xref: /openbmc/linux/arch/parisc/kernel/cache.c (revision 77423a62)
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 <linux/sched/mm.h>
22 #include <asm/pdc.h>
23 #include <asm/cache.h>
24 #include <asm/cacheflush.h>
25 #include <asm/tlbflush.h>
26 #include <asm/page.h>
27 #include <asm/processor.h>
28 #include <asm/sections.h>
29 #include <asm/shmparam.h>
30 #include <asm/mmu_context.h>
31 
32 int split_tlb __ro_after_init;
33 int dcache_stride __ro_after_init;
34 int icache_stride __ro_after_init;
35 EXPORT_SYMBOL(dcache_stride);
36 
37 void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
38 EXPORT_SYMBOL(flush_dcache_page_asm);
39 void purge_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
40 void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
41 
42 /* Internal implementation in arch/parisc/kernel/pacache.S */
43 void flush_data_cache_local(void *);  /* flushes local data-cache only */
44 void flush_instruction_cache_local(void); /* flushes local code-cache only */
45 
46 /* On some machines (i.e., ones with the Merced bus), there can be
47  * only a single PxTLB broadcast at a time; this must be guaranteed
48  * by software. We need a spinlock around all TLB flushes to ensure
49  * this.
50  */
51 DEFINE_SPINLOCK(pa_tlb_flush_lock);
52 
53 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
54 int pa_serialize_tlb_flushes __ro_after_init;
55 #endif
56 
57 struct pdc_cache_info cache_info __ro_after_init;
58 #ifndef CONFIG_PA20
59 static struct pdc_btlb_info btlb_info __ro_after_init;
60 #endif
61 
62 DEFINE_STATIC_KEY_TRUE(parisc_has_cache);
63 DEFINE_STATIC_KEY_TRUE(parisc_has_dcache);
64 DEFINE_STATIC_KEY_TRUE(parisc_has_icache);
65 
66 static void cache_flush_local_cpu(void *dummy)
67 {
68 	if (static_branch_likely(&parisc_has_icache))
69 		flush_instruction_cache_local();
70 	if (static_branch_likely(&parisc_has_dcache))
71 		flush_data_cache_local(NULL);
72 }
73 
74 void flush_cache_all_local(void)
75 {
76 	cache_flush_local_cpu(NULL);
77 }
78 
79 void flush_cache_all(void)
80 {
81 	if (static_branch_likely(&parisc_has_cache))
82 		on_each_cpu(cache_flush_local_cpu, NULL, 1);
83 }
84 
85 static inline void flush_data_cache(void)
86 {
87 	if (static_branch_likely(&parisc_has_dcache))
88 		on_each_cpu(flush_data_cache_local, NULL, 1);
89 }
90 
91 
92 /* Kernel virtual address of pfn.  */
93 #define pfn_va(pfn)	__va(PFN_PHYS(pfn))
94 
95 void
96 __update_cache(pte_t pte)
97 {
98 	unsigned long pfn = pte_pfn(pte);
99 	struct page *page;
100 
101 	/* We don't have pte special.  As a result, we can be called with
102 	   an invalid pfn and we don't need to flush the kernel dcache page.
103 	   This occurs with FireGL card in C8000.  */
104 	if (!pfn_valid(pfn))
105 		return;
106 
107 	page = pfn_to_page(pfn);
108 	if (page_mapping_file(page) &&
109 	    test_bit(PG_dcache_dirty, &page->flags)) {
110 		flush_kernel_dcache_page_addr(pfn_va(pfn));
111 		clear_bit(PG_dcache_dirty, &page->flags);
112 	} else if (parisc_requires_coherency())
113 		flush_kernel_dcache_page_addr(pfn_va(pfn));
114 }
115 
116 void
117 show_cache_info(struct seq_file *m)
118 {
119 	char buf[32];
120 
121 	seq_printf(m, "I-cache\t\t: %ld KB\n",
122 		cache_info.ic_size/1024 );
123 	if (cache_info.dc_loop != 1)
124 		snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
125 	seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s, alias=%d)\n",
126 		cache_info.dc_size/1024,
127 		(cache_info.dc_conf.cc_wt ? "WT":"WB"),
128 		(cache_info.dc_conf.cc_sh ? ", shared I/D":""),
129 		((cache_info.dc_loop == 1) ? "direct mapped" : buf),
130 		cache_info.dc_conf.cc_alias
131 	);
132 	seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
133 		cache_info.it_size,
134 		cache_info.dt_size,
135 		cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
136 	);
137 
138 #ifndef CONFIG_PA20
139 	/* BTLB - Block TLB */
140 	if (btlb_info.max_size==0) {
141 		seq_printf(m, "BTLB\t\t: not supported\n" );
142 	} else {
143 		seq_printf(m,
144 		"BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
145 		"BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
146 		"BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
147 		btlb_info.max_size, (int)4096,
148 		btlb_info.max_size>>8,
149 		btlb_info.fixed_range_info.num_i,
150 		btlb_info.fixed_range_info.num_d,
151 		btlb_info.fixed_range_info.num_comb,
152 		btlb_info.variable_range_info.num_i,
153 		btlb_info.variable_range_info.num_d,
154 		btlb_info.variable_range_info.num_comb
155 		);
156 	}
157 #endif
158 }
159 
160 void __init
161 parisc_cache_init(void)
162 {
163 	if (pdc_cache_info(&cache_info) < 0)
164 		panic("parisc_cache_init: pdc_cache_info failed");
165 
166 #if 0
167 	printk("ic_size %lx dc_size %lx it_size %lx\n",
168 		cache_info.ic_size,
169 		cache_info.dc_size,
170 		cache_info.it_size);
171 
172 	printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
173 		cache_info.dc_base,
174 		cache_info.dc_stride,
175 		cache_info.dc_count,
176 		cache_info.dc_loop);
177 
178 	printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
179 		*(unsigned long *) (&cache_info.dc_conf),
180 		cache_info.dc_conf.cc_alias,
181 		cache_info.dc_conf.cc_block,
182 		cache_info.dc_conf.cc_line,
183 		cache_info.dc_conf.cc_shift);
184 	printk("	wt %d sh %d cst %d hv %d\n",
185 		cache_info.dc_conf.cc_wt,
186 		cache_info.dc_conf.cc_sh,
187 		cache_info.dc_conf.cc_cst,
188 		cache_info.dc_conf.cc_hv);
189 
190 	printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
191 		cache_info.ic_base,
192 		cache_info.ic_stride,
193 		cache_info.ic_count,
194 		cache_info.ic_loop);
195 
196 	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",
197 		cache_info.it_sp_base,
198 		cache_info.it_sp_stride,
199 		cache_info.it_sp_count,
200 		cache_info.it_loop,
201 		cache_info.it_off_base,
202 		cache_info.it_off_stride,
203 		cache_info.it_off_count);
204 
205 	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",
206 		cache_info.dt_sp_base,
207 		cache_info.dt_sp_stride,
208 		cache_info.dt_sp_count,
209 		cache_info.dt_loop,
210 		cache_info.dt_off_base,
211 		cache_info.dt_off_stride,
212 		cache_info.dt_off_count);
213 
214 	printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
215 		*(unsigned long *) (&cache_info.ic_conf),
216 		cache_info.ic_conf.cc_alias,
217 		cache_info.ic_conf.cc_block,
218 		cache_info.ic_conf.cc_line,
219 		cache_info.ic_conf.cc_shift);
220 	printk("	wt %d sh %d cst %d hv %d\n",
221 		cache_info.ic_conf.cc_wt,
222 		cache_info.ic_conf.cc_sh,
223 		cache_info.ic_conf.cc_cst,
224 		cache_info.ic_conf.cc_hv);
225 
226 	printk("D-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
227 		cache_info.dt_conf.tc_sh,
228 		cache_info.dt_conf.tc_page,
229 		cache_info.dt_conf.tc_cst,
230 		cache_info.dt_conf.tc_aid,
231 		cache_info.dt_conf.tc_sr);
232 
233 	printk("I-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
234 		cache_info.it_conf.tc_sh,
235 		cache_info.it_conf.tc_page,
236 		cache_info.it_conf.tc_cst,
237 		cache_info.it_conf.tc_aid,
238 		cache_info.it_conf.tc_sr);
239 #endif
240 
241 	split_tlb = 0;
242 	if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
243 		if (cache_info.dt_conf.tc_sh == 2)
244 			printk(KERN_WARNING "Unexpected TLB configuration. "
245 			"Will flush I/D separately (could be optimized).\n");
246 
247 		split_tlb = 1;
248 	}
249 
250 	/* "New and Improved" version from Jim Hull
251 	 *	(1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
252 	 * The following CAFL_STRIDE is an optimized version, see
253 	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
254 	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
255 	 */
256 #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
257 	dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
258 	icache_stride = CAFL_STRIDE(cache_info.ic_conf);
259 #undef CAFL_STRIDE
260 
261 #ifndef CONFIG_PA20
262 	if (pdc_btlb_info(&btlb_info) < 0) {
263 		memset(&btlb_info, 0, sizeof btlb_info);
264 	}
265 #endif
266 
267 	if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
268 						PDC_MODEL_NVA_UNSUPPORTED) {
269 		printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
270 #if 0
271 		panic("SMP kernel required to avoid non-equivalent aliasing");
272 #endif
273 	}
274 }
275 
276 void disable_sr_hashing(void)
277 {
278 	int srhash_type, retval;
279 	unsigned long space_bits;
280 
281 	switch (boot_cpu_data.cpu_type) {
282 	case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
283 		BUG();
284 		return;
285 
286 	case pcxs:
287 	case pcxt:
288 	case pcxt_:
289 		srhash_type = SRHASH_PCXST;
290 		break;
291 
292 	case pcxl:
293 		srhash_type = SRHASH_PCXL;
294 		break;
295 
296 	case pcxl2: /* pcxl2 doesn't support space register hashing */
297 		return;
298 
299 	default: /* Currently all PA2.0 machines use the same ins. sequence */
300 		srhash_type = SRHASH_PA20;
301 		break;
302 	}
303 
304 	disable_sr_hashing_asm(srhash_type);
305 
306 	retval = pdc_spaceid_bits(&space_bits);
307 	/* If this procedure isn't implemented, don't panic. */
308 	if (retval < 0 && retval != PDC_BAD_OPTION)
309 		panic("pdc_spaceid_bits call failed.\n");
310 	if (space_bits != 0)
311 		panic("SpaceID hashing is still on!\n");
312 }
313 
314 static inline void
315 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
316 		   unsigned long physaddr)
317 {
318 	if (!static_branch_likely(&parisc_has_cache))
319 		return;
320 	preempt_disable();
321 	flush_dcache_page_asm(physaddr, vmaddr);
322 	if (vma->vm_flags & VM_EXEC)
323 		flush_icache_page_asm(physaddr, vmaddr);
324 	preempt_enable();
325 }
326 
327 static void flush_user_cache_page(struct vm_area_struct *vma, unsigned long vmaddr)
328 {
329 	unsigned long flags, space, pgd, prot;
330 #ifdef CONFIG_TLB_PTLOCK
331 	unsigned long pgd_lock;
332 #endif
333 
334 	vmaddr &= PAGE_MASK;
335 
336 	preempt_disable();
337 
338 	/* Set context for flush */
339 	local_irq_save(flags);
340 	prot = mfctl(8);
341 	space = mfsp(SR_USER);
342 	pgd = mfctl(25);
343 #ifdef CONFIG_TLB_PTLOCK
344 	pgd_lock = mfctl(28);
345 #endif
346 	switch_mm_irqs_off(NULL, vma->vm_mm, NULL);
347 	local_irq_restore(flags);
348 
349 	flush_user_dcache_range_asm(vmaddr, vmaddr + PAGE_SIZE);
350 	if (vma->vm_flags & VM_EXEC)
351 		flush_user_icache_range_asm(vmaddr, vmaddr + PAGE_SIZE);
352 	flush_tlb_page(vma, vmaddr);
353 
354 	/* Restore previous context */
355 	local_irq_save(flags);
356 #ifdef CONFIG_TLB_PTLOCK
357 	mtctl(pgd_lock, 28);
358 #endif
359 	mtctl(pgd, 25);
360 	mtsp(space, SR_USER);
361 	mtctl(prot, 8);
362 	local_irq_restore(flags);
363 
364 	preempt_enable();
365 }
366 
367 static inline pte_t *get_ptep(struct mm_struct *mm, unsigned long addr)
368 {
369 	pte_t *ptep = NULL;
370 	pgd_t *pgd = mm->pgd;
371 	p4d_t *p4d;
372 	pud_t *pud;
373 	pmd_t *pmd;
374 
375 	if (!pgd_none(*pgd)) {
376 		p4d = p4d_offset(pgd, addr);
377 		if (!p4d_none(*p4d)) {
378 			pud = pud_offset(p4d, addr);
379 			if (!pud_none(*pud)) {
380 				pmd = pmd_offset(pud, addr);
381 				if (!pmd_none(*pmd))
382 					ptep = pte_offset_map(pmd, addr);
383 			}
384 		}
385 	}
386 	return ptep;
387 }
388 
389 static inline bool pte_needs_flush(pte_t pte)
390 {
391 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_NO_CACHE))
392 		== (_PAGE_PRESENT | _PAGE_ACCESSED);
393 }
394 
395 void flush_dcache_page(struct page *page)
396 {
397 	struct address_space *mapping = page_mapping_file(page);
398 	struct vm_area_struct *mpnt;
399 	unsigned long offset;
400 	unsigned long addr, old_addr = 0;
401 	unsigned long count = 0;
402 	pgoff_t pgoff;
403 
404 	if (mapping && !mapping_mapped(mapping)) {
405 		set_bit(PG_dcache_dirty, &page->flags);
406 		return;
407 	}
408 
409 	flush_kernel_dcache_page_addr(page_address(page));
410 
411 	if (!mapping)
412 		return;
413 
414 	pgoff = page->index;
415 
416 	/*
417 	 * We have carefully arranged in arch_get_unmapped_area() that
418 	 * *any* mappings of a file are always congruently mapped (whether
419 	 * declared as MAP_PRIVATE or MAP_SHARED), so we only need
420 	 * to flush one address here for them all to become coherent
421 	 * on machines that support equivalent aliasing
422 	 */
423 	flush_dcache_mmap_lock(mapping);
424 	vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
425 		offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
426 		addr = mpnt->vm_start + offset;
427 		if (parisc_requires_coherency()) {
428 			pte_t *ptep;
429 
430 			ptep = get_ptep(mpnt->vm_mm, addr);
431 			if (ptep && pte_needs_flush(*ptep))
432 				flush_user_cache_page(mpnt, addr);
433 		} else {
434 			/*
435 			 * The TLB is the engine of coherence on parisc:
436 			 * The CPU is entitled to speculate any page
437 			 * with a TLB mapping, so here we kill the
438 			 * mapping then flush the page along a special
439 			 * flush only alias mapping. This guarantees that
440 			 * the page is no-longer in the cache for any
441 			 * process and nor may it be speculatively read
442 			 * in (until the user or kernel specifically
443 			 * accesses it, of course)
444 			 */
445 			flush_tlb_page(mpnt, addr);
446 			if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
447 					!= (addr & (SHM_COLOUR - 1))) {
448 				__flush_cache_page(mpnt, addr, page_to_phys(page));
449 				/*
450 				 * Software is allowed to have any number
451 				 * of private mappings to a page.
452 				 */
453 				if (!(mpnt->vm_flags & VM_SHARED))
454 					continue;
455 				if (old_addr)
456 					pr_err("INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n",
457 						old_addr, addr, mpnt->vm_file);
458 				old_addr = addr;
459 			}
460 		}
461 		WARN_ON(++count == 4096);
462 	}
463 	flush_dcache_mmap_unlock(mapping);
464 }
465 EXPORT_SYMBOL(flush_dcache_page);
466 
467 /* Defined in arch/parisc/kernel/pacache.S */
468 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
469 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
470 
471 #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
472 static unsigned long parisc_cache_flush_threshold __ro_after_init = FLUSH_THRESHOLD;
473 
474 #define FLUSH_TLB_THRESHOLD (16*1024) /* 16 KiB minimum TLB threshold */
475 static unsigned long parisc_tlb_flush_threshold __ro_after_init = ~0UL;
476 
477 void __init parisc_setup_cache_timing(void)
478 {
479 	unsigned long rangetime, alltime;
480 	unsigned long size;
481 	unsigned long threshold, threshold2;
482 
483 	alltime = mfctl(16);
484 	flush_data_cache();
485 	alltime = mfctl(16) - alltime;
486 
487 	size = (unsigned long)(_end - _text);
488 	rangetime = mfctl(16);
489 	flush_kernel_dcache_range((unsigned long)_text, size);
490 	rangetime = mfctl(16) - rangetime;
491 
492 	printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
493 		alltime, size, rangetime);
494 
495 	threshold = L1_CACHE_ALIGN((unsigned long)((uint64_t)size * alltime / rangetime));
496 	pr_info("Calculated flush threshold is %lu KiB\n",
497 		threshold/1024);
498 
499 	/*
500 	 * The threshold computed above isn't very reliable. The following
501 	 * heuristic works reasonably well on c8000/rp3440.
502 	 */
503 	threshold2 = cache_info.dc_size * num_online_cpus();
504 	parisc_cache_flush_threshold = threshold2;
505 	printk(KERN_INFO "Cache flush threshold set to %lu KiB\n",
506 		parisc_cache_flush_threshold/1024);
507 
508 	/* calculate TLB flush threshold */
509 
510 	/* On SMP machines, skip the TLB measure of kernel text which
511 	 * has been mapped as huge pages. */
512 	if (num_online_cpus() > 1 && !parisc_requires_coherency()) {
513 		threshold = max(cache_info.it_size, cache_info.dt_size);
514 		threshold *= PAGE_SIZE;
515 		threshold /= num_online_cpus();
516 		goto set_tlb_threshold;
517 	}
518 
519 	size = (unsigned long)_end - (unsigned long)_text;
520 	rangetime = mfctl(16);
521 	flush_tlb_kernel_range((unsigned long)_text, (unsigned long)_end);
522 	rangetime = mfctl(16) - rangetime;
523 
524 	alltime = mfctl(16);
525 	flush_tlb_all();
526 	alltime = mfctl(16) - alltime;
527 
528 	printk(KERN_INFO "Whole TLB flush %lu cycles, Range flush %lu bytes %lu cycles\n",
529 		alltime, size, rangetime);
530 
531 	threshold = PAGE_ALIGN((num_online_cpus() * size * alltime) / rangetime);
532 	printk(KERN_INFO "Calculated TLB flush threshold %lu KiB\n",
533 		threshold/1024);
534 
535 set_tlb_threshold:
536 	if (threshold > FLUSH_TLB_THRESHOLD)
537 		parisc_tlb_flush_threshold = threshold;
538 	else
539 		parisc_tlb_flush_threshold = FLUSH_TLB_THRESHOLD;
540 
541 	printk(KERN_INFO "TLB flush threshold set to %lu KiB\n",
542 		parisc_tlb_flush_threshold/1024);
543 }
544 
545 extern void purge_kernel_dcache_page_asm(unsigned long);
546 extern void clear_user_page_asm(void *, unsigned long);
547 extern void copy_user_page_asm(void *, void *, unsigned long);
548 
549 void flush_kernel_dcache_page_addr(const void *addr)
550 {
551 	unsigned long flags;
552 
553 	flush_kernel_dcache_page_asm(addr);
554 	purge_tlb_start(flags);
555 	pdtlb(SR_KERNEL, addr);
556 	purge_tlb_end(flags);
557 }
558 EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
559 
560 static void flush_cache_page_if_present(struct vm_area_struct *vma,
561 	unsigned long vmaddr, unsigned long pfn)
562 {
563 	pte_t *ptep = get_ptep(vma->vm_mm, vmaddr);
564 
565 	/*
566 	 * The pte check is racy and sometimes the flush will trigger
567 	 * a non-access TLB miss. Hopefully, the page has already been
568 	 * flushed.
569 	 */
570 	if (ptep && pte_needs_flush(*ptep))
571 		flush_cache_page(vma, vmaddr, pfn);
572 }
573 
574 void copy_user_highpage(struct page *to, struct page *from,
575 	unsigned long vaddr, struct vm_area_struct *vma)
576 {
577 	void *kto, *kfrom;
578 
579 	kfrom = kmap_local_page(from);
580 	kto = kmap_local_page(to);
581 	flush_cache_page_if_present(vma, vaddr, page_to_pfn(from));
582 	copy_page_asm(kto, kfrom);
583 	kunmap_local(kto);
584 	kunmap_local(kfrom);
585 }
586 
587 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
588 		unsigned long user_vaddr, void *dst, void *src, int len)
589 {
590 	flush_cache_page_if_present(vma, user_vaddr, page_to_pfn(page));
591 	memcpy(dst, src, len);
592 	flush_kernel_dcache_range_asm((unsigned long)dst, (unsigned long)dst + len);
593 }
594 
595 void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
596 		unsigned long user_vaddr, void *dst, void *src, int len)
597 {
598 	flush_cache_page_if_present(vma, user_vaddr, page_to_pfn(page));
599 	memcpy(dst, src, len);
600 }
601 
602 /* __flush_tlb_range()
603  *
604  * returns 1 if all TLBs were flushed.
605  */
606 int __flush_tlb_range(unsigned long sid, unsigned long start,
607 		      unsigned long end)
608 {
609 	unsigned long flags;
610 
611 	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
612 	    end - start >= parisc_tlb_flush_threshold) {
613 		flush_tlb_all();
614 		return 1;
615 	}
616 
617 	/* Purge TLB entries for small ranges using the pdtlb and
618 	   pitlb instructions.  These instructions execute locally
619 	   but cause a purge request to be broadcast to other TLBs.  */
620 	while (start < end) {
621 		purge_tlb_start(flags);
622 		mtsp(sid, SR_TEMP1);
623 		pdtlb(SR_TEMP1, start);
624 		pitlb(SR_TEMP1, start);
625 		purge_tlb_end(flags);
626 		start += PAGE_SIZE;
627 	}
628 	return 0;
629 }
630 
631 static void flush_cache_pages(struct vm_area_struct *vma, unsigned long start, unsigned long end)
632 {
633 	unsigned long addr, pfn;
634 	pte_t *ptep;
635 
636 	for (addr = start; addr < end; addr += PAGE_SIZE) {
637 		/*
638 		 * The vma can contain pages that aren't present. Although
639 		 * the pte search is expensive, we need the pte to find the
640 		 * page pfn and to check whether the page should be flushed.
641 		 */
642 		ptep = get_ptep(vma->vm_mm, addr);
643 		if (ptep && pte_needs_flush(*ptep)) {
644 			if (parisc_requires_coherency()) {
645 				flush_user_cache_page(vma, addr);
646 			} else {
647 				pfn = pte_pfn(*ptep);
648 				if (WARN_ON(!pfn_valid(pfn)))
649 					return;
650 				__flush_cache_page(vma, addr, PFN_PHYS(pfn));
651 			}
652 		}
653 	}
654 }
655 
656 static inline unsigned long mm_total_size(struct mm_struct *mm)
657 {
658 	struct vm_area_struct *vma;
659 	unsigned long usize = 0;
660 
661 	for (vma = mm->mmap; vma && usize < parisc_cache_flush_threshold; vma = vma->vm_next)
662 		usize += vma->vm_end - vma->vm_start;
663 	return usize;
664 }
665 
666 void flush_cache_mm(struct mm_struct *mm)
667 {
668 	struct vm_area_struct *vma;
669 
670 	/*
671 	 * Flushing the whole cache on each cpu takes forever on
672 	 * rp3440, etc. So, avoid it if the mm isn't too big.
673 	 *
674 	 * Note that we must flush the entire cache on machines
675 	 * with aliasing caches to prevent random segmentation
676 	 * faults.
677 	 */
678 	if (!parisc_requires_coherency()
679 	    ||  mm_total_size(mm) >= parisc_cache_flush_threshold) {
680 		if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
681 			return;
682 		flush_tlb_all();
683 		flush_cache_all();
684 		return;
685 	}
686 
687 	/* Flush mm */
688 	for (vma = mm->mmap; vma; vma = vma->vm_next)
689 		flush_cache_pages(vma, vma->vm_start, vma->vm_end);
690 }
691 
692 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
693 {
694 	if (!parisc_requires_coherency()
695 	    || end - start >= parisc_cache_flush_threshold) {
696 		if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
697 			return;
698 		flush_tlb_range(vma, start, end);
699 		flush_cache_all();
700 		return;
701 	}
702 
703 	flush_cache_pages(vma, start, end);
704 }
705 
706 void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
707 {
708 	if (WARN_ON(!pfn_valid(pfn)))
709 		return;
710 	if (parisc_requires_coherency())
711 		flush_user_cache_page(vma, vmaddr);
712 	else
713 		__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
714 }
715 
716 void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
717 {
718 	if (!PageAnon(page))
719 		return;
720 
721 	if (parisc_requires_coherency()) {
722 		if (vma->vm_flags & VM_SHARED)
723 			flush_data_cache();
724 		else
725 			flush_user_cache_page(vma, vmaddr);
726 		return;
727 	}
728 
729 	flush_tlb_page(vma, vmaddr);
730 	preempt_disable();
731 	flush_dcache_page_asm(page_to_phys(page), vmaddr);
732 	preempt_enable();
733 }
734 
735 void flush_kernel_vmap_range(void *vaddr, int size)
736 {
737 	unsigned long start = (unsigned long)vaddr;
738 	unsigned long end = start + size;
739 
740 	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
741 	    (unsigned long)size >= parisc_cache_flush_threshold) {
742 		flush_tlb_kernel_range(start, end);
743 		flush_data_cache();
744 		return;
745 	}
746 
747 	flush_kernel_dcache_range_asm(start, end);
748 	flush_tlb_kernel_range(start, end);
749 }
750 EXPORT_SYMBOL(flush_kernel_vmap_range);
751 
752 void invalidate_kernel_vmap_range(void *vaddr, int size)
753 {
754 	unsigned long start = (unsigned long)vaddr;
755 	unsigned long end = start + size;
756 
757 	/* Ensure DMA is complete */
758 	asm_syncdma();
759 
760 	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
761 	    (unsigned long)size >= parisc_cache_flush_threshold) {
762 		flush_tlb_kernel_range(start, end);
763 		flush_data_cache();
764 		return;
765 	}
766 
767 	purge_kernel_dcache_range_asm(start, end);
768 	flush_tlb_kernel_range(start, end);
769 }
770 EXPORT_SYMBOL(invalidate_kernel_vmap_range);
771