Re: [PATCH] cpuidle: add riscv cpuidle driver
On Sun, 13 Sep 2020 18:52:03 PDT (-0700), li...@allwinnertech.com wrote:
This patch adds a cpuidle driver for systems based RISCV architecture.
This patch supports state WFI. Other states will be supported in the
future.
Signed-off-by: liush
---
arch/riscv/Kconfig | 7 +
arch/riscv/include/asm/cpuidle.h | 7 +
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/cpuidle.c | 8 ++
drivers/cpuidle/Kconfig | 5
drivers/cpuidle/Kconfig.riscv| 11
drivers/cpuidle/Makefile | 4 +++
drivers/cpuidle/cpuidle-riscv.c | 55
8 files changed, 98 insertions(+)
create mode 100644 arch/riscv/include/asm/cpuidle.h
create mode 100644 arch/riscv/kernel/cpuidle.c
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..c7ddb9d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -86,6 +86,7 @@ config RISCV
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
+ select CPU_IDLE
config ARCH_MMAP_RND_BITS_MIN
default 18 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 ..2599d2f
--- /dev/null
+++ b/arch/riscv/include/asm/cpuidle.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __RISCV_CPUIDLE_H
+#define __RISCV_CPUIDLE_H
+
+extern void cpu_do_idle(void);
+
+#endif
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index dc93710..396ba9c 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -29,6 +29,7 @@ obj-y += riscv_ksyms.o
obj-y += stacktrace.o
obj-y += cacheinfo.o
obj-y += patch.o
+obj-y += cpuidle.o
Presumably we want this to be a Kconfig option, if only to avoid excess size on
the smaller systems?
obj-$(CONFIG_MMU) += vdso.o vdso/
obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
diff --git a/arch/riscv/kernel/cpuidle.c b/arch/riscv/kernel/cpuidle.c
new file mode 100644
index ..a3289e7
--- /dev/null
+++ b/arch/riscv/kernel/cpuidle.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+#include
+
+void cpu_do_idle(void)
+{
+ __asm__ __volatile__ ("wfi");
+
We have wait_for_interrupt() that does this already, but it's one line so it
doesn't really matter. Either way, there's an extra newline here.
Additionally, we have arch_cpu_idle() which is calling cpu_do_idle() on other
platforms. Presumably we should be doing something similar, under the
assumption that we will eventually have cpu_do_idle() hook into CPU idle
drivers here?
+}
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 ..e86d36b
--- /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
Looks like there's some space/tab issues here. IIRC checkpatch will catch this
sort of thing.
+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 ..5dddcfa
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-riscv.c
@@ -0,0 +1,55 @@
+// 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
+#include
+#include
+#include
Re: [PATCH] cpuidle: add riscv cpuidle driver
On Mon, Sep 14, 2020 at 7:22 AM liush wrote:
>
> This patch adds a cpuidle driver for systems based RISCV architecture.
> This patch supports state WFI. Other states will be supported in the
> future.
First of all thanks for taking up the CPUIDLE efforts for RISC-V.
The commit description can be bit simplified as follows:
"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
> ---
> arch/riscv/Kconfig | 7 +
> arch/riscv/include/asm/cpuidle.h | 7 +
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/kernel/cpuidle.c | 8 ++
> drivers/cpuidle/Kconfig | 5
> drivers/cpuidle/Kconfig.riscv| 11
> drivers/cpuidle/Makefile | 4 +++
> drivers/cpuidle/cpuidle-riscv.c | 55
>
> 8 files changed, 98 insertions(+)
> create mode 100644 arch/riscv/include/asm/cpuidle.h
> create mode 100644 arch/riscv/kernel/cpuidle.c
> 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..c7ddb9d 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -86,6 +86,7 @@ config RISCV
> select SPARSE_IRQ
> select SYSCTL_EXCEPTION_TRACE
> select THREAD_INFO_IN_TASK
> + select CPU_IDLE
Place "select CPU_IDLE" in alphabetical order under
"config RISCV".
>
> config ARCH_MMAP_RND_BITS_MIN
> default 18 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 ..2599d2f
> --- /dev/null
> +++ b/arch/riscv/include/asm/cpuidle.h
> @@ -0,0 +1,7 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __RISCV_CPUIDLE_H
> +#define __RISCV_CPUIDLE_H
> +
> +extern void cpu_do_idle(void);
> +
> +#endif
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index dc93710..396ba9c 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -29,6 +29,7 @@ obj-y += riscv_ksyms.o
> obj-y += stacktrace.o
> obj-y += cacheinfo.o
> obj-y += patch.o
> +obj-y += cpuidle.o
> obj-$(CONFIG_MMU) += vdso.o vdso/
>
> obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
> diff --git a/arch/riscv/kernel/cpuidle.c b/arch/riscv/kernel/cpuidle.c
> new file mode 100644
> index ..a3289e7
> --- /dev/null
> +++ b/arch/riscv/kernel/cpuidle.c
> @@ -0,0 +1,8 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include
> +
> +void cpu_do_idle(void)
> +{
> + __asm__ __volatile__ ("wfi");
> +
You should directly use the wait_for_interrupt() macro defined
in asm/processor.h.
I think we don't need a separate kernel/cpuidle.c source file as
of now. Maybe in-future we can add if required.
I suggest making cpu_do_idle() as "static inline" in asm/cpuidle.h
This way you will only need asm/cpuidle.h for the current changes.
> +}
> 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 ..e86d36b
> --- /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
Re: [PATCH] cpuidle: add riscv cpuidle driver
On 14/09/2020 03:52, liush wrote:
> This patch adds a cpuidle driver for systems based RISCV architecture.
> This patch supports state WFI. Other states will be supported in the
> future.
>
> Signed-off-by: liush
> ---
[ ... ]
>
> obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
> diff --git a/arch/riscv/kernel/cpuidle.c b/arch/riscv/kernel/cpuidle.c
> new file mode 100644
> index ..a3289e7
> --- /dev/null
> +++ b/arch/riscv/kernel/cpuidle.c
> @@ -0,0 +1,8 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include
> +
> +void cpu_do_idle(void)
> +{
> + __asm__ __volatile__ ("wfi");
> +
extra line
> +}
As for the next deeper states should end up with the cpu_do_idle
function, isn't there an extra operation with the wfi() like flushing
the l1 cache?
> 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 ..e86d36b
> --- /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.
Identation
Rest looks ok for me.
--
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