2 * code for switching cores into non-secure state and into HYP mode
4 * Copyright (c) 2013 Andre Przywara <andre.przywara@linaro.org>
6 * SPDX-License-Identifier: GPL-2.0+
10 #include <linux/linkage.h>
12 #include <asm/armv7.h>
18 /* the vector table for secure state and HYP mode */
22 adr pc, _secure_monitor
30 * secure monitor handler
31 * U-boot calls this "software interrupt" in start.S
32 * This is executed on a "smc" instruction, we use a "smc #0" to switch
33 * to non-secure state.
34 * We use only r0 and r1 here, due to constraints in the caller.
37 mrc p15, 0, r1, c1, c1, 0 @ read SCR
38 bic r1, r1, #0x4e @ clear IRQ, FIQ, EA, nET bits
39 orr r1, r1, #0x31 @ enable NS, AW, FW bits
41 mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
42 and r0, r0, #CPUID_ARM_VIRT_MASK @ mask virtualization bits
43 cmp r0, #(1 << CPUID_ARM_VIRT_SHIFT)
44 #ifdef CONFIG_ARMV7_VIRT
45 orreq r1, r1, #0x100 @ allow HVC instruction
48 mcr p15, 0, r1, c1, c1, 0 @ write SCR (with NS bit set)
51 #ifdef CONFIG_ARMV7_VIRT
52 mrceq p15, 0, r0, c12, c0, 1 @ get MVBAR value
53 mcreq p15, 4, r0, c12, c0, 0 @ write HVBAR
57 @ Reset CNTVOFF to 0 before leaving monitor mode
58 mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
59 ands r0, r0, #CPUID_ARM_GENTIMER_MASK @ test arch timer bits
61 mcrrne p15, 4, r0, r0, c14 @ Reset CNTVOFF to zero
63 movs pc, lr @ return to non-secure SVC
66 mrs lr, elr_hyp @ for older asm: .byte 0x00, 0xe3, 0x0e, 0xe1
67 mov pc, lr @ do no switch modes, but
71 * Secondary CPUs start here and call the code for the core specific parts
72 * of the non-secure and HYP mode transition. The GIC distributor specific
73 * code has already been executed by a C function before.
74 * Then they go back to wfi and wait to be woken up by the kernel again.
79 msr cpsr, r0 @ disable interrupts
81 mcr p15, 0, r1, c12, c0, 0 @ set VBAR
84 mov r12, r0 @ save GICC address
85 #ifdef CONFIG_ARMV7_VIRT
89 ldr r1, [r12, #GICC_IAR] @ acknowledge IPI
90 str r1, [r12, #GICC_EOIR] @ signal end of interrupt
92 adr r0, _smp_pen @ do not use this address again
93 b smp_waitloop @ wait for IPIs, board specific
97 * Switch a core to non-secure state.
99 * 1. initialize the GIC per-core interface
100 * 2. allow coprocessor access in non-secure modes
101 * 3. switch the cpu mode (by calling "smc #0")
103 * Called from smp_pen by secondary cores and directly by the BSP.
104 * Do not assume that the stack is available and only use registers
107 * PERIPHBASE is used to get the GIC address. This could be 40 bits long,
108 * though, but we check this in C before calling this function.
111 #ifdef CONFIG_ARM_GIC_BASE_ADDRESS
112 ldr r2, =CONFIG_ARM_GIC_BASE_ADDRESS
114 mrc p15, 4, r2, c15, c0, 0 @ read CBAR
115 bfc r2, #0, #15 @ clear reserved bits
117 add r3, r2, #GIC_DIST_OFFSET @ GIC dist i/f offset
118 mvn r1, #0 @ all bits to 1
119 str r1, [r3, #GICD_IGROUPRn] @ allow private interrupts
121 mrc p15, 0, r0, c0, c0, 0 @ read MIDR
122 ldr r1, =MIDR_PRIMARY_PART_MASK
123 and r0, r0, r1 @ mask out variant and revision
125 ldr r1, =MIDR_CORTEX_A7_R0P0 & MIDR_PRIMARY_PART_MASK
126 cmp r0, r1 @ check for Cortex-A7
128 ldr r1, =MIDR_CORTEX_A15_R0P0 & MIDR_PRIMARY_PART_MASK
129 cmpne r0, r1 @ check for Cortex-A15
131 movne r1, #GIC_CPU_OFFSET_A9 @ GIC CPU offset for A9
132 moveq r1, #GIC_CPU_OFFSET_A15 @ GIC CPU offset for A15/A7
133 add r3, r2, r1 @ r3 = GIC CPU i/f addr
135 mov r1, #1 @ set GICC_CTLR[enable]
136 str r1, [r3, #GICC_CTLR] @ and clear all other bits
138 str r1, [r3, #GICC_PMR] @ set priority mask register
142 mcr p15, 0, r1, c1, c1, 2 @ NSACR = all copros to non-sec
144 /* The CNTFRQ register of the generic timer needs to be
145 * programmed in secure state. Some primary bootloaders / firmware
146 * omit this, so if the frequency is provided in the configuration,
147 * we do this here instead.
148 * But first check if we have the generic timer.
150 #ifdef CONFIG_SYS_CLK_FREQ
151 mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
152 and r0, r0, #CPUID_ARM_GENTIMER_MASK @ mask arch timer bits
153 cmp r0, #(1 << CPUID_ARM_GENTIMER_SHIFT)
154 ldreq r1, =CONFIG_SYS_CLK_FREQ
155 mcreq p15, 0, r1, c14, c0, 0 @ write CNTFRQ
158 adr r1, _monitor_vectors
159 mcr p15, 0, r1, c12, c0, 1 @ set MVBAR to secure vectors
161 mrc p15, 0, ip, c12, c0, 0 @ save secure copy of VBAR
164 smc #0 @ call into MONITOR mode
166 mcr p15, 0, ip, c12, c0, 0 @ write non-secure copy of VBAR
169 str r1, [r3, #GICC_CTLR] @ enable non-secure CPU i/f
170 add r2, r2, #GIC_DIST_OFFSET
171 str r1, [r2, #GICD_CTLR] @ allow private interrupts
173 mov r0, r3 @ return GICC address
176 ENDPROC(_nonsec_init)
178 #ifdef CONFIG_SMP_PEN_ADDR
179 /* void __weak smp_waitloop(unsigned previous_address); */
182 ldr r1, =CONFIG_SMP_PEN_ADDR @ load start address
184 cmp r0, r1 @ make sure we dont execute this code
185 beq smp_waitloop @ again (due to a spurious wakeup)
187 ENDPROC(smp_waitloop)
191 ENTRY(_switch_to_hyp)
193 mov r1, sp @ save SVC copy of LR and SP
195 hvc #0 @ for older asm: .byte 0x70, 0x00, 0x40, 0xe1
197 mov lr, r0 @ restore SVC copy of LR and SP
200 ENDPROC(_switch_to_hyp)