1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * linux/arch/arm/mm/proc-arm926.S: MMU functions for ARM926EJ-S
4 *
5 * Copyright (C) 1999-2001 ARM Limited
6 * Copyright (C) 2000 Deep Blue Solutions Ltd.
7 * hacked for non-paged-MM by Hyok S. Choi, 2003.
8 *
9 * These are the low level assembler for performing cache and TLB
10 * functions on the arm926.
11 *
12 * CONFIG_CPU_ARM926_CPU_IDLE -> nohlt
13 */
14#include <linux/linkage.h>
15#include <linux/init.h>
16#include <linux/pgtable.h>
17#include <asm/assembler.h>
18#include <asm/hwcap.h>
19#include <asm/pgtable-hwdef.h>
20#include <asm/page.h>
21#include <asm/ptrace.h>
22#include "proc-macros.S"
23
24/*
25 * This is the maximum size of an area which will be invalidated
26 * using the single invalidate entry instructions. Anything larger
27 * than this, and we go for the whole cache.
28 *
29 * This value should be chosen such that we choose the cheapest
30 * alternative.
31 */
32#define CACHE_DLIMIT 16384
33
34/*
35 * the cache line size of the I and D cache
36 */
37#define CACHE_DLINESIZE 32
38
39 .text
40/*
41 * cpu_arm926_proc_init()
42 */
43ENTRY(cpu_arm926_proc_init)
44 ret lr
45
46/*
47 * cpu_arm926_proc_fin()
48 */
49ENTRY(cpu_arm926_proc_fin)
50 mrc p15, 0, r0, c1, c0, 0 @ ctrl register
51 bic r0, r0, #0x1000 @ ...i............
52 bic r0, r0, #0x000e @ ............wca.
53 mcr p15, 0, r0, c1, c0, 0 @ disable caches
54 ret lr
55
56/*
57 * cpu_arm926_reset(loc)
58 *
59 * Perform a soft reset of the system. Put the CPU into the
60 * same state as it would be if it had been reset, and branch
61 * to what would be the reset vector.
62 *
63 * loc: location to jump to for soft reset
64 */
65 .align 5
66 .pushsection .idmap.text, "ax"
67ENTRY(cpu_arm926_reset)
68 mov ip, #0
69 mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches
70 mcr p15, 0, ip, c7, c10, 4 @ drain WB
71#ifdef CONFIG_MMU
72 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
73#endif
74 mrc p15, 0, ip, c1, c0, 0 @ ctrl register
75 bic ip, ip, #0x000f @ ............wcam
76 bic ip, ip, #0x1100 @ ...i...s........
77 mcr p15, 0, ip, c1, c0, 0 @ ctrl register
78 ret r0
79ENDPROC(cpu_arm926_reset)
80 .popsection
81
82/*
83 * cpu_arm926_do_idle()
84 *
85 * Called with IRQs disabled
86 */
87 .align 10
88ENTRY(cpu_arm926_do_idle)
89 mov r0, #0
90 mrc p15, 0, r1, c1, c0, 0 @ Read control register
91 mcr p15, 0, r0, c7, c10, 4 @ Drain write buffer
92 bic r2, r1, #1 << 12
93 mrs r3, cpsr @ Disable FIQs while Icache
94 orr ip, r3, #PSR_F_BIT @ is disabled
95 msr cpsr_c, ip
96 mcr p15, 0, r2, c1, c0, 0 @ Disable I cache
97 mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt
98 mcr p15, 0, r1, c1, c0, 0 @ Restore ICache enable
99 msr cpsr_c, r3 @ Restore FIQ state
100 ret lr
101
102/*
103 * flush_icache_all()
104 *
105 * Unconditionally clean and invalidate the entire icache.
106 */
107ENTRY(arm926_flush_icache_all)
108 mov r0, #0
109 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
110 ret lr
111ENDPROC(arm926_flush_icache_all)
112
113/*
114 * flush_user_cache_all()
115 *
116 * Clean and invalidate all cache entries in a particular
117 * address space.
118 */
119ENTRY(arm926_flush_user_cache_all)
120 /* FALLTHROUGH */
121
122/*
123 * flush_kern_cache_all()
124 *
125 * Clean and invalidate the entire cache.
126 */
127ENTRY(arm926_flush_kern_cache_all)
128 mov r2, #VM_EXEC
129 mov ip, #0
130__flush_whole_cache:
131#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
132 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
133#else
1341: mrc p15, 0, APSR_nzcv, c7, c14, 3 @ test,clean,invalidate
135 bne 1b
136#endif
137 tst r2, #VM_EXEC
138 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
139 mcrne p15, 0, ip, c7, c10, 4 @ drain WB
140 ret lr
141
142/*
143 * flush_user_cache_range(start, end, flags)
144 *
145 * Clean and invalidate a range of cache entries in the
146 * specified address range.
147 *
148 * - start - start address (inclusive)
149 * - end - end address (exclusive)
150 * - flags - vm_flags describing address space
151 */
152ENTRY(arm926_flush_user_cache_range)
153 mov ip, #0
154 sub r3, r1, r0 @ calculate total size
155 cmp r3, #CACHE_DLIMIT
156 bgt __flush_whole_cache
1571: tst r2, #VM_EXEC
158#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
159 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
160 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
161 add r0, r0, #CACHE_DLINESIZE
162 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
163 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
164 add r0, r0, #CACHE_DLINESIZE
165#else
166 mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry
167 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
168 add r0, r0, #CACHE_DLINESIZE
169 mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry
170 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
171 add r0, r0, #CACHE_DLINESIZE
172#endif
173 cmp r0, r1
174 blo 1b
175 tst r2, #VM_EXEC
176 mcrne p15, 0, ip, c7, c10, 4 @ drain WB
177 ret lr
178
179/*
180 * coherent_kern_range(start, end)
181 *
182 * Ensure coherency between the Icache and the Dcache in the
183 * region described by start, end. If you have non-snooping
184 * Harvard caches, you need to implement this function.
185 *
186 * - start - virtual start address
187 * - end - virtual end address
188 */
189ENTRY(arm926_coherent_kern_range)
190 /* FALLTHROUGH */
191
192/*
193 * coherent_user_range(start, end)
194 *
195 * Ensure coherency between the Icache and the Dcache in the
196 * region described by start, end. If you have non-snooping
197 * Harvard caches, you need to implement this function.
198 *
199 * - start - virtual start address
200 * - end - virtual end address
201 */
202ENTRY(arm926_coherent_user_range)
203 bic r0, r0, #CACHE_DLINESIZE - 1
2041: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
205 mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
206 add r0, r0, #CACHE_DLINESIZE
207 cmp r0, r1
208 blo 1b
209 mcr p15, 0, r0, c7, c10, 4 @ drain WB
210 mov r0, #0
211 ret lr
212
213/*
214 * flush_kern_dcache_area(void *addr, size_t size)
215 *
216 * Ensure no D cache aliasing occurs, either with itself or
217 * the I cache
218 *
219 * - addr - kernel address
220 * - size - region size
221 */
222ENTRY(arm926_flush_kern_dcache_area)
223 add r1, r0, r1
2241: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
225 add r0, r0, #CACHE_DLINESIZE
226 cmp r0, r1
227 blo 1b
228 mov r0, #0
229 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
230 mcr p15, 0, r0, c7, c10, 4 @ drain WB
231 ret lr
232
233/*
234 * dma_inv_range(start, end)
235 *
236 * Invalidate (discard) the specified virtual address range.
237 * May not write back any entries. If 'start' or 'end'
238 * are not cache line aligned, those lines must be written
239 * back.
240 *
241 * - start - virtual start address
242 * - end - virtual end address
243 *
244 * (same as v4wb)
245 */
246arm926_dma_inv_range:
247#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
248 tst r0, #CACHE_DLINESIZE - 1
249 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry
250 tst r1, #CACHE_DLINESIZE - 1
251 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry
252#endif
253 bic r0, r0, #CACHE_DLINESIZE - 1
2541: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
255 add r0, r0, #CACHE_DLINESIZE
256 cmp r0, r1
257 blo 1b
258 mcr p15, 0, r0, c7, c10, 4 @ drain WB
259 ret lr
260
261/*
262 * dma_clean_range(start, end)
263 *
264 * Clean the specified virtual address range.
265 *
266 * - start - virtual start address
267 * - end - virtual end address
268 *
269 * (same as v4wb)
270 */
271arm926_dma_clean_range:
272#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
273 bic r0, r0, #CACHE_DLINESIZE - 1
2741: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
275 add r0, r0, #CACHE_DLINESIZE
276 cmp r0, r1
277 blo 1b
278#endif
279 mcr p15, 0, r0, c7, c10, 4 @ drain WB
280 ret lr
281
282/*
283 * dma_flush_range(start, end)
284 *
285 * Clean and invalidate the specified virtual address range.
286 *
287 * - start - virtual start address
288 * - end - virtual end address
289 */
290ENTRY(arm926_dma_flush_range)
291 bic r0, r0, #CACHE_DLINESIZE - 1
2921:
293#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
294 mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry
295#else
296 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
297#endif
298 add r0, r0, #CACHE_DLINESIZE
299 cmp r0, r1
300 blo 1b
301 mcr p15, 0, r0, c7, c10, 4 @ drain WB
302 ret lr
303
304/*
305 * dma_map_area(start, size, dir)
306 * - start - kernel virtual start address
307 * - size - size of region
308 * - dir - DMA direction
309 */
310ENTRY(arm926_dma_map_area)
311 add r1, r1, r0
312 cmp r2, #DMA_TO_DEVICE
313 beq arm926_dma_clean_range
314 bcs arm926_dma_inv_range
315 b arm926_dma_flush_range
316ENDPROC(arm926_dma_map_area)
317
318/*
319 * dma_unmap_area(start, size, dir)
320 * - start - kernel virtual start address
321 * - size - size of region
322 * - dir - DMA direction
323 */
324ENTRY(arm926_dma_unmap_area)
325 ret lr
326ENDPROC(arm926_dma_unmap_area)
327
328 .globl arm926_flush_kern_cache_louis
329 .equ arm926_flush_kern_cache_louis, arm926_flush_kern_cache_all
330
331 @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
332 define_cache_functions arm926
333
334ENTRY(cpu_arm926_dcache_clean_area)
335#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
3361: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
337 add r0, r0, #CACHE_DLINESIZE
338 subs r1, r1, #CACHE_DLINESIZE
339 bhi 1b
340#endif
341 mcr p15, 0, r0, c7, c10, 4 @ drain WB
342 ret lr
343
344/* =============================== PageTable ============================== */
345
346/*
347 * cpu_arm926_switch_mm(pgd)
348 *
349 * Set the translation base pointer to be as described by pgd.
350 *
351 * pgd: new page tables
352 */
353 .align 5
354ENTRY(cpu_arm926_switch_mm)
355#ifdef CONFIG_MMU
356 mov ip, #0
357#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
358 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
359#else
360@ && 'Clean & Invalidate whole DCache'
3611: mrc p15, 0, APSR_nzcv, c7, c14, 3 @ test,clean,invalidate
362 bne 1b
363#endif
364 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
365 mcr p15, 0, ip, c7, c10, 4 @ drain WB
366 mcr p15, 0, r0, c2, c0, 0 @ load page table pointer
367 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
368#endif
369 ret lr
370
371/*
372 * cpu_arm926_set_pte_ext(ptep, pte, ext)
373 *
374 * Set a PTE and flush it out
375 */
376 .align 5
377ENTRY(cpu_arm926_set_pte_ext)
378#ifdef CONFIG_MMU
379 armv3_set_pte_ext
380 mov r0, r0
381#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH
382 mcr p15, 0, r0, c7, c10, 1 @ clean D entry
383#endif
384 mcr p15, 0, r0, c7, c10, 4 @ drain WB
385#endif
386 ret lr
387
388/* Suspend/resume support: taken from arch/arm/plat-s3c24xx/sleep.S */
389.globl cpu_arm926_suspend_size
390.equ cpu_arm926_suspend_size, 4 * 3
391#ifdef CONFIG_ARM_CPU_SUSPEND
392ENTRY(cpu_arm926_do_suspend)
393 stmfd sp!, {r4 - r6, lr}
394 mrc p15, 0, r4, c13, c0, 0 @ PID
395 mrc p15, 0, r5, c3, c0, 0 @ Domain ID
396 mrc p15, 0, r6, c1, c0, 0 @ Control register
397 stmia r0, {r4 - r6}
398 ldmfd sp!, {r4 - r6, pc}
399ENDPROC(cpu_arm926_do_suspend)
400
401ENTRY(cpu_arm926_do_resume)
402 mov ip, #0
403 mcr p15, 0, ip, c8, c7, 0 @ invalidate I+D TLBs
404 mcr p15, 0, ip, c7, c7, 0 @ invalidate I+D caches
405 ldmia r0, {r4 - r6}
406 mcr p15, 0, r4, c13, c0, 0 @ PID
407 mcr p15, 0, r5, c3, c0, 0 @ Domain ID
408 mcr p15, 0, r1, c2, c0, 0 @ TTB address
409 mov r0, r6 @ control register
410 b cpu_resume_mmu
411ENDPROC(cpu_arm926_do_resume)
412#endif
413
414 .type __arm926_setup, #function
415__arm926_setup:
416 mov r0, #0
417 mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4
418 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4
419#ifdef CONFIG_MMU
420 mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4
421#endif
422
423
424#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
425 mov r0, #4 @ disable write-back on caches explicitly
426 mcr p15, 7, r0, c15, c0, 0
427#endif
428
429 adr r5, arm926_crval
430 ldmia r5, {r5, r6}
431 mrc p15, 0, r0, c1, c0 @ get control register v4
432 bic r0, r0, r5
433 orr r0, r0, r6
434#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN
435 orr r0, r0, #0x4000 @ .1.. .... .... ....
436#endif
437 ret lr
438 .size __arm926_setup, . - __arm926_setup
439
440 /*
441 * R
442 * .RVI ZFRS BLDP WCAM
443 * .011 0001 ..11 0101
444 *
445 */
446 .type arm926_crval, #object
447arm926_crval:
448 crval clear=0x00007f3f, mmuset=0x00003135, ucset=0x00001134
449
450 __INITDATA
451
452 @ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
453 define_processor_functions arm926, dabort=v5tj_early_abort, pabort=legacy_pabort, suspend=1
454
455 .section ".rodata"
456
457 string cpu_arch_name, "armv5tej"
458 string cpu_elf_name, "v5"
459 string cpu_arm926_name, "ARM926EJ-S"
460
461 .align
462
463 .section ".proc.info.init", "a"
464
465 .type __arm926_proc_info,#object
466__arm926_proc_info:
467 .long 0x41069260 @ ARM926EJ-S (v5TEJ)
468 .long 0xff0ffff0
469 .long PMD_TYPE_SECT | \
470 PMD_SECT_BUFFERABLE | \
471 PMD_SECT_CACHEABLE | \
472 PMD_BIT4 | \
473 PMD_SECT_AP_WRITE | \
474 PMD_SECT_AP_READ
475 .long PMD_TYPE_SECT | \
476 PMD_BIT4 | \
477 PMD_SECT_AP_WRITE | \
478 PMD_SECT_AP_READ
479 initfn __arm926_setup, __arm926_proc_info
480 .long cpu_arch_name
481 .long cpu_elf_name
482 .long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA
483 .long cpu_arm926_name
484 .long arm926_processor_functions
485 .long v4wbi_tlb_fns
486 .long v4wb_user_fns
487 .long arm926_cache_fns
488 .size __arm926_proc_info, . - __arm926_proc_info
489

source code of linux/arch/arm/mm/proc-arm926.S