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>

diff --git a/arch/arm/mach-shmobile/common.h b/arch/arm/mach-shmobile/common.h
index a8fa4f7e1f601dc88f15048ef54aaf5f9c2df50d..43c1ac696274175779b9ea20636a263ed54e22e2 100644 (file)
--- a/arch/arm/mach-shmobile/common.h
+++ b/arch/arm/mach-shmobile/common.h
@@ -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,

diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S
index 32e0bf6e3ccb9bd317c68be65ef7071a0c05eeed..cef8e8c555f84b926adfa95e45c421b6759c665a 100644 (file)
--- a/arch/arm/mach-shmobile/headsmp.S
+++ b/arch/arm/mach-shmobile/headsmp.S
@@ -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
  */