Re: [PATCH 04/12] riscv: cleanup the default power off implementation

Paul Walmsley
2019-10-31T23:56:36Z

On Mon, 28 Oct 2019, Christoph Hellwig wrote:

> Move the sbi poweroff to a separate function and file that is only
> compiled if CONFIG_SBI is set. Provide a new default fallback
> power off that just sits in a wfi loop to save some power.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Reviewed-by: Atish Patra <atish.patra@wdc.com>

And here's the other part of this patch, queued for v5.5-rc1.

- Paul

From: Christoph Hellwig <hch@lst.de>
Date: Mon, 28 Oct 2019 13:10:35 +0100
Subject: [PATCH] riscv: cleanup the default power off implementation

Move the sbi poweroff to a separate function and file that is only
compiled if CONFIG_SBI is set.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
[paul.walmsley@sifive.com: split the WFI fix into a separate patch]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
---
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/reset.c | 2 --
arch/riscv/kernel/sbi.c | 17 +++++++++++++++++
3 files changed, 18 insertions(+), 2 deletions(-)
create mode 100644 arch/riscv/kernel/sbi.c

diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 696020ff72db..d8c35fa93cc6 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -41,5 +41,6 @@ obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_PERF_EVENTS) += perf_callchain.o
obj-$(CONFIG_HAVE_PERF_REGS) += perf_regs.o
+obj-$(CONFIG_RISCV_SBI) += sbi.o

clean:
diff --git a/arch/riscv/kernel/reset.c b/arch/riscv/kernel/reset.c
index 485be426d9b1..ee5878d968cc 100644
--- a/arch/riscv/kernel/reset.c
+++ b/arch/riscv/kernel/reset.c
@@ -5,11 +5,9 @@

#include <linux/reboot.h>
#include <linux/pm.h>
-#include <asm/sbi.h>

static void default_power_off(void)
{
- sbi_shutdown();
while (1)
wait_for_interrupt();
}
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
new file mode 100644
index 000000000000..f6c7c3e82d28
--- /dev/null
+++ b/arch/riscv/kernel/sbi.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <asm/sbi.h>
+
+static void sbi_power_off(void)
+{
+ sbi_shutdown();
+}
+
+static int __init sbi_init(void)
+{
+ pm_power_off = sbi_power_off;
+ return 0;
+}
+early_initcall(sbi_init);
--
2.24.0.rc0