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From: Christoph Hellwig <hch@lst.de>
To: Palmer Dabbelt <palmer@sifive.com>,
	Paul Walmsley <paul.walmsley@sifive.com>
Cc: Atish Patra <atish.patra@wdc.com>,
	Damien Le Moal <damien.lemoal@wdc.com>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 06/15] riscv: cleanup the default power off implementation
Date: Thu, 17 Oct 2019 19:37:34 +0200
Message-ID: <20191017173743.5430-7-hch@lst.de> (raw)
In-Reply-To: <20191017173743.5430-1-hch@lst.de>

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: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/kernel/Makefile |  1 +
 arch/riscv/kernel/reset.c  |  5 ++---
 arch/riscv/kernel/sbi.c    | 17 +++++++++++++++++
 3 files changed, 20 insertions(+), 3 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 d0fe623bfb8f..5e4e69859af1 100644
--- a/arch/riscv/kernel/reset.c
+++ b/arch/riscv/kernel/reset.c
@@ -4,12 +4,11 @@
  */
 
 #include <linux/reboot.h>
-#include <asm/sbi.h>
 
 static void default_power_off(void)
 {
-	sbi_shutdown();
-	while (1);
+	while (1)
+		wait_for_interrupt();
 }
 
 void (*pm_power_off)(void) = default_power_off;
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);
-- 
2.20.1


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  parent reply index

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-17 17:37 RISC-V nommu support v5 Christoph Hellwig
2019-10-17 17:37 ` [PATCH 01/15] riscv: cleanup <asm/bug.h> Christoph Hellwig
2019-10-18  2:50   ` Anup Patel
2019-10-23 22:04   ` Paul Walmsley
2019-10-17 17:37 ` [PATCH 02/15] riscv: cleanup do_trap_break Christoph Hellwig
2019-10-18  2:51   ` Anup Patel
2019-10-23 22:05   ` Paul Walmsley
2019-10-17 17:37 ` [PATCH 03/15] riscv: abstract out CSR names for supervisor vs machine mode Christoph Hellwig
2019-10-18  2:51   ` Anup Patel
2019-10-18 23:55   ` Paul Walmsley
2019-10-28  8:12     ` Christoph Hellwig
2019-10-17 17:37 ` [PATCH 04/15] riscv: don't allow selecting SBI based drivers for M-mode Christoph Hellwig
2019-10-18  2:52   ` Anup Patel
2019-10-17 17:37 ` [PATCH 05/15] riscv: poison SBI calls " Christoph Hellwig
2019-10-18  2:53   ` Anup Patel
2019-10-17 17:37 ` Christoph Hellwig [this message]
2019-10-18  2:53   ` [PATCH 06/15] riscv: cleanup the default power off implementation Anup Patel
2019-10-17 17:37 ` [PATCH 07/15] riscv: implement remote sfence.i using IPIs Christoph Hellwig
2019-10-18  2:55   ` Anup Patel
2019-10-17 17:37 ` [PATCH 08/15] riscv: add support for MMIO access to the timer registers Christoph Hellwig
2019-10-18  2:57   ` Anup Patel
2019-10-17 17:37 ` [PATCH 09/15] riscv: provide native clint access for M-mode Christoph Hellwig
2019-10-18  3:00   ` Anup Patel
2019-11-14  7:39   ` Paul Walmsley
2019-10-17 17:37 ` [PATCH 10/15] riscv: read the hart ID from mhartid on boot Christoph Hellwig
2019-10-18  3:01   ` Anup Patel
2019-11-14  7:40   ` Paul Walmsley
2019-10-17 17:37 ` [PATCH 11/15] riscv: use the correct interrupt levels for M-mode Christoph Hellwig
2019-10-18  3:01   ` Anup Patel
2019-10-17 17:37 ` [PATCH 12/15] riscv: clear the instruction cache and all registers when booting Christoph Hellwig
2019-10-18  3:05   ` Anup Patel
2019-10-17 17:37 ` [PATCH 13/15] riscv: add nommu support Christoph Hellwig
2019-10-18  3:04   ` Anup Patel
2019-10-17 17:37 ` [PATCH 14/15] riscv: provide a flat image loader Christoph Hellwig
2019-10-18  3:06   ` Anup Patel
2019-10-17 17:37 ` [PATCH 15/15] riscv: disable the EFI PECOFF header for M-mode Christoph Hellwig
2019-10-18  3:06   ` Anup Patel
2019-10-18  3:08 ` RISC-V nommu support v5 Anup Patel
2019-10-18  3:29   ` Paul Walmsley
2019-10-18 15:25     ` Christoph Hellwig
2019-10-18 23:46       ` Paul Walmsley

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