From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lina Iyer Subject: Re: [PATCH v10 18/27] drivers: firmware: psci: Add support for PM domains using genpd Date: Mon, 3 Dec 2018 09:37:17 -0700 Message-ID: <20181203163717.GN18262@codeaurora.org> References: <20181129174700.16585-1-ulf.hansson@linaro.org> <20181129174700.16585-19-ulf.hansson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <20181129174700.16585-19-ulf.hansson@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson Cc: "Rafael J . Wysocki" , Sudeep Holla , Lorenzo Pieralisi , Mark Rutland , Daniel Lezcano , linux-pm@vger.kernel.org, "Raju P . L . S . S . S . N" , Stephen Boyd , Tony Lindgren , Kevin Hilman , Viresh Kumar , Vincent Guittot , Geert Uytterhoeven , linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org On Thu, Nov 29 2018 at 10:49 -0700, Ulf Hansson wrote: >When the hierarchical CPU topology layout is used in DT, we need to setup >the corresponding PM domain data structures, as to allow a CPU and a group >of CPUs to be power managed accordingly. Let's enable this by deploying >support through the genpd interface. > >Additionally, when the OS initiated mode is supported by the PSCI FW, let's >also parse the domain idle states DT bindings as to make genpd responsible >for the state selection, when the states are compatible with >"domain-idle-state". Otherwise, when only Platform Coordinated mode is >supported, we rely solely on the state selection to be managed through the >regular cpuidle framework. > >If the initialization of the PM domain data structures succeeds and the OS >initiated mode is supported, we try to switch to it. In case it fails, >let's fall back into a degraded mode, rather than bailing out and returning >an error code. > >Due to that the OS initiated mode may become enabled, we need to adjust to >maintain backwards compatibility for a kernel started through a kexec call. >Do this by explicitly switch to Platform Coordinated mode during boot. > >To try to initiate the PM domain data structures, the PSCI driver shall >call the new function, psci_dt_init_pm_domains(). However, this is done >from following changes. > >Cc: Lina Iyer >Co-developed-by: Lina Iyer >Signed-off-by: Ulf Hansson >--- > >Changes in V10: > - Enable the PM domains to be used for both PC and OSI mode. > - Fixup error paths. > - Move the management of kexec started kernels into this patch. > - Rewrite changelog. > >--- > drivers/firmware/psci/Makefile | 2 +- > drivers/firmware/psci/psci.c | 7 +- > drivers/firmware/psci/psci.h | 6 + > drivers/firmware/psci/psci_pm_domain.c | 262 +++++++++++++++++++++++++ > 4 files changed, 275 insertions(+), 2 deletions(-) > create mode 100644 drivers/firmware/psci/psci_pm_domain.c > >diff --git a/drivers/firmware/psci/Makefile b/drivers/firmware/psci/Makefile >index 1956b882470f..ff300f1fec86 100644 >--- a/drivers/firmware/psci/Makefile >+++ b/drivers/firmware/psci/Makefile >@@ -1,4 +1,4 @@ > # SPDX-License-Identifier: GPL-2.0 > # >-obj-$(CONFIG_ARM_PSCI_FW) += psci.o >+obj-$(CONFIG_ARM_PSCI_FW) += psci.o psci_pm_domain.o > obj-$(CONFIG_ARM_PSCI_CHECKER) += psci_checker.o >diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c >index 623591b541a4..19af2093151b 100644 >--- a/drivers/firmware/psci/psci.c >+++ b/drivers/firmware/psci/psci.c >@@ -704,9 +704,14 @@ static int __init psci_1_0_init(struct device_node *np) > if (err) > return err; > >- if (psci_has_osi_support()) >+ if (psci_has_osi_support()) { > pr_info("OSI mode supported.\n"); > >+ /* Make sure we default to PC mode. */ >+ invoke_psci_fn(PSCI_1_0_FN_SET_SUSPEND_MODE, >+ PSCI_1_0_SUSPEND_MODE_PC, 0, 0); >+ } >+ > return 0; > } > >diff --git a/drivers/firmware/psci/psci.h b/drivers/firmware/psci/psci.h >index 7d9d38fd57e1..8cf6d7206fab 100644 >--- a/drivers/firmware/psci/psci.h >+++ b/drivers/firmware/psci/psci.h >@@ -11,4 +11,10 @@ void psci_set_domain_state(u32 state); > bool psci_has_osi_support(void); > int psci_dt_parse_state_node(struct device_node *np, u32 *state); > >+#ifdef CONFIG_CPU_IDLE >+int psci_dt_init_pm_domains(struct device_node *np); >+#else >+static inline int psci_dt_init_pm_domains(struct device_node *np) { return 0; } >+#endif >+ > #endif /* __PSCI_H */ >diff --git a/drivers/firmware/psci/psci_pm_domain.c b/drivers/firmware/psci/psci_pm_domain.c >new file mode 100644 >index 000000000000..d0dc38e96f85 >--- /dev/null >+++ b/drivers/firmware/psci/psci_pm_domain.c >@@ -0,0 +1,262 @@ >+// SPDX-License-Identifier: GPL-2.0 >+/* >+ * PM domains for CPUs via genpd - managed by PSCI. >+ * >+ * Copyright (C) 2018 Linaro Ltd. >+ * Author: Ulf Hansson >+ * >+ */ >+ >+#define pr_fmt(fmt) "psci: " fmt >+ >+#include >+#include >+#include >+#include >+#include >+ >+#include "psci.h" >+ >+#ifdef CONFIG_CPU_IDLE >+ >+struct psci_pd_provider { >+ struct list_head link; >+ struct device_node *node; >+}; >+ >+static LIST_HEAD(psci_pd_providers); >+static bool osi_mode_enabled; >+ >+static int psci_pd_power_off(struct generic_pm_domain *pd) >+{ >+ struct genpd_power_state *state = &pd->states[pd->state_idx]; >+ u32 *pd_state; >+ u32 composite_pd_state; >+ >+ /* If we have failed to enable OSI mode, then abort power off. */ >+ if (psci_has_osi_support() && !osi_mode_enabled) >+ return -EBUSY; >+ >+ if (!state->data) >+ return 0; >+ >+ /* When OSI mode is enabled, set the corresponding domain state. */ >+ pd_state = state->data; >+ composite_pd_state = *pd_state | psci_get_domain_state(); This should not be needed. The domain_state should be 0x0 being set after coming out of idle. >+ psci_set_domain_state(composite_pd_state); The three lines can be summarized as: psci_set_domain_state(*state->data); Thanks, Lina