1/*
2 *  PowerPC version
3 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
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)
9 *
10 *  Derived from "arch/i386/mm/init.c"
11 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
12 *
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.
17 *
18 */
19
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>
27#include <linux/mm.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>
39
40#include <asm/pgalloc.h>
41#include <asm/prom.h>
42#include <asm/io.h>
43#include <asm/mmu_context.h>
44#include <asm/pgtable.h>
45#include <asm/mmu.h>
46#include <asm/smp.h>
47#include <asm/machdep.h>
48#include <asm/btext.h>
49#include <asm/tlb.h>
50#include <asm/sections.h>
51#include <asm/sparsemem.h>
52#include <asm/vdso.h>
53#include <asm/fixmap.h>
54#include <asm/swiotlb.h>
55#include <asm/rtas.h>
56
57#include "mmu_decl.h"
58
59#ifndef CPU_FTR_COHERENT_ICACHE
60#define CPU_FTR_COHERENT_ICACHE	0	/* XXX for now */
61#define CPU_FTR_NOEXECUTE	0
62#endif
63
64unsigned long long memory_limit;
65
66#ifdef CONFIG_HIGHMEM
67pte_t *kmap_pte;
68EXPORT_SYMBOL(kmap_pte);
69pgprot_t kmap_prot;
70EXPORT_SYMBOL(kmap_prot);
71
72static inline pte_t *virt_to_kpte(unsigned long vaddr)
73{
74	return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
75			vaddr), vaddr), vaddr);
76}
77#endif
78
79int page_is_ram(unsigned long pfn)
80{
81#ifndef CONFIG_PPC64	/* XXX for now */
82	return pfn < max_pfn;
83#else
84	unsigned long paddr = (pfn << PAGE_SHIFT);
85	struct memblock_region *reg;
86
87	for_each_memblock(memory, reg)
88		if (paddr >= reg->base && paddr < (reg->base + reg->size))
89			return 1;
90	return 0;
91#endif
92}
93
94pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
95			      unsigned long size, pgprot_t vma_prot)
96{
97	if (ppc_md.phys_mem_access_prot)
98		return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
99
100	if (!page_is_ram(pfn))
101		vma_prot = pgprot_noncached(vma_prot);
102
103	return vma_prot;
104}
105EXPORT_SYMBOL(phys_mem_access_prot);
106
107#ifdef CONFIG_MEMORY_HOTPLUG
108
109#ifdef CONFIG_NUMA
110int memory_add_physaddr_to_nid(u64 start)
111{
112	return hot_add_scn_to_nid(start);
113}
114#endif
115
116int arch_add_memory(int nid, u64 start, u64 size)
117{
118	struct pglist_data *pgdata;
119	struct zone *zone;
120	unsigned long start_pfn = start >> PAGE_SHIFT;
121	unsigned long nr_pages = size >> PAGE_SHIFT;
122
123	pgdata = NODE_DATA(nid);
124
125	start = (unsigned long)__va(start);
126	if (create_section_mapping(start, start + size))
127		return -EINVAL;
128
129	/* this should work for most non-highmem platforms */
130	zone = pgdata->node_zones +
131		zone_for_memory(nid, start, size, 0);
132
133	return __add_pages(nid, zone, start_pfn, nr_pages);
134}
135
136#ifdef CONFIG_MEMORY_HOTREMOVE
137int arch_remove_memory(u64 start, u64 size)
138{
139	unsigned long start_pfn = start >> PAGE_SHIFT;
140	unsigned long nr_pages = size >> PAGE_SHIFT;
141	struct zone *zone;
142	int ret;
143
144	zone = page_zone(pfn_to_page(start_pfn));
145	ret = __remove_pages(zone, start_pfn, nr_pages);
146	if (ret)
147		return ret;
148
149	/* Remove htab bolted mappings for this section of memory */
150	start = (unsigned long)__va(start);
151	ret = remove_section_mapping(start, start + size);
152
153	/* Ensure all vmalloc mappings are flushed in case they also
154	 * hit that section of memory
155	 */
156	vm_unmap_aliases();
157
158	return ret;
159}
160#endif
161#endif /* CONFIG_MEMORY_HOTPLUG */
162
163/*
164 * walk_memory_resource() needs to make sure there is no holes in a given
165 * memory range.  PPC64 does not maintain the memory layout in /proc/iomem.
166 * Instead it maintains it in memblock.memory structures.  Walk through the
167 * memory regions, find holes and callback for contiguous regions.
168 */
169int
170walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
171		void *arg, int (*func)(unsigned long, unsigned long, void *))
172{
173	struct memblock_region *reg;
174	unsigned long end_pfn = start_pfn + nr_pages;
175	unsigned long tstart, tend;
176	int ret = -1;
177
178	for_each_memblock(memory, reg) {
179		tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
180		tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
181		if (tstart >= tend)
182			continue;
183		ret = (*func)(tstart, tend - tstart, arg);
184		if (ret)
185			break;
186	}
187	return ret;
188}
189EXPORT_SYMBOL_GPL(walk_system_ram_range);
190
191#ifndef CONFIG_NEED_MULTIPLE_NODES
192void __init initmem_init(void)
193{
194	max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
195	min_low_pfn = MEMORY_START >> PAGE_SHIFT;
196#ifdef CONFIG_HIGHMEM
197	max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
198#endif
199
200	/* Place all memblock_regions in the same node and merge contiguous
201	 * memblock_regions
202	 */
203	memblock_set_node(0, (phys_addr_t)ULLONG_MAX, &memblock.memory, 0);
204
205	/* XXX need to clip this if using highmem? */
206	sparse_memory_present_with_active_regions(0);
207	sparse_init();
208}
209
210/* mark pages that don't exist as nosave */
211static int __init mark_nonram_nosave(void)
212{
213	struct memblock_region *reg, *prev = NULL;
214
215	for_each_memblock(memory, reg) {
216		if (prev &&
217		    memblock_region_memory_end_pfn(prev) < memblock_region_memory_base_pfn(reg))
218			register_nosave_region(memblock_region_memory_end_pfn(prev),
219					       memblock_region_memory_base_pfn(reg));
220		prev = reg;
221	}
222	return 0;
223}
224#else /* CONFIG_NEED_MULTIPLE_NODES */
225static int __init mark_nonram_nosave(void)
226{
227	return 0;
228}
229#endif
230
231static bool zone_limits_final;
232
233static unsigned long max_zone_pfns[MAX_NR_ZONES] = {
234	[0 ... MAX_NR_ZONES - 1] = ~0UL
235};
236
237/*
238 * Restrict the specified zone and all more restrictive zones
239 * to be below the specified pfn.  May not be called after
240 * paging_init().
241 */
242void __init limit_zone_pfn(enum zone_type zone, unsigned long pfn_limit)
243{
244	int i;
245
246	if (WARN_ON(zone_limits_final))
247		return;
248
249	for (i = zone; i >= 0; i--) {
250		if (max_zone_pfns[i] > pfn_limit)
251			max_zone_pfns[i] = pfn_limit;
252	}
253}
254
255/*
256 * Find the least restrictive zone that is entirely below the
257 * specified pfn limit.  Returns < 0 if no suitable zone is found.
258 *
259 * pfn_limit must be u64 because it can exceed 32 bits even on 32-bit
260 * systems -- the DMA limit can be higher than any possible real pfn.
261 */
262int dma_pfn_limit_to_zone(u64 pfn_limit)
263{
264	enum zone_type top_zone = ZONE_NORMAL;
265	int i;
266
267#ifdef CONFIG_HIGHMEM
268	top_zone = ZONE_HIGHMEM;
269#endif
270
271	for (i = top_zone; i >= 0; i--) {
272		if (max_zone_pfns[i] <= pfn_limit)
273			return i;
274	}
275
276	return -EPERM;
277}
278
279/*
280 * paging_init() sets up the page tables - in fact we've already done this.
281 */
282void __init paging_init(void)
283{
284	unsigned long long total_ram = memblock_phys_mem_size();
285	phys_addr_t top_of_ram = memblock_end_of_DRAM();
286	enum zone_type top_zone;
287
288#ifdef CONFIG_PPC32
289	unsigned long v = __fix_to_virt(__end_of_fixed_addresses - 1);
290	unsigned long end = __fix_to_virt(FIX_HOLE);
291
292	for (; v < end; v += PAGE_SIZE)
293		map_page(v, 0, 0); /* XXX gross */
294#endif
295
296#ifdef CONFIG_HIGHMEM
297	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
298	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
299
300	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
301	kmap_prot = PAGE_KERNEL;
302#endif /* CONFIG_HIGHMEM */
303
304	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
305	       (unsigned long long)top_of_ram, total_ram);
306	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
307	       (long int)((top_of_ram - total_ram) >> 20));
308
309#ifdef CONFIG_HIGHMEM
310	top_zone = ZONE_HIGHMEM;
311	limit_zone_pfn(ZONE_NORMAL, lowmem_end_addr >> PAGE_SHIFT);
312#else
313	top_zone = ZONE_NORMAL;
314#endif
315
316	limit_zone_pfn(top_zone, top_of_ram >> PAGE_SHIFT);
317	zone_limits_final = true;
318	free_area_init_nodes(max_zone_pfns);
319
320	mark_nonram_nosave();
321}
322
323void __init mem_init(void)
324{
325	/*
326	 * book3s is limited to 16 page sizes due to encoding this in
327	 * a 4-bit field for slices.
328	 */
329	BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
330
331#ifdef CONFIG_SWIOTLB
332	swiotlb_init(0);
333#endif
334
335	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
336	set_max_mapnr(max_pfn);
337	free_all_bootmem();
338
339#ifdef CONFIG_HIGHMEM
340	{
341		unsigned long pfn, highmem_mapnr;
342
343		highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
344		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
345			phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
346			struct page *page = pfn_to_page(pfn);
347			if (!memblock_is_reserved(paddr))
348				free_highmem_page(page);
349		}
350	}
351#endif /* CONFIG_HIGHMEM */
352
353#if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
354	/*
355	 * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
356	 * functions.... do it here for the non-smp case.
357	 */
358	per_cpu(next_tlbcam_idx, smp_processor_id()) =
359		(mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
360#endif
361
362	mem_init_print_info(NULL);
363#ifdef CONFIG_PPC32
364	pr_info("Kernel virtual memory layout:\n");
365	pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
366#ifdef CONFIG_HIGHMEM
367	pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
368		PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
369#endif /* CONFIG_HIGHMEM */
370#ifdef CONFIG_NOT_COHERENT_CACHE
371	pr_info("  * 0x%08lx..0x%08lx  : consistent mem\n",
372		IOREMAP_TOP, IOREMAP_TOP + CONFIG_CONSISTENT_SIZE);
373#endif /* CONFIG_NOT_COHERENT_CACHE */
374	pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
375		ioremap_bot, IOREMAP_TOP);
376	pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
377		VMALLOC_START, VMALLOC_END);
378#endif /* CONFIG_PPC32 */
379}
380
381void free_initmem(void)
382{
383	ppc_md.progress = ppc_printk_progress;
384	free_initmem_default(POISON_FREE_INITMEM);
385}
386
387#ifdef CONFIG_BLK_DEV_INITRD
388void __init free_initrd_mem(unsigned long start, unsigned long end)
389{
390	free_reserved_area((void *)start, (void *)end, -1, "initrd");
391}
392#endif
393
394/*
395 * This is called when a page has been modified by the kernel.
396 * It just marks the page as not i-cache clean.  We do the i-cache
397 * flush later when the page is given to a user process, if necessary.
398 */
399void flush_dcache_page(struct page *page)
400{
401	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
402		return;
403	/* avoid an atomic op if possible */
404	if (test_bit(PG_arch_1, &page->flags))
405		clear_bit(PG_arch_1, &page->flags);
406}
407EXPORT_SYMBOL(flush_dcache_page);
408
409void flush_dcache_icache_page(struct page *page)
410{
411#ifdef CONFIG_HUGETLB_PAGE
412	if (PageCompound(page)) {
413		flush_dcache_icache_hugepage(page);
414		return;
415	}
416#endif
417#ifdef CONFIG_BOOKE
418	{
419		void *start = kmap_atomic(page);
420		__flush_dcache_icache(start);
421		kunmap_atomic(start);
422	}
423#elif defined(CONFIG_8xx) || defined(CONFIG_PPC64)
424	/* On 8xx there is no need to kmap since highmem is not supported */
425	__flush_dcache_icache(page_address(page));
426#else
427	__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
428#endif
429}
430EXPORT_SYMBOL(flush_dcache_icache_page);
431
432void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
433{
434	clear_page(page);
435
436	/*
437	 * We shouldn't have to do this, but some versions of glibc
438	 * require it (ld.so assumes zero filled pages are icache clean)
439	 * - Anton
440	 */
441	flush_dcache_page(pg);
442}
443EXPORT_SYMBOL(clear_user_page);
444
445void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
446		    struct page *pg)
447{
448	copy_page(vto, vfrom);
449
450	/*
451	 * We should be able to use the following optimisation, however
452	 * there are two problems.
453	 * Firstly a bug in some versions of binutils meant PLT sections
454	 * were not marked executable.
455	 * Secondly the first word in the GOT section is blrl, used
456	 * to establish the GOT address. Until recently the GOT was
457	 * not marked executable.
458	 * - Anton
459	 */
460#if 0
461	if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
462		return;
463#endif
464
465	flush_dcache_page(pg);
466}
467
468void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
469			     unsigned long addr, int len)
470{
471	unsigned long maddr;
472
473	maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
474	flush_icache_range(maddr, maddr + len);
475	kunmap(page);
476}
477EXPORT_SYMBOL(flush_icache_user_range);
478
479/*
480 * This is called at the end of handling a user page fault, when the
481 * fault has been handled by updating a PTE in the linux page tables.
482 * We use it to preload an HPTE into the hash table corresponding to
483 * the updated linux PTE.
484 *
485 * This must always be called with the pte lock held.
486 */
487void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
488		      pte_t *ptep)
489{
490#ifdef CONFIG_PPC_STD_MMU
491	/*
492	 * We don't need to worry about _PAGE_PRESENT here because we are
493	 * called with either mm->page_table_lock held or ptl lock held
494	 */
495	unsigned long access = 0, trap;
496
497	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
498	if (!pte_young(*ptep) || address >= TASK_SIZE)
499		return;
500
501	/* We try to figure out if we are coming from an instruction
502	 * access fault and pass that down to __hash_page so we avoid
503	 * double-faulting on execution of fresh text. We have to test
504	 * for regs NULL since init will get here first thing at boot
505	 *
506	 * We also avoid filling the hash if not coming from a fault
507	 */
508	if (current->thread.regs == NULL)
509		return;
510	trap = TRAP(current->thread.regs);
511	if (trap == 0x400)
512		access |= _PAGE_EXEC;
513	else if (trap != 0x300)
514		return;
515	hash_preload(vma->vm_mm, address, access, trap);
516#endif /* CONFIG_PPC_STD_MMU */
517#if (defined(CONFIG_PPC_BOOK3E_64) || defined(CONFIG_PPC_FSL_BOOK3E)) \
518	&& defined(CONFIG_HUGETLB_PAGE)
519	if (is_vm_hugetlb_page(vma))
520		book3e_hugetlb_preload(vma, address, *ptep);
521#endif
522}
523
524/*
525 * System memory should not be in /proc/iomem but various tools expect it
526 * (eg kdump).
527 */
528static int __init add_system_ram_resources(void)
529{
530	struct memblock_region *reg;
531
532	for_each_memblock(memory, reg) {
533		struct resource *res;
534		unsigned long base = reg->base;
535		unsigned long size = reg->size;
536
537		res = kzalloc(sizeof(struct resource), GFP_KERNEL);
538		WARN_ON(!res);
539
540		if (res) {
541			res->name = "System RAM";
542			res->start = base;
543			res->end = base + size - 1;
544			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
545			WARN_ON(request_resource(&iomem_resource, res) < 0);
546		}
547	}
548
549	return 0;
550}
551subsys_initcall(add_system_ram_resources);
552
553#ifdef CONFIG_STRICT_DEVMEM
554/*
555 * devmem_is_allowed(): check to see if /dev/mem access to a certain address
556 * is valid. The argument is a physical page number.
557 *
558 * Access has to be given to non-kernel-ram areas as well, these contain the
559 * PCI mmio resources as well as potential bios/acpi data regions.
560 */
561int devmem_is_allowed(unsigned long pfn)
562{
563	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
564		return 0;
565	if (!page_is_ram(pfn))
566		return 1;
567	if (page_is_rtas_user_buf(pfn))
568		return 1;
569	return 0;
570}
571#endif /* CONFIG_STRICT_DEVMEM */
572