2 * code for switching cores into non-secure state
4 * Copyright (c) 2013 Andre Przywara <andre.przywara@linaro.org>
6 * See file CREDITS for list of people who contributed to this
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of
12 * the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 #include <linux/linkage.h>
28 #include <asm/armv7.h>
32 /* the vector table for secure state */
36 adr pc, _secure_monitor
44 * secure monitor handler
45 * U-boot calls this "software interrupt" in start.S
46 * This is executed on a "smc" instruction, we use a "smc #0" to switch
47 * to non-secure state.
48 * We use only r0 and r1 here, due to constraints in the caller.
52 mrc p15, 0, r1, c1, c1, 0 @ read SCR
53 bic r1, r1, #0x4e @ clear IRQ, FIQ, EA, nET bits
54 orr r1, r1, #0x31 @ enable NS, AW, FW bits
56 mcr p15, 0, r1, c1, c1, 0 @ write SCR (with NS bit set)
58 movs pc, lr @ return to non-secure SVC
61 * Secondary CPUs start here and call the code for the core specific parts
62 * of the non-secure and HYP mode transition. The GIC distributor specific
63 * code has already been executed by a C function before.
64 * Then they go back to wfi and wait to be woken up by the kernel again.
69 msr cpsr, r0 @ disable interrupts
71 mcr p15, 0, r1, c12, c0, 0 @ set VBAR
75 ldr r1, [r0, #GICC_IAR] @ acknowledge IPI
76 str r1, [r0, #GICC_EOIR] @ signal end of interrupt
78 adr r0, _smp_pen @ do not use this address again
79 b smp_waitloop @ wait for IPIs, board specific
83 * Switch a core to non-secure state.
85 * 1. initialize the GIC per-core interface
86 * 2. allow coprocessor access in non-secure modes
87 * 3. switch the cpu mode (by calling "smc #0")
89 * Called from smp_pen by secondary cores and directly by the BSP.
90 * Do not assume that the stack is available and only use registers
93 * PERIPHBASE is used to get the GIC address. This could be 40 bits long,
94 * though, but we check this in C before calling this function.
97 #ifdef CONFIG_ARM_GIC_BASE_ADDRESS
98 ldr r2, =CONFIG_ARM_GIC_BASE_ADDRESS
100 mrc p15, 4, r2, c15, c0, 0 @ read CBAR
101 bfc r2, #0, #15 @ clear reserved bits
103 add r3, r2, #GIC_DIST_OFFSET @ GIC dist i/f offset
104 mvn r1, #0 @ all bits to 1
105 str r1, [r3, #GICD_IGROUPRn] @ allow private interrupts
107 mrc p15, 0, r0, c0, c0, 0 @ read MIDR
108 ldr r1, =MIDR_PRIMARY_PART_MASK
109 and r0, r0, r1 @ mask out variant and revision
111 ldr r1, =MIDR_CORTEX_A7_R0P0 & MIDR_PRIMARY_PART_MASK
112 cmp r0, r1 @ check for Cortex-A7
114 ldr r1, =MIDR_CORTEX_A15_R0P0 & MIDR_PRIMARY_PART_MASK
115 cmpne r0, r1 @ check for Cortex-A15
117 movne r1, #GIC_CPU_OFFSET_A9 @ GIC CPU offset for A9
118 moveq r1, #GIC_CPU_OFFSET_A15 @ GIC CPU offset for A15/A7
119 add r3, r2, r1 @ r3 = GIC CPU i/f addr
121 mov r1, #1 @ set GICC_CTLR[enable]
122 str r1, [r3, #GICC_CTLR] @ and clear all other bits
124 str r1, [r3, #GICC_PMR] @ set priority mask register
128 mcr p15, 0, r1, c1, c1, 2 @ NSACR = all copros to non-sec
130 /* The CNTFRQ register of the generic timer needs to be
131 * programmed in secure state. Some primary bootloaders / firmware
132 * omit this, so if the frequency is provided in the configuration,
133 * we do this here instead.
134 * But first check if we have the generic timer.
136 #ifdef CONFIG_SYS_CLK_FREQ
137 mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
138 and r0, r0, #CPUID_ARM_GENTIMER_MASK @ mask arch timer bits
139 cmp r0, #(1 << CPUID_ARM_GENTIMER_SHIFT)
140 ldreq r1, =CONFIG_SYS_CLK_FREQ
141 mcreq p15, 0, r1, c14, c0, 0 @ write CNTFRQ
144 adr r1, _monitor_vectors
145 mcr p15, 0, r1, c12, c0, 1 @ set MVBAR to secure vectors
147 mrc p15, 0, ip, c12, c0, 0 @ save secure copy of VBAR
150 smc #0 @ call into MONITOR mode
152 mcr p15, 0, ip, c12, c0, 0 @ write non-secure copy of VBAR
155 str r1, [r3, #GICC_CTLR] @ enable non-secure CPU i/f
156 add r2, r2, #GIC_DIST_OFFSET
157 str r1, [r2, #GICD_CTLR] @ allow private interrupts
159 mov r0, r3 @ return GICC address
162 ENDPROC(_nonsec_init)
164 #ifdef CONFIG_SMP_PEN_ADDR
165 /* void __weak smp_waitloop(unsigned previous_address); */
168 ldr r1, =CONFIG_SMP_PEN_ADDR @ load start address
170 cmp r0, r1 @ make sure we dont execute this code
171 beq smp_waitloop @ again (due to a spurious wakeup)
173 ENDPROC(smp_waitloop)