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authorLinus Torvalds <torvalds@linux-foundation.org>2008-01-28 16:52:50 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2008-01-28 16:52:50 -0500
commite189f3495c4e30fc84fc9241096edf3932e23439 (patch)
tree5916c89ace81537a02ae01869386ba6caafdab9c /arch/sh/mm/cache-sh5.c
parentf4798748dee00c807a63f5518f08b3df161e0f6d (diff)
parent6582d7b7376aa587d74b08c74457dc28abc1a9fa (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (197 commits) sh: add spi header and r2d platform data V3 sh: update r7780rp interrupt code sh: remove consistent alloc stuff from the machine vector sh: use declared coherent memory for dreamcast pci ethernet adapter sh: declared coherent memory support V2 sh: Add support for SDK7780 board. sh: constify function pointer tables sh: Kill off -traditional for linker script. cdrom: Add support for Sega Dreamcast GD-ROM. sh: Kill off hs7751rvoip reference from arch/sh/Kconfig. sh: Drop r7780rp_defconfig, use r7780mp_defconfig as kbuild default. sh: Kill off dead HS771RVoIP board support. sh: r7785rp: Fix up DECLARE_INTC_DESC() arg mismatch. sh: r7785rp: Hook up the rest of the HL7785 FPGA IRQ vectors. sh: r2d - enable sm501 usb host function sh: remove voyagergx sh: r2d - add lcd planel timings to sm501 platform data sh: Add OHCI and UDC platform devices for SH7720. sh: intc - remove default interrupt priority tables sh: Correct pte size mismatch for X2 TLB. ...
Diffstat (limited to 'arch/sh/mm/cache-sh5.c')
-rw-r--r--arch/sh/mm/cache-sh5.c1029
1 files changed, 1029 insertions, 0 deletions
diff --git a/arch/sh/mm/cache-sh5.c b/arch/sh/mm/cache-sh5.c
new file mode 100644
index 000000000000..4617e3aeee73
--- /dev/null
+++ b/arch/sh/mm/cache-sh5.c
@@ -0,0 +1,1029 @@
1/*
2 * arch/sh/mm/cache-sh5.c
3 *
4 * Original version Copyright (C) 2000, 2001 Paolo Alberelli
5 * Second version Copyright (C) benedict.gaster@superh.com 2002
6 * Third version Copyright Richard.Curnow@superh.com 2003
7 * Hacks to third version Copyright (C) 2003 Paul Mundt
8 *
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
11 * for more details.
12 */
13#include <linux/init.h>
14#include <linux/mman.h>
15#include <linux/mm.h>
16#include <linux/threads.h>
17#include <asm/page.h>
18#include <asm/pgtable.h>
19#include <asm/processor.h>
20#include <asm/cache.h>
21#include <asm/tlb.h>
22#include <asm/io.h>
23#include <asm/uaccess.h>
24#include <asm/mmu_context.h>
25#include <asm/pgalloc.h> /* for flush_itlb_range */
26
27#include <linux/proc_fs.h>
28
29/* This function is in entry.S */
30extern unsigned long switch_and_save_asid(unsigned long new_asid);
31
32/* Wired TLB entry for the D-cache */
33static unsigned long long dtlb_cache_slot;
34
35/**
36 * sh64_cache_init()
37 *
38 * This is pretty much just a straightforward clone of the SH
39 * detect_cpu_and_cache_system().
40 *
41 * This function is responsible for setting up all of the cache
42 * info dynamically as well as taking care of CPU probing and
43 * setting up the relevant subtype data.
44 *
45 * FIXME: For the time being, we only really support the SH5-101
46 * out of the box, and don't support dynamic probing for things
47 * like the SH5-103 or even cut2 of the SH5-101. Implement this
48 * later!
49 */
50int __init sh64_cache_init(void)
51{
52 /*
53 * First, setup some sane values for the I-cache.
54 */
55 cpu_data->icache.ways = 4;
56 cpu_data->icache.sets = 256;
57 cpu_data->icache.linesz = L1_CACHE_BYTES;
58
59 /*
60 * FIXME: This can probably be cleaned up a bit as well.. for example,
61 * do we really need the way shift _and_ the way_step_shift ?? Judging
62 * by the existing code, I would guess no.. is there any valid reason
63 * why we need to be tracking this around?
64 */
65 cpu_data->icache.way_shift = 13;
66 cpu_data->icache.entry_shift = 5;
67 cpu_data->icache.set_shift = 4;
68 cpu_data->icache.way_step_shift = 16;
69 cpu_data->icache.asid_shift = 2;
70
71 /*
72 * way offset = cache size / associativity, so just don't factor in
73 * associativity in the first place..
74 */
75 cpu_data->icache.way_ofs = cpu_data->icache.sets *
76 cpu_data->icache.linesz;
77
78 cpu_data->icache.asid_mask = 0x3fc;
79 cpu_data->icache.idx_mask = 0x1fe0;
80 cpu_data->icache.epn_mask = 0xffffe000;
81 cpu_data->icache.flags = 0;
82
83 /*
84 * Next, setup some sane values for the D-cache.
85 *
86 * On the SH5, these are pretty consistent with the I-cache settings,
87 * so we just copy over the existing definitions.. these can be fixed
88 * up later, especially if we add runtime CPU probing.
89 *
90 * Though in the meantime it saves us from having to duplicate all of
91 * the above definitions..
92 */
93 cpu_data->dcache = cpu_data->icache;
94
95 /*
96 * Setup any cache-related flags here
97 */
98#if defined(CONFIG_DCACHE_WRITE_THROUGH)
99 set_bit(SH_CACHE_MODE_WT, &(cpu_data->dcache.flags));
100#elif defined(CONFIG_DCACHE_WRITE_BACK)
101 set_bit(SH_CACHE_MODE_WB, &(cpu_data->dcache.flags));
102#endif
103
104 /*
105 * We also need to reserve a slot for the D-cache in the DTLB, so we
106 * do this now ..
107 */
108 dtlb_cache_slot = sh64_get_wired_dtlb_entry();
109
110 return 0;
111}
112
113#ifdef CONFIG_DCACHE_DISABLED
114#define sh64_dcache_purge_all() do { } while (0)
115#define sh64_dcache_purge_coloured_phy_page(paddr, eaddr) do { } while (0)
116#define sh64_dcache_purge_user_range(mm, start, end) do { } while (0)
117#define sh64_dcache_purge_phy_page(paddr) do { } while (0)
118#define sh64_dcache_purge_virt_page(mm, eaddr) do { } while (0)
119#define sh64_dcache_purge_kernel_range(start, end) do { } while (0)
120#define sh64_dcache_wback_current_user_range(start, end) do { } while (0)
121#endif
122
123/*##########################################################################*/
124
125/* From here onwards, a rewrite of the implementation,
126 by Richard.Curnow@superh.com.
127
128 The major changes in this compared to the old version are;
129 1. use more selective purging through OCBP instead of using ALLOCO to purge
130 by natural replacement. This avoids purging out unrelated cache lines
131 that happen to be in the same set.
132 2. exploit the APIs copy_user_page and clear_user_page better
133 3. be more selective about I-cache purging, in particular use invalidate_all
134 more sparingly.
135
136 */
137
138/*##########################################################################
139 SUPPORT FUNCTIONS
140 ##########################################################################*/
141
142/****************************************************************************/
143/* The following group of functions deal with mapping and unmapping a temporary
144 page into the DTLB slot that have been set aside for our exclusive use. */
145/* In order to accomplish this, we use the generic interface for adding and
146 removing a wired slot entry as defined in arch/sh/mm/tlb-sh5.c */
147/****************************************************************************/
148
149static unsigned long slot_own_flags;
150
151static inline void sh64_setup_dtlb_cache_slot(unsigned long eaddr, unsigned long asid, unsigned long paddr)
152{
153 local_irq_save(slot_own_flags);
154 sh64_setup_tlb_slot(dtlb_cache_slot, eaddr, asid, paddr);
155}
156
157static inline void sh64_teardown_dtlb_cache_slot(void)
158{
159 sh64_teardown_tlb_slot(dtlb_cache_slot);
160 local_irq_restore(slot_own_flags);
161}
162
163/****************************************************************************/
164
165#ifndef CONFIG_ICACHE_DISABLED
166
167static void __inline__ sh64_icache_inv_all(void)
168{
169 unsigned long long addr, flag, data;
170 unsigned int flags;
171
172 addr=ICCR0;
173 flag=ICCR0_ICI;
174 data=0;
175
176 /* Make this a critical section for safety (probably not strictly necessary.) */
177 local_irq_save(flags);
178
179 /* Without %1 it gets unexplicably wrong */
180 asm volatile("getcfg %3, 0, %0\n\t"
181 "or %0, %2, %0\n\t"
182 "putcfg %3, 0, %0\n\t"
183 "synci"
184 : "=&r" (data)
185 : "0" (data), "r" (flag), "r" (addr));
186
187 local_irq_restore(flags);
188}
189
190static void sh64_icache_inv_kernel_range(unsigned long start, unsigned long end)
191{
192 /* Invalidate range of addresses [start,end] from the I-cache, where
193 * the addresses lie in the kernel superpage. */
194
195 unsigned long long ullend, addr, aligned_start;
196#if (NEFF == 32)
197 aligned_start = (unsigned long long)(signed long long)(signed long) start;
198#else
199#error "NEFF != 32"
200#endif
201 aligned_start &= L1_CACHE_ALIGN_MASK;
202 addr = aligned_start;
203#if (NEFF == 32)
204 ullend = (unsigned long long) (signed long long) (signed long) end;
205#else
206#error "NEFF != 32"
207#endif
208 while (addr <= ullend) {
209 asm __volatile__ ("icbi %0, 0" : : "r" (addr));
210 addr += L1_CACHE_BYTES;
211 }
212}
213
214static void sh64_icache_inv_user_page(struct vm_area_struct *vma, unsigned long eaddr)
215{
216 /* If we get called, we know that vma->vm_flags contains VM_EXEC.
217 Also, eaddr is page-aligned. */
218
219 unsigned long long addr, end_addr;
220 unsigned long flags = 0;
221 unsigned long running_asid, vma_asid;
222 addr = eaddr;
223 end_addr = addr + PAGE_SIZE;
224
225 /* Check whether we can use the current ASID for the I-cache
226 invalidation. For example, if we're called via
227 access_process_vm->flush_cache_page->here, (e.g. when reading from
228 /proc), 'running_asid' will be that of the reader, not of the
229 victim.
230
231 Also, note the risk that we might get pre-empted between the ASID
232 compare and blocking IRQs, and before we regain control, the
233 pid->ASID mapping changes. However, the whole cache will get
234 invalidated when the mapping is renewed, so the worst that can
235 happen is that the loop below ends up invalidating somebody else's
236 cache entries.
237 */
238
239 running_asid = get_asid();
240 vma_asid = (vma->vm_mm->context & MMU_CONTEXT_ASID_MASK);
241 if (running_asid != vma_asid) {
242 local_irq_save(flags);
243 switch_and_save_asid(vma_asid);
244 }
245 while (addr < end_addr) {
246 /* Worth unrolling a little */
247 asm __volatile__("icbi %0, 0" : : "r" (addr));
248 asm __volatile__("icbi %0, 32" : : "r" (addr));
249 asm __volatile__("icbi %0, 64" : : "r" (addr));
250 asm __volatile__("icbi %0, 96" : : "r" (addr));
251 addr += 128;
252 }
253 if (running_asid != vma_asid) {
254 switch_and_save_asid(running_asid);
255 local_irq_restore(flags);
256 }
257}
258
259/****************************************************************************/
260
261static void sh64_icache_inv_user_page_range(struct mm_struct *mm,
262 unsigned long start, unsigned long end)
263{
264 /* Used for invalidating big chunks of I-cache, i.e. assume the range
265 is whole pages. If 'start' or 'end' is not page aligned, the code
266 is conservative and invalidates to the ends of the enclosing pages.
267 This is functionally OK, just a performance loss. */
268
269 /* See the comments below in sh64_dcache_purge_user_range() regarding
270 the choice of algorithm. However, for the I-cache option (2) isn't
271 available because there are no physical tags so aliases can't be
272 resolved. The icbi instruction has to be used through the user
273 mapping. Because icbi is cheaper than ocbp on a cache hit, it
274 would be cheaper to use the selective code for a large range than is
275 possible with the D-cache. Just assume 64 for now as a working
276 figure.
277 */
278
279 int n_pages;
280
281 if (!mm) return;
282
283 n_pages = ((end - start) >> PAGE_SHIFT);
284 if (n_pages >= 64) {
285 sh64_icache_inv_all();
286 } else {
287 unsigned long aligned_start;
288 unsigned long eaddr;
289 unsigned long after_last_page_start;
290 unsigned long mm_asid, current_asid;
291 unsigned long long flags = 0ULL;
292
293 mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
294 current_asid = get_asid();
295
296 if (mm_asid != current_asid) {
297 /* Switch ASID and run the invalidate loop under cli */
298 local_irq_save(flags);
299 switch_and_save_asid(mm_asid);
300 }
301
302 aligned_start = start & PAGE_MASK;
303 after_last_page_start = PAGE_SIZE + ((end - 1) & PAGE_MASK);
304
305 while (aligned_start < after_last_page_start) {
306 struct vm_area_struct *vma;
307 unsigned long vma_end;
308 vma = find_vma(mm, aligned_start);
309 if (!vma || (aligned_start <= vma->vm_end)) {
310 /* Avoid getting stuck in an error condition */
311 aligned_start += PAGE_SIZE;
312 continue;
313 }
314 vma_end = vma->vm_end;
315 if (vma->vm_flags & VM_EXEC) {
316 /* Executable */
317 eaddr = aligned_start;
318 while (eaddr < vma_end) {
319 sh64_icache_inv_user_page(vma, eaddr);
320 eaddr += PAGE_SIZE;
321 }
322 }
323 aligned_start = vma->vm_end; /* Skip to start of next region */
324 }
325 if (mm_asid != current_asid) {
326 switch_and_save_asid(current_asid);
327 local_irq_restore(flags);
328 }
329 }
330}
331
332static void sh64_icache_inv_user_small_range(struct mm_struct *mm,
333 unsigned long start, int len)
334{
335
336 /* Invalidate a small range of user context I-cache, not necessarily
337 page (or even cache-line) aligned. */
338
339 unsigned long long eaddr = start;
340 unsigned long long eaddr_end = start + len;
341 unsigned long current_asid, mm_asid;
342 unsigned long long flags;
343 unsigned long long epage_start;
344
345 /* Since this is used inside ptrace, the ASID in the mm context
346 typically won't match current_asid. We'll have to switch ASID to do
347 this. For safety, and given that the range will be small, do all
348 this under cli.
349
350 Note, there is a hazard that the ASID in mm->context is no longer
351 actually associated with mm, i.e. if the mm->context has started a
352 new cycle since mm was last active. However, this is just a
353 performance issue: all that happens is that we invalidate lines
354 belonging to another mm, so the owning process has to refill them
355 when that mm goes live again. mm itself can't have any cache
356 entries because there will have been a flush_cache_all when the new
357 mm->context cycle started. */
358
359 /* Align to start of cache line. Otherwise, suppose len==8 and start
360 was at 32N+28 : the last 4 bytes wouldn't get invalidated. */
361 eaddr = start & L1_CACHE_ALIGN_MASK;
362 eaddr_end = start + len;
363
364 local_irq_save(flags);
365 mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
366 current_asid = switch_and_save_asid(mm_asid);
367
368 epage_start = eaddr & PAGE_MASK;
369
370 while (eaddr < eaddr_end)
371 {
372 asm __volatile__("icbi %0, 0" : : "r" (eaddr));
373 eaddr += L1_CACHE_BYTES;
374 }
375 switch_and_save_asid(current_asid);
376 local_irq_restore(flags);
377}
378
379static void sh64_icache_inv_current_user_range(unsigned long start, unsigned long end)
380{
381 /* The icbi instruction never raises ITLBMISS. i.e. if there's not a
382 cache hit on the virtual tag the instruction ends there, without a
383 TLB lookup. */
384
385 unsigned long long aligned_start;
386 unsigned long long ull_end;
387 unsigned long long addr;
388
389 ull_end = end;
390
391 /* Just invalidate over the range using the natural addresses. TLB
392 miss handling will be OK (TBC). Since it's for the current process,
393 either we're already in the right ASID context, or the ASIDs have
394 been recycled since we were last active in which case we might just
395 invalidate another processes I-cache entries : no worries, just a
396 performance drop for him. */
397 aligned_start = start & L1_CACHE_ALIGN_MASK;
398 addr = aligned_start;
399 while (addr < ull_end) {
400 asm __volatile__ ("icbi %0, 0" : : "r" (addr));
401 asm __volatile__ ("nop");
402 asm __volatile__ ("nop");
403 addr += L1_CACHE_BYTES;
404 }
405}
406
407#endif /* !CONFIG_ICACHE_DISABLED */
408
409/****************************************************************************/
410
411#ifndef CONFIG_DCACHE_DISABLED
412
413/* Buffer used as the target of alloco instructions to purge data from cache
414 sets by natural eviction. -- RPC */
415#define DUMMY_ALLOCO_AREA_SIZE L1_CACHE_SIZE_BYTES + (1024 * 4)
416static unsigned char dummy_alloco_area[DUMMY_ALLOCO_AREA_SIZE] __cacheline_aligned = { 0, };
417
418/****************************************************************************/
419
420static void __inline__ sh64_dcache_purge_sets(int sets_to_purge_base, int n_sets)
421{
422 /* Purge all ways in a particular block of sets, specified by the base
423 set number and number of sets. Can handle wrap-around, if that's
424 needed. */
425
426 int dummy_buffer_base_set;
427 unsigned long long eaddr, eaddr0, eaddr1;
428 int j;
429 int set_offset;
430
431 dummy_buffer_base_set = ((int)&dummy_alloco_area & cpu_data->dcache.idx_mask) >> cpu_data->dcache.entry_shift;
432 set_offset = sets_to_purge_base - dummy_buffer_base_set;
433
434 for (j=0; j<n_sets; j++, set_offset++) {
435 set_offset &= (cpu_data->dcache.sets - 1);
436 eaddr0 = (unsigned long long)dummy_alloco_area + (set_offset << cpu_data->dcache.entry_shift);
437
438 /* Do one alloco which hits the required set per cache way. For
439 write-back mode, this will purge the #ways resident lines. There's
440 little point unrolling this loop because the allocos stall more if
441 they're too close together. */
442 eaddr1 = eaddr0 + cpu_data->dcache.way_ofs * cpu_data->dcache.ways;
443 for (eaddr=eaddr0; eaddr<eaddr1; eaddr+=cpu_data->dcache.way_ofs) {
444 asm __volatile__ ("alloco %0, 0" : : "r" (eaddr));
445 asm __volatile__ ("synco"); /* TAKum03020 */
446 }
447
448 eaddr1 = eaddr0 + cpu_data->dcache.way_ofs * cpu_data->dcache.ways;
449 for (eaddr=eaddr0; eaddr<eaddr1; eaddr+=cpu_data->dcache.way_ofs) {
450 /* Load from each address. Required because alloco is a NOP if
451 the cache is write-through. Write-through is a config option. */
452 if (test_bit(SH_CACHE_MODE_WT, &(cpu_data->dcache.flags)))
453 *(volatile unsigned char *)(int)eaddr;
454 }
455 }
456
457 /* Don't use OCBI to invalidate the lines. That costs cycles directly.
458 If the dummy block is just left resident, it will naturally get
459 evicted as required. */
460
461 return;
462}
463
464/****************************************************************************/
465
466static void sh64_dcache_purge_all(void)
467{
468 /* Purge the entire contents of the dcache. The most efficient way to
469 achieve this is to use alloco instructions on a region of unused
470 memory equal in size to the cache, thereby causing the current
471 contents to be discarded by natural eviction. The alternative,
472 namely reading every tag, setting up a mapping for the corresponding
473 page and doing an OCBP for the line, would be much more expensive.
474 */
475
476 sh64_dcache_purge_sets(0, cpu_data->dcache.sets);
477
478 return;
479
480}
481
482/****************************************************************************/
483
484static void sh64_dcache_purge_kernel_range(unsigned long start, unsigned long end)
485{
486 /* Purge the range of addresses [start,end] from the D-cache. The
487 addresses lie in the superpage mapping. There's no harm if we
488 overpurge at either end - just a small performance loss. */
489 unsigned long long ullend, addr, aligned_start;
490#if (NEFF == 32)
491 aligned_start = (unsigned long long)(signed long long)(signed long) start;
492#else
493#error "NEFF != 32"
494#endif
495 aligned_start &= L1_CACHE_ALIGN_MASK;
496 addr = aligned_start;
497#if (NEFF == 32)
498 ullend = (unsigned long long) (signed long long) (signed long) end;
499#else
500#error "NEFF != 32"
501#endif
502 while (addr <= ullend) {
503 asm __volatile__ ("ocbp %0, 0" : : "r" (addr));
504 addr += L1_CACHE_BYTES;
505 }
506 return;
507}
508
509/* Assumes this address (+ (2**n_synbits) pages up from it) aren't used for
510 anything else in the kernel */
511#define MAGIC_PAGE0_START 0xffffffffec000000ULL
512
513static void sh64_dcache_purge_coloured_phy_page(unsigned long paddr, unsigned long eaddr)
514{
515 /* Purge the physical page 'paddr' from the cache. It's known that any
516 cache lines requiring attention have the same page colour as the the
517 address 'eaddr'.
518
519 This relies on the fact that the D-cache matches on physical tags
520 when no virtual tag matches. So we create an alias for the original
521 page and purge through that. (Alternatively, we could have done
522 this by switching ASID to match the original mapping and purged
523 through that, but that involves ASID switching cost + probably a
524 TLBMISS + refill anyway.)
525 */
526
527 unsigned long long magic_page_start;
528 unsigned long long magic_eaddr, magic_eaddr_end;
529
530 magic_page_start = MAGIC_PAGE0_START + (eaddr & CACHE_OC_SYN_MASK);
531
532 /* As long as the kernel is not pre-emptible, this doesn't need to be
533 under cli/sti. */
534
535 sh64_setup_dtlb_cache_slot(magic_page_start, get_asid(), paddr);
536
537 magic_eaddr = magic_page_start;
538 magic_eaddr_end = magic_eaddr + PAGE_SIZE;
539 while (magic_eaddr < magic_eaddr_end) {
540 /* Little point in unrolling this loop - the OCBPs are blocking
541 and won't go any quicker (i.e. the loop overhead is parallel
542 to part of the OCBP execution.) */
543 asm __volatile__ ("ocbp %0, 0" : : "r" (magic_eaddr));
544 magic_eaddr += L1_CACHE_BYTES;
545 }
546
547 sh64_teardown_dtlb_cache_slot();
548}
549
550/****************************************************************************/
551
552static void sh64_dcache_purge_phy_page(unsigned long paddr)
553{
554 /* Pure a page given its physical start address, by creating a
555 temporary 1 page mapping and purging across that. Even if we know
556 the virtual address (& vma or mm) of the page, the method here is
557 more elegant because it avoids issues of coping with page faults on
558 the purge instructions (i.e. no special-case code required in the
559 critical path in the TLB miss handling). */
560
561 unsigned long long eaddr_start, eaddr, eaddr_end;
562 int i;
563
564 /* As long as the kernel is not pre-emptible, this doesn't need to be
565 under cli/sti. */
566
567 eaddr_start = MAGIC_PAGE0_START;
568 for (i=0; i < (1 << CACHE_OC_N_SYNBITS); i++) {
569 sh64_setup_dtlb_cache_slot(eaddr_start, get_asid(), paddr);
570
571 eaddr = eaddr_start;
572 eaddr_end = eaddr + PAGE_SIZE;
573 while (eaddr < eaddr_end) {
574 asm __volatile__ ("ocbp %0, 0" : : "r" (eaddr));
575 eaddr += L1_CACHE_BYTES;
576 }
577
578 sh64_teardown_dtlb_cache_slot();
579 eaddr_start += PAGE_SIZE;
580 }
581}
582
583static void sh64_dcache_purge_user_pages(struct mm_struct *mm,
584 unsigned long addr, unsigned long end)
585{
586 pgd_t *pgd;
587 pmd_t *pmd;
588 pte_t *pte;
589 pte_t entry;
590 spinlock_t *ptl;
591 unsigned long paddr;
592
593 if (!mm)
594 return; /* No way to find physical address of page */
595
596 pgd = pgd_offset(mm, addr);
597 if (pgd_bad(*pgd))
598 return;
599
600 pmd = pmd_offset(pgd, addr);
601 if (pmd_none(*pmd) || pmd_bad(*pmd))
602 return;
603
604 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
605 do {
606 entry = *pte;
607 if (pte_none(entry) || !pte_present(entry))
608 continue;
609 paddr = pte_val(entry) & PAGE_MASK;
610 sh64_dcache_purge_coloured_phy_page(paddr, addr);
611 } while (pte++, addr += PAGE_SIZE, addr != end);
612 pte_unmap_unlock(pte - 1, ptl);
613}
614/****************************************************************************/
615
616static void sh64_dcache_purge_user_range(struct mm_struct *mm,
617 unsigned long start, unsigned long end)
618{
619 /* There are at least 5 choices for the implementation of this, with
620 pros (+), cons(-), comments(*):
621
622 1. ocbp each line in the range through the original user's ASID
623 + no lines spuriously evicted
624 - tlbmiss handling (must either handle faults on demand => extra
625 special-case code in tlbmiss critical path), or map the page in
626 advance (=> flush_tlb_range in advance to avoid multiple hits)
627 - ASID switching
628 - expensive for large ranges
629
630 2. temporarily map each page in the range to a special effective
631 address and ocbp through the temporary mapping; relies on the
632 fact that SH-5 OCB* always do TLB lookup and match on ptags (they
633 never look at the etags)
634 + no spurious evictions
635 - expensive for large ranges
636 * surely cheaper than (1)
637
638 3. walk all the lines in the cache, check the tags, if a match
639 occurs create a page mapping to ocbp the line through
640 + no spurious evictions
641 - tag inspection overhead
642 - (especially for small ranges)
643 - potential cost of setting up/tearing down page mapping for
644 every line that matches the range
645 * cost partly independent of range size
646
647 4. walk all the lines in the cache, check the tags, if a match
648 occurs use 4 * alloco to purge the line (+3 other probably
649 innocent victims) by natural eviction
650 + no tlb mapping overheads
651 - spurious evictions
652 - tag inspection overhead
653
654 5. implement like flush_cache_all
655 + no tag inspection overhead
656 - spurious evictions
657 - bad for small ranges
658
659 (1) can be ruled out as more expensive than (2). (2) appears best
660 for small ranges. The choice between (3), (4) and (5) for large
661 ranges and the range size for the large/small boundary need
662 benchmarking to determine.
663
664 For now use approach (2) for small ranges and (5) for large ones.
665
666 */
667
668 int n_pages;
669
670 n_pages = ((end - start) >> PAGE_SHIFT);
671 if (n_pages >= 64 || ((start ^ (end - 1)) & PMD_MASK)) {
672#if 1
673 sh64_dcache_purge_all();
674#else
675 unsigned long long set, way;
676 unsigned long mm_asid = mm->context & MMU_CONTEXT_ASID_MASK;
677 for (set = 0; set < cpu_data->dcache.sets; set++) {
678 unsigned long long set_base_config_addr = CACHE_OC_ADDRESS_ARRAY + (set << cpu_data->dcache.set_shift);
679 for (way = 0; way < cpu_data->dcache.ways; way++) {
680 unsigned long long config_addr = set_base_config_addr + (way << cpu_data->dcache.way_step_shift);
681 unsigned long long tag0;
682 unsigned long line_valid;
683
684 asm __volatile__("getcfg %1, 0, %0" : "=r" (tag0) : "r" (config_addr));
685 line_valid = tag0 & SH_CACHE_VALID;
686 if (line_valid) {
687 unsigned long cache_asid;
688 unsigned long epn;
689
690 cache_asid = (tag0 & cpu_data->dcache.asid_mask) >> cpu_data->dcache.asid_shift;
691 /* The next line needs some
692 explanation. The virtual tags
693 encode bits [31:13] of the virtual
694 address, bit [12] of the 'tag' being
695 implied by the cache set index. */
696 epn = (tag0 & cpu_data->dcache.epn_mask) | ((set & 0x80) << cpu_data->dcache.entry_shift);
697
698 if ((cache_asid == mm_asid) && (start <= epn) && (epn < end)) {
699 /* TODO : could optimise this
700 call by batching multiple
701 adjacent sets together. */
702 sh64_dcache_purge_sets(set, 1);
703 break; /* Don't waste time inspecting other ways for this set */
704 }
705 }
706 }
707 }
708#endif
709 } else {
710 /* Small range, covered by a single page table page */
711 start &= PAGE_MASK; /* should already be so */
712 end = PAGE_ALIGN(end); /* should already be so */
713 sh64_dcache_purge_user_pages(mm, start, end);
714 }
715 return;
716}
717
718static void sh64_dcache_wback_current_user_range(unsigned long start, unsigned long end)
719{
720 unsigned long long aligned_start;
721 unsigned long long ull_end;
722 unsigned long long addr;
723
724 ull_end = end;
725
726 /* Just wback over the range using the natural addresses. TLB miss
727 handling will be OK (TBC) : the range has just been written to by
728 the signal frame setup code, so the PTEs must exist.
729
730 Note, if we have CONFIG_PREEMPT and get preempted inside this loop,
731 it doesn't matter, even if the pid->ASID mapping changes whilst
732 we're away. In that case the cache will have been flushed when the
733 mapping was renewed. So the writebacks below will be nugatory (and
734 we'll doubtless have to fault the TLB entry/ies in again with the
735 new ASID), but it's a rare case.
736 */
737 aligned_start = start & L1_CACHE_ALIGN_MASK;
738 addr = aligned_start;
739 while (addr < ull_end) {
740 asm __volatile__ ("ocbwb %0, 0" : : "r" (addr));
741 addr += L1_CACHE_BYTES;
742 }
743}
744
745/****************************************************************************/
746
747/* These *MUST* lie in an area of virtual address space that's otherwise unused. */
748#define UNIQUE_EADDR_START 0xe0000000UL
749#define UNIQUE_EADDR_END 0xe8000000UL
750
751static unsigned long sh64_make_unique_eaddr(unsigned long user_eaddr, unsigned long paddr)
752{
753 /* Given a physical address paddr, and a user virtual address
754 user_eaddr which will eventually be mapped to it, create a one-off
755 kernel-private eaddr mapped to the same paddr. This is used for
756 creating special destination pages for copy_user_page and
757 clear_user_page */
758
759 static unsigned long current_pointer = UNIQUE_EADDR_START;
760 unsigned long coloured_pointer;
761
762 if (current_pointer == UNIQUE_EADDR_END) {
763 sh64_dcache_purge_all();
764 current_pointer = UNIQUE_EADDR_START;
765 }
766
767 coloured_pointer = (current_pointer & ~CACHE_OC_SYN_MASK) | (user_eaddr & CACHE_OC_SYN_MASK);
768 sh64_setup_dtlb_cache_slot(coloured_pointer, get_asid(), paddr);
769
770 current_pointer += (PAGE_SIZE << CACHE_OC_N_SYNBITS);
771
772 return coloured_pointer;
773}
774
775/****************************************************************************/
776
777static void sh64_copy_user_page_coloured(void *to, void *from, unsigned long address)
778{
779 void *coloured_to;
780
781 /* Discard any existing cache entries of the wrong colour. These are
782 present quite often, if the kernel has recently used the page
783 internally, then given it up, then it's been allocated to the user.
784 */
785 sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long) to);
786
787 coloured_to = (void *) sh64_make_unique_eaddr(address, __pa(to));
788 sh64_page_copy(from, coloured_to);
789
790 sh64_teardown_dtlb_cache_slot();
791}
792
793static void sh64_clear_user_page_coloured(void *to, unsigned long address)
794{
795 void *coloured_to;
796
797 /* Discard any existing kernel-originated lines of the wrong colour (as
798 above) */
799 sh64_dcache_purge_coloured_phy_page(__pa(to), (unsigned long) to);
800
801 coloured_to = (void *) sh64_make_unique_eaddr(address, __pa(to));
802 sh64_page_clear(coloured_to);
803
804 sh64_teardown_dtlb_cache_slot();
805}
806
807#endif /* !CONFIG_DCACHE_DISABLED */
808
809/****************************************************************************/
810
811/*##########################################################################
812 EXTERNALLY CALLABLE API.
813 ##########################################################################*/
814
815/* These functions are described in Documentation/cachetlb.txt.
816 Each one of these functions varies in behaviour depending on whether the
817 I-cache and/or D-cache are configured out.
818
819 Note that the Linux term 'flush' corresponds to what is termed 'purge' in
820 the sh/sh64 jargon for the D-cache, i.e. write back dirty data then
821 invalidate the cache lines, and 'invalidate' for the I-cache.
822 */
823
824#undef FLUSH_TRACE
825
826void flush_cache_all(void)
827{
828 /* Invalidate the entire contents of both caches, after writing back to
829 memory any dirty data from the D-cache. */
830 sh64_dcache_purge_all();
831 sh64_icache_inv_all();
832}
833
834/****************************************************************************/
835
836void flush_cache_mm(struct mm_struct *mm)
837{
838 /* Invalidate an entire user-address space from both caches, after
839 writing back dirty data (e.g. for shared mmap etc). */
840
841 /* This could be coded selectively by inspecting all the tags then
842 doing 4*alloco on any set containing a match (as for
843 flush_cache_range), but fork/exit/execve (where this is called from)
844 are expensive anyway. */
845
846 /* Have to do a purge here, despite the comments re I-cache below.
847 There could be odd-coloured dirty data associated with the mm still
848 in the cache - if this gets written out through natural eviction
849 after the kernel has reused the page there will be chaos.
850 */
851
852 sh64_dcache_purge_all();
853
854 /* The mm being torn down won't ever be active again, so any Icache
855 lines tagged with its ASID won't be visible for the rest of the
856 lifetime of this ASID cycle. Before the ASID gets reused, there
857 will be a flush_cache_all. Hence we don't need to touch the
858 I-cache. This is similar to the lack of action needed in
859 flush_tlb_mm - see fault.c. */
860}
861
862/****************************************************************************/
863
864void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
865 unsigned long end)
866{
867 struct mm_struct *mm = vma->vm_mm;
868
869 /* Invalidate (from both caches) the range [start,end) of virtual
870 addresses from the user address space specified by mm, after writing
871 back any dirty data.
872
873 Note, 'end' is 1 byte beyond the end of the range to flush. */
874
875 sh64_dcache_purge_user_range(mm, start, end);
876 sh64_icache_inv_user_page_range(mm, start, end);
877}
878
879/****************************************************************************/
880
881void flush_cache_page(struct vm_area_struct *vma, unsigned long eaddr, unsigned long pfn)
882{
883 /* Invalidate any entries in either cache for the vma within the user
884 address space vma->vm_mm for the page starting at virtual address
885 'eaddr'. This seems to be used primarily in breaking COW. Note,
886 the I-cache must be searched too in case the page in question is
887 both writable and being executed from (e.g. stack trampolines.)
888
889 Note, this is called with pte lock held.
890 */
891
892 sh64_dcache_purge_phy_page(pfn << PAGE_SHIFT);
893
894 if (vma->vm_flags & VM_EXEC) {
895 sh64_icache_inv_user_page(vma, eaddr);
896 }
897}
898
899/****************************************************************************/
900
901#ifndef CONFIG_DCACHE_DISABLED
902
903void copy_user_page(void *to, void *from, unsigned long address, struct page *page)
904{
905 /* 'from' and 'to' are kernel virtual addresses (within the superpage
906 mapping of the physical RAM). 'address' is the user virtual address
907 where the copy 'to' will be mapped after. This allows a custom
908 mapping to be used to ensure that the new copy is placed in the
909 right cache sets for the user to see it without having to bounce it
910 out via memory. Note however : the call to flush_page_to_ram in
911 (generic)/mm/memory.c:(break_cow) undoes all this good work in that one
912 very important case!
913
914 TBD : can we guarantee that on every call, any cache entries for
915 'from' are in the same colour sets as 'address' also? i.e. is this
916 always used just to deal with COW? (I suspect not). */
917
918 /* There are two possibilities here for when the page 'from' was last accessed:
919 * by the kernel : this is OK, no purge required.
920 * by the/a user (e.g. for break_COW) : need to purge.
921
922 If the potential user mapping at 'address' is the same colour as
923 'from' there is no need to purge any cache lines from the 'from'
924 page mapped into cache sets of colour 'address'. (The copy will be
925 accessing the page through 'from').
926 */
927
928 if (((address ^ (unsigned long) from) & CACHE_OC_SYN_MASK) != 0) {
929 sh64_dcache_purge_coloured_phy_page(__pa(from), address);
930 }
931
932 if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0) {
933 /* No synonym problem on destination */
934 sh64_page_copy(from, to);
935 } else {
936 sh64_copy_user_page_coloured(to, from, address);
937 }
938
939 /* Note, don't need to flush 'from' page from the cache again - it's
940 done anyway by the generic code */
941}
942
943void clear_user_page(void *to, unsigned long address, struct page *page)
944{
945 /* 'to' is a kernel virtual address (within the superpage
946 mapping of the physical RAM). 'address' is the user virtual address
947 where the 'to' page will be mapped after. This allows a custom
948 mapping to be used to ensure that the new copy is placed in the
949 right cache sets for the user to see it without having to bounce it
950 out via memory.
951 */
952
953 if (((address ^ (unsigned long) to) & CACHE_OC_SYN_MASK) == 0) {
954 /* No synonym problem on destination */
955 sh64_page_clear(to);
956 } else {
957 sh64_clear_user_page_coloured(to, address);
958 }
959}
960
961#endif /* !CONFIG_DCACHE_DISABLED */
962
963/****************************************************************************/
964
965void flush_dcache_page(struct page *page)
966{
967 sh64_dcache_purge_phy_page(page_to_phys(page));
968 wmb();
969}
970
971/****************************************************************************/
972
973void flush_icache_range(unsigned long start, unsigned long end)
974{
975 /* Flush the range [start,end] of kernel virtual adddress space from
976 the I-cache. The corresponding range must be purged from the
977 D-cache also because the SH-5 doesn't have cache snooping between
978 the caches. The addresses will be visible through the superpage
979 mapping, therefore it's guaranteed that there no cache entries for
980 the range in cache sets of the wrong colour.
981
982 Primarily used for cohering the I-cache after a module has
983 been loaded. */
984
985 /* We also make sure to purge the same range from the D-cache since
986 flush_page_to_ram() won't be doing this for us! */
987
988 sh64_dcache_purge_kernel_range(start, end);
989 wmb();
990 sh64_icache_inv_kernel_range(start, end);
991}
992
993/****************************************************************************/
994
995void flush_icache_user_range(struct vm_area_struct *vma,
996 struct page *page, unsigned long addr, int len)
997{
998 /* Flush the range of user (defined by vma->vm_mm) address space
999 starting at 'addr' for 'len' bytes from the cache. The range does
1000 not straddle a page boundary, the unique physical page containing
1001 the range is 'page'. This seems to be used mainly for invalidating
1002 an address range following a poke into the program text through the
1003 ptrace() call from another process (e.g. for BRK instruction
1004 insertion). */
1005
1006 sh64_dcache_purge_coloured_phy_page(page_to_phys(page), addr);
1007 mb();
1008
1009 if (vma->vm_flags & VM_EXEC) {
1010 sh64_icache_inv_user_small_range(vma->vm_mm, addr, len);
1011 }
1012}
1013
1014/*##########################################################################
1015 ARCH/SH64 PRIVATE CALLABLE API.
1016 ##########################################################################*/
1017
1018void flush_cache_sigtramp(unsigned long start, unsigned long end)
1019{
1020 /* For the address range [start,end), write back the data from the
1021 D-cache and invalidate the corresponding region of the I-cache for
1022 the current process. Used to flush signal trampolines on the stack
1023 to make them executable. */
1024
1025 sh64_dcache_wback_current_user_range(start, end);
1026 wmb();
1027 sh64_icache_inv_current_user_range(start, end);
1028}
1029