[PATCH 00/02] ARM: shmobile: Per-CPU SMP boot / sleep code

[PATCH 00/02] ARM: shmobile: Per-CPU SMP boot / sleep code

[Magnus Damm]

ARM: shmobile: Per-CPU SMP boot / sleep code

[PATCH 01/02] ARM: shmobile: Introduce per-CPU SMP boot / sleep code
[PATCH 02/02] ARM: shmobile: Per-CPU SMP boot / sleep code for SCU SoCs

This series adds per-CPU SMP boot / sleep code to mach-shmobile and ties
it in with the Cortex-A9 SoCs using the shared SCU code. With this code
in place mach-shmobile has a common per-CPU demuxer that CPUs to start
from and a place where CPUs also go to sleep (perhaps forever).

Signed-off-by: Magnus Damm <damm@opensource.se>
---

 Written against renesas.git renesas-devel-20130731 and
 [PATCH 00/07] ARM: shmobile: sh73a0, r8a7779 and emev2 SMP SCU rework
 
 Requires "[PATCH] ARM: Fix memblock_reserve() to include stext" during
 run time to allow test of CPU Hotplug with v3.11-rc kernels.

 arch/arm/mach-shmobile/headsmp.S             |   50 ++++++++++++++++++++++++++
 arch/arm/mach-shmobile/include/mach/common.h |    4 ++
 arch/arm/mach-shmobile/platsmp-scu.c         |   17 +++++---
 arch/arm/mach-shmobile/platsmp.c             |   18 +++++++++
 4 files changed, 83 insertions(+), 6 deletions(-)

[PATCH 01/02] ARM: shmobile: Introduce per-CPU SMP boot / sleep code

[Magnus Damm]

From: Magnus Damm <damm@opensource.se>

Add per-CPU SMP boot / sleep code that can be used by all
SoCs included in mach-shmobile.

The boot code reads out the per-CPU MPIDR id value and
matches it with the value stored for any CPU number, and
if there is a match and the boot function is set as well
then the boot function will be executed.

The sleep code simply uses WFI and then jumps back to the
boot code to see if anyone has asked to wake up that CPU,
if not it will sleep again.

Signed-off-by: Magnus Damm <damm@opensource.se>
---

 arch/arm/mach-shmobile/headsmp.S             |   50 ++++++++++++++++++++++++++
 arch/arm/mach-shmobile/include/mach/common.h |    4 ++
 arch/arm/mach-shmobile/platsmp.c             |   18 +++++++++
 3 files changed, 72 insertions(+)

--- 0001/arch/arm/mach-shmobile/headsmp.S
+++ work/arch/arm/mach-shmobile/headsmp.S	2013-07-31 12:23:20.000000000 +0900
@@ -40,3 +40,53 @@ shmobile_boot_fn:
 	.globl	shmobile_boot_arg
 shmobile_boot_arg:
 2:	.space	4
+
+/*
+ * Per-CPU SMP boot function/argument selection code based on MPIDR
+ */
+
+ENTRY(shmobile_smp_boot)
+						@ r0 = MPIDR_HWID_BITMASK
+	mrc	p15, 0, r1, c0, c0, 5		@ r1 = MPIDR
+	and	r0, r1, r0			@ r0 = cpu_logical_map() value
+	mov	r1, #0				@ r1 = CPU index
+	adr	r5, 1f				@ array of per-cpu mpidr values
+	adr	r6, 2f				@ array of per-cpu functions
+	adr	r7, 3f				@ 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, #CONFIG_NR_CPUS
+	blo	shmobile_smp_boot_find_mpidr
+
+	b	shmobile_smp_sleep
+	
+shmobile_smp_boot_found:
+	ldr	r0, [r7, r1, lsl #2]
+	mov	pc, r9
+ENDPROC(shmobile_smp_boot)
+
+ENTRY(shmobile_smp_sleep)
+	wfi
+	b	shmobile_smp_boot
+ENDPROC(shmobile_smp_sleep)
+
+	.globl	shmobile_smp_mpidr
+shmobile_smp_mpidr:
+1:	.space	CONFIG_NR_CPUS * 4
+	.globl	shmobile_smp_fn
+shmobile_smp_fn:
+2:	.space	CONFIG_NR_CPUS * 4
+	.globl	shmobile_smp_arg
+shmobile_smp_arg:
+3:	.space	CONFIG_NR_CPUS * 4
+
--- 0006/arch/arm/mach-shmobile/include/mach/common.h
+++ work/arch/arm/mach-shmobile/include/mach/common.h	2013-07-31 12:18:01.000000000 +0900
@@ -10,6 +10,10 @@ extern void shmobile_setup_console(void)
 extern void shmobile_boot_vector(void);
 extern unsigned long shmobile_boot_fn;
 extern unsigned long shmobile_boot_arg;
+extern void shmobile_smp_boot(void);
+extern void shmobile_smp_sleep(void);
+extern void shmobile_smp_hook(unsigned int cpu, unsigned long fn,
+			      unsigned long arg);
 extern void shmobile_boot_scu(void);
 extern void shmobile_smp_scu_prepare_cpus(unsigned int max_cpus);
 extern int shmobile_smp_scu_boot_secondary(unsigned int cpu,
--- 0001/arch/arm/mach-shmobile/platsmp.c
+++ work/arch/arm/mach-shmobile/platsmp.c	2013-07-31 12:18:01.000000000 +0900
@@ -12,6 +12,9 @@
  */
 #include <linux/init.h>
 #include <linux/smp.h>
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <mach/common.h>
 
 void __init shmobile_smp_init_cpus(unsigned int ncores)
 {
@@ -26,3 +29,18 @@ void __init shmobile_smp_init_cpus(unsig
 	for (i = 0; i < ncores; i++)
 		set_cpu_possible(i, true);
 }
+
+extern unsigned long shmobile_smp_fn[];
+extern unsigned long shmobile_smp_arg[];
+extern unsigned long shmobile_smp_mpidr[];
+
+void shmobile_smp_hook(unsigned int cpu, unsigned long fn, unsigned long arg)
+{
+	shmobile_smp_fn[cpu] = 0;
+	flush_cache_all();
+
+	shmobile_smp_mpidr[cpu] = cpu_logical_map(cpu);
+	shmobile_smp_fn[cpu] = fn;
+	shmobile_smp_arg[cpu] = arg;
+	flush_cache_all();
+}

[PATCH 02/02] ARM: shmobile: Per-CPU SMP boot / sleep code for SCU SoCs

[Magnus Damm]

From: Magnus Damm <damm@opensource.se>

Hook in the per-CPU boot and sleep code in the shared
mach-shmobile SCU code. CPUs may be kept in the asm
routine until ->boot_secondary() when the per-CPU
boot vector is installed. At the end of ->die() the
asm sleep routine is invoked.

Signed-off-by: Magnus Damm <damm@opensource.se>
---

 arch/arm/mach-shmobile/platsmp-scu.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

--- 0006/arch/arm/mach-shmobile/platsmp-scu.c
+++ work/arch/arm/mach-shmobile/platsmp-scu.c	2013-07-31 12:18:32.000000000 +0900
@@ -18,8 +18,9 @@
 
 void __init shmobile_smp_scu_prepare_cpus(unsigned int max_cpus)
 {
-	shmobile_boot_fn = virt_to_phys(shmobile_boot_scu);
-	shmobile_boot_arg = (unsigned long)shmobile_scu_base;
+	/* install boot code shared by all CPUs */
+	shmobile_boot_fn = virt_to_phys(shmobile_smp_boot);
+	shmobile_boot_arg = MPIDR_HWID_BITMASK;
 
 	/* enable SCU and cache coherency on booting CPU */
 	scu_enable(shmobile_scu_base);
@@ -28,22 +29,26 @@ void __init shmobile_smp_scu_prepare_cpu
 
 int shmobile_smp_scu_boot_secondary(unsigned int cpu, struct task_struct *idle)
 {
-	/* do nothing for now */
+	/* For this particular CPU register SCU boot vector */
+	shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu),
+			  (unsigned long)shmobile_scu_base);
 	return 0;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
 void shmobile_smp_scu_cpu_die(unsigned int cpu)
 {
+	/* For this particular CPU deregister boot vector */
+	shmobile_smp_hook(cpu, 0, 0);
+
 	dsb();
 	flush_cache_all();
 
 	/* disable cache coherency */
 	scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
 
-	/* Endless loop until reset */
-	while (1)
-		cpu_do_idle();
+	/* jump to shared mach-shmobile sleep / reset code */
+	shmobile_smp_sleep();
 }
 
 static int shmobile_smp_scu_psr_core_disabled(int cpu)

Re: [PATCH 01/02] ARM: shmobile: Introduce per-CPU SMP boot / sleep code

[Simon Horman]

On Thu, Aug 01, 2013 at 03:38:18AM +0900, Magnus Damm wrote:
> From: Magnus Damm <damm@opensource.se>
> 
> Add per-CPU SMP boot / sleep code that can be used by all
> SoCs included in mach-shmobile.
> 
> The boot code reads out the per-CPU MPIDR id value and
> matches it with the value stored for any CPU number, and
> if there is a match and the boot function is set as well
> then the boot function will be executed.
> 
> The sleep code simply uses WFI and then jumps back to the
> boot code to see if anyone has asked to wake up that CPU,
> if not it will sleep again.
> 
> Signed-off-by: Magnus Damm <damm@opensource.se>

Hi Magnus,

I have queued this up for v3.12 in the smp branch
with the following whitespace changes:

> ---
> 
>  arch/arm/mach-shmobile/headsmp.S             |   50 ++++++++++++++++++++++++++
>  arch/arm/mach-shmobile/include/mach/common.h |    4 ++
>  arch/arm/mach-shmobile/platsmp.c             |   18 +++++++++
>  3 files changed, 72 insertions(+)
> 
> --- 0001/arch/arm/mach-shmobile/headsmp.S
> +++ work/arch/arm/mach-shmobile/headsmp.S	2013-07-31 12:23:20.000000000 +0900
> @@ -40,3 +40,53 @@ shmobile_boot_fn:
>  	.globl	shmobile_boot_arg
>  shmobile_boot_arg:
>  2:	.space	4
> +
> +/*
> + * Per-CPU SMP boot function/argument selection code based on MPIDR
> + */
> +
> +ENTRY(shmobile_smp_boot)
> +						@ r0 = MPIDR_HWID_BITMASK
> +	mrc	p15, 0, r1, c0, c0, 5		@ r1 = MPIDR
> +	and	r0, r1, r0			@ r0 = cpu_logical_map() value
> +	mov	r1, #0				@ r1 = CPU index
> +	adr	r5, 1f				@ array of per-cpu mpidr values
> +	adr	r6, 2f				@ array of per-cpu functions
> +	adr	r7, 3f				@ array of per-cpu arguments
> +	

Removed trailing whitespace from line above.

> +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
> +	

Removed trailing whitespace from line above.

> +shmobile_smp_boot_next:
> +	add	r1, r1, #1
> +	cmp	r1, #CONFIG_NR_CPUS
> +	blo	shmobile_smp_boot_find_mpidr
> +
> +	b	shmobile_smp_sleep
> +	

Removed trailing whitespace from line above.

> +shmobile_smp_boot_found:
> +	ldr	r0, [r7, r1, lsl #2]
> +	mov	pc, r9
> +ENDPROC(shmobile_smp_boot)
> +
> +ENTRY(shmobile_smp_sleep)
> +	wfi
> +	b	shmobile_smp_boot
> +ENDPROC(shmobile_smp_sleep)
> +
> +	.globl	shmobile_smp_mpidr
> +shmobile_smp_mpidr:
> +1:	.space	CONFIG_NR_CPUS * 4
> +	.globl	shmobile_smp_fn
> +shmobile_smp_fn:
> +2:	.space	CONFIG_NR_CPUS * 4
> +	.globl	shmobile_smp_arg
> +shmobile_smp_arg:
> +3:	.space	CONFIG_NR_CPUS * 4
> +

Remove trailing blank line from line above.

> --- 0006/arch/arm/mach-shmobile/include/mach/common.h
> +++ work/arch/arm/mach-shmobile/include/mach/common.h	2013-07-31 12:18:01.000000000 +0900
> @@ -10,6 +10,10 @@ extern void shmobile_setup_console(void)
>  extern void shmobile_boot_vector(void);
>  extern unsigned long shmobile_boot_fn;
>  extern unsigned long shmobile_boot_arg;
> +extern void shmobile_smp_boot(void);
> +extern void shmobile_smp_sleep(void);
> +extern void shmobile_smp_hook(unsigned int cpu, unsigned long fn,
> +			      unsigned long arg);
>  extern void shmobile_boot_scu(void);
>  extern void shmobile_smp_scu_prepare_cpus(unsigned int max_cpus);
>  extern int shmobile_smp_scu_boot_secondary(unsigned int cpu,
> --- 0001/arch/arm/mach-shmobile/platsmp.c
> +++ work/arch/arm/mach-shmobile/platsmp.c	2013-07-31 12:18:01.000000000 +0900
> @@ -12,6 +12,9 @@
>   */
>  #include <linux/init.h>
>  #include <linux/smp.h>
> +#include <asm/cacheflush.h>
> +#include <asm/smp_plat.h>
> +#include <mach/common.h>
>  
>  void __init shmobile_smp_init_cpus(unsigned int ncores)
>  {
> @@ -26,3 +29,18 @@ void __init shmobile_smp_init_cpus(unsig
>  	for (i = 0; i < ncores; i++)
>  		set_cpu_possible(i, true);
>  }
> +
> +extern unsigned long shmobile_smp_fn[];
> +extern unsigned long shmobile_smp_arg[];
> +extern unsigned long shmobile_smp_mpidr[];
> +
> +void shmobile_smp_hook(unsigned int cpu, unsigned long fn, unsigned long arg)
> +{
> +	shmobile_smp_fn[cpu] = 0;
> +	flush_cache_all();
> +
> +	shmobile_smp_mpidr[cpu] = cpu_logical_map(cpu);
> +	shmobile_smp_fn[cpu] = fn;
> +	shmobile_smp_arg[cpu] = arg;
> +	flush_cache_all();
> +}
> 

Re: [PATCH 02/02] ARM: shmobile: Per-CPU SMP boot / sleep code for SCU SoCs

[Simon Horman]

On Thu, Aug 01, 2013 at 03:38:27AM +0900, Magnus Damm wrote:
> From: Magnus Damm <damm@opensource.se>
> 
> Hook in the per-CPU boot and sleep code in the shared
> mach-shmobile SCU code. CPUs may be kept in the asm
> routine until ->boot_secondary() when the per-CPU
> boot vector is installed. At the end of ->die() the
> asm sleep routine is invoked.
> 
> Signed-off-by: Magnus Damm <damm@opensource.se>

Thanks, I have queued this up for v3.12 in the smp branch.