From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lina Iyer Subject: Re: [PATCH v8 4/8] arm64: kernel: introduce cpu_init_idle CPU operation Date: Wed, 3 Sep 2014 11:34:37 -0600 Message-ID: <20140903173437.GI92149@ilina-mac.local> References: <1409585324-3678-1-git-send-email-lorenzo.pieralisi@arm.com> <1409585324-3678-5-git-send-email-lorenzo.pieralisi@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <1409585324-3678-5-git-send-email-lorenzo.pieralisi@arm.com> Sender: linux-pm-owner@vger.kernel.org To: Lorenzo Pieralisi Cc: linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, Mark Rutland , Sudeep Holla , Catalin Marinas , Charles Garcia Tobin , Nicolas Pitre , Rob Herring , Grant Likely , Peter De Schrijver , Santosh Shilimkar , Daniel Lezcano , Amit Kucheria , Vincent Guittot , Antti Miettinen , Stephen Boyd , Kevin Hilman , Sebastian Capella , Tomasz Figa , Mark Brown , Paul Walmsley , Chander Kashyap List-Id: devicetree@vger.kernel.org On Mon, Sep 01 2014 at 09:28 -0600, Lorenzo Pieralisi wrote: >The CPUidle subsystem on ARM64 machines requires the idle states >implementation back-end to initialize idle states parameter upon >boot. This patch adds a hook in the CPU operations structure that >should be initialized by the CPU operations back-end in order to >provide a function that initializes cpu idle states. > >This patch also adds the infrastructure to arm64 kernel required >to export the CPU operations based initialization interface, so >that drivers (ie CPUidle) can use it when they are initialized >at probe time. > I like the change for ARM64. However, that raises a question, how do I have the same driver that should get probed by a platform device (on 32 bit ARM) and getting called from cpu_init_idle on ARM64? >Reviewed-by: Catalin Marinas >Signed-off-by: Lorenzo Pieralisi >--- > arch/arm64/include/asm/cpu_ops.h | 3 +++ > arch/arm64/include/asm/cpuidle.h | 13 +++++++++++++ > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/cpuidle.c | 31 +++++++++++++++++++++++++++++++ > 4 files changed, 48 insertions(+) > create mode 100644 arch/arm64/include/asm/cpuidle.h > create mode 100644 arch/arm64/kernel/cpuidle.c > >diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h >index d7b4b38..47dfa31 100644 >--- a/arch/arm64/include/asm/cpu_ops.h >+++ b/arch/arm64/include/asm/cpu_ops.h >@@ -28,6 +28,8 @@ struct device_node; > * enable-method property. > * @cpu_init: Reads any data necessary for a specific enable-method from the > * devicetree, for a given cpu node and proposed logical id. >+ * @cpu_init_idle: Reads any data necessary to initialize CPU idle states from >+ * devicetree, for a given cpu node and proposed logical id. > * @cpu_prepare: Early one-time preparation step for a cpu. If there is a > * mechanism for doing so, tests whether it is possible to boot > * the given CPU. >@@ -47,6 +49,7 @@ struct device_node; > struct cpu_operations { > const char *name; > int (*cpu_init)(struct device_node *, unsigned int); >+ int (*cpu_init_idle)(struct device_node *, unsigned int); > int (*cpu_prepare)(unsigned int); > int (*cpu_boot)(unsigned int); > void (*cpu_postboot)(void); >diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h >new file mode 100644 >index 0000000..b52a993 >--- /dev/null >+++ b/arch/arm64/include/asm/cpuidle.h >@@ -0,0 +1,13 @@ >+#ifndef __ASM_CPUIDLE_H >+#define __ASM_CPUIDLE_H >+ >+#ifdef CONFIG_CPU_IDLE >+extern int cpu_init_idle(unsigned int cpu); >+#else >+static inline int cpu_init_idle(unsigned int cpu) >+{ >+ return -EOPNOTSUPP; >+} >+#endif >+ >+#endif >diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile >index 383d81d..be78980 100644 >--- a/arch/arm64/kernel/Makefile >+++ b/arch/arm64/kernel/Makefile >@@ -27,6 +27,7 @@ arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o > arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o > arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o > arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o >+arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o > arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o > arm64-obj-$(CONFIG_KGDB) += kgdb.o > arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o >diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c >new file mode 100644 >index 0000000..19d17f5 >--- /dev/null >+++ b/arch/arm64/kernel/cpuidle.c >@@ -0,0 +1,31 @@ >+/* >+ * ARM64 CPU idle arch support >+ * >+ * Copyright (C) 2014 ARM Ltd. >+ * Author: Lorenzo Pieralisi >+ * >+ * This program is free software; you can redistribute it and/or modify >+ * it under the terms of the GNU General Public License version 2 as >+ * published by the Free Software Foundation. >+ */ >+ >+#include >+#include >+ >+#include >+#include >+ >+int cpu_init_idle(unsigned int cpu) >+{ >+ int ret = -EOPNOTSUPP; >+ struct device_node *cpu_node = of_cpu_device_node_get(cpu); >+ >+ if (!cpu_node) >+ return -ENODEV; >+ >+ if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle) >+ ret = cpu_ops[cpu]->cpu_init_idle(cpu_node, cpu); >+ >+ of_node_put(cpu_node); >+ return ret; >+} >-- >1.9.1 > > From mboxrd@z Thu Jan 1 00:00:00 1970 From: lina.iyer@linaro.org (Lina Iyer) Date: Wed, 3 Sep 2014 11:34:37 -0600 Subject: [PATCH v8 4/8] arm64: kernel: introduce cpu_init_idle CPU operation In-Reply-To: <1409585324-3678-5-git-send-email-lorenzo.pieralisi@arm.com> References: <1409585324-3678-1-git-send-email-lorenzo.pieralisi@arm.com> <1409585324-3678-5-git-send-email-lorenzo.pieralisi@arm.com> Message-ID: <20140903173437.GI92149@ilina-mac.local> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Sep 01 2014 at 09:28 -0600, Lorenzo Pieralisi wrote: >The CPUidle subsystem on ARM64 machines requires the idle states >implementation back-end to initialize idle states parameter upon >boot. This patch adds a hook in the CPU operations structure that >should be initialized by the CPU operations back-end in order to >provide a function that initializes cpu idle states. > >This patch also adds the infrastructure to arm64 kernel required >to export the CPU operations based initialization interface, so >that drivers (ie CPUidle) can use it when they are initialized >at probe time. > I like the change for ARM64. However, that raises a question, how do I have the same driver that should get probed by a platform device (on 32 bit ARM) and getting called from cpu_init_idle on ARM64? >Reviewed-by: Catalin Marinas >Signed-off-by: Lorenzo Pieralisi >--- > arch/arm64/include/asm/cpu_ops.h | 3 +++ > arch/arm64/include/asm/cpuidle.h | 13 +++++++++++++ > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/cpuidle.c | 31 +++++++++++++++++++++++++++++++ > 4 files changed, 48 insertions(+) > create mode 100644 arch/arm64/include/asm/cpuidle.h > create mode 100644 arch/arm64/kernel/cpuidle.c > >diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h >index d7b4b38..47dfa31 100644 >--- a/arch/arm64/include/asm/cpu_ops.h >+++ b/arch/arm64/include/asm/cpu_ops.h >@@ -28,6 +28,8 @@ struct device_node; > * enable-method property. > * @cpu_init: Reads any data necessary for a specific enable-method from the > * devicetree, for a given cpu node and proposed logical id. >+ * @cpu_init_idle: Reads any data necessary to initialize CPU idle states from >+ * devicetree, for a given cpu node and proposed logical id. > * @cpu_prepare: Early one-time preparation step for a cpu. If there is a > * mechanism for doing so, tests whether it is possible to boot > * the given CPU. >@@ -47,6 +49,7 @@ struct device_node; > struct cpu_operations { > const char *name; > int (*cpu_init)(struct device_node *, unsigned int); >+ int (*cpu_init_idle)(struct device_node *, unsigned int); > int (*cpu_prepare)(unsigned int); > int (*cpu_boot)(unsigned int); > void (*cpu_postboot)(void); >diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h >new file mode 100644 >index 0000000..b52a993 >--- /dev/null >+++ b/arch/arm64/include/asm/cpuidle.h >@@ -0,0 +1,13 @@ >+#ifndef __ASM_CPUIDLE_H >+#define __ASM_CPUIDLE_H >+ >+#ifdef CONFIG_CPU_IDLE >+extern int cpu_init_idle(unsigned int cpu); >+#else >+static inline int cpu_init_idle(unsigned int cpu) >+{ >+ return -EOPNOTSUPP; >+} >+#endif >+ >+#endif >diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile >index 383d81d..be78980 100644 >--- a/arch/arm64/kernel/Makefile >+++ b/arch/arm64/kernel/Makefile >@@ -27,6 +27,7 @@ arm64-obj-$(CONFIG_PERF_EVENTS) += perf_regs.o > arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o > arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o > arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND) += sleep.o suspend.o >+arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o > arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o > arm64-obj-$(CONFIG_KGDB) += kgdb.o > arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o >diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c >new file mode 100644 >index 0000000..19d17f5 >--- /dev/null >+++ b/arch/arm64/kernel/cpuidle.c >@@ -0,0 +1,31 @@ >+/* >+ * ARM64 CPU idle arch support >+ * >+ * Copyright (C) 2014 ARM Ltd. >+ * Author: Lorenzo Pieralisi >+ * >+ * This program is free software; you can redistribute it and/or modify >+ * it under the terms of the GNU General Public License version 2 as >+ * published by the Free Software Foundation. >+ */ >+ >+#include >+#include >+ >+#include >+#include >+ >+int cpu_init_idle(unsigned int cpu) >+{ >+ int ret = -EOPNOTSUPP; >+ struct device_node *cpu_node = of_cpu_device_node_get(cpu); >+ >+ if (!cpu_node) >+ return -ENODEV; >+ >+ if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle) >+ ret = cpu_ops[cpu]->cpu_init_idle(cpu_node, cpu); >+ >+ of_node_put(cpu_node); >+ return ret; >+} >-- >1.9.1 > >