xref: /openbmc/linux/arch/parisc/kernel/cache.c (revision 799a545b)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1999-2006 Helge Deller <deller@gmx.de> (07-13-1999)
7  * Copyright (C) 1999 SuSE GmbH Nuernberg
8  * Copyright (C) 2000 Philipp Rumpf (prumpf@tux.org)
9  *
10  * Cache and TLB management
11  *
12  */
13 
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/module.h>
18 #include <linux/seq_file.h>
19 #include <linux/pagemap.h>
20 #include <linux/sched.h>
21 #include <asm/pdc.h>
22 #include <asm/cache.h>
23 #include <asm/cacheflush.h>
24 #include <asm/tlbflush.h>
25 #include <asm/page.h>
26 #include <asm/pgalloc.h>
27 #include <asm/processor.h>
28 #include <asm/sections.h>
29 #include <asm/shmparam.h>
30 
31 int split_tlb __read_mostly;
32 int dcache_stride __read_mostly;
33 int icache_stride __read_mostly;
34 EXPORT_SYMBOL(dcache_stride);
35 
36 void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
37 EXPORT_SYMBOL(flush_dcache_page_asm);
38 void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
39 
40 
41 /* On some machines (e.g. ones with the Merced bus), there can be
42  * only a single PxTLB broadcast at a time; this must be guaranteed
43  * by software.  We put a spinlock around all TLB flushes  to
44  * ensure this.
45  */
46 DEFINE_SPINLOCK(pa_tlb_lock);
47 
48 struct pdc_cache_info cache_info __read_mostly;
49 #ifndef CONFIG_PA20
50 static struct pdc_btlb_info btlb_info __read_mostly;
51 #endif
52 
53 #ifdef CONFIG_SMP
54 void
55 flush_data_cache(void)
56 {
57 	on_each_cpu(flush_data_cache_local, NULL, 1);
58 }
59 void
60 flush_instruction_cache(void)
61 {
62 	on_each_cpu(flush_instruction_cache_local, NULL, 1);
63 }
64 #endif
65 
66 void
67 flush_cache_all_local(void)
68 {
69 	flush_instruction_cache_local(NULL);
70 	flush_data_cache_local(NULL);
71 }
72 EXPORT_SYMBOL(flush_cache_all_local);
73 
74 /* Virtual address of pfn.  */
75 #define pfn_va(pfn)	__va(PFN_PHYS(pfn))
76 
77 void
78 update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
79 {
80 	unsigned long pfn = pte_pfn(*ptep);
81 	struct page *page;
82 
83 	/* We don't have pte special.  As a result, we can be called with
84 	   an invalid pfn and we don't need to flush the kernel dcache page.
85 	   This occurs with FireGL card in C8000.  */
86 	if (!pfn_valid(pfn))
87 		return;
88 
89 	page = pfn_to_page(pfn);
90 	if (page_mapping(page) && test_bit(PG_dcache_dirty, &page->flags)) {
91 		flush_kernel_dcache_page_addr(pfn_va(pfn));
92 		clear_bit(PG_dcache_dirty, &page->flags);
93 	} else if (parisc_requires_coherency())
94 		flush_kernel_dcache_page_addr(pfn_va(pfn));
95 }
96 
97 void
98 show_cache_info(struct seq_file *m)
99 {
100 	char buf[32];
101 
102 	seq_printf(m, "I-cache\t\t: %ld KB\n",
103 		cache_info.ic_size/1024 );
104 	if (cache_info.dc_loop != 1)
105 		snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
106 	seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s)\n",
107 		cache_info.dc_size/1024,
108 		(cache_info.dc_conf.cc_wt ? "WT":"WB"),
109 		(cache_info.dc_conf.cc_sh ? ", shared I/D":""),
110 		((cache_info.dc_loop == 1) ? "direct mapped" : buf));
111 	seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
112 		cache_info.it_size,
113 		cache_info.dt_size,
114 		cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
115 	);
116 
117 #ifndef CONFIG_PA20
118 	/* BTLB - Block TLB */
119 	if (btlb_info.max_size==0) {
120 		seq_printf(m, "BTLB\t\t: not supported\n" );
121 	} else {
122 		seq_printf(m,
123 		"BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
124 		"BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
125 		"BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
126 		btlb_info.max_size, (int)4096,
127 		btlb_info.max_size>>8,
128 		btlb_info.fixed_range_info.num_i,
129 		btlb_info.fixed_range_info.num_d,
130 		btlb_info.fixed_range_info.num_comb,
131 		btlb_info.variable_range_info.num_i,
132 		btlb_info.variable_range_info.num_d,
133 		btlb_info.variable_range_info.num_comb
134 		);
135 	}
136 #endif
137 }
138 
139 void __init
140 parisc_cache_init(void)
141 {
142 	if (pdc_cache_info(&cache_info) < 0)
143 		panic("parisc_cache_init: pdc_cache_info failed");
144 
145 #if 0
146 	printk("ic_size %lx dc_size %lx it_size %lx\n",
147 		cache_info.ic_size,
148 		cache_info.dc_size,
149 		cache_info.it_size);
150 
151 	printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
152 		cache_info.dc_base,
153 		cache_info.dc_stride,
154 		cache_info.dc_count,
155 		cache_info.dc_loop);
156 
157 	printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
158 		*(unsigned long *) (&cache_info.dc_conf),
159 		cache_info.dc_conf.cc_alias,
160 		cache_info.dc_conf.cc_block,
161 		cache_info.dc_conf.cc_line,
162 		cache_info.dc_conf.cc_shift);
163 	printk("	wt %d sh %d cst %d hv %d\n",
164 		cache_info.dc_conf.cc_wt,
165 		cache_info.dc_conf.cc_sh,
166 		cache_info.dc_conf.cc_cst,
167 		cache_info.dc_conf.cc_hv);
168 
169 	printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
170 		cache_info.ic_base,
171 		cache_info.ic_stride,
172 		cache_info.ic_count,
173 		cache_info.ic_loop);
174 
175 	printk("IT  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx off_base 0x%lx off_stride 0x%lx off_count 0x%lx\n",
176 		cache_info.it_sp_base,
177 		cache_info.it_sp_stride,
178 		cache_info.it_sp_count,
179 		cache_info.it_loop,
180 		cache_info.it_off_base,
181 		cache_info.it_off_stride,
182 		cache_info.it_off_count);
183 
184 	printk("DT  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx off_base 0x%lx off_stride 0x%lx off_count 0x%lx\n",
185 		cache_info.dt_sp_base,
186 		cache_info.dt_sp_stride,
187 		cache_info.dt_sp_count,
188 		cache_info.dt_loop,
189 		cache_info.dt_off_base,
190 		cache_info.dt_off_stride,
191 		cache_info.dt_off_count);
192 
193 	printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
194 		*(unsigned long *) (&cache_info.ic_conf),
195 		cache_info.ic_conf.cc_alias,
196 		cache_info.ic_conf.cc_block,
197 		cache_info.ic_conf.cc_line,
198 		cache_info.ic_conf.cc_shift);
199 	printk("	wt %d sh %d cst %d hv %d\n",
200 		cache_info.ic_conf.cc_wt,
201 		cache_info.ic_conf.cc_sh,
202 		cache_info.ic_conf.cc_cst,
203 		cache_info.ic_conf.cc_hv);
204 
205 	printk("D-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
206 		cache_info.dt_conf.tc_sh,
207 		cache_info.dt_conf.tc_page,
208 		cache_info.dt_conf.tc_cst,
209 		cache_info.dt_conf.tc_aid,
210 		cache_info.dt_conf.tc_sr);
211 
212 	printk("I-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
213 		cache_info.it_conf.tc_sh,
214 		cache_info.it_conf.tc_page,
215 		cache_info.it_conf.tc_cst,
216 		cache_info.it_conf.tc_aid,
217 		cache_info.it_conf.tc_sr);
218 #endif
219 
220 	split_tlb = 0;
221 	if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
222 		if (cache_info.dt_conf.tc_sh == 2)
223 			printk(KERN_WARNING "Unexpected TLB configuration. "
224 			"Will flush I/D separately (could be optimized).\n");
225 
226 		split_tlb = 1;
227 	}
228 
229 	/* "New and Improved" version from Jim Hull
230 	 *	(1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
231 	 * The following CAFL_STRIDE is an optimized version, see
232 	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
233 	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
234 	 */
235 #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
236 	dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
237 	icache_stride = CAFL_STRIDE(cache_info.ic_conf);
238 #undef CAFL_STRIDE
239 
240 #ifndef CONFIG_PA20
241 	if (pdc_btlb_info(&btlb_info) < 0) {
242 		memset(&btlb_info, 0, sizeof btlb_info);
243 	}
244 #endif
245 
246 	if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
247 						PDC_MODEL_NVA_UNSUPPORTED) {
248 		printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
249 #if 0
250 		panic("SMP kernel required to avoid non-equivalent aliasing");
251 #endif
252 	}
253 }
254 
255 void disable_sr_hashing(void)
256 {
257 	int srhash_type, retval;
258 	unsigned long space_bits;
259 
260 	switch (boot_cpu_data.cpu_type) {
261 	case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
262 		BUG();
263 		return;
264 
265 	case pcxs:
266 	case pcxt:
267 	case pcxt_:
268 		srhash_type = SRHASH_PCXST;
269 		break;
270 
271 	case pcxl:
272 		srhash_type = SRHASH_PCXL;
273 		break;
274 
275 	case pcxl2: /* pcxl2 doesn't support space register hashing */
276 		return;
277 
278 	default: /* Currently all PA2.0 machines use the same ins. sequence */
279 		srhash_type = SRHASH_PA20;
280 		break;
281 	}
282 
283 	disable_sr_hashing_asm(srhash_type);
284 
285 	retval = pdc_spaceid_bits(&space_bits);
286 	/* If this procedure isn't implemented, don't panic. */
287 	if (retval < 0 && retval != PDC_BAD_OPTION)
288 		panic("pdc_spaceid_bits call failed.\n");
289 	if (space_bits != 0)
290 		panic("SpaceID hashing is still on!\n");
291 }
292 
293 static inline void
294 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
295 		   unsigned long physaddr)
296 {
297 	preempt_disable();
298 	flush_dcache_page_asm(physaddr, vmaddr);
299 	if (vma->vm_flags & VM_EXEC)
300 		flush_icache_page_asm(physaddr, vmaddr);
301 	preempt_enable();
302 }
303 
304 void flush_dcache_page(struct page *page)
305 {
306 	struct address_space *mapping = page_mapping(page);
307 	struct vm_area_struct *mpnt;
308 	unsigned long offset;
309 	unsigned long addr, old_addr = 0;
310 	pgoff_t pgoff;
311 
312 	if (mapping && !mapping_mapped(mapping)) {
313 		set_bit(PG_dcache_dirty, &page->flags);
314 		return;
315 	}
316 
317 	flush_kernel_dcache_page(page);
318 
319 	if (!mapping)
320 		return;
321 
322 	pgoff = page->index;
323 
324 	/* We have carefully arranged in arch_get_unmapped_area() that
325 	 * *any* mappings of a file are always congruently mapped (whether
326 	 * declared as MAP_PRIVATE or MAP_SHARED), so we only need
327 	 * to flush one address here for them all to become coherent */
328 
329 	flush_dcache_mmap_lock(mapping);
330 	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
331 		offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
332 		addr = mpnt->vm_start + offset;
333 
334 		/* The TLB is the engine of coherence on parisc: The
335 		 * CPU is entitled to speculate any page with a TLB
336 		 * mapping, so here we kill the mapping then flush the
337 		 * page along a special flush only alias mapping.
338 		 * This guarantees that the page is no-longer in the
339 		 * cache for any process and nor may it be
340 		 * speculatively read in (until the user or kernel
341 		 * specifically accesses it, of course) */
342 
343 		flush_tlb_page(mpnt, addr);
344 		if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
345 				      != (addr & (SHM_COLOUR - 1))) {
346 			__flush_cache_page(mpnt, addr, page_to_phys(page));
347 			if (old_addr)
348 				printk(KERN_ERR "INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %s\n", old_addr, addr, mpnt->vm_file ? (char *)mpnt->vm_file->f_path.dentry->d_name.name : "(null)");
349 			old_addr = addr;
350 		}
351 	}
352 	flush_dcache_mmap_unlock(mapping);
353 }
354 EXPORT_SYMBOL(flush_dcache_page);
355 
356 /* Defined in arch/parisc/kernel/pacache.S */
357 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
358 EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
359 EXPORT_SYMBOL(flush_data_cache_local);
360 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
361 
362 #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
363 static unsigned long parisc_cache_flush_threshold __read_mostly = FLUSH_THRESHOLD;
364 
365 #define FLUSH_TLB_THRESHOLD (2*1024*1024) /* 2MB initial TLB threshold */
366 static unsigned long parisc_tlb_flush_threshold __read_mostly = FLUSH_TLB_THRESHOLD;
367 
368 void __init parisc_setup_cache_timing(void)
369 {
370 	unsigned long rangetime, alltime;
371 	unsigned long size, start;
372 
373 	alltime = mfctl(16);
374 	flush_data_cache();
375 	alltime = mfctl(16) - alltime;
376 
377 	size = (unsigned long)(_end - _text);
378 	rangetime = mfctl(16);
379 	flush_kernel_dcache_range((unsigned long)_text, size);
380 	rangetime = mfctl(16) - rangetime;
381 
382 	printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
383 		alltime, size, rangetime);
384 
385 	/* Racy, but if we see an intermediate value, it's ok too... */
386 	parisc_cache_flush_threshold = size * alltime / rangetime;
387 
388 	parisc_cache_flush_threshold = L1_CACHE_ALIGN(parisc_cache_flush_threshold);
389 	if (!parisc_cache_flush_threshold)
390 		parisc_cache_flush_threshold = FLUSH_THRESHOLD;
391 
392 	if (parisc_cache_flush_threshold > cache_info.dc_size)
393 		parisc_cache_flush_threshold = cache_info.dc_size;
394 
395 	printk(KERN_INFO "Setting cache flush threshold to %lu kB\n",
396 		parisc_cache_flush_threshold/1024);
397 
398 	/* calculate TLB flush threshold */
399 
400 	alltime = mfctl(16);
401 	flush_tlb_all();
402 	alltime = mfctl(16) - alltime;
403 
404 	size = PAGE_SIZE;
405 	start = (unsigned long) _text;
406 	rangetime = mfctl(16);
407 	while (start < (unsigned long) _end) {
408 		flush_tlb_kernel_range(start, start + PAGE_SIZE);
409 		start += PAGE_SIZE;
410 		size += PAGE_SIZE;
411 	}
412 	rangetime = mfctl(16) - rangetime;
413 
414 	printk(KERN_DEBUG "Whole TLB flush %lu cycles, flushing %lu bytes %lu cycles\n",
415 		alltime, size, rangetime);
416 
417 	parisc_tlb_flush_threshold = size * alltime / rangetime;
418 	parisc_tlb_flush_threshold *= num_online_cpus();
419 	parisc_tlb_flush_threshold = PAGE_ALIGN(parisc_tlb_flush_threshold);
420 	if (!parisc_tlb_flush_threshold)
421 		parisc_tlb_flush_threshold = FLUSH_TLB_THRESHOLD;
422 
423 	printk(KERN_INFO "Setting TLB flush threshold to %lu kB\n",
424 		parisc_tlb_flush_threshold/1024);
425 }
426 
427 extern void purge_kernel_dcache_page_asm(unsigned long);
428 extern void clear_user_page_asm(void *, unsigned long);
429 extern void copy_user_page_asm(void *, void *, unsigned long);
430 
431 void flush_kernel_dcache_page_addr(void *addr)
432 {
433 	unsigned long flags;
434 
435 	flush_kernel_dcache_page_asm(addr);
436 	purge_tlb_start(flags);
437 	pdtlb_kernel(addr);
438 	purge_tlb_end(flags);
439 }
440 EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
441 
442 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
443 	struct page *pg)
444 {
445        /* Copy using kernel mapping.  No coherency is needed (all in
446 	  kunmap) for the `to' page.  However, the `from' page needs to
447 	  be flushed through a mapping equivalent to the user mapping
448 	  before it can be accessed through the kernel mapping. */
449 	preempt_disable();
450 	flush_dcache_page_asm(__pa(vfrom), vaddr);
451 	preempt_enable();
452 	copy_page_asm(vto, vfrom);
453 }
454 EXPORT_SYMBOL(copy_user_page);
455 
456 /* __flush_tlb_range()
457  *
458  * returns 1 if all TLBs were flushed.
459  */
460 int __flush_tlb_range(unsigned long sid, unsigned long start,
461 		      unsigned long end)
462 {
463 	unsigned long flags, size;
464 
465 	size = (end - start);
466 	if (size >= parisc_tlb_flush_threshold) {
467 		flush_tlb_all();
468 		return 1;
469 	}
470 
471 	/* Purge TLB entries for small ranges using the pdtlb and
472 	   pitlb instructions.  These instructions execute locally
473 	   but cause a purge request to be broadcast to other TLBs.  */
474 	if (likely(!split_tlb)) {
475 		while (start < end) {
476 			purge_tlb_start(flags);
477 			mtsp(sid, 1);
478 			pdtlb(start);
479 			purge_tlb_end(flags);
480 			start += PAGE_SIZE;
481 		}
482 		return 0;
483 	}
484 
485 	/* split TLB case */
486 	while (start < end) {
487 		purge_tlb_start(flags);
488 		mtsp(sid, 1);
489 		pdtlb(start);
490 		pitlb(start);
491 		purge_tlb_end(flags);
492 		start += PAGE_SIZE;
493 	}
494 	return 0;
495 }
496 
497 static void cacheflush_h_tmp_function(void *dummy)
498 {
499 	flush_cache_all_local();
500 }
501 
502 void flush_cache_all(void)
503 {
504 	on_each_cpu(cacheflush_h_tmp_function, NULL, 1);
505 }
506 
507 static inline unsigned long mm_total_size(struct mm_struct *mm)
508 {
509 	struct vm_area_struct *vma;
510 	unsigned long usize = 0;
511 
512 	for (vma = mm->mmap; vma; vma = vma->vm_next)
513 		usize += vma->vm_end - vma->vm_start;
514 	return usize;
515 }
516 
517 static inline pte_t *get_ptep(pgd_t *pgd, unsigned long addr)
518 {
519 	pte_t *ptep = NULL;
520 
521 	if (!pgd_none(*pgd)) {
522 		pud_t *pud = pud_offset(pgd, addr);
523 		if (!pud_none(*pud)) {
524 			pmd_t *pmd = pmd_offset(pud, addr);
525 			if (!pmd_none(*pmd))
526 				ptep = pte_offset_map(pmd, addr);
527 		}
528 	}
529 	return ptep;
530 }
531 
532 void flush_cache_mm(struct mm_struct *mm)
533 {
534 	struct vm_area_struct *vma;
535 	pgd_t *pgd;
536 
537 	/* Flushing the whole cache on each cpu takes forever on
538 	   rp3440, etc.  So, avoid it if the mm isn't too big.  */
539 	if (mm_total_size(mm) >= parisc_cache_flush_threshold) {
540 		flush_cache_all();
541 		return;
542 	}
543 
544 	if (mm->context == mfsp(3)) {
545 		for (vma = mm->mmap; vma; vma = vma->vm_next) {
546 			flush_user_dcache_range_asm(vma->vm_start, vma->vm_end);
547 			if ((vma->vm_flags & VM_EXEC) == 0)
548 				continue;
549 			flush_user_icache_range_asm(vma->vm_start, vma->vm_end);
550 		}
551 		return;
552 	}
553 
554 	pgd = mm->pgd;
555 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
556 		unsigned long addr;
557 
558 		for (addr = vma->vm_start; addr < vma->vm_end;
559 		     addr += PAGE_SIZE) {
560 			unsigned long pfn;
561 			pte_t *ptep = get_ptep(pgd, addr);
562 			if (!ptep)
563 				continue;
564 			pfn = pte_pfn(*ptep);
565 			if (!pfn_valid(pfn))
566 				continue;
567 			__flush_cache_page(vma, addr, PFN_PHYS(pfn));
568 		}
569 	}
570 }
571 
572 void
573 flush_user_dcache_range(unsigned long start, unsigned long end)
574 {
575 	if ((end - start) < parisc_cache_flush_threshold)
576 		flush_user_dcache_range_asm(start,end);
577 	else
578 		flush_data_cache();
579 }
580 
581 void
582 flush_user_icache_range(unsigned long start, unsigned long end)
583 {
584 	if ((end - start) < parisc_cache_flush_threshold)
585 		flush_user_icache_range_asm(start,end);
586 	else
587 		flush_instruction_cache();
588 }
589 
590 void flush_cache_range(struct vm_area_struct *vma,
591 		unsigned long start, unsigned long end)
592 {
593 	unsigned long addr;
594 	pgd_t *pgd;
595 
596 	BUG_ON(!vma->vm_mm->context);
597 
598 	if ((end - start) >= parisc_cache_flush_threshold) {
599 		flush_cache_all();
600 		return;
601 	}
602 
603 	if (vma->vm_mm->context == mfsp(3)) {
604 		flush_user_dcache_range_asm(start, end);
605 		if (vma->vm_flags & VM_EXEC)
606 			flush_user_icache_range_asm(start, end);
607 		return;
608 	}
609 
610 	pgd = vma->vm_mm->pgd;
611 	for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
612 		unsigned long pfn;
613 		pte_t *ptep = get_ptep(pgd, addr);
614 		if (!ptep)
615 			continue;
616 		pfn = pte_pfn(*ptep);
617 		if (pfn_valid(pfn))
618 			__flush_cache_page(vma, addr, PFN_PHYS(pfn));
619 	}
620 }
621 
622 void
623 flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
624 {
625 	BUG_ON(!vma->vm_mm->context);
626 
627 	if (pfn_valid(pfn)) {
628 		flush_tlb_page(vma, vmaddr);
629 		__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
630 	}
631 }
632