linux_dsm_epyc7002/arch/arm/mach-shmobile/headsmp.S
Fabrizio Castro 58adf1ba0d ARM: shmobile: Add watchdog support
On R-Car Gen2 and RZ/G1 platforms, we use the SBAR registers to make non
boot CPUs run a routine designed to bring up SMP and deal with hot plug.
The value contained in the SBAR registers is not initialized by a WDT
triggered reset, which means that after a WDT triggered reset we jump
to the SMP bring up routine, preventing the system from executing the
bootrom code.

The purpose of this patch is to jump to the bootrom code in case of a
WDT triggered reset, and keep the SMP functionality untouched.
In order to tell if the code had been called due to the WDT overflowing
we are testing WOVF from register RWTCSRA.

The new function shmobile_boot_vector_gen2 isn't replacing
shmobile_boot_vector for backward compatibility reasons. The kernel
will install the best option (either shmobile_boot_vector or
shmobile_boot_vector_gen2) to ICRAM1 after parsing the device tree,
according to the amount of memory available.

Since shmobile_boot_vector has become bigger, "reg" property of nodes
compatible with "renesas,smp-sram" now need to be set to a value
greater or equal to "<0 0x60>".

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
[simon: dropped #ifdef from common.h]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2018-03-13 20:52:19 +01:00

151 lines
3.2 KiB
ArmAsm

/*
* SMP support for R-Mobile / SH-Mobile
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2010 Takashi Yoshii
*
* Based on vexpress, Copyright (c) 2003 ARM Limited, All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/threads.h>
#include <asm/assembler.h>
#include <asm/memory.h>
#define SCTLR_MMU 0x01
#define BOOTROM_ADDRESS 0xE6340000
#define RWTCSRA_ADDRESS 0xE6020004
#define RWTCSRA_WOVF 0x10
/*
* Reset vector for secondary CPUs.
* This will be mapped at address 0 by SBAR register.
* We need _long_ jump to the physical address.
*/
.arm
.align 12
ENTRY(shmobile_boot_vector)
ldr r1, 1f
bx r1
ENDPROC(shmobile_boot_vector)
.align 2
.globl shmobile_boot_fn
shmobile_boot_fn:
1: .space 4
.globl shmobile_boot_size
shmobile_boot_size:
.long . - shmobile_boot_vector
#ifdef CONFIG_ARCH_RCAR_GEN2
/*
* Reset vector for R-Car Gen2 and RZ/G1 secondary CPUs.
* This will be mapped at address 0 by SBAR register.
*/
ENTRY(shmobile_boot_vector_gen2)
mrc p15, 0, r0, c0, c0, 5 @ r0 = MPIDR
ldr r1, shmobile_boot_cpu_gen2
cmp r0, r1
bne shmobile_smp_continue_gen2
mrc p15, 0, r1, c1, c0, 0 @ r1 = SCTLR
and r0, r1, #SCTLR_MMU
cmp r0, #SCTLR_MMU
beq shmobile_smp_continue_gen2
ldr r0, rwtcsra
mov r1, #0
ldrb r1, [r0]
and r0, r1, #RWTCSRA_WOVF
cmp r0, #RWTCSRA_WOVF
bne shmobile_smp_continue_gen2
ldr r0, bootrom
bx r0
shmobile_smp_continue_gen2:
ldr r1, shmobile_boot_fn_gen2
bx r1
ENDPROC(shmobile_boot_vector_gen2)
.align 4
rwtcsra:
.word RWTCSRA_ADDRESS
bootrom:
.word BOOTROM_ADDRESS
.globl shmobile_boot_cpu_gen2
shmobile_boot_cpu_gen2:
.word 0x00000000
.align 2
.globl shmobile_boot_fn_gen2
shmobile_boot_fn_gen2:
.space 4
.globl shmobile_boot_size_gen2
shmobile_boot_size_gen2:
.long . - shmobile_boot_vector_gen2
#endif /* CONFIG_ARCH_RCAR_GEN2 */
/*
* Per-CPU SMP boot function/argument selection code based on MPIDR
*/
ENTRY(shmobile_smp_boot)
mrc p15, 0, r1, c0, c0, 5 @ r1 = MPIDR
and r0, r1, #0xffffff @ MPIDR_HWID_BITMASK
@ r0 = cpu_logical_map() value
mov r1, #0 @ r1 = CPU index
adr r2, 1f
ldmia r2, {r5, r6, r7}
add r5, r5, r2 @ array of per-cpu mpidr values
add r6, r6, r2 @ array of per-cpu functions
add r7, r7, r2 @ array of per-cpu arguments
shmobile_smp_boot_find_mpidr:
ldr r8, [r5, r1, lsl #2]
cmp r8, r0
bne shmobile_smp_boot_next
ldr r9, [r6, r1, lsl #2]
cmp r9, #0
bne shmobile_smp_boot_found
shmobile_smp_boot_next:
add r1, r1, #1
cmp r1, #NR_CPUS
blo shmobile_smp_boot_find_mpidr
b shmobile_smp_sleep
shmobile_smp_boot_found:
ldr r0, [r7, r1, lsl #2]
ret r9
ENDPROC(shmobile_smp_boot)
ENTRY(shmobile_smp_sleep)
wfi
b shmobile_smp_boot
ENDPROC(shmobile_smp_sleep)
.align 2
1: .long shmobile_smp_mpidr - .
.long shmobile_smp_fn - 1b
.long shmobile_smp_arg - 1b
.bss
.globl shmobile_smp_mpidr
shmobile_smp_mpidr:
.space NR_CPUS * 4
.globl shmobile_smp_fn
shmobile_smp_fn:
.space NR_CPUS * 4
.globl shmobile_smp_arg
shmobile_smp_arg:
.space NR_CPUS * 4