* [v2] cpuidle: add riscv cpuidle driver
@ 2020-09-21 8:09 liush
2020-09-21 15:10 ` kernel test robot
0 siblings, 1 reply; 2+ messages in thread
From: liush @ 2020-09-21 8:09 UTC (permalink / raw)
To: paul.walmsley, palmer, aou, rjw, daniel.lezcano,
christian.brauner, keescook, amanieu, guoren
Cc: liush, linux-riscv, linux-kernel, linux-pm
This patch adds a simple cpuidle driver for RISC-V systems using
the WFI state. Other states will be supported in the future.
Signed-off-by: liush <liush@allwinnertech.com>
---
Changes in v2:
- call "mb()" before run "WFI" in cpu_do_idle
- modify commit description
- place "select CPU_IDLE" in alphabetical order
- replace "__asm__ __volatile__ ("wfi")" with "wait_for_interrupt()"
- delete "cpuidle.c",move "cpu_do_idle()" to cpuidle.h
- modify "arch_cpu_idle", "cpu_do_idle" can be called by
"arch_cpu_idle"
- fix space/tab issues
- modify riscv_low_level_suspend_enter to __weak mode
arch/riscv/Kconfig | 7 ++++++
arch/riscv/include/asm/cpuidle.h | 16 ++++++++++++
arch/riscv/kernel/process.c | 3 ++-
drivers/cpuidle/Kconfig | 5 ++++
drivers/cpuidle/Kconfig.riscv | 11 ++++++++
drivers/cpuidle/Makefile | 4 +++
drivers/cpuidle/cpuidle-riscv.c | 54 ++++++++++++++++++++++++++++++++++++++++
7 files changed, 99 insertions(+), 1 deletion(-)
create mode 100644 arch/riscv/include/asm/cpuidle.h
create mode 100644 drivers/cpuidle/Kconfig.riscv
create mode 100644 drivers/cpuidle/cpuidle-riscv.c
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index df18372..799bf86 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -33,6 +33,7 @@ config RISCV
select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
select CLONE_BACKWARDS
select COMMON_CLK
+ select CPU_IDLE
select EDAC_SUPPORT
select GENERIC_ARCH_TOPOLOGY if SMP
select GENERIC_ATOMIC64 if !64BIT
@@ -407,6 +408,12 @@ config BUILTIN_DTB
depends on RISCV_M_MODE
depends on OF
+menu "CPU Power Management"
+
+source "drivers/cpuidle/Kconfig"
+
+endmenu
+
menu "Power management options"
source "kernel/power/Kconfig"
diff --git a/arch/riscv/include/asm/cpuidle.h b/arch/riscv/include/asm/cpuidle.h
new file mode 100644
index 00000000..599b810
--- /dev/null
+++ b/arch/riscv/include/asm/cpuidle.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __RISCV_CPUIDLE_H
+#define __RISCV_CPUIDLE_H
+
+static inline void cpu_do_idle(void)
+{
+ /*
+ * Add mb() here to ensure that all
+ * IO/MEM access are completed prior
+ * to enter WFI.
+ */
+ mb();
+ wait_for_interrupt();
+}
+
+#endif
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 2b97c49..5431aaa 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -21,6 +21,7 @@
#include <asm/string.h>
#include <asm/switch_to.h>
#include <asm/thread_info.h>
+#include <asm/cpuidle.h>
register unsigned long gp_in_global __asm__("gp");
@@ -35,7 +36,7 @@ extern asmlinkage void ret_from_kernel_thread(void);
void arch_cpu_idle(void)
{
- wait_for_interrupt();
+ cpu_do_idle();
local_irq_enable();
}
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index c0aeedd..f6be0fd 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -62,6 +62,11 @@ depends on PPC
source "drivers/cpuidle/Kconfig.powerpc"
endmenu
+menu "RISCV CPU Idle Drivers"
+depends on RISCV
+source "drivers/cpuidle/Kconfig.riscv"
+endmenu
+
config HALTPOLL_CPUIDLE
tristate "Halt poll cpuidle driver"
depends on X86 && KVM_GUEST
diff --git a/drivers/cpuidle/Kconfig.riscv b/drivers/cpuidle/Kconfig.riscv
new file mode 100644
index 00000000..7bec059
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.riscv
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# RISCV CPU Idle drivers
+#
+config RISCV_CPUIDLE
+ bool "Generic RISCV CPU idle Driver"
+ select DT_IDLE_STATES
+ select CPU_IDLE_MULTIPLE_DRIVERS
+ help
+ Select this option to enable generic cpuidle driver for RISCV.
+ Now only support C0 State.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 26bbc5e..4c83c4e 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -34,3 +34,7 @@ obj-$(CONFIG_MIPS_CPS_CPUIDLE) += cpuidle-cps.o
# POWERPC drivers
obj-$(CONFIG_PSERIES_CPUIDLE) += cpuidle-pseries.o
obj-$(CONFIG_POWERNV_CPUIDLE) += cpuidle-powernv.o
+
+###############################################################################
+# RISCV drivers
+obj-$(CONFIG_RISCV_CPUIDLE) += cpuidle-riscv.o
diff --git a/drivers/cpuidle/cpuidle-riscv.c b/drivers/cpuidle/cpuidle-riscv.c
new file mode 100644
index 00000000..2ada1d5
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-riscv.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V CPU idle driver.
+ *
+ * Copyright (C) 2020-2022 Allwinner Ltd
+ *
+ * Based on code - driver/cpuidle/cpuidle-at91.c
+ *
+ */
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <asm/cpuidle.h>
+
+#define MAX_IDLE_STATES 1
+
+int __weak riscv_low_level_suspend_enter(int state)
+{
+ return 0;
+}
+
+/* Actual code that puts the SoC in different idle states */
+static int riscv_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv,
+ int index)
+{
+ return CPU_PM_CPU_IDLE_ENTER_PARAM(riscv_low_level_suspend_enter,
+ index, 0);
+}
+
+static struct cpuidle_driver riscv_idle_driver = {
+ .name = "riscv_idle",
+ .owner = THIS_MODULE,
+ .states[0] = {
+ .enter = riscv_enter_idle,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .name = "WFI",
+ .desc = "RISCV WFI",
+ },
+ .state_count = MAX_IDLE_STATES,
+};
+
+static int __init riscv_cpuidle_init(void)
+{
+ return cpuidle_register(&riscv_idle_driver, NULL);
+}
+
+device_initcall(riscv_cpuidle_init);
--
2.7.4
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [v2] cpuidle: add riscv cpuidle driver
2020-09-21 8:09 [v2] cpuidle: add riscv cpuidle driver liush
@ 2020-09-21 15:10 ` kernel test robot
0 siblings, 0 replies; 2+ messages in thread
From: kernel test robot @ 2020-09-21 15:10 UTC (permalink / raw)
To: liush, paul.walmsley, palmer, aou, rjw, daniel.lezcano,
christian.brauner, keescook, amanieu, guoren
Cc: linux-riscv, kbuild-all
[-- Attachment #1: Type: text/plain, Size: 1988 bytes --]
Hi liush,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on pm/linux-next]
[also build test WARNING on linus/master v5.9-rc6 next-20200921]
[cannot apply to daniel.lezcano/clockevents/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/liush/cpuidle-add-riscv-cpuidle-driver/20200921-161139
base: https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: riscv-allyesconfig (attached as .config)
compiler: riscv64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=riscv
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/cpuidle/cpuidle-riscv.c:22:12: warning: no previous prototype for 'riscv_low_level_suspend_enter' [-Wmissing-prototypes]
22 | int __weak riscv_low_level_suspend_enter(int state)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# https://github.com/0day-ci/linux/commit/30d1da9b67239e99038b0bad282b70454865be02
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review liush/cpuidle-add-riscv-cpuidle-driver/20200921-161139
git checkout 30d1da9b67239e99038b0bad282b70454865be02
vim +/riscv_low_level_suspend_enter +22 drivers/cpuidle/cpuidle-riscv.c
21
> 22 int __weak riscv_low_level_suspend_enter(int state)
23 {
24 return 0;
25 }
26
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
[-- Attachment #2: .config.gz --]
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http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 2+ messages in thread
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