| blob | 224ce226a01bc24f5c561dd7b0680c5970803d34 |
1 /*
2 * linux/arch/arm/mm/arm925.S: MMU functions for ARM925
3 *
4 * Copyright (C) 1999,2000 ARM Limited
5 * Copyright (C) 2000 Deep Blue Solutions Ltd.
6 * Copyright (C) 2002 RidgeRun, Inc.
7 * Copyright (C) 2002-2003 MontaVista Software, Inc.
8 *
9 * Update for Linux-2.6 and cache flush improvements
10 * Copyright (C) 2004 Nokia Corporation by Tony Lindgren <tony@atomide.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 *
26 *
27 * These are the low level assembler for performing cache and TLB
28 * functions on the arm925.
29 *
30 * CONFIG_CPU_ARM925_CPU_IDLE -> nohlt
31 *
32 * Some additional notes based on deciphering the TI TRM on OMAP-5910:
33 *
34 * NOTE1: The TI925T Configuration Register bit "D-cache clean and flush
35 * entry mode" must be 0 to flush the entries in both segments
36 * at once. This is the default value. See TRM 2-20 and 2-24 for
37 * more information.
38 *
39 * NOTE2: Default is the "D-cache clean and flush entry mode". It looks
40 * like the "Transparent mode" must be on for partial cache flushes
41 * to work in this mode. This mode only works with 16-bit external
42 * memory. See TRM 2-24 for more information.
43 *
44 * NOTE3: Write-back cache flushing seems to be flakey with devices using
45 * direct memory access, such as USB OHCI. The workaround is to use
46 * write-through cache with CONFIG_CPU_DCACHE_WRITETHROUGH (this is
47 * the default for OMAP-1510).
48 */
50 #include <linux/linkage.h>
51 #include <linux/config.h>
52 #include <linux/init.h>
53 #include <asm/assembler.h>
54 #include <asm/pgtable-hwdef.h>
55 #include <asm/pgtable.h>
56 #include <asm/procinfo.h>
57 #include <asm/page.h>
58 #include <asm/ptrace.h>
59 #include "proc-macros.S"
61 /*
62 * The size of one data cache line.
63 */
64 #define CACHE_DLINESIZE 16
66 /*
67 * The number of data cache segments.
68 */
69 #define CACHE_DSEGMENTS 2
71 /*
72 * The number of lines in a cache segment.
73 */
74 #define CACHE_DENTRIES 256
76 /*
77 * This is the size at which it becomes more efficient to
78 * clean the whole cache, rather than using the individual
79 * cache line maintainence instructions.
80 */
81 #define CACHE_DLIMIT 8192
83 .text
84 /*
85 * cpu_arm925_proc_init()
86 */
87 ENTRY(cpu_arm925_proc_init)
88 mov pc, lr
90 /*
91 * cpu_arm925_proc_fin()
92 */
93 ENTRY(cpu_arm925_proc_fin)
94 stmfd sp!, {lr}
95 mov ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE
96 msr cpsr_c, ip
97 bl arm925_flush_kern_cache_all
98 mrc p15, 0, r0, c1, c0, 0 @ ctrl register
99 bic r0, r0, #0x1000 @ ...i............
100 bic r0, r0, #0x000e @ ............wca.
101 mcr p15, 0, r0, c1, c0, 0 @ disable caches
102 ldmfd sp!, {pc}
104 /*
105 * cpu_arm925_reset(loc)
106 *
107 * Perform a soft reset of the system. Put the CPU into the
108 * same state as it would be if it had been reset, and branch
109 * to what would be the reset vector.
110 *
111 * loc: location to jump to for soft reset
112 */
113 .align 5
114 ENTRY(cpu_arm925_reset)
115 /* Send software reset to MPU and DSP */
116 mov ip, #0xff000000
117 orr ip, ip, #0x00fe0000
118 orr ip, ip, #0x0000ce00
119 mov r4, #1
120 strh r4, [ip, #0x10]
122 mov ip, #0
123 mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches
124 mcr p15, 0, ip, c7, c10, 4 @ drain WB
125 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
126 mrc p15, 0, ip, c1, c0, 0 @ ctrl register
127 bic ip, ip, #0x000f @ ............wcam
128 bic ip, ip, #0x1100 @ ...i...s........
129 mcr p15, 0, ip, c1, c0, 0 @ ctrl register
130 mov pc, r0
132 /*
133 * cpu_arm925_do_idle()
134 *
135 * Called with IRQs disabled
136 */
137 .align 10
138 ENTRY(cpu_arm925_do_idle)
139 mov r0, #0
140 mrc p15, 0, r1, c1, c0, 0 @ Read control register
141 mcr p15, 0, r0, c7, c10, 4 @ Drain write buffer
142 bic r2, r1, #1 << 12
143 mcr p15, 0, r2, c1, c0, 0 @ Disable I cache
144 mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
145 mcr p15, 0, r1, c1, c0, 0 @ Restore ICache enable
146 mov pc, lr
148 /*
149 * flush_user_cache_all()
150 *
151 * Clean and invalidate all cache entries in a particular
152 * address space.
153 */
154 ENTRY(arm925_flush_user_cache_all)
155 /* FALLTHROUGH */
157 /*
158 * flush_kern_cache_all()
159 *
160 * Clean and invalidate the entire cache.
161 */
162 ENTRY(arm925_flush_kern_cache_all)
163 mov r2, #VM_EXEC
164 mov ip, #0
165 __flush_whole_cache:
166 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
167 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
168 #else
169 /* Flush entries in both segments at once, see NOTE1 above */
170 mov r3, #(CACHE_DENTRIES - 1) << 4 @ 256 entries in segment
171 2: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index
172 subs r3, r3, #1 << 4
173 bcs 2b @ entries 255 to 0
174 #endif
175 tst r2, #VM_EXEC
176 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
177 mcrne p15, 0, ip, c7, c10, 4 @ drain WB
178 mov pc, lr
180 /*
181 * flush_user_cache_range(start, end, flags)
182 *
183 * Clean and invalidate a range of cache entries in the
184 * specified address range.
185 *
186 * - start - start address (inclusive)
187 * - end - end address (exclusive)
188 * - flags - vm_flags describing address space
189 */
190 ENTRY(arm925_flush_user_cache_range)
191 mov ip, #0
192 sub r3, r1, r0 @ calculate total size
193 cmp r3, #CACHE_DLIMIT
194 bgt __flush_whole_cache
195 1: tst r2, #VM_EXEC
196 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
197 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
198 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
199 add r0, r0, #CACHE_DLINESIZE
200 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
201 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
202 add r0, r0, #CACHE_DLINESIZE
203 #else
204 mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry
205 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
206 add r0, r0, #CACHE_DLINESIZE
207 mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry
208 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
209 add r0, r0, #CACHE_DLINESIZE
210 #endif
211 cmp r0, r1
212 blo 1b
213 tst r2, #VM_EXEC
214 mcrne p15, 0, ip, c7, c10, 4 @ drain WB
215 mov pc, lr
217 /*
218 * coherent_kern_range(start, end)
219 *
220 * Ensure coherency between the Icache and the Dcache in the
221 * region described by start, end. If you have non-snooping
222 * Harvard caches, you need to implement this function.
223 *
224 * - start - virtual start address
225 * - end - virtual end address
226 */
227 ENTRY(arm925_coherent_kern_range)
228 /* FALLTHROUGH */
230 /*
231 * coherent_user_range(start, end)
232 *
233 * Ensure coherency between the Icache and the Dcache in the
234 * region described by start, end. If you have non-snooping
235 * Harvard caches, you need to implement this function.
236 *
237 * - start - virtual start address
238 * - end - virtual end address
239 */
240 ENTRY(arm925_coherent_user_range)
241 bic r0, r0, #CACHE_DLINESIZE - 1
242 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
243 mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
244 add r0, r0, #CACHE_DLINESIZE
245 cmp r0, r1
246 blo 1b
247 mcr p15, 0, r0, c7, c10, 4 @ drain WB
248 mov pc, lr
250 /*
251 * flush_kern_dcache_page(void *page)
252 *
253 * Ensure no D cache aliasing occurs, either with itself or
254 * the I cache
255 *
256 * - addr - page aligned address
257 */
258 ENTRY(arm925_flush_kern_dcache_page)
259 add r1, r0, #PAGE_SZ
260 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
261 add r0, r0, #CACHE_DLINESIZE
262 cmp r0, r1
263 blo 1b
264 mov r0, #0
265 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
266 mcr p15, 0, r0, c7, c10, 4 @ drain WB
267 mov pc, lr
269 /*
270 * dma_inv_range(start, end)
271 *
272 * Invalidate (discard) the specified virtual address range.
273 * May not write back any entries. If 'start' or 'end'
274 * are not cache line aligned, those lines must be written
275 * back.
276 *
277 * - start - virtual start address
278 * - end - virtual end address
279 *
280 * (same as v4wb)
281 */
282 ENTRY(arm925_dma_inv_range)
283 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
284 tst r0, #CACHE_DLINESIZE - 1
285 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
286 tst r1, #CACHE_DLINESIZE - 1
287 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry
288 #endif
289 bic r0, r0, #CACHE_DLINESIZE - 1
290 1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
291 add r0, r0, #CACHE_DLINESIZE
292 cmp r0, r1
293 blo 1b
294 mcr p15, 0, r0, c7, c10, 4 @ drain WB
295 mov pc, lr
297 /*
298 * dma_clean_range(start, end)
299 *
300 * Clean the specified virtual address range.
301 *
302 * - start - virtual start address
303 * - end - virtual end address
304 *
305 * (same as v4wb)
306 */
307 ENTRY(arm925_dma_clean_range)
308 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
309 bic r0, r0, #CACHE_DLINESIZE - 1
310 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
311 add r0, r0, #CACHE_DLINESIZE
312 cmp r0, r1
313 blo 1b
314 #endif
315 mcr p15, 0, r0, c7, c10, 4 @ drain WB
316 mov pc, lr
318 /*
319 * dma_flush_range(start, end)
320 *
321 * Clean and invalidate the specified virtual address range.
322 *
323 * - start - virtual start address
324 * - end - virtual end address
325 */
326 ENTRY(arm925_dma_flush_range)
327 bic r0, r0, #CACHE_DLINESIZE - 1
328 1:
329 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
330 mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
331 #else
332 mcr p15, 0, r0, c7, c10, 1 @ clean D entry
333 #endif
334 add r0, r0, #CACHE_DLINESIZE
335 cmp r0, r1
336 blo 1b
337 mcr p15, 0, r0, c7, c10, 4 @ drain WB
338 mov pc, lr
340 ENTRY(arm925_cache_fns)
341 .long arm925_flush_kern_cache_all
342 .long arm925_flush_user_cache_all
343 .long arm925_flush_user_cache_range
344 .long arm925_coherent_kern_range
345 .long arm925_coherent_user_range
346 .long arm925_flush_kern_dcache_page
347 .long arm925_dma_inv_range
348 .long arm925_dma_clean_range
349 .long arm925_dma_flush_range
351 ENTRY(cpu_arm925_dcache_clean_area)
352 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
353 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
354 add r0, r0, #CACHE_DLINESIZE
355 subs r1, r1, #CACHE_DLINESIZE
356 bhi 1b
357 #endif
358 mcr p15, 0, r0, c7, c10, 4 @ drain WB
359 mov pc, lr
361 /* =============================== PageTable ============================== */
363 /*
364 * cpu_arm925_switch_mm(pgd)
365 *
366 * Set the translation base pointer to be as described by pgd.
367 *
368 * pgd: new page tables
369 */
370 .align 5
371 ENTRY(cpu_arm925_switch_mm)
372 mov ip, #0
373 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
374 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
375 #else
376 /* Flush entries in bothe segments at once, see NOTE1 above */
377 mov r3, #(CACHE_DENTRIES - 1) << 4 @ 256 entries in segment
378 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index
379 subs r3, r3, #1 << 4
380 bcs 2b @ entries 255 to 0
381 #endif
382 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
383 mcr p15, 0, ip, c7, c10, 4 @ drain WB
384 mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
385 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
386 mov pc, lr
388 /*
389 * cpu_arm925_set_pte(ptep, pte)
390 *
391 * Set a PTE and flush it out
392 */
393 .align 5
394 ENTRY(cpu_arm925_set_pte)
395 str r1, [r0], #-2048 @ linux version
397 eor r1, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
399 bic r2, r1, #PTE_SMALL_AP_MASK
400 bic r2, r2, #PTE_TYPE_MASK
401 orr r2, r2, #PTE_TYPE_SMALL
403 tst r1, #L_PTE_USER @ User?
404 orrne r2, r2, #PTE_SMALL_AP_URO_SRW
406 tst r1, #L_PTE_WRITE | L_PTE_DIRTY @ Write and Dirty?
407 orreq r2, r2, #PTE_SMALL_AP_UNO_SRW
409 tst r1, #L_PTE_PRESENT | L_PTE_YOUNG @ Present and Young?
410 movne r2, #0
412 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
413 eor r3, r2, #0x0a @ C & small page?
414 tst r3, #0x0b
415 biceq r2, r2, #4
416 #endif
417 str r2, [r0] @ hardware version
418 mov r0, r0
419 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
420 mcr p15, 0, r0, c7, c10, 1 @ clean D entry
421 #endif
422 mcr p15, 0, r0, c7, c10, 4 @ drain WB
423 mov pc, lr
425 __INIT
427 .type __arm925_setup, #function
428 __arm925_setup:
429 mov r0, #0
430 #if defined(CONFIG_CPU_ICACHE_STREAMING_DISABLE)
431 orr r0,r0,#1 << 7
432 #endif
434 /* Transparent on, D-cache clean & flush mode. See NOTE2 above */
435 orr r0,r0,#1 << 1 @ transparent mode on
436 mcr p15, 0, r0, c15, c1, 0 @ write TI config register
438 mov r0, #0
439 mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4
440 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4
441 mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4
443 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
444 mov r0, #4 @ disable write-back on caches explicitly
445 mcr p15, 7, r0, c15, c0, 0
446 #endif
448 mrc p15, 0, r0, c1, c0 @ get control register v4
449 ldr r5, arm925_cr1_clear
450 bic r0, r0, r5
451 ldr r5, arm925_cr1_set
452 orr r0, r0, r5
453 #ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
454 orr r0, r0, #0x4000 @ .1.. .... .... ....
455 #endif
456 mov pc, lr
457 .size __arm925_setup, . - __arm925_setup
459 /*
460 * R
461 * .RVI ZFRS BLDP WCAM
462 * .011 0001 ..11 1101
463 *
464 */
465 .type arm925_cr1_clear, #object
466 .type arm925_cr1_set, #object
467 arm925_cr1_clear:
468 .word 0x7f3f
469 arm925_cr1_set:
470 .word 0x313d
472 __INITDATA
474 /*
475 * Purpose : Function pointers used to access above functions - all calls
476 * come through these
477 */
478 .type arm925_processor_functions, #object
479 arm925_processor_functions:
480 .word v4t_early_abort
481 .word cpu_arm925_proc_init
482 .word cpu_arm925_proc_fin
483 .word cpu_arm925_reset
484 .word cpu_arm925_do_idle
485 .word cpu_arm925_dcache_clean_area
486 .word cpu_arm925_switch_mm
487 .word cpu_arm925_set_pte
488 .size arm925_processor_functions, . - arm925_processor_functions
490 .section ".rodata"
492 .type cpu_arch_name, #object
493 cpu_arch_name:
494 .asciz "armv4t"
495 .size cpu_arch_name, . - cpu_arch_name
497 .type cpu_elf_name, #object
498 cpu_elf_name:
499 .asciz "v4"
500 .size cpu_elf_name, . - cpu_elf_name
502 .type cpu_arm925_name, #object
503 cpu_arm925_name:
504 .ascii "ARM925T"
505 #ifndef CONFIG_CPU_ICACHE_DISABLE
506 .ascii "i"
507 #endif
508 #ifndef CONFIG_CPU_DCACHE_DISABLE
509 .ascii "d"
510 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
511 .ascii "(wt)"
512 #else
513 .ascii "(wb)"
514 #endif
515 #ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
516 .ascii "RR"
517 #endif
518 #endif
519 .ascii "\0"
520 .size cpu_arm925_name, . - cpu_arm925_name
522 .align
524 .section ".proc.info.init", #alloc, #execinstr
526 .type __arm925_proc_info,#object
527 __arm925_proc_info:
528 .long 0x54029250
529 .long 0xfffffff0
530 .long PMD_TYPE_SECT | \
531 PMD_BIT4 | \
532 PMD_SECT_AP_WRITE | \
533 PMD_SECT_AP_READ
534 b __arm925_setup
535 .long cpu_arch_name
536 .long cpu_elf_name
537 .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
538 .long cpu_arm925_name
539 .long arm925_processor_functions
540 .long v4wbi_tlb_fns
541 .long v4wb_user_fns
542 .long arm925_cache_fns
543 .size __arm925_proc_info, . - __arm925_proc_info
545 .type __arm915_proc_info,#object
546 __arm915_proc_info:
547 .long 0x54029150
548 .long 0xfffffff0
549 .long PMD_TYPE_SECT | \
550 PMD_BIT4 | \
551 PMD_SECT_AP_WRITE | \
552 PMD_SECT_AP_READ
553 b __arm925_setup
554 .long cpu_arch_name
555 .long cpu_elf_name
556 .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB
557 .long cpu_arm925_name
558 .long arm925_processor_functions
559 .long v4wbi_tlb_fns
560 .long v4wb_user_fns
561 .long arm925_cache_fns
562 .size __arm925_proc_info, . - __arm925_proc_info