u-boot/arch/arm/include/asm/macro.h
Peter Hoyes c48fec6e7c armv8: Initialize CNTFRQ if at highest exception level
CNTFRQ_EL0 is only writable from the highest supported exception
level on the platform. For Armv8-A, this is typically EL3, but
technically EL2 and EL3 are optional so it may need to be
initialized at EL2 or EL1. For Armv8-R, the highest exception
level is always EL2.

This patch moves the initialization outside of the switch_el
block and uses a new macro branch_if_not_highest_el which
dynamically detects whether it is at the highest supported
exception level.

Linux's docs state that CNTFRQ_EL0 should be initialized by the
bootloader. If not set, the the U-Boot prompt countdown hangs.

Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
2021-07-23 18:53:46 -04:00

355 lines
8.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* include/asm-arm/macro.h
*
* Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*/
#ifndef __ASM_ARM_MACRO_H__
#define __ASM_ARM_MACRO_H__
#ifdef CONFIG_ARM64
#include <asm/system.h>
#endif
#ifdef __ASSEMBLY__
/*
* These macros provide a convenient way to write 8, 16 and 32 bit data
* to any address.
* Registers r4 and r5 are used, any data in these registers are
* overwritten by the macros.
* The macros are valid for any ARM architecture, they do not implement
* any memory barriers so caution is recommended when using these when the
* caches are enabled or on a multi-core system.
*/
.macro write32, addr, data
ldr r4, =\addr
ldr r5, =\data
str r5, [r4]
.endm
.macro write16, addr, data
ldr r4, =\addr
ldrh r5, =\data
strh r5, [r4]
.endm
.macro write8, addr, data
ldr r4, =\addr
ldrb r5, =\data
strb r5, [r4]
.endm
/*
* This macro generates a loop that can be used for delays in the code.
* Register r4 is used, any data in this register is overwritten by the
* macro.
* The macro is valid for any ARM architeture. The actual time spent in the
* loop will vary from CPU to CPU though.
*/
.macro wait_timer, time
ldr r4, =\time
1:
nop
subs r4, r4, #1
bcs 1b
.endm
#ifdef CONFIG_ARM64
/*
* Register aliases.
*/
lr .req x30
/*
* Branch according to exception level
*/
.macro switch_el, xreg, el3_label, el2_label, el1_label
mrs \xreg, CurrentEL
cmp \xreg, 0xc
b.eq \el3_label
cmp \xreg, 0x8
b.eq \el2_label
cmp \xreg, 0x4
b.eq \el1_label
.endm
/*
* Branch if we are not in the highest exception level
*/
.macro branch_if_not_highest_el, xreg, label
switch_el \xreg, 3f, 2f, 1f
2: mrs \xreg, ID_AA64PFR0_EL1
and \xreg, \xreg, #(ID_AA64PFR0_EL1_EL3)
cbnz \xreg, \label
b 3f
1: mrs \xreg, ID_AA64PFR0_EL1
and \xreg, \xreg, #(ID_AA64PFR0_EL1_EL3 | ID_AA64PFR0_EL1_EL2)
cbnz \xreg, \label
3:
.endm
/*
* Branch if current processor is a Cortex-A57 core.
*/
.macro branch_if_a57_core, xreg, a57_label
mrs \xreg, midr_el1
lsr \xreg, \xreg, #4
and \xreg, \xreg, #0x00000FFF
cmp \xreg, #0xD07 /* Cortex-A57 MPCore processor. */
b.eq \a57_label
.endm
/*
* Branch if current processor is a Cortex-A53 core.
*/
.macro branch_if_a53_core, xreg, a53_label
mrs \xreg, midr_el1
lsr \xreg, \xreg, #4
and \xreg, \xreg, #0x00000FFF
cmp \xreg, #0xD03 /* Cortex-A53 MPCore processor. */
b.eq \a53_label
.endm
/*
* Branch if current processor is a slave,
* choose processor with all zero affinity value as the master.
*/
.macro branch_if_slave, xreg, slave_label
#ifdef CONFIG_ARMV8_MULTIENTRY
/* NOTE: MPIDR handling will be erroneous on multi-cluster machines */
mrs \xreg, mpidr_el1
tst \xreg, #0xff /* Test Affinity 0 */
b.ne \slave_label
lsr \xreg, \xreg, #8
tst \xreg, #0xff /* Test Affinity 1 */
b.ne \slave_label
lsr \xreg, \xreg, #8
tst \xreg, #0xff /* Test Affinity 2 */
b.ne \slave_label
lsr \xreg, \xreg, #16
tst \xreg, #0xff /* Test Affinity 3 */
b.ne \slave_label
#endif
.endm
/*
* Branch if current processor is a master,
* choose processor with all zero affinity value as the master.
*/
.macro branch_if_master, xreg1, xreg2, master_label
#ifdef CONFIG_ARMV8_MULTIENTRY
/* NOTE: MPIDR handling will be erroneous on multi-cluster machines */
mrs \xreg1, mpidr_el1
lsr \xreg2, \xreg1, #32
lsl \xreg2, \xreg2, #32
lsl \xreg1, \xreg1, #40
lsr \xreg1, \xreg1, #40
orr \xreg1, \xreg1, \xreg2
cbz \xreg1, \master_label
#else
b \master_label
#endif
.endm
/*
* Switch from EL3 to EL2 for ARMv8
* @ep: kernel entry point
* @flag: The execution state flag for lower exception
* level, ES_TO_AARCH64 or ES_TO_AARCH32
* @tmp: temporary register
*
* For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
* For loading 64-bit OS, x0 is physical address to the FDT blob.
* They will be passed to the guest.
*/
.macro armv8_switch_to_el2_m, ep, flag, tmp
msr cptr_el3, xzr /* Disable coprocessor traps to EL3 */
mov \tmp, #CPTR_EL2_RES1
msr cptr_el2, \tmp /* Disable coprocessor traps to EL2 */
/* Initialize Generic Timers */
msr cntvoff_el2, xzr
/* Initialize SCTLR_EL2
*
* setting RES1 bits (29,28,23,22,18,16,11,5,4) to 1
* and RES0 bits (31,30,27,26,24,21,20,17,15-13,10-6) +
* EE,WXN,I,SA,C,A,M to 0
*/
ldr \tmp, =(SCTLR_EL2_RES1 | SCTLR_EL2_EE_LE |\
SCTLR_EL2_WXN_DIS | SCTLR_EL2_ICACHE_DIS |\
SCTLR_EL2_SA_DIS | SCTLR_EL2_DCACHE_DIS |\
SCTLR_EL2_ALIGN_DIS | SCTLR_EL2_MMU_DIS)
msr sctlr_el2, \tmp
mov \tmp, sp
msr sp_el2, \tmp /* Migrate SP */
mrs \tmp, vbar_el3
msr vbar_el2, \tmp /* Migrate VBAR */
/* Check switch to AArch64 EL2 or AArch32 Hypervisor mode */
cmp \flag, #ES_TO_AARCH32
b.eq 1f
/*
* The next lower exception level is AArch64, 64bit EL2 | HCE |
* RES1 (Bits[5:4]) | Non-secure EL0/EL1.
* and the SMD depends on requirements.
*/
#ifdef CONFIG_ARMV8_PSCI
ldr \tmp, =(SCR_EL3_RW_AARCH64 | SCR_EL3_HCE_EN |\
SCR_EL3_RES1 | SCR_EL3_NS_EN)
#else
ldr \tmp, =(SCR_EL3_RW_AARCH64 | SCR_EL3_HCE_EN |\
SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
SCR_EL3_NS_EN)
#endif
#ifdef CONFIG_ARMV8_EA_EL3_FIRST
orr \tmp, \tmp, #SCR_EL3_EA_EN
#endif
msr scr_el3, \tmp
/* Return to the EL2_SP2 mode from EL3 */
ldr \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
SPSR_EL_M_AARCH64 | SPSR_EL_M_EL2H)
msr spsr_el3, \tmp
msr elr_el3, \ep
eret
1:
/*
* The next lower exception level is AArch32, 32bit EL2 | HCE |
* SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
*/
ldr \tmp, =(SCR_EL3_RW_AARCH32 | SCR_EL3_HCE_EN |\
SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
SCR_EL3_NS_EN)
msr scr_el3, \tmp
/* Return to AArch32 Hypervisor mode */
ldr \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
SPSR_EL_M_HYP)
msr spsr_el3, \tmp
msr elr_el3, \ep
eret
.endm
/*
* Switch from EL2 to EL1 for ARMv8
* @ep: kernel entry point
* @flag: The execution state flag for lower exception
* level, ES_TO_AARCH64 or ES_TO_AARCH32
* @tmp: temporary register
*
* For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
* For loading 64-bit OS, x0 is physical address to the FDT blob.
* They will be passed to the guest.
*/
.macro armv8_switch_to_el1_m, ep, flag, tmp
/* Initialize Generic Timers */
mrs \tmp, cnthctl_el2
/* Enable EL1 access to timers */
orr \tmp, \tmp, #(CNTHCTL_EL2_EL1PCEN_EN |\
CNTHCTL_EL2_EL1PCTEN_EN)
msr cnthctl_el2, \tmp
msr cntvoff_el2, xzr
/* Initilize MPID/MPIDR registers */
mrs \tmp, midr_el1
msr vpidr_el2, \tmp
mrs \tmp, mpidr_el1
msr vmpidr_el2, \tmp
/* Disable coprocessor traps */
mov \tmp, #CPTR_EL2_RES1
msr cptr_el2, \tmp /* Disable coprocessor traps to EL2 */
msr hstr_el2, xzr /* Disable coprocessor traps to EL2 */
mov \tmp, #CPACR_EL1_FPEN_EN
msr cpacr_el1, \tmp /* Enable FP/SIMD at EL1 */
/* SCTLR_EL1 initialization
*
* setting RES1 bits (29,28,23,22,20,11) to 1
* and RES0 bits (31,30,27,21,17,13,10,6) +
* UCI,EE,EOE,WXN,nTWE,nTWI,UCT,DZE,I,UMA,SED,ITD,
* CP15BEN,SA0,SA,C,A,M to 0
*/
ldr \tmp, =(SCTLR_EL1_RES1 | SCTLR_EL1_UCI_DIS |\
SCTLR_EL1_EE_LE | SCTLR_EL1_WXN_DIS |\
SCTLR_EL1_NTWE_DIS | SCTLR_EL1_NTWI_DIS |\
SCTLR_EL1_UCT_DIS | SCTLR_EL1_DZE_DIS |\
SCTLR_EL1_ICACHE_DIS | SCTLR_EL1_UMA_DIS |\
SCTLR_EL1_SED_EN | SCTLR_EL1_ITD_EN |\
SCTLR_EL1_CP15BEN_DIS | SCTLR_EL1_SA0_DIS |\
SCTLR_EL1_SA_DIS | SCTLR_EL1_DCACHE_DIS |\
SCTLR_EL1_ALIGN_DIS | SCTLR_EL1_MMU_DIS)
msr sctlr_el1, \tmp
mov \tmp, sp
msr sp_el1, \tmp /* Migrate SP */
mrs \tmp, vbar_el2
msr vbar_el1, \tmp /* Migrate VBAR */
/* Check switch to AArch64 EL1 or AArch32 Supervisor mode */
cmp \flag, #ES_TO_AARCH32
b.eq 1f
/* Initialize HCR_EL2 */
ldr \tmp, =(HCR_EL2_RW_AARCH64 | HCR_EL2_HCD_DIS)
msr hcr_el2, \tmp
/* Return to the EL1_SP1 mode from EL2 */
ldr \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
SPSR_EL_M_AARCH64 | SPSR_EL_M_EL1H)
msr spsr_el2, \tmp
msr elr_el2, \ep
eret
1:
/* Initialize HCR_EL2 */
ldr \tmp, =(HCR_EL2_RW_AARCH32 | HCR_EL2_HCD_DIS)
msr hcr_el2, \tmp
/* Return to AArch32 Supervisor mode from EL2 */
ldr \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
SPSR_EL_M_SVC)
msr spsr_el2, \tmp
msr elr_el2, \ep
eret
.endm
#if defined(CONFIG_GICV3)
.macro gic_wait_for_interrupt_m xreg1
0 : wfi
mrs \xreg1, ICC_IAR1_EL1
msr ICC_EOIR1_EL1, \xreg1
cbnz \xreg1, 0b
.endm
#elif defined(CONFIG_GICV2)
.macro gic_wait_for_interrupt_m xreg1, wreg2
0 : wfi
ldr \wreg2, [\xreg1, GICC_AIAR]
str \wreg2, [\xreg1, GICC_AEOIR]
and \wreg2, \wreg2, #0x3ff
cbnz \wreg2, 0b
.endm
#endif
#endif /* CONFIG_ARM64 */
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ARM_MACRO_H__ */