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 [thread overview]
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 other threads:[~2020-02-12 10:35 UTC|newest]
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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