Re: [PATCH 2/6] mips: Add N64 machine type

[Jiaxun Yang <jiaxun.yang@flygoat.com>]

在 2020/12/26 上午1:00, Lauri Kasanen 写道:
> Signed-off-by: Lauri Kasanen <cand@gmx.com>
> ---
>   arch/mips/Kbuild.platforms           |  1 +
>   arch/mips/Kconfig                    | 12 ++++++++
>   arch/mips/include/asm/mach-n64/irq.h |  9 ++++++
>   arch/mips/include/asm/n64/irq.h      | 26 ++++++++++++++++
>   arch/mips/n64/Makefile               |  6 ++++
>   arch/mips/n64/Platform               |  7 +++++
>   arch/mips/n64/init.c                 | 59 ++++++++++++++++++++++++++++++++++++
>   arch/mips/n64/irq.c                  | 34 +++++++++++++++++++++
>   8 files changed, 154 insertions(+)
>   create mode 100644 arch/mips/include/asm/mach-n64/irq.h
>   create mode 100644 arch/mips/include/asm/n64/irq.h
>   create mode 100644 arch/mips/n64/Makefile
>   create mode 100644 arch/mips/n64/Platform
>   create mode 100644 arch/mips/n64/init.c
>   create mode 100644 arch/mips/n64/irq.c
>
> diff --git a/arch/mips/Kbuild.platforms b/arch/mips/Kbuild.platforms
> index 5483e38..3e39590 100644
> --- a/arch/mips/Kbuild.platforms
> +++ b/arch/mips/Kbuild.platforms
> @@ -18,6 +18,7 @@ platform-$(CONFIG_MACH_LOONGSON2EF)	+= loongson2ef/
>   platform-$(CONFIG_MACH_LOONGSON32)	+= loongson32/
>   platform-$(CONFIG_MACH_LOONGSON64)	+= loongson64/
>   platform-$(CONFIG_MIPS_MALTA)		+= mti-malta/
> +platform-$(CONFIG_MIPS_N64)		+= n64/
>   platform-$(CONFIG_NLM_COMMON)		+= netlogic/
>   platform-$(CONFIG_PIC32MZDA)		+= pic32/
>   platform-$(CONFIG_MACH_PISTACHIO)	+= pistachio/
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index 4b52588..2922bb6 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -605,6 +605,18 @@ config MACH_VR41XX
>   	select SYS_SUPPORTS_MIPS16
>   	select GPIOLIB
>
> +config MIPS_N64

Hi Lauri,

Thanks for your patch!

I'd prefer name it with MACH_NINTENDO64 or something,
N64 is also MIPS 64bit ABI, it sounds confusing.

> +	bool "Nintendo 64 console"
> +	select CEVT_R4K
> +	select CSRC_R4K
> +	select SYS_HAS_CPU_R4300
> +	select SYS_SUPPORTS_BIG_ENDIAN
> +	select SYS_SUPPORTS_ZBOOT
> +	select SYS_SUPPORTS_32BIT_KERNEL
> +	select SYS_SUPPORTS_64BIT_KERNEL
> +	select DMA_NONCOHERENT
> +	select IRQ_MIPS_CPU
> +
>   config RALINK
>   	bool "Ralink based machines"
>   	select CEVT_R4K
> diff --git a/arch/mips/include/asm/mach-n64/irq.h b/arch/mips/include/asm/mach-n64/irq.h
> new file mode 100644
> index 0000000..4d4a1ea
> --- /dev/null
> +++ b/arch/mips/include/asm/mach-n64/irq.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __ASM_MACH_N64_IRQ_H
> +#define __ASM_MACH_N64_IRQ_H
> +
> +#include <asm/n64/irq.h> /* for MIPS_CPU_IRQ_BASE */
> +
> +#include <asm/mach-generic/irq.h>
> +
> +#endif /* __ASM_MACH_N64_IRQ_H */
> diff --git a/arch/mips/include/asm/n64/irq.h b/arch/mips/include/asm/n64/irq.h
> new file mode 100644
> index 0000000..00f89ca
> --- /dev/null
> +++ b/arch/mips/include/asm/n64/irq.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Interrupt numbers for N64
> + *
> + * Copyright (C) 2020 Lauri Kasanen
> + */
> +#ifndef __N64_IRQ_H
> +#define __N64_IRQ_H
> +
> +#define NR_IRQS 8
> +
> +/*
> + * CPU core Interrupt Numbers
> + */
> +#define MIPS_CPU_IRQ_BASE	0
> +#define MIPS_CPU_IRQ(x)		(MIPS_CPU_IRQ_BASE + (x))
> +#define MIPS_SOFTINT0_IRQ	MIPS_CPU_IRQ(0)
> +#define MIPS_SOFTINT1_IRQ	MIPS_CPU_IRQ(1)
> +#define RCP_IRQ			MIPS_CPU_IRQ(2)
> +#define CART_IRQ		MIPS_CPU_IRQ(3)
> +#define PRENMI_IRQ		MIPS_CPU_IRQ(4)
> +#define RDBR_IRQ		MIPS_CPU_IRQ(5)
> +#define RDBW_IRQ		MIPS_CPU_IRQ(6)
> +#define TIMER_IRQ		MIPS_CPU_IRQ(7)
> +
> +#endif /* __N64_IRQ_H */
> diff --git a/arch/mips/n64/Makefile b/arch/mips/n64/Makefile
> new file mode 100644
> index 0000000..b64a05a
> --- /dev/null
> +++ b/arch/mips/n64/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Nintendo 64
> +#
> +
> +obj-y := init.o irq.o
> diff --git a/arch/mips/n64/Platform b/arch/mips/n64/Platform
> new file mode 100644
> index 0000000..bf5edba
> --- /dev/null
> +++ b/arch/mips/n64/Platform
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Nintendo 64
> +#
> +
> +cflags-$(CONFIG_MIPS_N64)    += -I$(srctree)/arch/mips/include/asm/mach-n64
> +load-$(CONFIG_MIPS_N64)      += 0xffffffff80101000
> diff --git a/arch/mips/n64/init.c b/arch/mips/n64/init.c
> new file mode 100644
> index 0000000..6fb622d
> --- /dev/null
> +++ b/arch/mips/n64/init.c
> @@ -0,0 +1,59 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + *  Nintendo 64 init.
> + *
> + *  Copyright (C) 2020	Lauri Kasanen
> + */
> +#include <linux/init.h>
> +#include <linux/ioport.h>
> +#include <linux/irq.h>
> +#include <linux/memblock.h>
> +#include <linux/string.h>
> +
> +#include <asm/bootinfo.h>
> +#include <asm/time.h>
> +
> +#define IO_MEM_RESOURCE_START	0UL
> +#define IO_MEM_RESOURCE_END	0x1fffffffUL
> +
> +static void __init iomem_resource_init(void)
> +{
> +	iomem_resource.start = IO_MEM_RESOURCE_START;
> +	iomem_resource.end = IO_MEM_RESOURCE_END;
> +}
> +
> +const char *get_system_type(void)
> +{
> +	return "Nintendo 64";
> +}
> +
> +void __init prom_init(void)
> +{
> +	int argc, i;
> +	const char **argv;
> +
> +	argc = fw_arg0;
> +	argv = (const char **)fw_arg1;
> +
> +	for (i = 1; i < argc; i++) {
> +		strlcat(arcs_cmdline, argv[i], COMMAND_LINE_SIZE);
> +		if (i < (argc - 1))
> +			strlcat(arcs_cmdline, " ", COMMAND_LINE_SIZE);
> +	}
> +}

Please use: fw_init_cmdline.

> +
> +void __init prom_free_prom_memory(void)
> +{
> +}
> +
> +void __init plat_mem_setup(void)
> +{
> +	iomem_resource_init();
> +	memblock_add(0x0, 8 * 1024 * 1024); // Bootloader blocks the 4mb config
> +}
> +
> +void __init plat_time_init(void)
> +{
> +	// 93.75 MHz cpu, count register runs at half rate
> +	mips_hpt_frequency = 93750000 / 2;
> +}
> diff --git a/arch/mips/n64/irq.c b/arch/mips/n64/irq.c
> new file mode 100644
> index 0000000..3eb0079
> --- /dev/null
> +++ b/arch/mips/n64/irq.c
> @@ -0,0 +1,34 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + *  N64 IRQ
> + *
> + *  Copyright (C) 2020 Lauri Kasanen
> + */
> +#include <linux/export.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +
> +#include <asm/irq_cpu.h>
> +
> +asmlinkage void plat_irq_dispatch(void)
> +{
> +	unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM;
> +
> +	if (pending & CAUSEF_IP7)
> +		do_IRQ(TIMER_IRQ);
> +	else if (pending & CAUSEF_IP4)
> +		do_IRQ(PRENMI_IRQ);
> +	else if (pending & CAUSEF_IP2)
> +		do_IRQ(RCP_IRQ);
> +	else if (pending & CAUSEF_IP0)
> +		do_IRQ(MIPS_SOFTINT0_IRQ);
> +	else if (pending & CAUSEF_IP1)
> +		do_IRQ(MIPS_SOFTINT1_IRQ);
> +	else
> +		spurious_interrupt();
> +}

Actually we have plat_irq_dispatch at irq-mips-cpu.c.
Any special reason to override it?

Thanks.

- Jiaxun

> +
> +void __init arch_init_irq(void)
> +{
> +	mips_cpu_irq_init();
> +}
> --
> 2.6.2
>