On 06/05/18 04:28, Michel Pollet wrote:
> The Renesas R9A06G032 second CA7 is parked in a ROM pen at boot time, it
> requires a special enable method to get it started.
>
> Signed-off-by: Michel Pollet <michel.pollet@xxxxxxxxxxxxxx>
> ---
> arch/arm/mach-shmobile/Makefile | 1 +
> arch/arm/mach-shmobile/smp-r9a06g032.c | 79 ++++++++++++++++++++++++++++++++++
> 2 files changed, 80 insertions(+)
> create mode 100644 arch/arm/mach-shmobile/smp-r9a06g032.c
>
> diff --git a/arch/arm/mach-shmobile/Makefile b/arch/arm/mach-shmobile/Makefile
> index 1939f52..d7fc98f 100644
> --- a/arch/arm/mach-shmobile/Makefile
> +++ b/arch/arm/mach-shmobile/Makefile
> @@ -34,6 +34,7 @@ smp-$(CONFIG_ARCH_SH73A0) += smp-sh73a0.o headsmp-scu.o platsmp-scu.o
> smp-$(CONFIG_ARCH_R8A7779) += smp-r8a7779.o headsmp-scu.o platsmp-scu.o
> smp-$(CONFIG_ARCH_R8A7790) += smp-r8a7790.o
> smp-$(CONFIG_ARCH_R8A7791) += smp-r8a7791.o
> +smp-$(CONFIG_ARCH_R9A06G032) += smp-r9a06g032.o
> smp-$(CONFIG_ARCH_EMEV2) += smp-emev2.o headsmp-scu.o platsmp-scu.o
>
> # PM objects
> diff --git a/arch/arm/mach-shmobile/smp-r9a06g032.c b/arch/arm/mach-shmobile/smp-r9a06g032.c
> new file mode 100644
> index 0000000..cd40e6e
> --- /dev/null
> +++ b/arch/arm/mach-shmobile/smp-r9a06g032.c
> @@ -0,0 +1,79 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * R9A06G032 Second CA7 enabler.
> + *
> + * Copyright (C) 2018 Renesas Electronics Europe Limited
> + *
> + * Michel Pollet <michel.pollet@xxxxxxxxxxxxxx>, <buserror@xxxxxxxxx>
> + * Derived from action,s500-smp
> + */
> +
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/smp.h>
> +
> +/*
> + * The second CPU is parked in ROM at boot time. It requires waking it after
> + * writing an address into the BOOTADDR register of sysctrl.
> + *
> + * So the default value of the "cpu-release-addr" corresponds to BOOTADDR...
> + *
> + * *However* the BOOTADDR register is not available when the kernel
> + * starts in NONSEC mode.
> + *
> + * So for NONSEC mode, the bootloader re-parks the second CPU into a pen
> + * in SRAM, and changes the "cpu-release-addr" of linux's DT to a SRAM address,
> + * which is not restricted.
The binding document for cpu-release-addr does not have a definition for 32 bit
arm. The existing definition is only 64 bit arm. Please add the definition
for 32 bit arm to patch 1.
-Frank
> + */
> +
> +static void __iomem *cpu_bootaddr;
> +
> +static DEFINE_SPINLOCK(cpu_lock);
> +
> +static int r9a06g032_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
> +{
> + if (!cpu_bootaddr)
> + return -ENODEV;
> +
> + spin_lock(&cpu_lock);
> +
> + writel(__pa_symbol(secondary_startup), cpu_bootaddr);
> + arch_send_wakeup_ipi_mask(cpumask_of(cpu));
> +
> + spin_unlock(&cpu_lock);
> +
> + return 0;
> +}
> +
> +static void __init r9a06g032_smp_prepare_cpus(unsigned int max_cpus)
> +{
> + struct device_node *dn;
> + int ret;
> + u32 bootaddr;
> +
> + dn = of_get_cpu_node(1, NULL);
> + if (!dn) {
> + pr_err("CPU#1: missing device tree node\n");
> + return;
> + }
> + /*
> + * Determine the address from which the CPU is polling.
> + * The bootloader *does* change this property
> + */
> + ret = of_property_read_u32(dn, "cpu-release-addr", &bootaddr);
> + of_node_put(dn);
> + if (ret) {
> + pr_err("CPU#1: invalid cpu-release-addr property\n");
> + return;
> + }
> + pr_info("CPU#1: cpu-release-addr %08x\n", bootaddr);
> +
> + cpu_bootaddr = ioremap(bootaddr, sizeof(bootaddr));
> +}
> +
> +static const struct smp_operations r9a06g032_smp_ops __initconst = {
> + .smp_prepare_cpus = r9a06g032_smp_prepare_cpus,
> + .smp_boot_secondary = r9a06g032_smp_boot_secondary,
> +};
> +CPU_METHOD_OF_DECLARE(r9a06g032_smp, "renesas,r9a06g032-smp", &r9a06g032_smp_ops);
>
