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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>
This commit is contained in:
Fabrizio Castro 2018-02-28 17:40:22 +00:00 committed by Simon Horman
parent 60fc75bdf5
commit 58adf1ba0d
2 changed files with 59 additions and 0 deletions
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4
arch/arm/mach-shmobile/common.h
View File

@ -7,6 +7,10 @@ extern void shmobile_init_delay(void);
extern void shmobile_boot_vector(void);
extern unsigned long shmobile_boot_fn;
extern unsigned long shmobile_boot_size;
extern void shmobile_boot_vector_gen2(void);
extern unsigned long shmobile_boot_fn_gen2;
extern unsigned long shmobile_boot_cpu_gen2;
extern unsigned long shmobile_boot_size_gen2;
extern void shmobile_smp_boot(void);
extern void shmobile_smp_sleep(void);
extern void shmobile_smp_hook(unsigned int cpu, unsigned long fn,

55
arch/arm/mach-shmobile/headsmp.S
View File

@ -16,6 +16,11 @@
#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.
@ -37,6 +42,56 @@ shmobile_boot_fn:
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
*/