Re: [PATCH 01/02] ARM: shmobile: Add r8a73a4 SMP support using APMU code

From: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 01/02] ARM: shmobile: Add r8a73a4 SMP support using APMU code
Date: Thu, 22 Aug 2013 14:54:48 +0000	[thread overview]
Message-ID: <52162638.5080107@arm.com> (raw)
In-Reply-To: <20130807225540.9856.67383.sendpatchset@w520>

On 07/08/13 23:55, Magnus Damm wrote:
> From: Magnus Damm <damm@opensource.se>
> 
> Add r8a73a4 SMP support using the shared APMU code. To enable
> SMP the r8a73a4 specific DTS needs to be updated to include
> CPU cores, and this is happening in a separate patch.
> 
> Signed-off-by: Magnus Damm <damm@opensource.se>
> ---
> 
>  arch/arm/mach-shmobile/Makefile               |    1 
>  arch/arm/mach-shmobile/include/mach/r8a73a4.h |    1 
>  arch/arm/mach-shmobile/setup-r8a73a4.c        |    3 +
>  arch/arm/mach-shmobile/smp-r8a73a4.c          |   75 +++++++++++++++++++++++++
>  4 files changed, 80 insertions(+)
> 
> --- 0001/arch/arm/mach-shmobile/Makefile
> +++ work/arch/arm/mach-shmobile/Makefile	2013-08-07 20:07:31.000000000 +0900
> @@ -33,6 +33,7 @@ endif
>  # SMP objects
>  smp-y				:= platsmp.o headsmp.o
>  smp-$(CONFIG_ARCH_SH73A0)	+= smp-sh73a0.o headsmp-scu.o platsmp-scu.o
> +smp-$(CONFIG_ARCH_R8A73A4)	+= smp-r8a73a4.o platsmp-apmu.o
platsmp-apmu.c is introducing new bindings which IMO is not required.
I have responded to that patch, but it would be nice to combine that
patch in a single series for easier review for at least one platform
using it.

>  smp-$(CONFIG_ARCH_R8A7779)	+= smp-r8a7779.o headsmp-scu.o platsmp-scu.o
>  smp-$(CONFIG_ARCH_EMEV2)	+= smp-emev2.o headsmp-scu.o platsmp-scu.o
>  
> --- 0008/arch/arm/mach-shmobile/include/mach/r8a73a4.h
> +++ work/arch/arm/mach-shmobile/include/mach/r8a73a4.h	2013-08-07 20:08:02.000000000 +0900
> @@ -6,5 +6,6 @@ void r8a73a4_add_dt_devices(void);
>  void r8a73a4_clock_init(void);
>  void r8a73a4_pinmux_init(void);
>  void r8a73a4_init_early(void);
> +extern struct smp_operations r8a73a4_smp_ops;
>  
>  #endif /* __ASM_R8A73A4_H__ */
> --- 0008/arch/arm/mach-shmobile/setup-r8a73a4.c
> +++ work/arch/arm/mach-shmobile/setup-r8a73a4.c	2013-08-07 20:07:48.000000000 +0900
> @@ -212,6 +212,9 @@ void __init r8a73a4_init_early(void)
>  #ifndef CONFIG_ARM_ARCH_TIMER
>  	shmobile_setup_delay(1500, 2, 4); /* Cortex-A15 @ 1500MHz */
>  #endif
> +#ifdef CONFIG_SMP
> +	smp_set_ops(&r8a73a4_smp_ops);
> +#endif
>  }
>  
>  #ifdef CONFIG_USE_OF
> --- /dev/null
> +++ work/arch/arm/mach-shmobile/smp-r8a73a4.c	2013-08-07 20:09:10.000000000 +0900
> @@ -0,0 +1,75 @@
> +/*
> + * SMP support for r8a73a4
> + *
> + * Copyright (C) 2012-2013 Renesas Solutions Corp.
> + * Copyright (C) 2012 Takashi Yoshii <takashi.yoshii.ze@renesas.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/smp.h>
> +#include <asm/smp_plat.h>
> +#include <mach/common.h>
> +
> +#define SYSC		0xe6180000
> +#define CA7BAR		0x4020
> +#define CA15BAR		0x6020
> +#define RESCNT		0x801c
> +#define MERAM		0xe8080000
> +#define CCI_BASE	0xf0190000
> +#define CCI_SLAVE3	0x4000
> +#define CCI_SLAVE4	0x5000
> +#define CCI_SNOOP	0x0000
> +#define CCI_STATUS	0x000c
Have a look at cci driver and its bindings, these slave addresses needs
to be part of DTS.

> +
> +static void __init r8a73a4_smp_prepare_cpus(unsigned int max_cpus)
> +{
> +	u32 bar;
> +	void __iomem *p;
> +
> +	/* let APMU code install data related to shmobile_boot_vector */
> +	shmobile_smp_apmu_prepare_cpus(max_cpus);
> +
> +	/* MERAM for jump stub, because BAR requires 256KB aligned address */
> +	p = ioremap_nocache(MERAM, shmobile_boot_size);
> +	memcpy_toio(p, shmobile_boot_vector, shmobile_boot_size);
> +	iounmap(p);
> +
> +	/* setup reset vector and disable reset */
> +	p = ioremap_nocache(SYSC, 0x9000);
> +	bar = (MERAM >> 8) & 0xfffffc00;
> +	writel_relaxed(bar, p + CA15BAR);
> +	writel_relaxed(bar, p + CA7BAR);
> +	writel_relaxed(bar | 0x10, p + CA15BAR);
> +	writel_relaxed(bar | 0x10, p + CA7BAR);
> +	writel_relaxed(readl_relaxed(p + RESCNT) & ~(1 << 10), p + RESCNT);
> +	writel_relaxed(readl_relaxed(p + RESCNT) & ~(1 << 9), p + RESCNT);
> +	iounmap(p);
> +
> +	/* enable snoop and DVM */
> +	p = ioremap_nocache(CCI_BASE, 0x8000);
> +	writel_relaxed(3, p + CCI_SLAVE3 + CCI_SNOOP);	/* CA15 */
> +	writel_relaxed(3, p + CCI_SLAVE4 + CCI_SNOOP);	/* CA7 */
> +	while (readl_relaxed(p + CCI_STATUS))
> +		/* wait for pending bit low */;
> +	iounmap(p);
You can use cci driver APIs for CCI control.

> +}
> +
> +struct smp_operations r8a73a4_smp_ops __initdata = {
> +	.smp_prepare_cpus	= r8a73a4_smp_prepare_cpus,
> +	.smp_boot_secondary	= shmobile_smp_apmu_boot_secondary,
> +#ifdef CONFIG_HOTPLUG_CPU
> +	.cpu_disable		= shmobile_smp_cpu_disable,
> +	.cpu_die		= shmobile_smp_apmu_cpu_die,
> +	.cpu_kill		= shmobile_smp_apmu_cpu_kill,
> +#endif
> +};
If you are running Linux in secure mode, you can reuse mcpm_smp_ops and
define these as part of mcpm_platform_ops

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