xref: /linux/arch/parisc/kernel/cache.c (revision f63a47b34b140ed1ca39d7e4bd4f1cdc617fc316)
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 <linux/vmalloc.h>
24  #include <asm/pdc.h>
25  #include <asm/cache.h>
26  #include <asm/cacheflush.h>
27  #include <asm/tlbflush.h>
28  #include <asm/page.h>
29  #include <asm/processor.h>
30  #include <asm/sections.h>
31  #include <asm/shmparam.h>
32  #include <asm/mmu_context.h>
33  #include <asm/cachectl.h>
34  
35  #define PTR_PAGE_ALIGN_DOWN(addr) PTR_ALIGN_DOWN(addr, PAGE_SIZE)
36  
37  /*
38   * When nonzero, use _PAGE_ACCESSED bit to try to reduce the number
39   * of page flushes done flush_cache_page_if_present. There are some
40   * pros and cons in using this option. It may increase the risk of
41   * random segmentation faults.
42   */
43  #define CONFIG_FLUSH_PAGE_ACCESSED	0
44  
45  int split_tlb __ro_after_init;
46  int dcache_stride __ro_after_init;
47  int icache_stride __ro_after_init;
48  EXPORT_SYMBOL(dcache_stride);
49  
50  /* Internal implementation in arch/parisc/kernel/pacache.S */
51  void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
52  EXPORT_SYMBOL(flush_dcache_page_asm);
53  void purge_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr);
54  void flush_icache_page_asm(unsigned long phys_addr, unsigned long vaddr);
55  void flush_data_cache_local(void *);  /* flushes local data-cache only */
56  void flush_instruction_cache_local(void); /* flushes local code-cache only */
57  
58  static void flush_kernel_dcache_page_addr(const void *addr);
59  
60  /* On some machines (i.e., ones with the Merced bus), there can be
61   * only a single PxTLB broadcast at a time; this must be guaranteed
62   * by software. We need a spinlock around all TLB flushes to ensure
63   * this.
64   */
65  DEFINE_SPINLOCK(pa_tlb_flush_lock);
66  
67  #if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
68  int pa_serialize_tlb_flushes __ro_after_init;
69  #endif
70  
71  struct pdc_cache_info cache_info __ro_after_init;
72  #ifndef CONFIG_PA20
73  struct pdc_btlb_info btlb_info;
74  #endif
75  
76  DEFINE_STATIC_KEY_TRUE(parisc_has_cache);
77  DEFINE_STATIC_KEY_TRUE(parisc_has_dcache);
78  DEFINE_STATIC_KEY_TRUE(parisc_has_icache);
79  
80  static void cache_flush_local_cpu(void *dummy)
81  {
82  	if (static_branch_likely(&parisc_has_icache))
83  		flush_instruction_cache_local();
84  	if (static_branch_likely(&parisc_has_dcache))
85  		flush_data_cache_local(NULL);
86  }
87  
88  void flush_cache_all_local(void)
89  {
90  	cache_flush_local_cpu(NULL);
91  }
92  
93  void flush_cache_all(void)
94  {
95  	if (static_branch_likely(&parisc_has_cache))
96  		on_each_cpu(cache_flush_local_cpu, NULL, 1);
97  }
98  
99  static inline void flush_data_cache(void)
100  {
101  	if (static_branch_likely(&parisc_has_dcache))
102  		on_each_cpu(flush_data_cache_local, NULL, 1);
103  }
104  
105  
106  /* Kernel virtual address of pfn.  */
107  #define pfn_va(pfn)	__va(PFN_PHYS(pfn))
108  
109  void __update_cache(pte_t pte)
110  {
111  	unsigned long pfn = pte_pfn(pte);
112  	struct folio *folio;
113  	unsigned int nr;
114  
115  	/* We don't have pte special.  As a result, we can be called with
116  	   an invalid pfn and we don't need to flush the kernel dcache page.
117  	   This occurs with FireGL card in C8000.  */
118  	if (!pfn_valid(pfn))
119  		return;
120  
121  	folio = page_folio(pfn_to_page(pfn));
122  	pfn = folio_pfn(folio);
123  	nr = folio_nr_pages(folio);
124  	if (folio_flush_mapping(folio) &&
125  	    test_bit(PG_dcache_dirty, &folio->flags)) {
126  		while (nr--)
127  			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
128  		clear_bit(PG_dcache_dirty, &folio->flags);
129  	} else if (parisc_requires_coherency())
130  		while (nr--)
131  			flush_kernel_dcache_page_addr(pfn_va(pfn + nr));
132  }
133  
134  void
135  show_cache_info(struct seq_file *m)
136  {
137  	char buf[32];
138  
139  	seq_printf(m, "I-cache\t\t: %ld KB\n",
140  		cache_info.ic_size/1024 );
141  	if (cache_info.dc_loop != 1)
142  		snprintf(buf, 32, "%lu-way associative", cache_info.dc_loop);
143  	seq_printf(m, "D-cache\t\t: %ld KB (%s%s, %s, alias=%d)\n",
144  		cache_info.dc_size/1024,
145  		(cache_info.dc_conf.cc_wt ? "WT":"WB"),
146  		(cache_info.dc_conf.cc_sh ? ", shared I/D":""),
147  		((cache_info.dc_loop == 1) ? "direct mapped" : buf),
148  		cache_info.dc_conf.cc_alias
149  	);
150  	seq_printf(m, "ITLB entries\t: %ld\n" "DTLB entries\t: %ld%s\n",
151  		cache_info.it_size,
152  		cache_info.dt_size,
153  		cache_info.dt_conf.tc_sh ? " - shared with ITLB":""
154  	);
155  
156  #ifndef CONFIG_PA20
157  	/* BTLB - Block TLB */
158  	if (btlb_info.max_size==0) {
159  		seq_printf(m, "BTLB\t\t: not supported\n" );
160  	} else {
161  		seq_printf(m,
162  		"BTLB fixed\t: max. %d pages, pagesize=%d (%dMB)\n"
163  		"BTLB fix-entr.\t: %d instruction, %d data (%d combined)\n"
164  		"BTLB var-entr.\t: %d instruction, %d data (%d combined)\n",
165  		btlb_info.max_size, (int)4096,
166  		btlb_info.max_size>>8,
167  		btlb_info.fixed_range_info.num_i,
168  		btlb_info.fixed_range_info.num_d,
169  		btlb_info.fixed_range_info.num_comb,
170  		btlb_info.variable_range_info.num_i,
171  		btlb_info.variable_range_info.num_d,
172  		btlb_info.variable_range_info.num_comb
173  		);
174  	}
175  #endif
176  }
177  
178  void __init
179  parisc_cache_init(void)
180  {
181  	if (pdc_cache_info(&cache_info) < 0)
182  		panic("parisc_cache_init: pdc_cache_info failed");
183  
184  #if 0
185  	printk("ic_size %lx dc_size %lx it_size %lx\n",
186  		cache_info.ic_size,
187  		cache_info.dc_size,
188  		cache_info.it_size);
189  
190  	printk("DC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
191  		cache_info.dc_base,
192  		cache_info.dc_stride,
193  		cache_info.dc_count,
194  		cache_info.dc_loop);
195  
196  	printk("dc_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
197  		*(unsigned long *) (&cache_info.dc_conf),
198  		cache_info.dc_conf.cc_alias,
199  		cache_info.dc_conf.cc_block,
200  		cache_info.dc_conf.cc_line,
201  		cache_info.dc_conf.cc_shift);
202  	printk("	wt %d sh %d cst %d hv %d\n",
203  		cache_info.dc_conf.cc_wt,
204  		cache_info.dc_conf.cc_sh,
205  		cache_info.dc_conf.cc_cst,
206  		cache_info.dc_conf.cc_hv);
207  
208  	printk("IC  base 0x%lx stride 0x%lx count 0x%lx loop 0x%lx\n",
209  		cache_info.ic_base,
210  		cache_info.ic_stride,
211  		cache_info.ic_count,
212  		cache_info.ic_loop);
213  
214  	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",
215  		cache_info.it_sp_base,
216  		cache_info.it_sp_stride,
217  		cache_info.it_sp_count,
218  		cache_info.it_loop,
219  		cache_info.it_off_base,
220  		cache_info.it_off_stride,
221  		cache_info.it_off_count);
222  
223  	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",
224  		cache_info.dt_sp_base,
225  		cache_info.dt_sp_stride,
226  		cache_info.dt_sp_count,
227  		cache_info.dt_loop,
228  		cache_info.dt_off_base,
229  		cache_info.dt_off_stride,
230  		cache_info.dt_off_count);
231  
232  	printk("ic_conf = 0x%lx  alias %d blk %d line %d shift %d\n",
233  		*(unsigned long *) (&cache_info.ic_conf),
234  		cache_info.ic_conf.cc_alias,
235  		cache_info.ic_conf.cc_block,
236  		cache_info.ic_conf.cc_line,
237  		cache_info.ic_conf.cc_shift);
238  	printk("	wt %d sh %d cst %d hv %d\n",
239  		cache_info.ic_conf.cc_wt,
240  		cache_info.ic_conf.cc_sh,
241  		cache_info.ic_conf.cc_cst,
242  		cache_info.ic_conf.cc_hv);
243  
244  	printk("D-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
245  		cache_info.dt_conf.tc_sh,
246  		cache_info.dt_conf.tc_page,
247  		cache_info.dt_conf.tc_cst,
248  		cache_info.dt_conf.tc_aid,
249  		cache_info.dt_conf.tc_sr);
250  
251  	printk("I-TLB conf: sh %d page %d cst %d aid %d sr %d\n",
252  		cache_info.it_conf.tc_sh,
253  		cache_info.it_conf.tc_page,
254  		cache_info.it_conf.tc_cst,
255  		cache_info.it_conf.tc_aid,
256  		cache_info.it_conf.tc_sr);
257  #endif
258  
259  	split_tlb = 0;
260  	if (cache_info.dt_conf.tc_sh == 0 || cache_info.dt_conf.tc_sh == 2) {
261  		if (cache_info.dt_conf.tc_sh == 2)
262  			printk(KERN_WARNING "Unexpected TLB configuration. "
263  			"Will flush I/D separately (could be optimized).\n");
264  
265  		split_tlb = 1;
266  	}
267  
268  	/* "New and Improved" version from Jim Hull
269  	 *	(1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))
270  	 * The following CAFL_STRIDE is an optimized version, see
271  	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html
272  	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html
273  	 */
274  #define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))
275  	dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
276  	icache_stride = CAFL_STRIDE(cache_info.ic_conf);
277  #undef CAFL_STRIDE
278  
279  	/* stride needs to be non-zero, otherwise cache flushes will not work */
280  	WARN_ON(cache_info.dc_size && dcache_stride == 0);
281  	WARN_ON(cache_info.ic_size && icache_stride == 0);
282  
283  	if ((boot_cpu_data.pdc.capabilities & PDC_MODEL_NVA_MASK) ==
284  						PDC_MODEL_NVA_UNSUPPORTED) {
285  		printk(KERN_WARNING "parisc_cache_init: Only equivalent aliasing supported!\n");
286  #if 0
287  		panic("SMP kernel required to avoid non-equivalent aliasing");
288  #endif
289  	}
290  }
291  
292  void disable_sr_hashing(void)
293  {
294  	int srhash_type, retval;
295  	unsigned long space_bits;
296  
297  	switch (boot_cpu_data.cpu_type) {
298  	case pcx: /* We shouldn't get this far.  setup.c should prevent it. */
299  		BUG();
300  		return;
301  
302  	case pcxs:
303  	case pcxt:
304  	case pcxt_:
305  		srhash_type = SRHASH_PCXST;
306  		break;
307  
308  	case pcxl:
309  		srhash_type = SRHASH_PCXL;
310  		break;
311  
312  	case pcxl2: /* pcxl2 doesn't support space register hashing */
313  		return;
314  
315  	default: /* Currently all PA2.0 machines use the same ins. sequence */
316  		srhash_type = SRHASH_PA20;
317  		break;
318  	}
319  
320  	disable_sr_hashing_asm(srhash_type);
321  
322  	retval = pdc_spaceid_bits(&space_bits);
323  	/* If this procedure isn't implemented, don't panic. */
324  	if (retval < 0 && retval != PDC_BAD_OPTION)
325  		panic("pdc_spaceid_bits call failed.\n");
326  	if (space_bits != 0)
327  		panic("SpaceID hashing is still on!\n");
328  }
329  
330  static inline void
331  __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
332  		   unsigned long physaddr)
333  {
334  	if (!static_branch_likely(&parisc_has_cache))
335  		return;
336  
337  	/*
338  	 * The TLB is the engine of coherence on parisc.  The CPU is
339  	 * entitled to speculate any page with a TLB mapping, so here
340  	 * we kill the mapping then flush the page along a special flush
341  	 * only alias mapping. This guarantees that the page is no-longer
342  	 * in the cache for any process and nor may it be speculatively
343  	 * read in (until the user or kernel specifically accesses it,
344  	 * of course).
345  	 */
346  	flush_tlb_page(vma, vmaddr);
347  
348  	preempt_disable();
349  	flush_dcache_page_asm(physaddr, vmaddr);
350  	if (vma->vm_flags & VM_EXEC)
351  		flush_icache_page_asm(physaddr, vmaddr);
352  	preempt_enable();
353  }
354  
355  static void flush_kernel_dcache_page_addr(const void *addr)
356  {
357  	unsigned long vaddr = (unsigned long)addr;
358  	unsigned long flags;
359  
360  	/* Purge TLB entry to remove translation on all CPUs */
361  	purge_tlb_start(flags);
362  	pdtlb(SR_KERNEL, addr);
363  	purge_tlb_end(flags);
364  
365  	/* Use tmpalias flush to prevent data cache move-in */
366  	preempt_disable();
367  	flush_dcache_page_asm(__pa(vaddr), vaddr);
368  	preempt_enable();
369  }
370  
371  static void flush_kernel_icache_page_addr(const void *addr)
372  {
373  	unsigned long vaddr = (unsigned long)addr;
374  	unsigned long flags;
375  
376  	/* Purge TLB entry to remove translation on all CPUs */
377  	purge_tlb_start(flags);
378  	pdtlb(SR_KERNEL, addr);
379  	purge_tlb_end(flags);
380  
381  	/* Use tmpalias flush to prevent instruction cache move-in */
382  	preempt_disable();
383  	flush_icache_page_asm(__pa(vaddr), vaddr);
384  	preempt_enable();
385  }
386  
387  void kunmap_flush_on_unmap(const void *addr)
388  {
389  	flush_kernel_dcache_page_addr(addr);
390  }
391  EXPORT_SYMBOL(kunmap_flush_on_unmap);
392  
393  void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
394  		unsigned int nr)
395  {
396  	void *kaddr = page_address(page);
397  
398  	for (;;) {
399  		flush_kernel_dcache_page_addr(kaddr);
400  		flush_kernel_icache_page_addr(kaddr);
401  		if (--nr == 0)
402  			break;
403  		kaddr += PAGE_SIZE;
404  	}
405  }
406  
407  /*
408   * Walk page directory for MM to find PTEP pointer for address ADDR.
409   */
410  static inline pte_t *get_ptep(struct mm_struct *mm, unsigned long addr)
411  {
412  	pte_t *ptep = NULL;
413  	pgd_t *pgd = mm->pgd;
414  	p4d_t *p4d;
415  	pud_t *pud;
416  	pmd_t *pmd;
417  
418  	if (!pgd_none(*pgd)) {
419  		p4d = p4d_offset(pgd, addr);
420  		if (!p4d_none(*p4d)) {
421  			pud = pud_offset(p4d, addr);
422  			if (!pud_none(*pud)) {
423  				pmd = pmd_offset(pud, addr);
424  				if (!pmd_none(*pmd))
425  					ptep = pte_offset_map(pmd, addr);
426  			}
427  		}
428  	}
429  	return ptep;
430  }
431  
432  static inline bool pte_needs_flush(pte_t pte)
433  {
434  	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_NO_CACHE))
435  		== (_PAGE_PRESENT | _PAGE_ACCESSED);
436  }
437  
438  /*
439   * Return user physical address. Returns 0 if page is not present.
440   */
441  static inline unsigned long get_upa(struct mm_struct *mm, unsigned long addr)
442  {
443  	unsigned long flags, space, pgd, prot, pa;
444  #ifdef CONFIG_TLB_PTLOCK
445  	unsigned long pgd_lock;
446  #endif
447  
448  	/* Save context */
449  	local_irq_save(flags);
450  	prot = mfctl(8);
451  	space = mfsp(SR_USER);
452  	pgd = mfctl(25);
453  #ifdef CONFIG_TLB_PTLOCK
454  	pgd_lock = mfctl(28);
455  #endif
456  
457  	/* Set context for lpa_user */
458  	switch_mm_irqs_off(NULL, mm, NULL);
459  	pa = lpa_user(addr);
460  
461  	/* Restore previous context */
462  #ifdef CONFIG_TLB_PTLOCK
463  	mtctl(pgd_lock, 28);
464  #endif
465  	mtctl(pgd, 25);
466  	mtsp(space, SR_USER);
467  	mtctl(prot, 8);
468  	local_irq_restore(flags);
469  
470  	return pa;
471  }
472  
473  void flush_dcache_folio(struct folio *folio)
474  {
475  	struct address_space *mapping = folio_flush_mapping(folio);
476  	struct vm_area_struct *vma;
477  	unsigned long addr, old_addr = 0;
478  	void *kaddr;
479  	unsigned long count = 0;
480  	unsigned long i, nr, flags;
481  	pgoff_t pgoff;
482  
483  	if (mapping && !mapping_mapped(mapping)) {
484  		set_bit(PG_dcache_dirty, &folio->flags);
485  		return;
486  	}
487  
488  	nr = folio_nr_pages(folio);
489  	kaddr = folio_address(folio);
490  	for (i = 0; i < nr; i++)
491  		flush_kernel_dcache_page_addr(kaddr + i * PAGE_SIZE);
492  
493  	if (!mapping)
494  		return;
495  
496  	pgoff = folio->index;
497  
498  	/*
499  	 * We have carefully arranged in arch_get_unmapped_area() that
500  	 * *any* mappings of a file are always congruently mapped (whether
501  	 * declared as MAP_PRIVATE or MAP_SHARED), so we only need
502  	 * to flush one address here for them all to become coherent
503  	 * on machines that support equivalent aliasing
504  	 */
505  	flush_dcache_mmap_lock_irqsave(mapping, flags);
506  	vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff + nr - 1) {
507  		unsigned long offset = pgoff - vma->vm_pgoff;
508  		unsigned long pfn = folio_pfn(folio);
509  
510  		addr = vma->vm_start;
511  		nr = folio_nr_pages(folio);
512  		if (offset > -nr) {
513  			pfn -= offset;
514  			nr += offset;
515  		} else {
516  			addr += offset * PAGE_SIZE;
517  		}
518  		if (addr + nr * PAGE_SIZE > vma->vm_end)
519  			nr = (vma->vm_end - addr) / PAGE_SIZE;
520  
521  		if (old_addr == 0 || (old_addr & (SHM_COLOUR - 1))
522  					!= (addr & (SHM_COLOUR - 1))) {
523  			for (i = 0; i < nr; i++)
524  				__flush_cache_page(vma,
525  					addr + i * PAGE_SIZE,
526  					(pfn + i) * PAGE_SIZE);
527  			/*
528  			 * Software is allowed to have any number
529  			 * of private mappings to a page.
530  			 */
531  			if (!(vma->vm_flags & VM_SHARED))
532  				continue;
533  			if (old_addr)
534  				pr_err("INEQUIVALENT ALIASES 0x%lx and 0x%lx in file %pD\n",
535  					old_addr, addr, vma->vm_file);
536  			if (nr == folio_nr_pages(folio))
537  				old_addr = addr;
538  		}
539  		WARN_ON(++count == 4096);
540  	}
541  	flush_dcache_mmap_unlock_irqrestore(mapping, flags);
542  }
543  EXPORT_SYMBOL(flush_dcache_folio);
544  
545  /* Defined in arch/parisc/kernel/pacache.S */
546  EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
547  EXPORT_SYMBOL(flush_kernel_icache_range_asm);
548  
549  #define FLUSH_THRESHOLD 0x80000 /* 0.5MB */
550  static unsigned long parisc_cache_flush_threshold __ro_after_init = FLUSH_THRESHOLD;
551  
552  #define FLUSH_TLB_THRESHOLD (16*1024) /* 16 KiB minimum TLB threshold */
553  static unsigned long parisc_tlb_flush_threshold __ro_after_init = ~0UL;
554  
555  void __init parisc_setup_cache_timing(void)
556  {
557  	unsigned long rangetime, alltime;
558  	unsigned long size;
559  	unsigned long threshold, threshold2;
560  
561  	alltime = mfctl(16);
562  	flush_data_cache();
563  	alltime = mfctl(16) - alltime;
564  
565  	size = (unsigned long)(_end - _text);
566  	rangetime = mfctl(16);
567  	flush_kernel_dcache_range((unsigned long)_text, size);
568  	rangetime = mfctl(16) - rangetime;
569  
570  	printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",
571  		alltime, size, rangetime);
572  
573  	threshold = L1_CACHE_ALIGN((unsigned long)((uint64_t)size * alltime / rangetime));
574  	pr_info("Calculated flush threshold is %lu KiB\n",
575  		threshold/1024);
576  
577  	/*
578  	 * The threshold computed above isn't very reliable. The following
579  	 * heuristic works reasonably well on c8000/rp3440.
580  	 */
581  	threshold2 = cache_info.dc_size * num_online_cpus();
582  	parisc_cache_flush_threshold = threshold2;
583  	printk(KERN_INFO "Cache flush threshold set to %lu KiB\n",
584  		parisc_cache_flush_threshold/1024);
585  
586  	/* calculate TLB flush threshold */
587  
588  	/* On SMP machines, skip the TLB measure of kernel text which
589  	 * has been mapped as huge pages. */
590  	if (num_online_cpus() > 1 && !parisc_requires_coherency()) {
591  		threshold = max(cache_info.it_size, cache_info.dt_size);
592  		threshold *= PAGE_SIZE;
593  		threshold /= num_online_cpus();
594  		goto set_tlb_threshold;
595  	}
596  
597  	size = (unsigned long)_end - (unsigned long)_text;
598  	rangetime = mfctl(16);
599  	flush_tlb_kernel_range((unsigned long)_text, (unsigned long)_end);
600  	rangetime = mfctl(16) - rangetime;
601  
602  	alltime = mfctl(16);
603  	flush_tlb_all();
604  	alltime = mfctl(16) - alltime;
605  
606  	printk(KERN_INFO "Whole TLB flush %lu cycles, Range flush %lu bytes %lu cycles\n",
607  		alltime, size, rangetime);
608  
609  	threshold = PAGE_ALIGN((num_online_cpus() * size * alltime) / rangetime);
610  	printk(KERN_INFO "Calculated TLB flush threshold %lu KiB\n",
611  		threshold/1024);
612  
613  set_tlb_threshold:
614  	if (threshold > FLUSH_TLB_THRESHOLD)
615  		parisc_tlb_flush_threshold = threshold;
616  	else
617  		parisc_tlb_flush_threshold = FLUSH_TLB_THRESHOLD;
618  
619  	printk(KERN_INFO "TLB flush threshold set to %lu KiB\n",
620  		parisc_tlb_flush_threshold/1024);
621  }
622  
623  extern void purge_kernel_dcache_page_asm(unsigned long);
624  extern void clear_user_page_asm(void *, unsigned long);
625  extern void copy_user_page_asm(void *, void *, unsigned long);
626  
627  static void flush_cache_page_if_present(struct vm_area_struct *vma,
628  	unsigned long vmaddr)
629  {
630  #if CONFIG_FLUSH_PAGE_ACCESSED
631  	bool needs_flush = false;
632  	pte_t *ptep, pte;
633  
634  	ptep = get_ptep(vma->vm_mm, vmaddr);
635  	if (ptep) {
636  		pte = ptep_get(ptep);
637  		needs_flush = pte_needs_flush(pte);
638  		pte_unmap(ptep);
639  	}
640  	if (needs_flush)
641  		__flush_cache_page(vma, vmaddr, PFN_PHYS(pte_pfn(pte)));
642  #else
643  	struct mm_struct *mm = vma->vm_mm;
644  	unsigned long physaddr = get_upa(mm, vmaddr);
645  
646  	if (physaddr)
647  		__flush_cache_page(vma, vmaddr, PAGE_ALIGN_DOWN(physaddr));
648  #endif
649  }
650  
651  void copy_user_highpage(struct page *to, struct page *from,
652  	unsigned long vaddr, struct vm_area_struct *vma)
653  {
654  	void *kto, *kfrom;
655  
656  	kfrom = kmap_local_page(from);
657  	kto = kmap_local_page(to);
658  	__flush_cache_page(vma, vaddr, PFN_PHYS(page_to_pfn(from)));
659  	copy_page_asm(kto, kfrom);
660  	kunmap_local(kto);
661  	kunmap_local(kfrom);
662  }
663  
664  void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
665  		unsigned long user_vaddr, void *dst, void *src, int len)
666  {
667  	__flush_cache_page(vma, user_vaddr, PFN_PHYS(page_to_pfn(page)));
668  	memcpy(dst, src, len);
669  	flush_kernel_dcache_page_addr(PTR_PAGE_ALIGN_DOWN(dst));
670  }
671  
672  void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
673  		unsigned long user_vaddr, void *dst, void *src, int len)
674  {
675  	__flush_cache_page(vma, user_vaddr, PFN_PHYS(page_to_pfn(page)));
676  	memcpy(dst, src, len);
677  	flush_kernel_dcache_page_addr(PTR_PAGE_ALIGN_DOWN(src));
678  }
679  
680  /* __flush_tlb_range()
681   *
682   * returns 1 if all TLBs were flushed.
683   */
684  int __flush_tlb_range(unsigned long sid, unsigned long start,
685  		      unsigned long end)
686  {
687  	unsigned long flags;
688  
689  	if ((!IS_ENABLED(CONFIG_SMP) || !arch_irqs_disabled()) &&
690  	    end - start >= parisc_tlb_flush_threshold) {
691  		flush_tlb_all();
692  		return 1;
693  	}
694  
695  	/* Purge TLB entries for small ranges using the pdtlb and
696  	   pitlb instructions.  These instructions execute locally
697  	   but cause a purge request to be broadcast to other TLBs.  */
698  	while (start < end) {
699  		purge_tlb_start(flags);
700  		mtsp(sid, SR_TEMP1);
701  		pdtlb(SR_TEMP1, start);
702  		pitlb(SR_TEMP1, start);
703  		purge_tlb_end(flags);
704  		start += PAGE_SIZE;
705  	}
706  	return 0;
707  }
708  
709  static void flush_cache_pages(struct vm_area_struct *vma, unsigned long start, unsigned long end)
710  {
711  	unsigned long addr;
712  
713  	for (addr = start; addr < end; addr += PAGE_SIZE)
714  		flush_cache_page_if_present(vma, addr);
715  }
716  
717  static inline unsigned long mm_total_size(struct mm_struct *mm)
718  {
719  	struct vm_area_struct *vma;
720  	unsigned long usize = 0;
721  	VMA_ITERATOR(vmi, mm, 0);
722  
723  	for_each_vma(vmi, vma) {
724  		if (usize >= parisc_cache_flush_threshold)
725  			break;
726  		usize += vma->vm_end - vma->vm_start;
727  	}
728  	return usize;
729  }
730  
731  void flush_cache_mm(struct mm_struct *mm)
732  {
733  	struct vm_area_struct *vma;
734  	VMA_ITERATOR(vmi, mm, 0);
735  
736  	/*
737  	 * Flushing the whole cache on each cpu takes forever on
738  	 * rp3440, etc. So, avoid it if the mm isn't too big.
739  	 *
740  	 * Note that we must flush the entire cache on machines
741  	 * with aliasing caches to prevent random segmentation
742  	 * faults.
743  	 */
744  	if (!parisc_requires_coherency()
745  	    ||  mm_total_size(mm) >= parisc_cache_flush_threshold) {
746  		if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
747  			return;
748  		flush_tlb_all();
749  		flush_cache_all();
750  		return;
751  	}
752  
753  	/* Flush mm */
754  	for_each_vma(vmi, vma)
755  		flush_cache_pages(vma, vma->vm_start, vma->vm_end);
756  }
757  
758  void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
759  {
760  	if (!parisc_requires_coherency()
761  	    || end - start >= parisc_cache_flush_threshold) {
762  		if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled()))
763  			return;
764  		flush_tlb_range(vma, start, end);
765  		if (vma->vm_flags & VM_EXEC)
766  			flush_cache_all();
767  		else
768  			flush_data_cache();
769  		return;
770  	}
771  
772  	flush_cache_pages(vma, start & PAGE_MASK, end);
773  }
774  
775  void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn)
776  {
777  	__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));
778  }
779  
780  void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
781  {
782  	if (!PageAnon(page))
783  		return;
784  
785  	__flush_cache_page(vma, vmaddr, PFN_PHYS(page_to_pfn(page)));
786  }
787  
788  int ptep_clear_flush_young(struct vm_area_struct *vma, unsigned long addr,
789  			   pte_t *ptep)
790  {
791  	pte_t pte = ptep_get(ptep);
792  
793  	if (!pte_young(pte))
794  		return 0;
795  	set_pte(ptep, pte_mkold(pte));
796  #if CONFIG_FLUSH_PAGE_ACCESSED
797  	__flush_cache_page(vma, addr, PFN_PHYS(pte_pfn(pte)));
798  #endif
799  	return 1;
800  }
801  
802  /*
803   * After a PTE is cleared, we have no way to flush the cache for
804   * the physical page. On PA8800 and PA8900 processors, these lines
805   * can cause random cache corruption. Thus, we must flush the cache
806   * as well as the TLB when clearing a PTE that's valid.
807   */
808  pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr,
809  		       pte_t *ptep)
810  {
811  	struct mm_struct *mm = (vma)->vm_mm;
812  	pte_t pte = ptep_get_and_clear(mm, addr, ptep);
813  	unsigned long pfn = pte_pfn(pte);
814  
815  	if (pfn_valid(pfn))
816  		__flush_cache_page(vma, addr, PFN_PHYS(pfn));
817  	else if (pte_accessible(mm, pte))
818  		flush_tlb_page(vma, addr);
819  
820  	return pte;
821  }
822  
823  /*
824   * The physical address for pages in the ioremap case can be obtained
825   * from the vm_struct struct. I wasn't able to successfully handle the
826   * vmalloc and vmap cases. We have an array of struct page pointers in
827   * the uninitialized vmalloc case but the flush failed using page_to_pfn.
828   */
829  void flush_cache_vmap(unsigned long start, unsigned long end)
830  {
831  	unsigned long addr, physaddr;
832  	struct vm_struct *vm;
833  
834  	/* Prevent cache move-in */
835  	flush_tlb_kernel_range(start, end);
836  
837  	if (end - start >= parisc_cache_flush_threshold) {
838  		flush_cache_all();
839  		return;
840  	}
841  
842  	if (WARN_ON_ONCE(!is_vmalloc_addr((void *)start))) {
843  		flush_cache_all();
844  		return;
845  	}
846  
847  	vm = find_vm_area((void *)start);
848  	if (WARN_ON_ONCE(!vm)) {
849  		flush_cache_all();
850  		return;
851  	}
852  
853  	/* The physical addresses of IOREMAP regions are contiguous */
854  	if (vm->flags & VM_IOREMAP) {
855  		physaddr = vm->phys_addr;
856  		for (addr = start; addr < end; addr += PAGE_SIZE) {
857  			preempt_disable();
858  			flush_dcache_page_asm(physaddr, start);
859  			flush_icache_page_asm(physaddr, start);
860  			preempt_enable();
861  			physaddr += PAGE_SIZE;
862  		}
863  		return;
864  	}
865  
866  	flush_cache_all();
867  }
868  EXPORT_SYMBOL(flush_cache_vmap);
869  
870  /*
871   * The vm_struct has been retired and the page table is set up. The
872   * last page in the range is a guard page. Its physical address can't
873   * be determined using lpa, so there is no way to flush the range
874   * using flush_dcache_page_asm.
875   */
876  void flush_cache_vunmap(unsigned long start, unsigned long end)
877  {
878  	/* Prevent cache move-in */
879  	flush_tlb_kernel_range(start, end);
880  	flush_data_cache();
881  }
882  EXPORT_SYMBOL(flush_cache_vunmap);
883  
884  /*
885   * On systems with PA8800/PA8900 processors, there is no way to flush
886   * a vmap range other than using the architected loop to flush the
887   * entire cache. The page directory is not set up, so we can't use
888   * fdc, etc. FDCE/FICE don't work to flush a portion of the cache.
889   * L2 is physically indexed but FDCE/FICE instructions in virtual
890   * mode output their virtual address on the core bus, not their
891   * real address. As a result, the L2 cache index formed from the
892   * virtual address will most likely not be the same as the L2 index
893   * formed from the real address.
894   */
895  void flush_kernel_vmap_range(void *vaddr, int size)
896  {
897  	unsigned long start = (unsigned long)vaddr;
898  	unsigned long end = start + size;
899  
900  	flush_tlb_kernel_range(start, end);
901  
902  	if (!static_branch_likely(&parisc_has_dcache))
903  		return;
904  
905  	/* If interrupts are disabled, we can only do local flush */
906  	if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled())) {
907  		flush_data_cache_local(NULL);
908  		return;
909  	}
910  
911  	flush_data_cache();
912  }
913  EXPORT_SYMBOL(flush_kernel_vmap_range);
914  
915  void invalidate_kernel_vmap_range(void *vaddr, int size)
916  {
917  	unsigned long start = (unsigned long)vaddr;
918  	unsigned long end = start + size;
919  
920  	/* Ensure DMA is complete */
921  	asm_syncdma();
922  
923  	flush_tlb_kernel_range(start, end);
924  
925  	if (!static_branch_likely(&parisc_has_dcache))
926  		return;
927  
928  	/* If interrupts are disabled, we can only do local flush */
929  	if (WARN_ON(IS_ENABLED(CONFIG_SMP) && arch_irqs_disabled())) {
930  		flush_data_cache_local(NULL);
931  		return;
932  	}
933  
934  	flush_data_cache();
935  }
936  EXPORT_SYMBOL(invalidate_kernel_vmap_range);
937  
938  
939  SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, bytes,
940  	unsigned int, cache)
941  {
942  	unsigned long start, end;
943  	ASM_EXCEPTIONTABLE_VAR(error);
944  
945  	if (bytes == 0)
946  		return 0;
947  	if (!access_ok((void __user *) addr, bytes))
948  		return -EFAULT;
949  
950  	end = addr + bytes;
951  
952  	if (cache & DCACHE) {
953  		start = addr;
954  		__asm__ __volatile__ (
955  #ifdef CONFIG_64BIT
956  			"1: cmpb,*<<,n	%0,%2,1b\n"
957  #else
958  			"1: cmpb,<<,n	%0,%2,1b\n"
959  #endif
960  			"   fic,m	%3(%4,%0)\n"
961  			"2: sync\n"
962  			ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 2b, "%1")
963  			: "+r" (start), "+r" (error)
964  			: "r" (end), "r" (dcache_stride), "i" (SR_USER));
965  	}
966  
967  	if (cache & ICACHE && error == 0) {
968  		start = addr;
969  		__asm__ __volatile__ (
970  #ifdef CONFIG_64BIT
971  			"1: cmpb,*<<,n	%0,%2,1b\n"
972  #else
973  			"1: cmpb,<<,n	%0,%2,1b\n"
974  #endif
975  			"   fdc,m	%3(%4,%0)\n"
976  			"2: sync\n"
977  			ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 2b, "%1")
978  			: "+r" (start), "+r" (error)
979  			: "r" (end), "r" (icache_stride), "i" (SR_USER));
980  	}
981  
982  	return error;
983  }
984