diff mbox

[v7] ARM: shmobile: Add watchdog support

Message ID 1521026033-8494-1-git-send-email-fabrizio.castro@bp.renesas.com (mailing list archive)
State New, archived
Headers show

Commit Message

Fabrizio Castro March 14, 2018, 11:13 a.m. UTC
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>
---
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(+)

Comments

Simon Horman March 14, 2018, 12:43 p.m. UTC | #1
On Wed, Mar 14, 2018 at 11:13:53AM +0000, 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.castro@bp.renesas.com>
> Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@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.
Fabrizio Castro March 14, 2018, 1:26 p.m. UTC | #2
Hello Simon,

> Subject: Re: [PATCH v7] ARM: shmobile: Add watchdog support
>
> On Wed, Mar 14, 2018 at 11:13:53AM +0000, 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.castro@bp.renesas.com>
> > Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@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.
Simon Horman March 16, 2018, 11:49 a.m. UTC | #3
On Wed, Mar 14, 2018 at 01:26:52PM +0000, Fabrizio Castro wrote:
> Hello Simon,
> 
> > Subject: Re: [PATCH v7] ARM: shmobile: Add watchdog support
> >
> > On Wed, Mar 14, 2018 at 11:13:53AM +0000, 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.castro@bp.renesas.com>
> > > Signed-off-by: Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>
> > > Reviewed-by: Geert Uytterhoeven <geert+renesas@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.
diff mbox

Patch

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 <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
  */