xref: /openbmc/linux/arch/arm/mm/cache-v7m.S (revision 39f555fb) 
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/mm/cache-v7m.S
4 *
5 *  Based on linux/arch/arm/mm/cache-v7.S
6 *
7 *  Copyright (C) 2001 Deep Blue Solutions Ltd.
8 *  Copyright (C) 2005 ARM Ltd.
9 *
10 *  This is the "shell" of the ARMv7M processor support.
11 */
12#include <linux/linkage.h>
13#include <linux/init.h>
14#include <asm/assembler.h>
15#include <asm/errno.h>
16#include <asm/unwind.h>
17#include <asm/v7m.h>
18
19#include "proc-macros.S"
20
21.arch armv7-m
22
23/* Generic V7M read/write macros for memory mapped cache operations */
24.macro v7m_cache_read, rt, reg
25	movw	\rt, #:lower16:BASEADDR_V7M_SCB + \reg
26	movt	\rt, #:upper16:BASEADDR_V7M_SCB + \reg
27	ldr     \rt, [\rt]
28.endm
29
30.macro v7m_cacheop, rt, tmp, op, c = al
31	movw\c	\tmp, #:lower16:BASEADDR_V7M_SCB + \op
32	movt\c	\tmp, #:upper16:BASEADDR_V7M_SCB + \op
33	str\c	\rt, [\tmp]
34.endm
35
36
37.macro	read_ccsidr, rt
38	v7m_cache_read \rt, V7M_SCB_CCSIDR
39.endm
40
41.macro read_clidr, rt
42	v7m_cache_read \rt, V7M_SCB_CLIDR
43.endm
44
45.macro	write_csselr, rt, tmp
46	v7m_cacheop \rt, \tmp, V7M_SCB_CSSELR
47.endm
48
49/*
50 * dcisw: Invalidate data cache by set/way
51 */
52.macro dcisw, rt, tmp
53	v7m_cacheop \rt, \tmp, V7M_SCB_DCISW
54.endm
55
56/*
57 * dccisw: Clean and invalidate data cache by set/way
58 */
59.macro dccisw, rt, tmp
60	v7m_cacheop \rt, \tmp, V7M_SCB_DCCISW
61.endm
62
63/*
64 * dccimvac: Clean and invalidate data cache line by MVA to PoC.
65 */
66.irp    c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
67.macro dccimvac\c, rt, tmp
68	v7m_cacheop \rt, \tmp, V7M_SCB_DCCIMVAC, \c
69.endm
70.endr
71
72/*
73 * dcimvac: Invalidate data cache line by MVA to PoC
74 */
75.irp    c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
76.macro dcimvac\c, rt, tmp
77	v7m_cacheop \rt, \tmp, V7M_SCB_DCIMVAC, \c
78.endm
79.endr
80
81/*
82 * dccmvau: Clean data cache line by MVA to PoU
83 */
84.macro dccmvau, rt, tmp
85	v7m_cacheop \rt, \tmp, V7M_SCB_DCCMVAU
86.endm
87
88/*
89 * dccmvac: Clean data cache line by MVA to PoC
90 */
91.macro dccmvac,  rt, tmp
92	v7m_cacheop \rt, \tmp, V7M_SCB_DCCMVAC
93.endm
94
95/*
96 * icimvau: Invalidate instruction caches by MVA to PoU
97 */
98.macro icimvau, rt, tmp
99	v7m_cacheop \rt, \tmp, V7M_SCB_ICIMVAU
100.endm
101
102/*
103 * Invalidate the icache, inner shareable if SMP, invalidate BTB for UP.
104 * rt data ignored by ICIALLU(IS), so can be used for the address
105 */
106.macro invalidate_icache, rt
107	v7m_cacheop \rt, \rt, V7M_SCB_ICIALLU
108	mov \rt, #0
109.endm
110
111/*
112 * Invalidate the BTB, inner shareable if SMP.
113 * rt data ignored by BPIALL, so it can be used for the address
114 */
115.macro invalidate_bp, rt
116	v7m_cacheop \rt, \rt, V7M_SCB_BPIALL
117	mov \rt, #0
118.endm
119
120ENTRY(v7m_invalidate_l1)
121	mov	r0, #0
122
123	write_csselr r0, r1
124	read_ccsidr r0
125
126	movw	r1, #0x7fff
127	and	r2, r1, r0, lsr #13
128
129	movw	r1, #0x3ff
130
131	and	r3, r1, r0, lsr #3      @ NumWays - 1
132	add	r2, r2, #1              @ NumSets
133
134	and	r0, r0, #0x7
135	add	r0, r0, #4      @ SetShift
136
137	clz	r1, r3          @ WayShift
138	add	r4, r3, #1      @ NumWays
1391:	sub	r2, r2, #1      @ NumSets--
140	mov	r3, r4          @ Temp = NumWays
1412:	subs	r3, r3, #1      @ Temp--
142	mov	r5, r3, lsl r1
143	mov	r6, r2, lsl r0
144	orr	r5, r5, r6      @ Reg = (Temp<<WayShift)|(NumSets<<SetShift)
145	dcisw	r5, r6
146	bgt	2b
147	cmp	r2, #0
148	bgt	1b
149	dsb	st
150	isb
151	ret	lr
152ENDPROC(v7m_invalidate_l1)
153
154/*
155 *	v7m_flush_icache_all()
156 *
157 *	Flush the whole I-cache.
158 *
159 *	Registers:
160 *	r0 - set to 0
161 */
162ENTRY(v7m_flush_icache_all)
163	invalidate_icache r0
164	ret	lr
165ENDPROC(v7m_flush_icache_all)
166
167/*
168 *	v7m_flush_dcache_all()
169 *
170 *	Flush the whole D-cache.
171 *
172 *	Corrupted registers: r0-r7, r9-r11
173 */
174ENTRY(v7m_flush_dcache_all)
175	dmb					@ ensure ordering with previous memory accesses
176	read_clidr r0
177	mov	r3, r0, lsr #23			@ move LoC into position
178	ands	r3, r3, #7 << 1			@ extract LoC*2 from clidr
179	beq	finished			@ if loc is 0, then no need to clean
180start_flush_levels:
181	mov	r10, #0				@ start clean at cache level 0
182flush_levels:
183	add	r2, r10, r10, lsr #1		@ work out 3x current cache level
184	mov	r1, r0, lsr r2			@ extract cache type bits from clidr
185	and	r1, r1, #7			@ mask of the bits for current cache only
186	cmp	r1, #2				@ see what cache we have at this level
187	blt	skip				@ skip if no cache, or just i-cache
188#ifdef CONFIG_PREEMPTION
189	save_and_disable_irqs_notrace r9	@ make cssr&csidr read atomic
190#endif
191	write_csselr r10, r1			@ set current cache level
192	isb					@ isb to sych the new cssr&csidr
193	read_ccsidr r1				@ read the new csidr
194#ifdef CONFIG_PREEMPTION
195	restore_irqs_notrace r9
196#endif
197	and	r2, r1, #7			@ extract the length of the cache lines
198	add	r2, r2, #4			@ add 4 (line length offset)
199	movw	r4, #0x3ff
200	ands	r4, r4, r1, lsr #3		@ find maximum number on the way size
201	clz	r5, r4				@ find bit position of way size increment
202	movw	r7, #0x7fff
203	ands	r7, r7, r1, lsr #13		@ extract max number of the index size
204loop1:
205	mov	r9, r7				@ create working copy of max index
206loop2:
207	lsl	r6, r4, r5
208	orr	r11, r10, r6			@ factor way and cache number into r11
209	lsl	r6, r9, r2
210	orr	r11, r11, r6			@ factor index number into r11
211	dccisw	r11, r6				@ clean/invalidate by set/way
212	subs	r9, r9, #1			@ decrement the index
213	bge	loop2
214	subs	r4, r4, #1			@ decrement the way
215	bge	loop1
216skip:
217	add	r10, r10, #2			@ increment cache number
218	cmp	r3, r10
219	bgt	flush_levels
220finished:
221	mov	r10, #0				@ switch back to cache level 0
222	write_csselr r10, r3			@ select current cache level in cssr
223	dsb	st
224	isb
225	ret	lr
226ENDPROC(v7m_flush_dcache_all)
227
228/*
229 *	v7m_flush_cache_all()
230 *
231 *	Flush the entire cache system.
232 *  The data cache flush is now achieved using atomic clean / invalidates
233 *  working outwards from L1 cache. This is done using Set/Way based cache
234 *  maintenance instructions.
235 *  The instruction cache can still be invalidated back to the point of
236 *  unification in a single instruction.
237 *
238 */
239ENTRY(v7m_flush_kern_cache_all)
240	stmfd	sp!, {r4-r7, r9-r11, lr}
241	bl	v7m_flush_dcache_all
242	invalidate_icache r0
243	ldmfd	sp!, {r4-r7, r9-r11, lr}
244	ret	lr
245ENDPROC(v7m_flush_kern_cache_all)
246
247/*
248 *	v7m_flush_cache_all()
249 *
250 *	Flush all TLB entries in a particular address space
251 *
252 *	- mm    - mm_struct describing address space
253 */
254ENTRY(v7m_flush_user_cache_all)
255	/*FALLTHROUGH*/
256
257/*
258 *	v7m_flush_cache_range(start, end, flags)
259 *
260 *	Flush a range of TLB entries in the specified address space.
261 *
262 *	- start - start address (may not be aligned)
263 *	- end   - end address (exclusive, may not be aligned)
264 *	- flags	- vm_area_struct flags describing address space
265 *
266 *	It is assumed that:
267 *	- we have a VIPT cache.
268 */
269ENTRY(v7m_flush_user_cache_range)
270	ret	lr
271ENDPROC(v7m_flush_user_cache_all)
272ENDPROC(v7m_flush_user_cache_range)
273
274/*
275 *	v7m_coherent_kern_range(start,end)
276 *
277 *	Ensure that the I and D caches are coherent within specified
278 *	region.  This is typically used when code has been written to
279 *	a memory region, and will be executed.
280 *
281 *	- start   - virtual start address of region
282 *	- end     - virtual end address of region
283 *
284 *	It is assumed that:
285 *	- the Icache does not read data from the write buffer
286 */
287ENTRY(v7m_coherent_kern_range)
288	/* FALLTHROUGH */
289
290/*
291 *	v7m_coherent_user_range(start,end)
292 *
293 *	Ensure that the I and D caches are coherent within specified
294 *	region.  This is typically used when code has been written to
295 *	a memory region, and will be executed.
296 *
297 *	- start   - virtual start address of region
298 *	- end     - virtual end address of region
299 *
300 *	It is assumed that:
301 *	- the Icache does not read data from the write buffer
302 */
303ENTRY(v7m_coherent_user_range)
304 UNWIND(.fnstart		)
305	dcache_line_size r2, r3
306	sub	r3, r2, #1
307	bic	r12, r0, r3
3081:
309/*
310 * We use open coded version of dccmvau otherwise USER() would
311 * point at movw instruction.
312 */
313	dccmvau	r12, r3
314	add	r12, r12, r2
315	cmp	r12, r1
316	blo	1b
317	dsb	ishst
318	icache_line_size r2, r3
319	sub	r3, r2, #1
320	bic	r12, r0, r3
3212:
322	icimvau r12, r3
323	add	r12, r12, r2
324	cmp	r12, r1
325	blo	2b
326	invalidate_bp r0
327	dsb	ishst
328	isb
329	ret	lr
330 UNWIND(.fnend		)
331ENDPROC(v7m_coherent_kern_range)
332ENDPROC(v7m_coherent_user_range)
333
334/*
335 *	v7m_flush_kern_dcache_area(void *addr, size_t size)
336 *
337 *	Ensure that the data held in the page kaddr is written back
338 *	to the page in question.
339 *
340 *	- addr	- kernel address
341 *	- size	- region size
342 */
343ENTRY(v7m_flush_kern_dcache_area)
344	dcache_line_size r2, r3
345	add	r1, r0, r1
346	sub	r3, r2, #1
347	bic	r0, r0, r3
3481:
349	dccimvac r0, r3		@ clean & invalidate D line / unified line
350	add	r0, r0, r2
351	cmp	r0, r1
352	blo	1b
353	dsb	st
354	ret	lr
355ENDPROC(v7m_flush_kern_dcache_area)
356
357/*
358 *	v7m_dma_inv_range(start,end)
359 *
360 *	Invalidate the data cache within the specified region; we will
361 *	be performing a DMA operation in this region and we want to
362 *	purge old data in the cache.
363 *
364 *	- start   - virtual start address of region
365 *	- end     - virtual end address of region
366 */
367v7m_dma_inv_range:
368	dcache_line_size r2, r3
369	sub	r3, r2, #1
370	tst	r0, r3
371	bic	r0, r0, r3
372	dccimvacne r0, r3
373	addne	r0, r0, r2
374	subne	r3, r2, #1	@ restore r3, corrupted by v7m's dccimvac
375	tst	r1, r3
376	bic	r1, r1, r3
377	dccimvacne r1, r3
378	cmp	r0, r1
3791:
380	dcimvaclo r0, r3
381	addlo	r0, r0, r2
382	cmplo	r0, r1
383	blo	1b
384	dsb	st
385	ret	lr
386ENDPROC(v7m_dma_inv_range)
387
388/*
389 *	v7m_dma_clean_range(start,end)
390 *	- start   - virtual start address of region
391 *	- end     - virtual end address of region
392 */
393v7m_dma_clean_range:
394	dcache_line_size r2, r3
395	sub	r3, r2, #1
396	bic	r0, r0, r3
3971:
398	dccmvac r0, r3			@ clean D / U line
399	add	r0, r0, r2
400	cmp	r0, r1
401	blo	1b
402	dsb	st
403	ret	lr
404ENDPROC(v7m_dma_clean_range)
405
406/*
407 *	v7m_dma_flush_range(start,end)
408 *	- start   - virtual start address of region
409 *	- end     - virtual end address of region
410 */
411ENTRY(v7m_dma_flush_range)
412	dcache_line_size r2, r3
413	sub	r3, r2, #1
414	bic	r0, r0, r3
4151:
416	dccimvac r0, r3			 @ clean & invalidate D / U line
417	add	r0, r0, r2
418	cmp	r0, r1
419	blo	1b
420	dsb	st
421	ret	lr
422ENDPROC(v7m_dma_flush_range)
423
424/*
425 *	dma_map_area(start, size, dir)
426 *	- start	- kernel virtual start address
427 *	- size	- size of region
428 *	- dir	- DMA direction
429 */
430ENTRY(v7m_dma_map_area)
431	add	r1, r1, r0
432	teq	r2, #DMA_FROM_DEVICE
433	beq	v7m_dma_inv_range
434	b	v7m_dma_clean_range
435ENDPROC(v7m_dma_map_area)
436
437/*
438 *	dma_unmap_area(start, size, dir)
439 *	- start	- kernel virtual start address
440 *	- size	- size of region
441 *	- dir	- DMA direction
442 */
443ENTRY(v7m_dma_unmap_area)
444	add	r1, r1, r0
445	teq	r2, #DMA_TO_DEVICE
446	bne	v7m_dma_inv_range
447	ret	lr
448ENDPROC(v7m_dma_unmap_area)
449
450	.globl	v7m_flush_kern_cache_louis
451	.equ	v7m_flush_kern_cache_louis, v7m_flush_kern_cache_all
452
453	__INITDATA
454
455	@ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
456	define_cache_functions v7m
457