u-boot/arch/arm/cpu/armv7/nonsec_virt.S
Andre Przywara 3d5e52bd97 ARM: psci: move GIC address override to Kconfig
As the code to switch an ARM core from secure to the non-secure state
needs to know the base address of the Generic Interrupt Controller
(GIC), we read an Arm Cortex defined system register that is supposed to
hold that base address. However there are SoCs out there that get this
wrong, and this CBAR register either reads as 0 or points to the wrong
address. To accommodate those systems, so far we use a macro defined in
some platform specific header files, for affected boards.

To simplify future extensions, replace that macro with a Kconfig variable
that holds this override address, and define a default value for SoCs
that need it.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Sam Edwards <CFSworks@gmail.com>
2023-10-11 13:22:32 -04:00

224 lines
5.5 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* code for switching cores into non-secure state and into HYP mode
*
* Copyright (c) 2013 Andre Przywara <andre.przywara@linaro.org>
*/
#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
bl psci_stack_setup
@ Configure the PSCI backend
push {r0, r1, r2, ip}
bl psci_arch_init
pop {r0, r1, r2, ip}
#endif
#ifdef CONFIG_ARM_ERRATA_773022
mrc p15, 0, r5, c1, c0, 1
orr r5, r5, #(1 << 1)
mcr p15, 0, r5, c1, c0, 1
isb
#endif
#ifdef CONFIG_ARM_ERRATA_774769
mrc p15, 0, r5, c1, c0, 1
orr r5, r5, #(1 << 25)
mcr p15, 0, r5, c1, c0, 1
isb
#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
mrseq r3, sp_svc
msreq sp_hyp, r3 @ migrate SP
#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.
*/
#if CONFIG_COUNTER_FREQUENCY
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_COUNTER_FREQUENCY
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 CFG_SMP_PEN_ADDR
/* void __weak smp_waitloop(unsigned previous_address); */
WEAK(smp_waitloop)
wfi
ldr r1, =CFG_SMP_PEN_ADDR @ load start address
ldr r1, [r1]
#ifdef CONFIG_PEN_ADDR_BIG_ENDIAN
rev r1, r1
#endif
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)
#endif
.popsection