From: Damien Le Moal <damien.lemoal@wdc.com> To: linux-riscv@lists.infradead.org, Palmer Dabbelt <palmer@dabbelt.com> Cc: Anup Patel <Anup.Patel@wdc.com>, Paul Walmsley <paul.walmsley@sifive.com> Subject: [PATCH 05/10] riscv: Add SOC early init support Date: Wed, 12 Feb 2020 19:34:27 +0900 Message-ID: <20200212103432.660256-6-damien.lemoal@wdc.com> (raw) In-Reply-To: <20200212103432.660256-1-damien.lemoal@wdc.com> Add a mechanism for early SoC initialization for platforms that need additional hardware initialization not possible through the regular device tree and drivers mechanism. With this, a SoC specific initialization function can be called very early, before DTB parsing is done by parse_dtb() in Linux RISC-V kernel setup code. This can be very useful for early hardware initialization for No-MMU kernels booted directly in M-mode because it is quite likely that no other booting stage exist prior to the No-MMU kernel. Example use of a SoC early initialization is as follows: static void vendor_abc_early_init(const void *fdt) { /* * some early init code here that can use simple matches * against the flat device tree file. */ } SOC_EARLY_INIT_DECLARE("vendor,abc", abc_early_init); This early initialization function is executed only if the flat device tree for the board has a 'compatible = "vendor,abc"' entry; Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> --- arch/riscv/include/asm/soc.h | 23 +++++++++++++++++++++++ arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/head.S | 1 + arch/riscv/kernel/soc.c | 28 ++++++++++++++++++++++++++++ arch/riscv/kernel/vmlinux.lds.S | 6 ++++++ 5 files changed, 59 insertions(+) create mode 100644 arch/riscv/include/asm/soc.h create mode 100644 arch/riscv/kernel/soc.c diff --git a/arch/riscv/include/asm/soc.h b/arch/riscv/include/asm/soc.h new file mode 100644 index 000000000000..9b8c332cbe76 --- /dev/null +++ b/arch/riscv/include/asm/soc.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + */ + +#ifndef _ASM_RISCV_SOC_H +#define _ASM_RISCV_SOC_H + +#include <linux/of.h> +#include <linux/linkage.h> +#include <linux/types.h> + +#define SOC_EARLY_INIT_DECLARE(compat, fn) \ + static const struct of_device_id __soc_early_init \ + __used __section(__soc_early_init_table) \ + = { .compatible = compat, .data = fn } + +void soc_early_init(void); + +extern unsigned long __soc_early_init_table_start; +extern unsigned long __soc_early_init_table_end; + +#endif diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 97d0c35f8b37..e4a22999dbc6 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -10,6 +10,7 @@ endif extra-y += head.o extra-y += vmlinux.lds +obj-y += soc.o obj-y += cpu.o obj-y += cpufeature.o obj-y += entry.o diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 271860fc2c3f..a7768d6165d4 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -125,6 +125,7 @@ clear_bss_done: call kasan_early_init #endif /* Start the kernel */ + call soc_early_init call parse_dtb tail start_kernel diff --git a/arch/riscv/kernel/soc.c b/arch/riscv/kernel/soc.c new file mode 100644 index 000000000000..0b3b3dc9ad0f --- /dev/null +++ b/arch/riscv/kernel/soc.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + */ +#include <linux/init.h> +#include <linux/libfdt.h> +#include <asm/pgtable.h> +#include <asm/soc.h> + +/* + * This is called extremly early, before parse_dtb(), to allow initializing + * SoC hardware before memory or any device driver initialization. + */ +void __init soc_early_init(void) +{ + void (*early_fn)(const void *fdt); + const struct of_device_id *s; + const void *fdt = dtb_early_va; + + for (s = (void *)&__soc_early_init_table_start; + (void *)s < (void *)&__soc_early_init_table_end; s++) { + if (!fdt_node_check_compatible(fdt, 0, s->compatible)) { + early_fn = s->data; + early_fn(fdt); + return; + } + } +} diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S index 1e0193ded420..32b160942f40 100644 --- a/arch/riscv/kernel/vmlinux.lds.S +++ b/arch/riscv/kernel/vmlinux.lds.S @@ -24,6 +24,12 @@ SECTIONS HEAD_TEXT_SECTION INIT_TEXT_SECTION(PAGE_SIZE) INIT_DATA_SECTION(16) + . = ALIGN(8); + __soc_early_init_table : { + __soc_early_init_table_start = .; + KEEP(*(__soc_early_init_table)) + __soc_early_init_table_end = .; + } /* we have to discard exit text and such at runtime, not link time */ .exit.text : { -- 2.24.1
next prev parent reply index Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-12 10:34 [PATCH 00/10] Kendryte k210 SoC boards support Damien Le Moal 2020-02-12 10:34 ` [PATCH 01/10] riscv: Fix gitignore Damien Le Moal 2020-02-20 0:15 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 02/10] riscv: Force flat memory model with no-mmu Damien Le Moal 2020-02-14 20:18 ` Sean Anderson 2020-02-15 2:15 ` Damien Le Moal 2020-02-15 2:26 ` Sean Anderson 2020-02-15 2:40 ` Damien Le Moal 2020-03-02 3:48 ` Anup Patel 2020-03-04 18:38 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 03/10] riscv: Unaligned load/store handling for M_MODE Damien Le Moal 2020-03-02 3:57 ` Anup Patel 2020-03-04 19:28 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 04/10] riscv: Add BUILTIN_DTB support Damien Le Moal 2020-03-02 3:58 ` Anup Patel 2020-03-04 19:28 ` Palmer Dabbelt 2020-03-05 4:58 ` Anup Patel 2020-03-05 5:14 ` Damien Le Moal 2020-03-05 5:37 ` Anup Patel 2020-03-05 6:13 ` Damien Le Moal 2020-03-08 6:10 ` Anup Patel 2020-03-05 8:18 ` Atish Patra 2020-03-07 0:02 ` Sean Anderson 2020-03-07 1:51 ` Atish Patra 2020-03-07 2:08 ` Sean Anderson 2020-03-06 23:56 ` Sean Anderson 2020-02-12 10:34 ` Damien Le Moal [this message] 2020-03-04 19:28 ` [PATCH 05/10] riscv: Add SOC early init support Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 06/10] riscv: Add Kendryte K210 SoC support Damien Le Moal 2020-02-14 20:31 ` Sean Anderson 2020-03-04 19:38 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 07/10] riscv: Select required drivers for Kendryte SOC Damien Le Moal 2020-03-02 3:59 ` Anup Patel 2020-03-04 19:44 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 08/10] riscv: Add Kendryte K210 device tree Damien Le Moal 2020-02-14 20:51 ` Sean Anderson 2020-02-15 2:34 ` Damien Le Moal 2020-02-15 2:48 ` Sean Anderson 2020-02-15 3:00 ` Damien Le Moal 2020-02-18 14:12 ` Carlos Eduardo de Paula 2020-02-18 14:18 ` Sean Anderson 2020-02-18 14:30 ` Carlos Eduardo de Paula 2020-02-18 17:48 ` Sean Anderson 2020-02-18 19:26 ` Carlos Eduardo de Paula 2020-02-19 9:06 ` Wladimir J. van der Laan 2020-02-19 22:28 ` Sean Anderson 2020-02-20 10:48 ` Wladimir J. van der Laan 2020-02-22 19:07 ` Wladimir J. van der Laan 2020-04-01 17:55 ` Drew Fustini 2020-04-02 2:24 ` Damien Le Moal 2020-02-19 8:50 ` Wladimir J. van der Laan 2020-02-27 19:43 ` Sean Anderson 2020-03-02 4:06 ` Anup Patel 2020-03-02 4:15 ` Damien Le Moal 2020-03-02 4:22 ` Anup Patel 2020-03-02 4:51 ` Damien Le Moal 2020-03-02 5:05 ` Anup Patel 2020-03-02 5:08 ` Damien Le Moal 2020-03-07 0:18 ` Sean Anderson 2020-03-07 4:11 ` Anup Patel 2020-03-04 19:44 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 09/10] riscv: Kendryte K210 default config Damien Le Moal 2020-03-02 4:07 ` Anup Patel 2020-03-04 19:44 ` Palmer Dabbelt 2020-02-12 10:34 ` [PATCH 10/10] riscv: create a loader.bin for the kendryte kflash.py tool Damien Le Moal 2020-03-02 4:08 ` Anup Patel 2020-03-04 19:44 ` Palmer Dabbelt 2020-02-14 15:05 ` [PATCH 00/10] Kendryte k210 SoC boards support Carlos Eduardo de Paula 2020-02-15 2:02 ` Damien Le Moal 2020-02-17 13:28 ` Carlos Eduardo de Paula 2020-02-26 21:31 ` Carlos Eduardo de Paula 2020-02-27 2:18 ` Damien Le Moal 2020-02-28 20:32 ` Sean Anderson 2020-03-02 3:01 ` Damien Le Moal 2020-03-02 3:53 ` Sean Anderson 2020-03-02 4:11 ` Damien Le Moal 2020-03-02 4:18 ` Sean Anderson 2020-03-02 4:54 ` Damien Le Moal 2020-03-02 4:56 ` Sean Anderson 2020-03-02 5:03 ` Damien Le Moal 2020-03-02 4:17 ` Anup Patel 2020-03-02 4:21 ` Sean Anderson 2020-03-02 4:48 ` Damien Le Moal 2020-03-02 4:51 ` Damien Le Moal 2020-03-02 5:02 ` Sean Anderson 2020-03-02 5:11 ` Damien Le Moal 2020-03-02 5:25 ` Sean Anderson 2020-03-02 5:43 ` Damien Le Moal 2020-03-04 19:44 ` Palmer Dabbelt
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