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/*
* code for switching cores into non-secure state and into HYP mode
*
* Copyright (c) 2013 Andre Przywara <andre.przywara@linaro.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <linux/linkage.h>
#include <asm/gic.h>
#include <asm/armv7.h>
#include <asm/proc-armv/ptrace.h>
.arch_extension sec
.arch_extension virt
.pushsection ._secure.text, "ax"
.align 5
/* the vector table for secure state and HYP mode */
_monitor_vectors:
.word 0 /* reset */
.word 0 /* undef */
adr pc, _secure_monitor
.word 0
.word 0
.word 0
.word 0
.word 0
.macro is_cpu_virt_capable tmp
mrc p15, 0, \tmp, c0, c1, 1 @ read ID_PFR1
and \tmp, \tmp, #CPUID_ARM_VIRT_MASK @ mask virtualization bits
cmp \tmp, #(1 << CPUID_ARM_VIRT_SHIFT)
.endm
/*
* secure monitor handler
* U-boot calls this "software interrupt" in start.S
* This is executed on a "smc" instruction, we use a "smc #0" to switch
* to non-secure state.
* r0, r1, r2: passed to the callee
* ip: target PC
*/
_secure_monitor:
#ifdef CONFIG_ARMV7_PSCI
ldr r5, =_psci_vectors @ Switch to the next monitor
mcr p15, 0, r5, c12, c0, 1
isb
@ Obtain a secure stack, and configure the PSCI backend
bl psci_arch_init
#endif
mrc p15, 0, r5, c1, c1, 0 @ read SCR
bic r5, r5, #0x4a @ clear IRQ, EA, nET bits
orr r5, r5, #0x31 @ enable NS, AW, FW bits
@ FIQ preserved for secure mode
mov r6, #SVC_MODE @ default mode is SVC
is_cpu_virt_capable r4
#ifdef CONFIG_ARMV7_VIRT
orreq r5, r5, #0x100 @ allow HVC instruction
moveq r6, #HYP_MODE @ Enter the kernel as HYP
#endif
mcr p15, 0, r5, c1, c1, 0 @ write SCR (with NS bit set)
isb
bne 1f
@ Reset CNTVOFF to 0 before leaving monitor mode
mrc p15, 0, r4, c0, c1, 1 @ read ID_PFR1
ands r4, r4, #CPUID_ARM_GENTIMER_MASK @ test arch timer bits
movne r4, #0
mcrrne p15, 4, r4, r4, c14 @ Reset CNTVOFF to zero
1:
mov lr, ip
mov ip, #(F_BIT | I_BIT | A_BIT) @ Set A, I and F
tst lr, #1 @ Check for Thumb PC
orrne ip, ip, #T_BIT @ Set T if Thumb
orr ip, ip, r6 @ Slot target mode in
msr spsr_cxfs, ip @ Set full SPSR
movs pc, lr @ ERET to non-secure
ENTRY(_do_nonsec_entry)
mov ip, r0
mov r0, r1
mov r1, r2
mov r2, r3
smc #0
ENDPROC(_do_nonsec_entry)
.macro get_cbar_addr addr
#ifdef CONFIG_ARM_GIC_BASE_ADDRESS
ldr \addr, =CONFIG_ARM_GIC_BASE_ADDRESS
#else
mrc p15, 4, \addr, c15, c0, 0 @ read CBAR
bfc \addr, #0, #15 @ clear reserved bits
#endif
.endm
.macro get_gicd_addr addr
get_cbar_addr \addr
add \addr, \addr, #GIC_DIST_OFFSET @ GIC dist i/f offset
.endm
.macro get_gicc_addr addr, tmp
get_cbar_addr \addr
is_cpu_virt_capable \tmp
movne \tmp, #GIC_CPU_OFFSET_A9 @ GIC CPU offset for A9
moveq \tmp, #GIC_CPU_OFFSET_A15 @ GIC CPU offset for A15/A7
add \addr, \addr, \tmp
.endm
#ifndef CONFIG_ARMV7_PSCI
/*
* Secondary CPUs start here and call the code for the core specific parts
* of the non-secure and HYP mode transition. The GIC distributor specific
* code has already been executed by a C function before.
* Then they go back to wfi and wait to be woken up by the kernel again.
*/
ENTRY(_smp_pen)
cpsid i
cpsid f
bl _nonsec_init
adr r0, _smp_pen @ do not use this address again
b smp_waitloop @ wait for IPIs, board specific
ENDPROC(_smp_pen)
#endif
/*
* Switch a core to non-secure state.
*
* 1. initialize the GIC per-core interface
* 2. allow coprocessor access in non-secure modes
*
* Called from smp_pen by secondary cores and directly by the BSP.
* Do not assume that the stack is available and only use registers
* r0-r3 and r12.
*
* PERIPHBASE is used to get the GIC address. This could be 40 bits long,
* though, but we check this in C before calling this function.
*/
ENTRY(_nonsec_init)
get_gicd_addr r3
mvn r1, #0 @ all bits to 1
str r1, [r3, #GICD_IGROUPRn] @ allow private interrupts
get_gicc_addr r3, r1
mov r1, #3 @ Enable both groups
str r1, [r3, #GICC_CTLR] @ and clear all other bits
mov r1, #0xff
str r1, [r3, #GICC_PMR] @ set priority mask register
mrc p15, 0, r0, c1, c1, 2
movw r1, #0x3fff
movt r1, #0x0004
orr r0, r0, r1
mcr p15, 0, r0, c1, c1, 2 @ NSACR = all copros to non-sec
/* The CNTFRQ register of the generic timer needs to be
* programmed in secure state. Some primary bootloaders / firmware
* omit this, so if the frequency is provided in the configuration,
* we do this here instead.
* But first check if we have the generic timer.
*/
#ifdef CONFIG_SYS_CLK_FREQ
mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
and r0, r0, #CPUID_ARM_GENTIMER_MASK @ mask arch timer bits
cmp r0, #(1 << CPUID_ARM_GENTIMER_SHIFT)
ldreq r1, =CONFIG_SYS_CLK_FREQ
mcreq p15, 0, r1, c14, c0, 0 @ write CNTFRQ
#endif
adr r1, _monitor_vectors
mcr p15, 0, r1, c12, c0, 1 @ set MVBAR to secure vectors
isb
mov r0, r3 @ return GICC address
bx lr
ENDPROC(_nonsec_init)
#ifdef CONFIG_SMP_PEN_ADDR
/* void __weak smp_waitloop(unsigned previous_address); */
ENTRY(smp_waitloop)
wfi
ldr r1, =CONFIG_SMP_PEN_ADDR @ load start address
ldr r1, [r1]
cmp r0, r1 @ make sure we dont execute this code
beq smp_waitloop @ again (due to a spurious wakeup)
mov r0, r1
b _do_nonsec_entry
ENDPROC(smp_waitloop)
.weak smp_waitloop
#endif
.popsection
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