From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@ozlabs.org, Paul Mackerras <paulus@ozlabs.org>
Subject: Re: [PATCH v2 1/9] powerpc: Add Microwatt platform
Date: Sat, 19 Jun 2021 13:03:32 +1000 [thread overview]
Message-ID: <1624071540.0w83jhkdb0.astroid@bobo.none> (raw)
In-Reply-To: <YMwWbZVREsVug9R0@thinks.paulus.ozlabs.org>
Excerpts from Paul Mackerras's message of June 18, 2021 1:43 pm:
> Microwatt is a FPGA-based implementation of the Power ISA. It
> currently only implements little-endian 64-bit mode, and does
> not (yet) support SMP, VMX, VSX or transactional memory. It has an
> optional FPU, and an optional MMU (required for running Linux,
> obviously) which implements a configurable radix tree but not
> hypervisor mode or nested radix translation.
>
> This adds a new machine type to support FPGA-based SoCs with a
> Microwatt core. CONFIG_MATH_EMULATION can be selected for Microwatt
> SOCs which don't have the FPU.
The only thing I can think of is you may want to select PPC_RADIX and
other possible things that are required, but that's not a big deal at
the moment. I have a few kernel size reduction config patches (like
CONFIG_PPC_HASH) I might be able to upstream now for Microwatt, so I
could do a bit of a pass over the Kconfig stuff at that point.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
>
> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
> ---
> arch/powerpc/Kconfig | 2 +-
> arch/powerpc/platforms/Kconfig | 1 +
> arch/powerpc/platforms/Makefile | 1 +
> arch/powerpc/platforms/microwatt/Kconfig | 9 +++++++++
> arch/powerpc/platforms/microwatt/Makefile | 1 +
> arch/powerpc/platforms/microwatt/setup.c | 23 +++++++++++++++++++++++
> 6 files changed, 36 insertions(+), 1 deletion(-)
> create mode 100644 arch/powerpc/platforms/microwatt/Kconfig
> create mode 100644 arch/powerpc/platforms/microwatt/Makefile
> create mode 100644 arch/powerpc/platforms/microwatt/setup.c
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 386ae12d8523..5ce51c38a346 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -422,7 +422,7 @@ config HUGETLB_PAGE_SIZE_VARIABLE
>
> config MATH_EMULATION
> bool "Math emulation"
> - depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
> + depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE || PPC_MICROWATT
> select PPC_FPU_REGS
> help
> Some PowerPC chips designed for embedded applications do not have
> diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
> index 7a5e8f4541e3..74be4d06afbf 100644
> --- a/arch/powerpc/platforms/Kconfig
> +++ b/arch/powerpc/platforms/Kconfig
> @@ -20,6 +20,7 @@ source "arch/powerpc/platforms/embedded6xx/Kconfig"
> source "arch/powerpc/platforms/44x/Kconfig"
> source "arch/powerpc/platforms/40x/Kconfig"
> source "arch/powerpc/platforms/amigaone/Kconfig"
> +source "arch/powerpc/platforms/microwatt/Kconfig"
>
> config KVM_GUEST
> bool "KVM Guest support"
> diff --git a/arch/powerpc/platforms/Makefile b/arch/powerpc/platforms/Makefile
> index 143d4417f6cc..edcb54cdb1a8 100644
> --- a/arch/powerpc/platforms/Makefile
> +++ b/arch/powerpc/platforms/Makefile
> @@ -22,3 +22,4 @@ obj-$(CONFIG_PPC_CELL) += cell/
> obj-$(CONFIG_PPC_PS3) += ps3/
> obj-$(CONFIG_EMBEDDED6xx) += embedded6xx/
> obj-$(CONFIG_AMIGAONE) += amigaone/
> +obj-$(CONFIG_PPC_MICROWATT) += microwatt/
> diff --git a/arch/powerpc/platforms/microwatt/Kconfig b/arch/powerpc/platforms/microwatt/Kconfig
> new file mode 100644
> index 000000000000..3be01e78ce57
> --- /dev/null
> +++ b/arch/powerpc/platforms/microwatt/Kconfig
> @@ -0,0 +1,9 @@
> +# SPDX-License-Identifier: GPL-2.0
> +config PPC_MICROWATT
> + depends on PPC_BOOK3S_64 && !SMP
> + bool "Microwatt SoC platform"
> + select PPC_XICS
> + select PPC_NATIVE
> + help
> + This option enables support for FPGA-based Microwatt implementations.
> +
> diff --git a/arch/powerpc/platforms/microwatt/Makefile b/arch/powerpc/platforms/microwatt/Makefile
> new file mode 100644
> index 000000000000..e6885b3b2ee7
> --- /dev/null
> +++ b/arch/powerpc/platforms/microwatt/Makefile
> @@ -0,0 +1 @@
> +obj-y += setup.o
> diff --git a/arch/powerpc/platforms/microwatt/setup.c b/arch/powerpc/platforms/microwatt/setup.c
> new file mode 100644
> index 000000000000..d80d52612672
> --- /dev/null
> +++ b/arch/powerpc/platforms/microwatt/setup.c
> @@ -0,0 +1,23 @@
> +/*
> + * Microwatt FPGA-based SoC platform setup code.
> + *
> + * Copyright 2020 Paul Mackerras (paulus@ozlabs.org), IBM Corp.
> + */
> +
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/stddef.h>
> +#include <linux/init.h>
> +#include <asm/machdep.h>
> +#include <asm/time.h>
> +
> +static int __init microwatt_probe(void)
> +{
> + return of_machine_is_compatible("microwatt-soc");
> +}
> +
> +define_machine(microwatt) {
> + .name = "microwatt",
> + .probe = microwatt_probe,
> + .calibrate_decr = generic_calibrate_decr,
> +};
> --
> 2.31.1
>
>
next prev parent reply other threads:[~2021-06-19 3:04 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-18 3:42 [PATCH v2 0/9] powerpc: Add support for Microwatt soft-core Paul Mackerras
2021-06-18 3:43 ` [PATCH v2 1/9] powerpc: Add Microwatt platform Paul Mackerras
2021-06-19 3:03 ` Nicholas Piggin [this message]
2021-06-18 3:44 ` [PATCH v2 2/9] powerpc: Add Microwatt device tree Paul Mackerras
2021-06-19 14:26 ` Segher Boessenkool
2021-06-20 12:08 ` Paul Mackerras
2021-06-21 13:54 ` Segher Boessenkool
2021-06-18 3:45 ` [PATCH v2 3/9] powerpc/microwatt: Populate platform bus from device-tree Paul Mackerras
2021-06-18 3:45 ` [PATCH v2 4/9] powerpc/xics: Add a native ICS backend for microwatt Paul Mackerras
2021-06-18 3:46 ` [PATCH v2 5/9] powerpc/microwatt: Use standard 16550 UART for console Paul Mackerras
2021-06-18 7:40 ` Nicholas Piggin
2021-06-18 12:12 ` Paul Mackerras
2021-06-19 2:58 ` Nicholas Piggin
2021-08-12 13:14 ` Christophe Leroy
2021-08-12 16:09 ` Segher Boessenkool
2021-06-18 3:47 ` [PATCH v2 6/9] powerpc/microwatt: Add support for hardware random number generator Paul Mackerras
2021-06-19 3:08 ` Nicholas Piggin
2021-06-19 14:36 ` Segher Boessenkool
2021-06-20 8:19 ` Nicholas Piggin
2021-06-18 3:48 ` [PATCH v2 7/9] powerpc/microwatt: Add microwatt_defconfig Paul Mackerras
2021-06-18 3:49 ` [PATCH v2 8/9] powerpc/boot: Fixup device-tree on little endian Paul Mackerras
2021-06-19 3:14 ` Nicholas Piggin
2021-06-18 3:49 ` [PATCH v2 9/9] powerpc/boot: Add a boot wrapper for Microwatt Paul Mackerras
2021-06-19 3:16 ` Nicholas Piggin
2021-06-19 14:45 ` [PATCH v2 0/9] powerpc: Add support for Microwatt soft-core Segher Boessenkool
2021-06-24 14:03 ` Michael Ellerman
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