Re: [PATCH v7] ARM: shmobile: Add watchdog support

[Simon Horman]

On Wed, Mar 14, 2018 at 01:26:52PM +, Fabrizio Castro wrote:
> Hello Simon,
> 
> > Subject: Re: [PATCH v7] ARM: shmobile: Add watchdog support
> >
> > On Wed, Mar 14, 2018 at 11:13:53AM +, Fabrizio Castro wrote:
> > > 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.cas...@bp.renesas.com>
> > > Signed-off-by: Ramesh Shanmugasundaram 
> > > <ramesh.shanmugasunda...@bp.renesas.com>
> > > Reviewed-by: Geert Uytterhoeven <geert+rene...@glider.be>
> > > ---
> > > v6->v7:
> > > * restored ifdef within arch/arm/mach-shmobile/headsmp.S
> >
> > Thanks. I believe that this is the same as the hand modified
> > version of v5 that I applied yesterday.
> 
> yes, I believe v5 modified and applied by you is the same as v7.
> Thank you for taking the patch.

Likewise, thanks for the patches and for confirming this one is correct.

RE: [PATCH v7] ARM: shmobile: Add watchdog support

[Fabrizio Castro]

Hello Simon,

> Subject: Re: [PATCH v7] ARM: shmobile: Add watchdog support
>
> On Wed, Mar 14, 2018 at 11:13:53AM +, Fabrizio Castro wrote:
> > 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.cas...@bp.renesas.com>
> > Signed-off-by: Ramesh Shanmugasundaram 
> > <ramesh.shanmugasunda...@bp.renesas.com>
> > Reviewed-by: Geert Uytterhoeven <geert+rene...@glider.be>
> > ---
> > v6->v7:
> > * restored ifdef within arch/arm/mach-shmobile/headsmp.S
>
> Thanks. I believe that this is the same as the hand modified
> version of v5 that I applied yesterday.

yes, I believe v5 modified and applied by you is the same as v7.
Thank you for taking the patch.

Fab



Renesas Electronics Europe Ltd, Dukes Meadow, Millboard Road, Bourne End, 
Buckinghamshire, SL8 5FH, UK. Registered in England & Wales under Registered 
No. 04586709.

Re: [PATCH v7] ARM: shmobile: Add watchdog support

[Simon Horman]

On Wed, Mar 14, 2018 at 11:13:53AM +, Fabrizio Castro wrote:
> 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 
> Signed-off-by: Ramesh Shanmugasundaram 
> 
> Reviewed-by: Geert Uytterhoeven 
> ---
> v6->v7:
> * restored ifdef within arch/arm/mach-shmobile/headsmp.S

Thanks. I believe that this is the same as the hand modified
version of v5 that I applied yesterday.

[PATCH v7] ARM: shmobile: Add watchdog support

[Fabrizio Castro]

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 
Signed-off-by: Ramesh Shanmugasundaram 
Reviewed-by: Geert Uytterhoeven 
---
v6->v7:
* restored ifdef within arch/arm/mach-shmobile/headsmp.S

 arch/arm/mach-shmobile/common.h  |  4 +++
 arch/arm/mach-shmobile/headsmp.S | 55 
 2 files changed, 59 insertions(+)

diff --git a/arch/arm/mach-shmobile/common.h b/arch/arm/mach-shmobile/common.h
index a8fa4f7..43c1ac69 100644
--- 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 32e0bf6..cef8e8c 100644
--- a/arch/arm/mach-shmobile/headsmp.S
+++ b/arch/arm/mach-shmobile/headsmp.S
@@ -16,6 +16,11 @@
 #include 
 #include 
 
+#define SCTLR_MMU  0x01
+#define BOOTROM_ADDRESS0xE634
+#define RWTCSRA_ADDRESS0xE6020004
+#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
+   ldrbr1, [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   0x
+
+   .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
  */
-- 
2.7.4