xref: /openbmc/linux/arch/arm/mm/proc-v6.S (revision 455f9726) 
1/*
2 *  linux/arch/arm/mm/proc-v6.S
3 *
4 *  Copyright (C) 2001 Deep Blue Solutions Ltd.
5 *  Modified by Catalin Marinas for noMMU support
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 *  This is the "shell" of the ARMv6 processor support.
12 */
13#include <linux/init.h>
14#include <linux/linkage.h>
15#include <asm/assembler.h>
16#include <asm/asm-offsets.h>
17#include <asm/hwcap.h>
18#include <asm/pgtable-hwdef.h>
19#include <asm/pgtable.h>
20
21#include "proc-macros.S"
22
23#define D_CACHE_LINE_SIZE	32
24
25#define TTB_C		(1 << 0)
26#define TTB_S		(1 << 1)
27#define TTB_IMP		(1 << 2)
28#define TTB_RGN_NC	(0 << 3)
29#define TTB_RGN_WBWA	(1 << 3)
30#define TTB_RGN_WT	(2 << 3)
31#define TTB_RGN_WB	(3 << 3)
32
33#define TTB_FLAGS_UP	TTB_RGN_WBWA
34#define PMD_FLAGS_UP	PMD_SECT_WB
35#define TTB_FLAGS_SMP	TTB_RGN_WBWA|TTB_S
36#define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
37
38ENTRY(cpu_v6_proc_init)
39	ret	lr
40
41ENTRY(cpu_v6_proc_fin)
42	mrc	p15, 0, r0, c1, c0, 0		@ ctrl register
43	bic	r0, r0, #0x1000			@ ...i............
44	bic	r0, r0, #0x0006			@ .............ca.
45	mcr	p15, 0, r0, c1, c0, 0		@ disable caches
46	ret	lr
47
48/*
49 *	cpu_v6_reset(loc)
50 *
51 *	Perform a soft reset of the system.  Put the CPU into the
52 *	same state as it would be if it had been reset, and branch
53 *	to what would be the reset vector.
54 *
55 *	- loc   - location to jump to for soft reset
56 */
57	.align	5
58	.pushsection	.idmap.text, "ax"
59ENTRY(cpu_v6_reset)
60	mrc	p15, 0, r1, c1, c0, 0		@ ctrl register
61	bic	r1, r1, #0x1			@ ...............m
62	mcr	p15, 0, r1, c1, c0, 0		@ disable MMU
63	mov	r1, #0
64	mcr	p15, 0, r1, c7, c5, 4		@ ISB
65	ret	r0
66ENDPROC(cpu_v6_reset)
67	.popsection
68
69/*
70 *	cpu_v6_do_idle()
71 *
72 *	Idle the processor (eg, wait for interrupt).
73 *
74 *	IRQs are already disabled.
75 */
76ENTRY(cpu_v6_do_idle)
77	mov	r1, #0
78	mcr	p15, 0, r1, c7, c10, 4		@ DWB - WFI may enter a low-power mode
79	mcr	p15, 0, r1, c7, c0, 4		@ wait for interrupt
80	ret	lr
81
82ENTRY(cpu_v6_dcache_clean_area)
831:	mcr	p15, 0, r0, c7, c10, 1		@ clean D entry
84	add	r0, r0, #D_CACHE_LINE_SIZE
85	subs	r1, r1, #D_CACHE_LINE_SIZE
86	bhi	1b
87	ret	lr
88
89/*
90 *	cpu_v6_switch_mm(pgd_phys, tsk)
91 *
92 *	Set the translation table base pointer to be pgd_phys
93 *
94 *	- pgd_phys - physical address of new TTB
95 *
96 *	It is assumed that:
97 *	- we are not using split page tables
98 */
99ENTRY(cpu_v6_switch_mm)
100#ifdef CONFIG_MMU
101	mov	r2, #0
102	mmid	r1, r1				@ get mm->context.id
103	ALT_SMP(orr	r0, r0, #TTB_FLAGS_SMP)
104	ALT_UP(orr	r0, r0, #TTB_FLAGS_UP)
105	mcr	p15, 0, r2, c7, c5, 6		@ flush BTAC/BTB
106	mcr	p15, 0, r2, c7, c10, 4		@ drain write buffer
107	mcr	p15, 0, r0, c2, c0, 0		@ set TTB 0
108#ifdef CONFIG_PID_IN_CONTEXTIDR
109	mrc	p15, 0, r2, c13, c0, 1		@ read current context ID
110	bic	r2, r2, #0xff			@ extract the PID
111	and	r1, r1, #0xff
112	orr	r1, r1, r2			@ insert into new context ID
113#endif
114	mcr	p15, 0, r1, c13, c0, 1		@ set context ID
115#endif
116	ret	lr
117
118/*
119 *	cpu_v6_set_pte_ext(ptep, pte, ext)
120 *
121 *	Set a level 2 translation table entry.
122 *
123 *	- ptep  - pointer to level 2 translation table entry
124 *		  (hardware version is stored at -1024 bytes)
125 *	- pte   - PTE value to store
126 *	- ext	- value for extended PTE bits
127 */
128	armv6_mt_table cpu_v6
129
130ENTRY(cpu_v6_set_pte_ext)
131#ifdef CONFIG_MMU
132	armv6_set_pte_ext cpu_v6
133#endif
134	ret	lr
135
136/* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */
137.globl	cpu_v6_suspend_size
138.equ	cpu_v6_suspend_size, 4 * 6
139#ifdef CONFIG_ARM_CPU_SUSPEND
140ENTRY(cpu_v6_do_suspend)
141	stmfd	sp!, {r4 - r9, lr}
142	mrc	p15, 0, r4, c13, c0, 0	@ FCSE/PID
143#ifdef CONFIG_MMU
144	mrc	p15, 0, r5, c3, c0, 0	@ Domain ID
145	mrc	p15, 0, r6, c2, c0, 1	@ Translation table base 1
146#endif
147	mrc	p15, 0, r7, c1, c0, 1	@ auxiliary control register
148	mrc	p15, 0, r8, c1, c0, 2	@ co-processor access control
149	mrc	p15, 0, r9, c1, c0, 0	@ control register
150	stmia	r0, {r4 - r9}
151	ldmfd	sp!, {r4- r9, pc}
152ENDPROC(cpu_v6_do_suspend)
153
154ENTRY(cpu_v6_do_resume)
155	mov	ip, #0
156	mcr	p15, 0, ip, c7, c14, 0	@ clean+invalidate D cache
157	mcr	p15, 0, ip, c7, c5, 0	@ invalidate I cache
158	mcr	p15, 0, ip, c7, c15, 0	@ clean+invalidate cache
159	mcr	p15, 0, ip, c7, c10, 4	@ drain write buffer
160	mcr	p15, 0, ip, c13, c0, 1	@ set reserved context ID
161	ldmia	r0, {r4 - r9}
162	mcr	p15, 0, r4, c13, c0, 0	@ FCSE/PID
163#ifdef CONFIG_MMU
164	mcr	p15, 0, r5, c3, c0, 0	@ Domain ID
165	ALT_SMP(orr	r1, r1, #TTB_FLAGS_SMP)
166	ALT_UP(orr	r1, r1, #TTB_FLAGS_UP)
167	mcr	p15, 0, r1, c2, c0, 0	@ Translation table base 0
168	mcr	p15, 0, r6, c2, c0, 1	@ Translation table base 1
169	mcr	p15, 0, ip, c2, c0, 2	@ TTB control register
170#endif
171	mcr	p15, 0, r7, c1, c0, 1	@ auxiliary control register
172	mcr	p15, 0, r8, c1, c0, 2	@ co-processor access control
173	mcr	p15, 0, ip, c7, c5, 4	@ ISB
174	mov	r0, r9			@ control register
175	b	cpu_resume_mmu
176ENDPROC(cpu_v6_do_resume)
177#endif
178
179	string	cpu_v6_name, "ARMv6-compatible processor"
180
181	.align
182
183/*
184 *	__v6_setup
185 *
186 *	Initialise TLB, Caches, and MMU state ready to switch the MMU
187 *	on.  Return in r0 the new CP15 C1 control register setting.
188 *
189 *	We automatically detect if we have a Harvard cache, and use the
190 *	Harvard cache control instructions insead of the unified cache
191 *	control instructions.
192 *
193 *	This should be able to cover all ARMv6 cores.
194 *
195 *	It is assumed that:
196 *	- cache type register is implemented
197 */
198__v6_setup:
199#ifdef CONFIG_SMP
200	ALT_SMP(mrc	p15, 0, r0, c1, c0, 1)	@ Enable SMP/nAMP mode
201	ALT_UP(nop)
202	orr	r0, r0, #0x20
203	ALT_SMP(mcr	p15, 0, r0, c1, c0, 1)
204	ALT_UP(nop)
205#endif
206
207	mov	r0, #0
208	mcr	p15, 0, r0, c7, c14, 0		@ clean+invalidate D cache
209	mcr	p15, 0, r0, c7, c5, 0		@ invalidate I cache
210	mcr	p15, 0, r0, c7, c15, 0		@ clean+invalidate cache
211#ifdef CONFIG_MMU
212	mcr	p15, 0, r0, c8, c7, 0		@ invalidate I + D TLBs
213	mcr	p15, 0, r0, c2, c0, 2		@ TTB control register
214	ALT_SMP(orr	r4, r4, #TTB_FLAGS_SMP)
215	ALT_UP(orr	r4, r4, #TTB_FLAGS_UP)
216	ALT_SMP(orr	r8, r8, #TTB_FLAGS_SMP)
217	ALT_UP(orr	r8, r8, #TTB_FLAGS_UP)
218	mcr	p15, 0, r8, c2, c0, 1		@ load TTB1
219#endif /* CONFIG_MMU */
220	mcr	p15, 0, r0, c7, c10, 4		@ drain write buffer and
221						@ complete invalidations
222	adr	r5, v6_crval
223	ldmia	r5, {r5, r6}
224 ARM_BE8(orr	r6, r6, #1 << 25)		@ big-endian page tables
225	mrc	p15, 0, r0, c1, c0, 0		@ read control register
226	bic	r0, r0, r5			@ clear bits them
227	orr	r0, r0, r6			@ set them
228#ifdef CONFIG_ARM_ERRATA_364296
229	/*
230	 * Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data
231	 * corruption with hit-under-miss enabled). The conditional code below
232	 * (setting the undocumented bit 31 in the auxiliary control register
233	 * and the FI bit in the control register) disables hit-under-miss
234	 * without putting the processor into full low interrupt latency mode.
235	 */
236	ldr	r6, =0x4107b362			@ id for ARM1136 r0p2
237	mrc	p15, 0, r5, c0, c0, 0		@ get processor id
238	teq	r5, r6				@ check for the faulty core
239	mrceq	p15, 0, r5, c1, c0, 1		@ load aux control reg
240	orreq	r5, r5, #(1 << 31)		@ set the undocumented bit 31
241	mcreq	p15, 0, r5, c1, c0, 1		@ write aux control reg
242	orreq	r0, r0, #(1 << 21)		@ low interrupt latency configuration
243#endif
244	ret	lr				@ return to head.S:__ret
245
246	/*
247	 *         V X F   I D LR
248	 * .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
249	 * rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
250	 *         0 110       0011 1.00 .111 1101 < we want
251	 */
252	.type	v6_crval, #object
253v6_crval:
254	crval	clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c
255
256	__INITDATA
257
258	@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
259	define_processor_functions v6, dabort=v6_early_abort, pabort=v6_pabort, suspend=1
260
261	.section ".rodata"
262
263	string	cpu_arch_name, "armv6"
264	string	cpu_elf_name, "v6"
265	.align
266
267	.section ".proc.info.init", #alloc, #execinstr
268
269	/*
270	 * Match any ARMv6 processor core.
271	 */
272	.type	__v6_proc_info, #object
273__v6_proc_info:
274	.long	0x0007b000
275	.long	0x0007f000
276	ALT_SMP(.long \
277		PMD_TYPE_SECT | \
278		PMD_SECT_AP_WRITE | \
279		PMD_SECT_AP_READ | \
280		PMD_FLAGS_SMP)
281	ALT_UP(.long \
282		PMD_TYPE_SECT | \
283		PMD_SECT_AP_WRITE | \
284		PMD_SECT_AP_READ | \
285		PMD_FLAGS_UP)
286	.long   PMD_TYPE_SECT | \
287		PMD_SECT_XN | \
288		PMD_SECT_AP_WRITE | \
289		PMD_SECT_AP_READ
290	b	__v6_setup
291	.long	cpu_arch_name
292	.long	cpu_elf_name
293	/* See also feat_v6_fixup() for HWCAP_TLS */
294	.long	HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA|HWCAP_TLS
295	.long	cpu_v6_name
296	.long	v6_processor_functions
297	.long	v6wbi_tlb_fns
298	.long	v6_user_fns
299	.long	v6_cache_fns
300	.size	__v6_proc_info, . - __v6_proc_info
301