xref: /openbmc/linux/arch/powerpc/mm/pgtable_64.c (revision a9a08845)
1 /*
2  *  This file contains ioremap and related functions for 64-bit machines.
3  *
4  *  Derived from arch/ppc64/mm/init.c
5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6  *
7  *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
8  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
9  *    Copyright (C) 1996 Paul Mackerras
10  *
11  *  Derived from "arch/i386/mm/init.c"
12  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
13  *
14  *  Dave Engebretsen <engebret@us.ibm.com>
15  *      Rework for PPC64 port.
16  *
17  *  This program is free software; you can redistribute it and/or
18  *  modify it under the terms of the GNU General Public License
19  *  as published by the Free Software Foundation; either version
20  *  2 of the License, or (at your option) any later version.
21  *
22  */
23 
24 #include <linux/signal.h>
25 #include <linux/sched.h>
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/string.h>
29 #include <linux/export.h>
30 #include <linux/types.h>
31 #include <linux/mman.h>
32 #include <linux/mm.h>
33 #include <linux/swap.h>
34 #include <linux/stddef.h>
35 #include <linux/vmalloc.h>
36 #include <linux/memblock.h>
37 #include <linux/slab.h>
38 #include <linux/hugetlb.h>
39 
40 #include <asm/pgalloc.h>
41 #include <asm/page.h>
42 #include <asm/prom.h>
43 #include <asm/io.h>
44 #include <asm/mmu_context.h>
45 #include <asm/pgtable.h>
46 #include <asm/mmu.h>
47 #include <asm/smp.h>
48 #include <asm/machdep.h>
49 #include <asm/tlb.h>
50 #include <asm/trace.h>
51 #include <asm/processor.h>
52 #include <asm/cputable.h>
53 #include <asm/sections.h>
54 #include <asm/firmware.h>
55 #include <asm/dma.h>
56 #include <asm/powernv.h>
57 
58 #include "mmu_decl.h"
59 
60 #ifdef CONFIG_PPC_BOOK3S_64
61 #if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
62 #error TASK_SIZE_USER64 exceeds user VSID range
63 #endif
64 #endif
65 
66 #ifdef CONFIG_PPC_BOOK3S_64
67 /*
68  * partition table and process table for ISA 3.0
69  */
70 struct prtb_entry *process_tb;
71 struct patb_entry *partition_tb;
72 /*
73  * page table size
74  */
75 unsigned long __pte_index_size;
76 EXPORT_SYMBOL(__pte_index_size);
77 unsigned long __pmd_index_size;
78 EXPORT_SYMBOL(__pmd_index_size);
79 unsigned long __pud_index_size;
80 EXPORT_SYMBOL(__pud_index_size);
81 unsigned long __pgd_index_size;
82 EXPORT_SYMBOL(__pgd_index_size);
83 unsigned long __pmd_cache_index;
84 EXPORT_SYMBOL(__pmd_cache_index);
85 unsigned long __pte_table_size;
86 EXPORT_SYMBOL(__pte_table_size);
87 unsigned long __pmd_table_size;
88 EXPORT_SYMBOL(__pmd_table_size);
89 unsigned long __pud_table_size;
90 EXPORT_SYMBOL(__pud_table_size);
91 unsigned long __pgd_table_size;
92 EXPORT_SYMBOL(__pgd_table_size);
93 unsigned long __pmd_val_bits;
94 EXPORT_SYMBOL(__pmd_val_bits);
95 unsigned long __pud_val_bits;
96 EXPORT_SYMBOL(__pud_val_bits);
97 unsigned long __pgd_val_bits;
98 EXPORT_SYMBOL(__pgd_val_bits);
99 unsigned long __kernel_virt_start;
100 EXPORT_SYMBOL(__kernel_virt_start);
101 unsigned long __kernel_virt_size;
102 EXPORT_SYMBOL(__kernel_virt_size);
103 unsigned long __vmalloc_start;
104 EXPORT_SYMBOL(__vmalloc_start);
105 unsigned long __vmalloc_end;
106 EXPORT_SYMBOL(__vmalloc_end);
107 unsigned long __kernel_io_start;
108 EXPORT_SYMBOL(__kernel_io_start);
109 struct page *vmemmap;
110 EXPORT_SYMBOL(vmemmap);
111 unsigned long __pte_frag_nr;
112 EXPORT_SYMBOL(__pte_frag_nr);
113 unsigned long __pte_frag_size_shift;
114 EXPORT_SYMBOL(__pte_frag_size_shift);
115 unsigned long ioremap_bot;
116 #else /* !CONFIG_PPC_BOOK3S_64 */
117 unsigned long ioremap_bot = IOREMAP_BASE;
118 #endif
119 
120 /**
121  * __ioremap_at - Low level function to establish the page tables
122  *                for an IO mapping
123  */
124 void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
125 			    unsigned long flags)
126 {
127 	unsigned long i;
128 
129 	/* Make sure we have the base flags */
130 	if ((flags & _PAGE_PRESENT) == 0)
131 		flags |= pgprot_val(PAGE_KERNEL);
132 
133 	/* We don't support the 4K PFN hack with ioremap */
134 	if (flags & H_PAGE_4K_PFN)
135 		return NULL;
136 
137 	WARN_ON(pa & ~PAGE_MASK);
138 	WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
139 	WARN_ON(size & ~PAGE_MASK);
140 
141 	for (i = 0; i < size; i += PAGE_SIZE)
142 		if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
143 			return NULL;
144 
145 	return (void __iomem *)ea;
146 }
147 
148 /**
149  * __iounmap_from - Low level function to tear down the page tables
150  *                  for an IO mapping. This is used for mappings that
151  *                  are manipulated manually, like partial unmapping of
152  *                  PCI IOs or ISA space.
153  */
154 void __iounmap_at(void *ea, unsigned long size)
155 {
156 	WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
157 	WARN_ON(size & ~PAGE_MASK);
158 
159 	unmap_kernel_range((unsigned long)ea, size);
160 }
161 
162 void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
163 				unsigned long flags, void *caller)
164 {
165 	phys_addr_t paligned;
166 	void __iomem *ret;
167 
168 	/*
169 	 * Choose an address to map it to.
170 	 * Once the imalloc system is running, we use it.
171 	 * Before that, we map using addresses going
172 	 * up from ioremap_bot.  imalloc will use
173 	 * the addresses from ioremap_bot through
174 	 * IMALLOC_END
175 	 *
176 	 */
177 	paligned = addr & PAGE_MASK;
178 	size = PAGE_ALIGN(addr + size) - paligned;
179 
180 	if ((size == 0) || (paligned == 0))
181 		return NULL;
182 
183 	if (slab_is_available()) {
184 		struct vm_struct *area;
185 
186 		area = __get_vm_area_caller(size, VM_IOREMAP,
187 					    ioremap_bot, IOREMAP_END,
188 					    caller);
189 		if (area == NULL)
190 			return NULL;
191 
192 		area->phys_addr = paligned;
193 		ret = __ioremap_at(paligned, area->addr, size, flags);
194 		if (!ret)
195 			vunmap(area->addr);
196 	} else {
197 		ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
198 		if (ret)
199 			ioremap_bot += size;
200 	}
201 
202 	if (ret)
203 		ret += addr & ~PAGE_MASK;
204 	return ret;
205 }
206 
207 void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
208 			 unsigned long flags)
209 {
210 	return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
211 }
212 
213 void __iomem * ioremap(phys_addr_t addr, unsigned long size)
214 {
215 	unsigned long flags = pgprot_val(pgprot_noncached(__pgprot(0)));
216 	void *caller = __builtin_return_address(0);
217 
218 	if (ppc_md.ioremap)
219 		return ppc_md.ioremap(addr, size, flags, caller);
220 	return __ioremap_caller(addr, size, flags, caller);
221 }
222 
223 void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
224 {
225 	unsigned long flags = pgprot_val(pgprot_noncached_wc(__pgprot(0)));
226 	void *caller = __builtin_return_address(0);
227 
228 	if (ppc_md.ioremap)
229 		return ppc_md.ioremap(addr, size, flags, caller);
230 	return __ioremap_caller(addr, size, flags, caller);
231 }
232 
233 void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
234 			     unsigned long flags)
235 {
236 	void *caller = __builtin_return_address(0);
237 
238 	/* writeable implies dirty for kernel addresses */
239 	if (flags & _PAGE_WRITE)
240 		flags |= _PAGE_DIRTY;
241 
242 	/* we don't want to let _PAGE_EXEC leak out */
243 	flags &= ~_PAGE_EXEC;
244 	/*
245 	 * Force kernel mapping.
246 	 */
247 	flags &= ~_PAGE_USER;
248 	flags |= _PAGE_PRIVILEGED;
249 
250 	if (ppc_md.ioremap)
251 		return ppc_md.ioremap(addr, size, flags, caller);
252 	return __ioremap_caller(addr, size, flags, caller);
253 }
254 
255 
256 /*
257  * Unmap an IO region and remove it from imalloc'd list.
258  * Access to IO memory should be serialized by driver.
259  */
260 void __iounmap(volatile void __iomem *token)
261 {
262 	void *addr;
263 
264 	if (!slab_is_available())
265 		return;
266 
267 	addr = (void *) ((unsigned long __force)
268 			 PCI_FIX_ADDR(token) & PAGE_MASK);
269 	if ((unsigned long)addr < ioremap_bot) {
270 		printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
271 		       " at 0x%p\n", addr);
272 		return;
273 	}
274 	vunmap(addr);
275 }
276 
277 void iounmap(volatile void __iomem *token)
278 {
279 	if (ppc_md.iounmap)
280 		ppc_md.iounmap(token);
281 	else
282 		__iounmap(token);
283 }
284 
285 EXPORT_SYMBOL(ioremap);
286 EXPORT_SYMBOL(ioremap_wc);
287 EXPORT_SYMBOL(ioremap_prot);
288 EXPORT_SYMBOL(__ioremap);
289 EXPORT_SYMBOL(__ioremap_at);
290 EXPORT_SYMBOL(iounmap);
291 EXPORT_SYMBOL(__iounmap);
292 EXPORT_SYMBOL(__iounmap_at);
293 
294 #ifndef __PAGETABLE_PUD_FOLDED
295 /* 4 level page table */
296 struct page *pgd_page(pgd_t pgd)
297 {
298 	if (pgd_huge(pgd))
299 		return pte_page(pgd_pte(pgd));
300 	return virt_to_page(pgd_page_vaddr(pgd));
301 }
302 #endif
303 
304 struct page *pud_page(pud_t pud)
305 {
306 	if (pud_huge(pud))
307 		return pte_page(pud_pte(pud));
308 	return virt_to_page(pud_page_vaddr(pud));
309 }
310 
311 /*
312  * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
313  * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
314  */
315 struct page *pmd_page(pmd_t pmd)
316 {
317 	if (pmd_trans_huge(pmd) || pmd_huge(pmd) || pmd_devmap(pmd))
318 		return pte_page(pmd_pte(pmd));
319 	return virt_to_page(pmd_page_vaddr(pmd));
320 }
321 
322 #ifdef CONFIG_PPC_64K_PAGES
323 static pte_t *get_from_cache(struct mm_struct *mm)
324 {
325 	void *pte_frag, *ret;
326 
327 	spin_lock(&mm->page_table_lock);
328 	ret = mm->context.pte_frag;
329 	if (ret) {
330 		pte_frag = ret + PTE_FRAG_SIZE;
331 		/*
332 		 * If we have taken up all the fragments mark PTE page NULL
333 		 */
334 		if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
335 			pte_frag = NULL;
336 		mm->context.pte_frag = pte_frag;
337 	}
338 	spin_unlock(&mm->page_table_lock);
339 	return (pte_t *)ret;
340 }
341 
342 static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel)
343 {
344 	void *ret = NULL;
345 	struct page *page;
346 
347 	if (!kernel) {
348 		page = alloc_page(PGALLOC_GFP | __GFP_ACCOUNT);
349 		if (!page)
350 			return NULL;
351 		if (!pgtable_page_ctor(page)) {
352 			__free_page(page);
353 			return NULL;
354 		}
355 	} else {
356 		page = alloc_page(PGALLOC_GFP);
357 		if (!page)
358 			return NULL;
359 	}
360 
361 	ret = page_address(page);
362 	spin_lock(&mm->page_table_lock);
363 	/*
364 	 * If we find pgtable_page set, we return
365 	 * the allocated page with single fragement
366 	 * count.
367 	 */
368 	if (likely(!mm->context.pte_frag)) {
369 		set_page_count(page, PTE_FRAG_NR);
370 		mm->context.pte_frag = ret + PTE_FRAG_SIZE;
371 	}
372 	spin_unlock(&mm->page_table_lock);
373 
374 	return (pte_t *)ret;
375 }
376 
377 pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
378 {
379 	pte_t *pte;
380 
381 	pte = get_from_cache(mm);
382 	if (pte)
383 		return pte;
384 
385 	return __alloc_for_cache(mm, kernel);
386 }
387 #endif /* CONFIG_PPC_64K_PAGES */
388 
389 void pte_fragment_free(unsigned long *table, int kernel)
390 {
391 	struct page *page = virt_to_page(table);
392 	if (put_page_testzero(page)) {
393 		if (!kernel)
394 			pgtable_page_dtor(page);
395 		free_unref_page(page);
396 	}
397 }
398 
399 #ifdef CONFIG_SMP
400 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
401 {
402 	unsigned long pgf = (unsigned long)table;
403 
404 	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
405 	pgf |= shift;
406 	tlb_remove_table(tlb, (void *)pgf);
407 }
408 
409 void __tlb_remove_table(void *_table)
410 {
411 	void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
412 	unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
413 
414 	if (!shift)
415 		/* PTE page needs special handling */
416 		pte_fragment_free(table, 0);
417 	else {
418 		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
419 		kmem_cache_free(PGT_CACHE(shift), table);
420 	}
421 }
422 #else
423 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
424 {
425 	if (!shift) {
426 		/* PTE page needs special handling */
427 		pte_fragment_free(table, 0);
428 	} else {
429 		BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
430 		kmem_cache_free(PGT_CACHE(shift), table);
431 	}
432 }
433 #endif
434 
435 #ifdef CONFIG_PPC_BOOK3S_64
436 void __init mmu_partition_table_init(void)
437 {
438 	unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
439 	unsigned long ptcr;
440 
441 	BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
442 	partition_tb = __va(memblock_alloc_base(patb_size, patb_size,
443 						MEMBLOCK_ALLOC_ANYWHERE));
444 
445 	/* Initialize the Partition Table with no entries */
446 	memset((void *)partition_tb, 0, patb_size);
447 
448 	/*
449 	 * update partition table control register,
450 	 * 64 K size.
451 	 */
452 	ptcr = __pa(partition_tb) | (PATB_SIZE_SHIFT - 12);
453 	mtspr(SPRN_PTCR, ptcr);
454 	powernv_set_nmmu_ptcr(ptcr);
455 }
456 
457 void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
458 				   unsigned long dw1)
459 {
460 	unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
461 
462 	partition_tb[lpid].patb0 = cpu_to_be64(dw0);
463 	partition_tb[lpid].patb1 = cpu_to_be64(dw1);
464 
465 	/*
466 	 * Global flush of TLBs and partition table caches for this lpid.
467 	 * The type of flush (hash or radix) depends on what the previous
468 	 * use of this partition ID was, not the new use.
469 	 */
470 	asm volatile("ptesync" : : : "memory");
471 	if (old & PATB_HR) {
472 		asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
473 			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
474 		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
475 	} else {
476 		asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
477 			     "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
478 		trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
479 	}
480 	asm volatile("eieio; tlbsync; ptesync" : : : "memory");
481 }
482 EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
483 #endif /* CONFIG_PPC_BOOK3S_64 */
484 
485 #ifdef CONFIG_STRICT_KERNEL_RWX
486 void mark_rodata_ro(void)
487 {
488 	if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) {
489 		pr_warn("Warning: Unable to mark rodata read only on this CPU.\n");
490 		return;
491 	}
492 
493 	if (radix_enabled())
494 		radix__mark_rodata_ro();
495 	else
496 		hash__mark_rodata_ro();
497 }
498 
499 void mark_initmem_nx(void)
500 {
501 	if (radix_enabled())
502 		radix__mark_initmem_nx();
503 	else
504 		hash__mark_initmem_nx();
505 }
506 #endif
507