xref: /linux/arch/parisc/kernel/cache.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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 <linux/syscalls.h>
23 #include <asm/pdc.h>
24 #include <asm/cache.h>
25 #include <asm/cacheflush.h>
26 #include <asm/tlbflush.h>
27 #include <asm/page.h>
28 #include <asm/processor.h>
29 #include <asm/sections.h>
30 #include <asm/shmparam.h>
31 #include <asm/mmu_context.h>
32 #include <asm/cachectl.h>
33 
34 int split_tlb __ro_after_init;
35 int dcache_stride __ro_after_init;
36 int icache_stride __ro_after_init;
37 EXPORT_SYMBOL(dcache_stride);
38 
39 void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
40 EXPORT_SYMBOL(flush_dcache_page_asm);
41 void purge_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
42 void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
43 
44 /* Internal implementation in arch/parisc/kernel/pacache.S */
45 void flush_data_cache_local(void *);  /* flushes local data-cache only */
46 void flush_instruction_cache_local(void); /* flushes local code-cache only */
47 
48 /* On some machines (i.e., ones with the Merced bus), there can be
49  * only a single PxTLB broadcast at a time; this must be guaranteed
50  * by software. We need a spinlock around all TLB flushes to ensure
51  * this.
52  */
53 DEFINE_SPINLOCK(pa_tlb_flush_lock);
54 
55 #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
56 int pa_serialize_tlb_flushes __ro_after_init;
57 #endif
58 
59 struct pdc_cache_info cache_info __ro_after_init;
60 #ifndef CONFIG_PA20
61 struct pdc_btlb_info btlb_info;
62 #endif
63 
64 DEFINE_STATIC_KEY_TRUE(parisc_has_cache);
65 DEFINE_STATIC_KEY_TRUE(parisc_has_dcache);
66 DEFINE_STATIC_KEY_TRUE(parisc_has_icache);
67 
68 static void cache_flush_local_cpu(void *dummy)
69 {
70 	if (static_branch_likely(&parisc_has_icache))
71 		flush_instruction_cache_local();
72 	if (static_branch_likely(&parisc_has_dcache))
73 		flush_data_cache_local(NULL);
74 }
75 
76 void flush_cache_all_local(void)
77 {
78 	cache_flush_local_cpu(NULL);
79 }
80 
81 void flush_cache_all(void)
82 {
83 	if (static_branch_likely(&parisc_has_cache))
84 		on_each_cpu(cache_flush_local_cpu, NULL, 1);
85 }
86 
87 static inline void flush_data_cache(void)
88 {
89 	if (static_branch_likely(&parisc_has_dcache))
90 		on_each_cpu(flush_data_cache_local, NULL, 1);
91 }
92 
93 
94 /* Kernel virtual address of pfn.  */
95 #define pfn_va(pfn)	__va(PFN_PHYS(pfn))
96 
97 void __update_cache(pte_t pte)
98 {
99 	unsigned long pfn = pte_pfn(pte);
100 	struct folio *folio;
101 	unsigned int nr;
102 
103 	/* We don't have pte special.  As a result, we can be called with
104 	   an invalid pfn and we don't need to flush the kernel dcache page.
105 	   This occurs with FireGL card in C8000.  */
106 	if (!pfn_valid(pfn))
107 		return;
108 
109 	folio = page_folio(pfn_to_page(pfn));
110 	pfn = folio_pfn(folio);
111 	nr = folio_nr_pages(folio);
112 	if (folio_flush_mapping(folio) &&
113 	    test_bit(PG_dcache_dirty, &folio->flags)) {
114 		while (nr--)
115 			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
116 		clear_bit(PG_dcache_dirty, &folio->flags);
117 	} else if (parisc_requires_coherency())
118 		while (nr--)
119 			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
120 }
121 
122 void
123 show_cache_info(struct seq_file *m)
124 {
125 	char buf[32];
126 
127 	seq_printf(m, "I-cache\t\t: %ld KB\n",
128 		cache_info.ic_size/1024 );
129 	if (cache_info.dc_loop != 1)
130 		snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
131 	seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s, alias=%d)\n",
132 		cache_info.dc_size/1024,
133 		(cache_info.dc_conf.cc_wt ? "WT":"WB"),
134 		(cache_info.dc_conf.cc_sh ? ", shared I/D":""),
135 		((cache_info.dc_loop == 1) ? "direct mapped" : buf),
136 		cache_info.dc_conf.cc_alias
137 	);
138 	seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
139 		cache_info.it_size,
140 		cache_info.dt_size,
141 		cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
142 	);
143 
144 #ifndef CONFIG_PA20
145 	/* BTLB - Block TLB */
146 	if (btlb_info.max_size==0) {
147 		seq_printf(m, "BTLB\t\t: not supported\n" );
148 	} else {
149 		seq_printf(m,
150 		"BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
151 		"BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
152 		"BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
153 		btlb_info.max_size, (int)4096,
154 		btlb_info.max_size>>8,
155 		btlb_info.fixed_range_info.num_i,
156 		btlb_info.fixed_range_info.num_d,
157 		btlb_info.fixed_range_info.num_comb,
158 		btlb_info.variable_range_info.num_i,
159 		btlb_info.variable_range_info.num_d,
160 		btlb_info.variable_range_info.num_comb
161 		);
162 	}
163 #endif
164 }
165 
166 void __init
167 parisc_cache_init(void)
168 {
169 	if (pdc_cache_info(&cache_info) < 0)
170 		panic("parisc_cache_init: pdc_cache_info failed");
171 
172 #if 0
173 	printk("ic_size %lx dc_size %lx it_size %lx\n",
174 		cache_info.ic_size,
175 		cache_info.dc_size,
176 		cache_info.it_size);
177 
178 	printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
179 		cache_info.dc_base,
180 		cache_info.dc_stride,
181 		cache_info.dc_count,
182 		cache_info.dc_loop);
183 
184 	printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
185 		*(unsigned long *) (&cache_info.dc_conf),
186 		cache_info.dc_conf.cc_alias,
187 		cache_info.dc_conf.cc_block,
188 		cache_info.dc_conf.cc_line,
189 		cache_info.dc_conf.cc_shift);
190 	printk("	wt %d sh %d cst %d hv %d\n",
191 		cache_info.dc_conf.cc_wt,
192 		cache_info.dc_conf.cc_sh,
193 		cache_info.dc_conf.cc_cst,
194 		cache_info.dc_conf.cc_hv);
195 
196 	printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
197 		cache_info.ic_base,
198 		cache_info.ic_stride,
199 		cache_info.ic_count,
200 		cache_info.ic_loop);
201 
202 	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",
203 		cache_info.it_sp_base,
204 		cache_info.it_sp_stride,
205 		cache_info.it_sp_count,
206 		cache_info.it_loop,
207 		cache_info.it_off_base,
208 		cache_info.it_off_stride,
209 		cache_info.it_off_count);
210 
211 	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",
212 		cache_info.dt_sp_base,
213 		cache_info.dt_sp_stride,
214 		cache_info.dt_sp_count,
215 		cache_info.dt_loop,
216 		cache_info.dt_off_base,
217 		cache_info.dt_off_stride,
218 		cache_info.dt_off_count);
219 
220 	printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
221 		*(unsigned long *) (&cache_info.ic_conf),
222 		cache_info.ic_conf.cc_alias,
223 		cache_info.ic_conf.cc_block,
224 		cache_info.ic_conf.cc_line,
225 		cache_info.ic_conf.cc_shift);
226 	printk("	wt %d sh %d cst %d hv %d\n",
227 		cache_info.ic_conf.cc_wt,
228 		cache_info.ic_conf.cc_sh,
229 		cache_info.ic_conf.cc_cst,
230 		cache_info.ic_conf.cc_hv);
231 
232 	printk("D-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
233 		cache_info.dt_conf.tc_sh,
234 		cache_info.dt_conf.tc_page,
235 		cache_info.dt_conf.tc_cst,
236 		cache_info.dt_conf.tc_aid,
237 		cache_info.dt_conf.tc_sr);
238 
239 	printk("I-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
240 		cache_info.it_conf.tc_sh,
241 		cache_info.it_conf.tc_page,
242 		cache_info.it_conf.tc_cst,
243 		cache_info.it_conf.tc_aid,
244 		cache_info.it_conf.tc_sr);
245 #endif
246 
247 	split_tlb = 0;
248 	if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
249 		if (cache_info.dt_conf.tc_sh == 2)
250 			printk(KERN_WARNING "Unexpected TLB configuration. "
251 			"Will flush I/D separately (could be optimized).\n");
252 
253 		split_tlb = 1;
254 	}
255 
256 	/* "New and Improved" version from Jim Hull
257 	 *	(1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
258 	 * The following CAFL_STRIDE is an optimized version, see
259 	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
260 	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
261 	 */
262 #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
263 	dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
264 	icache_stride = CAFL_STRIDE(cache_info.ic_conf);
265 #undef CAFL_STRIDE
266 
267 	/* stride needs to be non-zero, otherwise cache flushes will not work */
268 	WARN_ON(cache_info.dc_size && dcache_stride == 0);
269 	WARN_ON(cache_info.ic_size && icache_stride == 0);
270 
271 	if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
272 						PDC_MODEL_NVA_UNSUPPORTED) {
273 		printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
274 #if 0
275 		panic("SMP kernel required to avoid non-equivalent aliasing");
276 #endif
277 	}
278 }
279 
280 void disable_sr_hashing(void)
281 {
282 	int srhash_type, retval;
283 	unsigned long space_bits;
284 
285 	switch (boot_cpu_data.cpu_type) {
286 	case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
287 		BUG();
288 		return;
289 
290 	case pcxs:
291 	case pcxt:
292 	case pcxt_:
293 		srhash_type = SRHASH_PCXST;
294 		break;
295 
296 	case pcxl:
297 		srhash_type = SRHASH_PCXL;
298 		break;
299 
300 	case pcxl2: /* pcxl2 doesn't support space register hashing */
301 		return;
302 
303 	default: /* Currently all PA2.0 machines use the same ins. sequence */
304 		srhash_type = SRHASH_PA20;
305 		break;
306 	}
307 
308 	disable_sr_hashing_asm(srhash_type);
309 
310 	retval = pdc_spaceid_bits(&space_bits);
311 	/* If this procedure isn't implemented, don't panic. */
312 	if (retval < 0 && retval != PDC_BAD_OPTION)
313 		panic("pdc_spaceid_bits call failed.\n");
314 	if (space_bits != 0)
315 		panic("SpaceID hashing is still on!\n");
316 }
317 
318 static inline void
319 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
320 		   unsigned long physaddr)
321 {
322 	if (!static_branch_likely(&parisc_has_cache))
323 		return;
324 	preempt_disable();
325 	flush_dcache_page_asm(physaddr, vmaddr);
326 	if (vma->vm_flags & VM_EXEC)
327 		flush_icache_page_asm(physaddr, vmaddr);
328 	preempt_enable();
329 }
330 
331 static void flush_user_cache_page(struct vm_area_struct *vma, unsigned long vmaddr)
332 {
333 	unsigned long flags, space, pgd, prot;
334 #ifdef CONFIG_TLB_PTLOCK
335 	unsigned long pgd_lock;
336 #endif
337 
338 	vmaddr &= PAGE_MASK;
339 
340 	preempt_disable();
341 
342 	/* Set context for flush */
343 	local_irq_save(flags);
344 	prot = mfctl(8);
345 	space = mfsp(SR_USER);
346 	pgd = mfctl(25);
347 #ifdef CONFIG_TLB_PTLOCK
348 	pgd_lock = mfctl(28);
349 #endif
350 	switch_mm_irqs_off(NULL, vma->vm_mm, NULL);
351 	local_irq_restore(flags);
352 
353 	flush_user_dcache_range_asm(vmaddr, vmaddr + PAGE_SIZE);
354 	if (vma->vm_flags & VM_EXEC)
355 		flush_user_icache_range_asm(vmaddr, vmaddr + PAGE_SIZE);
356 	flush_tlb_page(vma, vmaddr);
357 
358 	/* Restore previous context */
359 	local_irq_save(flags);
360 #ifdef CONFIG_TLB_PTLOCK
361 	mtctl(pgd_lock, 28);
362 #endif
363 	mtctl(pgd, 25);
364 	mtsp(space, SR_USER);
365 	mtctl(prot, 8);
366 	local_irq_restore(flags);
367 
368 	preempt_enable();
369 }
370 
371 void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
372 		unsigned int nr)
373 {
374 	void *kaddr = page_address(page);
375 
376 	for (;;) {
377 		flush_kernel_dcache_page_addr(kaddr);
378 		flush_kernel_icache_page(kaddr);
379 		if (--nr == 0)
380 			break;
381 		kaddr += PAGE_SIZE;
382 	}
383 }
384 
385 static inline pte_t *get_ptep(struct mm_struct *mm, unsigned long addr)
386 {
387 	pte_t *ptep = NULL;
388 	pgd_t *pgd = mm->pgd;
389 	p4d_t *p4d;
390 	pud_t *pud;
391 	pmd_t *pmd;
392 
393 	if (!pgd_none(*pgd)) {
394 		p4d = p4d_offset(pgd, addr);
395 		if (!p4d_none(*p4d)) {
396 			pud = pud_offset(p4d, addr);
397 			if (!pud_none(*pud)) {
398 				pmd = pmd_offset(pud, addr);
399 				if (!pmd_none(*pmd))
400 					ptep = pte_offset_map(pmd, addr);
401 			}
402 		}
403 	}
404 	return ptep;
405 }
406 
407 static inline bool pte_needs_flush(pte_t pte)
408 {
409 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_NO_CACHE))
410 		== (_PAGE_PRESENT | _PAGE_ACCESSED);
411 }
412 
413 void flush_dcache_folio(struct folio *folio)
414 {
415 	struct address_space *mapping = folio_flush_mapping(folio);
416 	struct vm_area_struct *vma;
417 	unsigned long addr, old_addr = 0;
418 	void *kaddr;
419 	unsigned long count = 0;
420 	unsigned long i, nr, flags;
421 	pgoff_t pgoff;
422 
423 	if (mapping && !mapping_mapped(mapping)) {
424 		set_bit(PG_dcache_dirty, &folio->flags);
425 		return;
426 	}
427 
428 	nr = folio_nr_pages(folio);
429 	kaddr = folio_address(folio);
430 	for (i = 0; i < nr; i++)
431 		flush_kernel_dcache_page_addr(kaddr + i * PAGE_SIZE);
432 
433 	if (!mapping)
434 		return;
435 
436 	pgoff = folio->index;
437 
438 	/*
439 	 * We have carefully arranged in arch_get_unmapped_area() that
440 	 * *any* mappings of a file are always congruently mapped (whether
441 	 * declared as MAP_PRIVATE or MAP_SHARED), so we only need
442 	 * to flush one address here for them all to become coherent
443 	 * on machines that support equivalent aliasing
444 	 */
445 	flush_dcache_mmap_lock_irqsave(mapping, flags);
446 	vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff + nr - 1) {
447 		unsigned long offset = pgoff - vma->vm_pgoff;
448 		unsigned long pfn = folio_pfn(folio);
449 
450 		addr = vma->vm_start;
451 		nr = folio_nr_pages(folio);
452 		if (offset > -nr) {
453 			pfn -= offset;
454 			nr += offset;
455 		} else {
456 			addr += offset * PAGE_SIZE;
457 		}
458 		if (addr + nr * PAGE_SIZE > vma->vm_end)
459 			nr = (vma->vm_end - addr) / PAGE_SIZE;
460 
461 		if (parisc_requires_coherency()) {
462 			for (i = 0; i < nr; i++) {
463 				pte_t *ptep = get_ptep(vma->vm_mm,
464 							addr + i * PAGE_SIZE);
465 				if (!ptep)
466 					continue;
467 				if (pte_needs_flush(*ptep))
468 					flush_user_cache_page(vma,
469 							addr + i * PAGE_SIZE);
470 				/* Optimise accesses to the same table? */
471 				pte_unmap(ptep);
472 			}
473 		} else {
474 			/*
475 			 * The TLB is the engine of coherence on parisc:
476 			 * The CPU is entitled to speculate any page
477 			 * with a TLB mapping, so here we kill the
478 			 * mapping then flush the page along a special
479 			 * flush only alias mapping. This guarantees that
480 			 * the page is no-longer in the cache for any
481 			 * process and nor may it be speculatively read
482 			 * in (until the user or kernel specifically
483 			 * accesses it, of course)
484 			 */
485 			for (i = 0; i < nr; i++)
486 				flush_tlb_page(vma, addr + i * PAGE_SIZE);
487 			if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
488 					!= (addr & (SHM_COLOUR - 1))) {
489 				for (i = 0; i < nr; i++)
490 					__flush_cache_page(vma,
491 						addr + i * PAGE_SIZE,
492 						(pfn + i) * PAGE_SIZE);
493 				/*
494 				 * Software is allowed to have any number
495 				 * of private mappings to a page.
496 				 */
497 				if (!(vma->vm_flags & VM_SHARED))
498 					continue;
499 				if (old_addr)
500 					pr_err("INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n",
501 						old_addr, addr, vma->vm_file);
502 				if (nr == folio_nr_pages(folio))
503 					old_addr = addr;
504 			}
505 		}
506 		WARN_ON(++count == 4096);
507 	}
508 	flush_dcache_mmap_unlock_irqrestore(mapping, flags);
509 }
510 EXPORT_SYMBOL(flush_dcache_folio);
511 
512 /* Defined in arch/parisc/kernel/pacache.S */
513 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
514 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
515 
516 #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
517 static unsigned long parisc_cache_flush_threshold __ro_after_init = FLUSH_THRESHOLD;
518 
519 #define FLUSH_TLB_THRESHOLD (16*1024) /* 16 KiB minimum TLB threshold */
520 static unsigned long parisc_tlb_flush_threshold __ro_after_init = ~0UL;
521 
522 void __init parisc_setup_cache_timing(void)
523 {
524 	unsigned long rangetime, alltime;
525 	unsigned long size;
526 	unsigned long threshold, threshold2;
527 
528 	alltime = mfctl(16);
529 	flush_data_cache();
530 	alltime = mfctl(16) - alltime;
531 
532 	size = (unsigned long)(_end - _text);
533 	rangetime = mfctl(16);
534 	flush_kernel_dcache_range((unsigned long)_text, size);
535 	rangetime = mfctl(16) - rangetime;
536 
537 	printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
538 		alltime, size, rangetime);
539 
540 	threshold = L1_CACHE_ALIGN((unsigned long)((uint64_t)size * alltime / rangetime));
541 	pr_info("Calculated flush threshold is %lu KiB\n",
542 		threshold/1024);
543 
544 	/*
545 	 * The threshold computed above isn't very reliable. The following
546 	 * heuristic works reasonably well on c8000/rp3440.
547 	 */
548 	threshold2 = cache_info.dc_size * num_online_cpus();
549 	parisc_cache_flush_threshold = threshold2;
550 	printk(KERN_INFO "Cache flush threshold set to %lu KiB\n",
551 		parisc_cache_flush_threshold/1024);
552 
553 	/* calculate TLB flush threshold */
554 
555 	/* On SMP machines, skip the TLB measure of kernel text which
556 	 * has been mapped as huge pages. */
557 	if (num_online_cpus() > 1 && !parisc_requires_coherency()) {
558 		threshold = max(cache_info.it_size, cache_info.dt_size);
559 		threshold *= PAGE_SIZE;
560 		threshold /= num_online_cpus();
561 		goto set_tlb_threshold;
562 	}
563 
564 	size = (unsigned long)_end - (unsigned long)_text;
565 	rangetime = mfctl(16);
566 	flush_tlb_kernel_range((unsigned long)_text, (unsigned long)_end);
567 	rangetime = mfctl(16) - rangetime;
568 
569 	alltime = mfctl(16);
570 	flush_tlb_all();
571 	alltime = mfctl(16) - alltime;
572 
573 	printk(KERN_INFO "Whole TLB flush %lu cycles, Range flush %lu bytes %lu cycles\n",
574 		alltime, size, rangetime);
575 
576 	threshold = PAGE_ALIGN((num_online_cpus() * size * alltime) / rangetime);
577 	printk(KERN_INFO "Calculated TLB flush threshold %lu KiB\n",
578 		threshold/1024);
579 
580 set_tlb_threshold:
581 	if (threshold > FLUSH_TLB_THRESHOLD)
582 		parisc_tlb_flush_threshold = threshold;
583 	else
584 		parisc_tlb_flush_threshold = FLUSH_TLB_THRESHOLD;
585 
586 	printk(KERN_INFO "TLB flush threshold set to %lu KiB\n",
587 		parisc_tlb_flush_threshold/1024);
588 }
589 
590 extern void purge_kernel_dcache_page_asm(unsigned long);
591 extern void clear_user_page_asm(void *, unsigned long);
592 extern void copy_user_page_asm(void *, void *, unsigned long);
593 
594 void flush_kernel_dcache_page_addr(const void *addr)
595 {
596 	unsigned long flags;
597 
598 	flush_kernel_dcache_page_asm(addr);
599 	purge_tlb_start(flags);
600 	pdtlb(SR_KERNEL, addr);
601 	purge_tlb_end(flags);
602 }
603 EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
604 
605 static void flush_cache_page_if_present(struct vm_area_struct *vma,
606 	unsigned long vmaddr, unsigned long pfn)
607 {
608 	bool needs_flush = false;
609 	pte_t *ptep;
610 
611 	/*
612 	 * The pte check is racy and sometimes the flush will trigger
613 	 * a non-access TLB miss. Hopefully, the page has already been
614 	 * flushed.
615 	 */
616 	ptep = get_ptep(vma->vm_mm, vmaddr);
617 	if (ptep) {
618 		needs_flush = pte_needs_flush(*ptep);
619 		pte_unmap(ptep);
620 	}
621 	if (needs_flush)
622 		flush_cache_page(vma, vmaddr, pfn);
623 }
624 
625 void copy_user_highpage(struct page *to, struct page *from,
626 	unsigned long vaddr, struct vm_area_struct *vma)
627 {
628 	void *kto, *kfrom;
629 
630 	kfrom = kmap_local_page(from);
631 	kto = kmap_local_page(to);
632 	flush_cache_page_if_present(vma, vaddr, page_to_pfn(from));
633 	copy_page_asm(kto, kfrom);
634 	kunmap_local(kto);
635 	kunmap_local(kfrom);
636 }
637 
638 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
639 		unsigned long user_vaddr, void *dst, void *src, int len)
640 {
641 	flush_cache_page_if_present(vma, user_vaddr, page_to_pfn(page));
642 	memcpy(dst, src, len);
643 	flush_kernel_dcache_range_asm((unsigned long)dst, (unsigned long)dst + len);
644 }
645 
646 void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
647 		unsigned long user_vaddr, void *dst, void *src, int len)
648 {
649 	flush_cache_page_if_present(vma, user_vaddr, page_to_pfn(page));
650 	memcpy(dst, src, len);
651 }
652 
653 /* __flush_tlb_range()
654  *
655  * returns 1 if all TLBs were flushed.
656  */
657 int __flush_tlb_range(unsigned long sid, unsigned long start,
658 		      unsigned long end)
659 {
660 	unsigned long flags;
661 
662 	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
663 	    end - start >= parisc_tlb_flush_threshold) {
664 		flush_tlb_all();
665 		return 1;
666 	}
667 
668 	/* Purge TLB entries for small ranges using the pdtlb and
669 	   pitlb instructions.  These instructions execute locally
670 	   but cause a purge request to be broadcast to other TLBs.  */
671 	while (start < end) {
672 		purge_tlb_start(flags);
673 		mtsp(sid, SR_TEMP1);
674 		pdtlb(SR_TEMP1, start);
675 		pitlb(SR_TEMP1, start);
676 		purge_tlb_end(flags);
677 		start += PAGE_SIZE;
678 	}
679 	return 0;
680 }
681 
682 static void flush_cache_pages(struct vm_area_struct *vma, unsigned long start, unsigned long end)
683 {
684 	unsigned long addr, pfn;
685 	pte_t *ptep;
686 
687 	for (addr = start; addr < end; addr += PAGE_SIZE) {
688 		bool needs_flush = false;
689 		/*
690 		 * The vma can contain pages that aren't present. Although
691 		 * the pte search is expensive, we need the pte to find the
692 		 * page pfn and to check whether the page should be flushed.
693 		 */
694 		ptep = get_ptep(vma->vm_mm, addr);
695 		if (ptep) {
696 			needs_flush = pte_needs_flush(*ptep);
697 			pfn = pte_pfn(*ptep);
698 			pte_unmap(ptep);
699 		}
700 		if (needs_flush) {
701 			if (parisc_requires_coherency()) {
702 				flush_user_cache_page(vma, addr);
703 			} else {
704 				if (WARN_ON(!pfn_valid(pfn)))
705 					return;
706 				__flush_cache_page(vma, addr, PFN_PHYS(pfn));
707 			}
708 		}
709 	}
710 }
711 
712 static inline unsigned long mm_total_size(struct mm_struct *mm)
713 {
714 	struct vm_area_struct *vma;
715 	unsigned long usize = 0;
716 	VMA_ITERATOR(vmi, mm, 0);
717 
718 	for_each_vma(vmi, vma) {
719 		if (usize >= parisc_cache_flush_threshold)
720 			break;
721 		usize += vma->vm_end - vma->vm_start;
722 	}
723 	return usize;
724 }
725 
726 void flush_cache_mm(struct mm_struct *mm)
727 {
728 	struct vm_area_struct *vma;
729 	VMA_ITERATOR(vmi, mm, 0);
730 
731 	/*
732 	 * Flushing the whole cache on each cpu takes forever on
733 	 * rp3440, etc. So, avoid it if the mm isn't too big.
734 	 *
735 	 * Note that we must flush the entire cache on machines
736 	 * with aliasing caches to prevent random segmentation
737 	 * faults.
738 	 */
739 	if (!parisc_requires_coherency()
740 	    ||  mm_total_size(mm) >= parisc_cache_flush_threshold) {
741 		if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
742 			return;
743 		flush_tlb_all();
744 		flush_cache_all();
745 		return;
746 	}
747 
748 	/* Flush mm */
749 	for_each_vma(vmi, vma)
750 		flush_cache_pages(vma, vma->vm_start, vma->vm_end);
751 }
752 
753 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
754 {
755 	if (!parisc_requires_coherency()
756 	    || end - start >= parisc_cache_flush_threshold) {
757 		if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
758 			return;
759 		flush_tlb_range(vma, start, end);
760 		flush_cache_all();
761 		return;
762 	}
763 
764 	flush_cache_pages(vma, start, end);
765 }
766 
767 void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
768 {
769 	if (WARN_ON(!pfn_valid(pfn)))
770 		return;
771 	if (parisc_requires_coherency())
772 		flush_user_cache_page(vma, vmaddr);
773 	else
774 		__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
775 }
776 
777 void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
778 {
779 	if (!PageAnon(page))
780 		return;
781 
782 	if (parisc_requires_coherency()) {
783 		if (vma->vm_flags & VM_SHARED)
784 			flush_data_cache();
785 		else
786 			flush_user_cache_page(vma, vmaddr);
787 		return;
788 	}
789 
790 	flush_tlb_page(vma, vmaddr);
791 	preempt_disable();
792 	flush_dcache_page_asm(page_to_phys(page), vmaddr);
793 	preempt_enable();
794 }
795 
796 void flush_kernel_vmap_range(void *vaddr, int size)
797 {
798 	unsigned long start = (unsigned long)vaddr;
799 	unsigned long end = start + size;
800 
801 	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
802 	    (unsigned long)size >= parisc_cache_flush_threshold) {
803 		flush_tlb_kernel_range(start, end);
804 		flush_data_cache();
805 		return;
806 	}
807 
808 	flush_kernel_dcache_range_asm(start, end);
809 	flush_tlb_kernel_range(start, end);
810 }
811 EXPORT_SYMBOL(flush_kernel_vmap_range);
812 
813 void invalidate_kernel_vmap_range(void *vaddr, int size)
814 {
815 	unsigned long start = (unsigned long)vaddr;
816 	unsigned long end = start + size;
817 
818 	/* Ensure DMA is complete */
819 	asm_syncdma();
820 
821 	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
822 	    (unsigned long)size >= parisc_cache_flush_threshold) {
823 		flush_tlb_kernel_range(start, end);
824 		flush_data_cache();
825 		return;
826 	}
827 
828 	purge_kernel_dcache_range_asm(start, end);
829 	flush_tlb_kernel_range(start, end);
830 }
831 EXPORT_SYMBOL(invalidate_kernel_vmap_range);
832 
833 
834 SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, bytes,
835 	unsigned int, cache)
836 {
837 	unsigned long start, end;
838 	ASM_EXCEPTIONTABLE_VAR(error);
839 
840 	if (bytes == 0)
841 		return 0;
842 	if (!access_ok((void __user *) addr, bytes))
843 		return -EFAULT;
844 
845 	end = addr + bytes;
846 
847 	if (cache & DCACHE) {
848 		start = addr;
849 		__asm__ __volatile__ (
850 #ifdef CONFIG_64BIT
851 			"1: cmpb,*<<,n	%0,%2,1b\n"
852 #else
853 			"1: cmpb,<<,n	%0,%2,1b\n"
854 #endif
855 			"   fic,m	%3(%4,%0)\n"
856 			"2: sync\n"
857 			ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 2b, "%1")
858 			: "+r" (start), "+r" (error)
859 			: "r" (end), "r" (dcache_stride), "i" (SR_USER));
860 	}
861 
862 	if (cache & ICACHE && error == 0) {
863 		start = addr;
864 		__asm__ __volatile__ (
865 #ifdef CONFIG_64BIT
866 			"1: cmpb,*<<,n	%0,%2,1b\n"
867 #else
868 			"1: cmpb,<<,n	%0,%2,1b\n"
869 #endif
870 			"   fdc,m	%3(%4,%0)\n"
871 			"2: sync\n"
872 			ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 2b, "%1")
873 			: "+r" (start), "+r" (error)
874 			: "r" (end), "r" (icache_stride), "i" (SR_USER));
875 	}
876 
877 	return error;
878 }
879