 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
98 unsigned long size, pgprot_t vma_prot)
100 if (ppc_md.phys_mem_access_prot)
101 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
103 if (!page_is_ram(pfn))
104 vma_prot = pgprot_noncached(vma_prot);
108 EXPORT_SYMBOL(phys_mem_access_prot);
110 #ifdef CONFIG_MEMORY_HOTPLUG
113 int memory_add_physaddr_to_nid(u64 start)
115 return hot_add_scn_to_nid(start);
119 int __weak create_section_mapping(unsigned long start, unsigned long end)
124 int __weak remove_section_mapping(unsigned long start, unsigned long end)
129 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
131 struct pglist_data *pgdata;
133 unsigned long start_pfn = start >> PAGE_SHIFT;
134 unsigned long nr_pages = size >> PAGE_SHIFT;
137 resize_hpt_for_hotplug(memblock_phys_mem_size());
139 pgdata = NODE_DATA(nid);
141 start = (unsigned long)__va(start);
142 rc = create_section_mapping(start, start + size);
145 "Unable to create mapping for hot added memory 0x%llx..0x%llx: %d\n",
146 start, start + size, rc);
150 /* this should work for most non-highmem platforms */
151 zone = pgdata->node_zones +
152 zone_for_memory(nid, start, size, 0, for_device);
154 return __add_pages(nid, zone, start_pfn, nr_pages);
157 #ifdef CONFIG_MEMORY_HOTREMOVE
158 int arch_remove_memory(u64 start, u64 size)
160 unsigned long start_pfn = start >> PAGE_SHIFT;
161 unsigned long nr_pages = size >> PAGE_SHIFT;
165 zone = page_zone(pfn_to_page(start_pfn));
166 ret = __remove_pages(zone, start_pfn, nr_pages);
170 /* Remove htab bolted mappings for this section of memory */
171 start = (unsigned long)__va(start);
172 ret = remove_section_mapping(start, start + size);
174 /* Ensure all vmalloc mappings are flushed in case they also
175 * hit that section of memory
179 resize_hpt_for_hotplug(memblock_phys_mem_size());
184 #endif /* CONFIG_MEMORY_HOTPLUG */
187 * walk_memory_resource() needs to make sure there is no holes in a given
188 * memory range. PPC64 does not maintain the memory layout in /proc/iomem.
189 * Instead it maintains it in memblock.memory structures. Walk through the
190 * memory regions, find holes and callback for contiguous regions.
193 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
194 void *arg, int (*func)(unsigned long, unsigned long, void *))
196 struct memblock_region *reg;
197 unsigned long end_pfn = start_pfn + nr_pages;
198 unsigned long tstart, tend;
201 for_each_memblock(memory, reg) {
202 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
203 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
206 ret = (*func)(tstart, tend - tstart, arg);
212 EXPORT_SYMBOL_GPL(walk_system_ram_range);
214 #ifndef CONFIG_NEED_MULTIPLE_NODES
215 void __init initmem_init(void)
217 max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
218 min_low_pfn = MEMORY_START >> PAGE_SHIFT;
219 #ifdef CONFIG_HIGHMEM
220 max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
223 /* Place all memblock_regions in the same node and merge contiguous
226 memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
228 /* XXX need to clip this if using highmem? */
229 sparse_memory_present_with_active_regions(0);
233 /* mark pages that don't exist as nosave */
234 static int __init mark_nonram_nosave(void)
236 struct memblock_region *reg, *prev = NULL;
238 for_each_memblock(memory, reg) {
240 memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
241 register_nosave_region(memblock_region_memory_end_pfn(prev),
242 memblock_region_memory_base_pfn(reg));
247 #else /* CONFIG_NEED_MULTIPLE_NODES */
248 static int __init mark_nonram_nosave(void)
254 static bool zone_limits_final;
257 * The memory zones past TOP_ZONE are managed by generic mm code.
258 * These should be set to zero since that's what every other
261 static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
262 [0 ... TOP_ZONE ] = ~0UL,
263 [TOP_ZONE + 1 ... MAX_NR_ZONES - 1] = 0
267 * Restrict the specified zone and all more restrictive zones
268 * to be below the specified pfn. May not be called after
271 void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
275 if (WARN_ON(zone_limits_final))
278 for (i = zone; i >= 0; i--) {
279 if (max_zone_pfns[i] > pfn_limit)
280 max_zone_pfns[i] = pfn_limit;
285 * Find the least restrictive zone that is entirely below the
286 * specified pfn limit. Returns < 0 if no suitable zone is found.
288 * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
289 * systems -- the DMA limit can be higher than any possible real pfn.
291 int dma_pfn_limit_to_zone(u64 pfn_limit)
295 for (i = TOP_ZONE; i >= 0; i--) {
296 if (max_zone_pfns[i] <= pfn_limit)
304 * paging_init() sets up the page tables - in fact we've already done this.
306 void __init paging_init(void)
308 unsigned long long total_ram = memblock_phys_mem_size();
309 phys_addr_t top_of_ram = memblock_end_of_DRAM();
312 unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
313 unsigned long end = __fix_to_virt(FIX_HOLE);
315 for (; v < end; v += PAGE_SIZE)
316 map_page(v, 0, 0); /* XXX gross */
319 #ifdef CONFIG_HIGHMEM
320 map_page(PKMAP_BASE, 0, 0); /* XXX gross */
321 pkmap_page_table = virt_to_kpte(PKMAP_BASE);
323 kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
324 kmap_prot = PAGE_KERNEL;
325 #endif /* CONFIG_HIGHMEM */
327 printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
328 (unsigned long long)top_of_ram, total_ram);
329 printk(KERN_DEBUG "Memory hole size: %ldMB\n",
330 (long int)((top_of_ram - total_ram) >> 20));
332 #ifdef CONFIG_HIGHMEM
333 limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
335 limit_zone_pfn(TOP_ZONE, top_of_ram >> PAGE_SHIFT);
336 zone_limits_final = true;
337 free_area_init_nodes(max_zone_pfns);
339 mark_nonram_nosave();
342 void __init mem_init(void)
345 * book3s is limited to 16 page sizes due to encoding this in
346 * a 4-bit field for slices.
348 BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
350 #ifdef CONFIG_SWIOTLB
354 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
355 set_max_mapnr(max_pfn);
358 #ifdef CONFIG_HIGHMEM
360 unsigned long pfn, highmem_mapnr;
362 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
363 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
364 phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
365 struct page *page = pfn_to_page(pfn);
366 if (!memblock_is_reserved(paddr))
367 free_highmem_page(page);
370 #endif /* CONFIG_HIGHMEM */
372 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
374 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
375 * functions.... do it here for the non-smp case.
377 per_cpu(next_tlbcam_idx, smp_processor_id()) =
378 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
381 mem_init_print_info(NULL);
383 pr_info("Kernel virtual memory layout:\n");
384 pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
385 #ifdef CONFIG_HIGHMEM
386 pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
387 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
388 #endif /* CONFIG_HIGHMEM */
389 #ifdef CONFIG_NOT_COHERENT_CACHE
390 pr_info(" * 0x%08lx..0x%08lx : consistent mem\n",
391 IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
392 #endif /* CONFIG_NOT_COHERENT_CACHE */
393 pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
394 ioremap_bot, IOREMAP_TOP);
395 pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
396 VMALLOC_START, VMALLOC_END);
397 #endif /* CONFIG_PPC32 */
400 void free_initmem(void)
402 ppc_md.progress = ppc_printk_progress;
403 free_initmem_default(POISON_FREE_INITMEM);
406 #ifdef CONFIG_BLK_DEV_INITRD
407 void __init free_initrd_mem(unsigned long start, unsigned long end)
409 free_reserved_area((void *)start, (void *)end, -1, "initrd");
414 * This is called when a page has been modified by the kernel.
415 * It just marks the page as not i-cache clean. We do the i-cache
416 * flush later when the page is given to a user process, if necessary.
418 void flush_dcache_page(struct page *page)
420 if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
422 /* avoid an atomic op if possible */
423 if (test_bit(PG_arch_1, &page->flags))
424 clear_bit(PG_arch_1, &page->flags);
426 EXPORT_SYMBOL(flush_dcache_page);
428 void flush_dcache_icache_page(struct page *page)
430 #ifdef CONFIG_HUGETLB_PAGE
431 if (PageCompound(page)) {
432 flush_dcache_icache_hugepage(page);
436 #if defined(CONFIG_8xx) || defined(CONFIG_PPC64)
437 /* On 8xx there is no need to kmap since highmem is not supported */
438 __flush_dcache_icache(page_address(page));
440 if (IS_ENABLED(CONFIG_BOOKE) || sizeof(phys_addr_t) > sizeof(void *)) {
441 void *start = kmap_atomic(page);
442 __flush_dcache_icache(start);
443 kunmap_atomic(start);
445 __flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
449 EXPORT_SYMBOL(flush_dcache_icache_page);
451 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
456 * We shouldn't have to do this, but some versions of glibc
457 * require it (ld.so assumes zero filled pages are icache clean)
460 flush_dcache_page(pg);
462 EXPORT_SYMBOL(clear_user_page);
464 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
467 copy_page(vto, vfrom);
470 * We should be able to use the following optimisation, however
471 * there are two problems.
472 * Firstly a bug in some versions of binutils meant PLT sections
473 * were not marked executable.
474 * Secondly the first word in the GOT section is blrl, used
475 * to establish the GOT address. Until recently the GOT was
476 * not marked executable.
480 if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
484 flush_dcache_page(pg);
487 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
488 unsigned long addr, int len)
492 maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
493 flush_icache_range(maddr, maddr + len);
496 EXPORT_SYMBOL(flush_icache_user_range);
499 * This is called at the end of handling a user page fault, when the
500 * fault has been handled by updating a PTE in the linux page tables.
501 * We use it to preload an HPTE into the hash table corresponding to
502 * the updated linux PTE.
504 * This must always be called with the pte lock held.
506 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
509 #ifdef CONFIG_PPC_STD_MMU
511 * We don't need to worry about _PAGE_PRESENT here because we are
512 * called with either mm->page_table_lock held or ptl lock held
514 unsigned long access, trap;
519 /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
520 if (!pte_young(*ptep) || address >= TASK_SIZE)
523 /* We try to figure out if we are coming from an instruction
524 * access fault and pass that down to __hash_page so we avoid
525 * double-faulting on execution of fresh text. We have to test
526 * for regs NULL since init will get here first thing at boot
528 * We also avoid filling the hash if not coming from a fault
531 trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL;
543 hash_preload(vma->vm_mm, address, access, trap);
544 #endif /* CONFIG_PPC_STD_MMU */
545 #if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
546 && defined(CONFIG_HUGETLB_PAGE)
547 if (is_vm_hugetlb_page(vma))
548 book3e_hugetlb_preload(vma, address, *ptep);
553 * System memory should not be in /proc/iomem but various tools expect it
556 static int __init add_system_ram_resources(void)
558 struct memblock_region *reg;
560 for_each_memblock(memory, reg) {
561 struct resource *res;
562 unsigned long base = reg->base;
563 unsigned long size = reg->size;
565 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
569 res->name = "System RAM";
571 res->end = base + size - 1;
572 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
573 WARN_ON(request_resource(&iomem_resource, res) < 0);
579 subsys_initcall(add_system_ram_resources);
581 #ifdef CONFIG_STRICT_DEVMEM
583 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
584 * is valid. The argument is a physical page number.
586 * Access has to be given to non-kernel-ram areas as well, these contain the
587 * PCI mmio resources as well as potential bios/acpi data regions.
589 int devmem_is_allowed(unsigned long pfn)
591 if (page_is_rtas_user_buf(pfn))
593 if (iomem_is_exclusive(PFN_PHYS(pfn)))
595 if (!page_is_ram(pfn))
599 #endif /* CONFIG_STRICT_DEVMEM */