xref: /openbmc/u-boot/arch/arm/cpu/armv7/nonsec_virt.S (revision e246b728) 
1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * code for switching cores into non-secure state and into HYP mode
4 *
5 * Copyright (c) 2013	Andre Przywara <andre.przywara@linaro.org>
6 */
7
8#include <config.h>
9#include <linux/linkage.h>
10#include <asm/gic.h>
11#include <asm/armv7.h>
12#include <asm/proc-armv/ptrace.h>
13
14.arch_extension sec
15.arch_extension virt
16
17	.pushsection ._secure.text, "ax"
18
19	.align	5
20/* the vector table for secure state and HYP mode */
21_monitor_vectors:
22	.word 0	/* reset */
23	.word 0 /* undef */
24	adr pc, _secure_monitor
25	.word 0
26	.word 0
27	.word 0
28	.word 0
29	.word 0
30
31.macro is_cpu_virt_capable	tmp
32	mrc	p15, 0, \tmp, c0, c1, 1		@ read ID_PFR1
33	and	\tmp, \tmp, #CPUID_ARM_VIRT_MASK	@ mask virtualization bits
34	cmp	\tmp, #(1 << CPUID_ARM_VIRT_SHIFT)
35.endm
36
37/*
38 * secure monitor handler
39 * U-Boot calls this "software interrupt" in start.S
40 * This is executed on a "smc" instruction, we use a "smc #0" to switch
41 * to non-secure state.
42 * r0, r1, r2: passed to the callee
43 * ip: target PC
44 */
45_secure_monitor:
46#ifdef CONFIG_ARMV7_PSCI
47	ldr	r5, =_psci_vectors		@ Switch to the next monitor
48	mcr	p15, 0, r5, c12, c0, 1
49	isb
50
51	@ Obtain a secure stack
52	bl	psci_stack_setup
53
54	@ Configure the PSCI backend
55	push	{r0, r1, r2, ip}
56	bl	psci_arch_init
57	pop	{r0, r1, r2, ip}
58#endif
59
60#ifdef CONFIG_ARM_ERRATA_773022
61	mrc	p15, 0, r5, c1, c0, 1
62	orr	r5, r5, #(1 << 1)
63	mcr	p15, 0, r5, c1, c0, 1
64	isb
65#endif
66
67#ifdef CONFIG_ARM_ERRATA_774769
68	mrc	p15, 0, r5, c1, c0, 1
69	orr	r5, r5, #(1 << 25)
70	mcr	p15, 0, r5, c1, c0, 1
71	isb
72#endif
73
74	mrc	p15, 0, r5, c1, c1, 0		@ read SCR
75	bic	r5, r5, #0x4a			@ clear IRQ, EA, nET bits
76	orr	r5, r5, #0x31			@ enable NS, AW, FW bits
77						@ FIQ preserved for secure mode
78	mov	r6, #SVC_MODE			@ default mode is SVC
79	is_cpu_virt_capable r4
80#ifdef CONFIG_ARMV7_VIRT
81	orreq	r5, r5, #0x100			@ allow HVC instruction
82	moveq	r6, #HYP_MODE			@ Enter the kernel as HYP
83	mrseq	r3, sp_svc
84	msreq	sp_hyp, r3			@ migrate SP
85#endif
86
87	mcr	p15, 0, r5, c1, c1, 0		@ write SCR (with NS bit set)
88	isb
89
90	bne	1f
91
92	@ Reset CNTVOFF to 0 before leaving monitor mode
93	mrc	p15, 0, r4, c0, c1, 1		@ read ID_PFR1
94	ands	r4, r4, #CPUID_ARM_GENTIMER_MASK	@ test arch timer bits
95	movne	r4, #0
96	mcrrne	p15, 4, r4, r4, c14		@ Reset CNTVOFF to zero
971:
98	mov	lr, ip
99	mov	ip, #(F_BIT | I_BIT | A_BIT)	@ Set A, I and F
100	tst	lr, #1				@ Check for Thumb PC
101	orrne	ip, ip, #T_BIT			@ Set T if Thumb
102	orr	ip, ip, r6			@ Slot target mode in
103	msr	spsr_cxfs, ip			@ Set full SPSR
104	movs	pc, lr				@ ERET to non-secure
105
106ENTRY(_do_nonsec_entry)
107	mov	ip, r0
108	mov	r0, r1
109	mov	r1, r2
110	mov	r2, r3
111	smc	#0
112ENDPROC(_do_nonsec_entry)
113
114.macro get_cbar_addr	addr
115#ifdef CONFIG_ARM_GIC_BASE_ADDRESS
116	ldr	\addr, =CONFIG_ARM_GIC_BASE_ADDRESS
117#else
118	mrc	p15, 4, \addr, c15, c0, 0	@ read CBAR
119	bfc	\addr, #0, #15			@ clear reserved bits
120#endif
121.endm
122
123.macro get_gicd_addr	addr
124	get_cbar_addr	\addr
125	add	\addr, \addr, #GIC_DIST_OFFSET	@ GIC dist i/f offset
126.endm
127
128.macro get_gicc_addr	addr, tmp
129	get_cbar_addr	\addr
130	is_cpu_virt_capable \tmp
131	movne	\tmp, #GIC_CPU_OFFSET_A9	@ GIC CPU offset for A9
132	moveq	\tmp, #GIC_CPU_OFFSET_A15	@ GIC CPU offset for A15/A7
133	add	\addr, \addr, \tmp
134.endm
135
136#ifndef CONFIG_ARMV7_PSCI
137/*
138 * Secondary CPUs start here and call the code for the core specific parts
139 * of the non-secure and HYP mode transition. The GIC distributor specific
140 * code has already been executed by a C function before.
141 * Then they go back to wfi and wait to be woken up by the kernel again.
142 */
143ENTRY(_smp_pen)
144	cpsid	i
145	cpsid	f
146
147	bl	_nonsec_init
148
149	adr	r0, _smp_pen			@ do not use this address again
150	b	smp_waitloop			@ wait for IPIs, board specific
151ENDPROC(_smp_pen)
152#endif
153
154/*
155 * Switch a core to non-secure state.
156 *
157 *  1. initialize the GIC per-core interface
158 *  2. allow coprocessor access in non-secure modes
159 *
160 * Called from smp_pen by secondary cores and directly by the BSP.
161 * Do not assume that the stack is available and only use registers
162 * r0-r3 and r12.
163 *
164 * PERIPHBASE is used to get the GIC address. This could be 40 bits long,
165 * though, but we check this in C before calling this function.
166 */
167ENTRY(_nonsec_init)
168	get_gicd_addr	r3
169
170	mvn	r1, #0				@ all bits to 1
171	str	r1, [r3, #GICD_IGROUPRn]	@ allow private interrupts
172
173	get_gicc_addr	r3, r1
174
175	mov	r1, #3				@ Enable both groups
176	str	r1, [r3, #GICC_CTLR]		@ and clear all other bits
177	mov	r1, #0xff
178	str	r1, [r3, #GICC_PMR]		@ set priority mask register
179
180	mrc	p15, 0, r0, c1, c1, 2
181	movw	r1, #0x3fff
182	movt	r1, #0x0004
183	orr	r0, r0, r1
184	mcr	p15, 0, r0, c1, c1, 2		@ NSACR = all copros to non-sec
185
186/* The CNTFRQ register of the generic timer needs to be
187 * programmed in secure state. Some primary bootloaders / firmware
188 * omit this, so if the frequency is provided in the configuration,
189 * we do this here instead.
190 * But first check if we have the generic timer.
191 */
192#ifdef COUNTER_FREQUENCY
193	mrc	p15, 0, r0, c0, c1, 1		@ read ID_PFR1
194	and	r0, r0, #CPUID_ARM_GENTIMER_MASK	@ mask arch timer bits
195	cmp	r0, #(1 << CPUID_ARM_GENTIMER_SHIFT)
196	ldreq	r1, =COUNTER_FREQUENCY
197	mcreq	p15, 0, r1, c14, c0, 0		@ write CNTFRQ
198#endif
199
200	adr	r1, _monitor_vectors
201	mcr	p15, 0, r1, c12, c0, 1		@ set MVBAR to secure vectors
202	isb
203
204	mov	r0, r3				@ return GICC address
205	bx	lr
206ENDPROC(_nonsec_init)
207
208#ifdef CONFIG_SMP_PEN_ADDR
209/* void __weak smp_waitloop(unsigned previous_address); */
210ENTRY(smp_waitloop)
211	wfi
212	ldr	r1, =CONFIG_SMP_PEN_ADDR	@ load start address
213	ldr	r1, [r1]
214#ifdef CONFIG_PEN_ADDR_BIG_ENDIAN
215	rev	r1, r1
216#endif
217	cmp	r0, r1			@ make sure we dont execute this code
218	beq	smp_waitloop		@ again (due to a spurious wakeup)
219	mov	r0, r1
220	b	_do_nonsec_entry
221ENDPROC(smp_waitloop)
222.weak smp_waitloop
223#endif
224
225	.popsection
226