From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3rD2Jm0hPkzDqMr for ; Tue, 24 May 2016 01:19:35 +1000 (AEST) Received: from localhost by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 23 May 2016 09:19:32 -0600 From: "Shreyas B. Prabhu" To: mpe@ellerman.id.au Cc: linuxppc-dev@lists.ozlabs.org, paulus@ozlabs.org, linux-kernel@vger.kernel.org, mikey@neuling.org, ego@linux.vnet.ibm.com, "Shreyas B. Prabhu" , "Rafael J. Wysocki" , Daniel Lezcano , linux-pm@vger.kernel.org Subject: [PATCH v3 8/9] cpuidle/powernv: Add support for POWER ISA v3 idle states Date: Mon, 23 May 2016 20:48:41 +0530 Message-Id: <1464016722-7488-9-git-send-email-shreyas@linux.vnet.ibm.com> In-Reply-To: <1464016722-7488-1-git-send-email-shreyas@linux.vnet.ibm.com> References: <1464016722-7488-1-git-send-email-shreyas@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , POWER ISA v3 defines a new idle processor core mechanism. In summary, a) new instruction named stop is added. b) new per thread SPR named PSSCR is added which controls the behavior of stop instruction. Supported idle states and value to be written to PSSCR register to enter any idle state is exposed via ibm,cpu-idle-state-names and ibm,cpu-idle-state-psscr respectively. To enter an idle state, platform provided power_stop() needs to be invoked with the appropriate PSSCR value. This patch adds support for this new mechanism in cpuidle powernv driver. Cc: Rafael J. Wysocki Cc: Daniel Lezcano Cc: linux-pm@vger.kernel.org Cc: Michael Ellerman Cc: Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Shreyas B. Prabhu --- drivers/cpuidle/cpuidle-powernv.c | 57 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 56 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c index e12dc30..efe5221 100644 --- a/drivers/cpuidle/cpuidle-powernv.c +++ b/drivers/cpuidle/cpuidle-powernv.c @@ -21,6 +21,7 @@ #include #define MAX_POWERNV_IDLE_STATES 8 +#define MAX_IDLE_STATE_NAME_LEN 10 struct cpuidle_driver powernv_idle_driver = { .name = "powernv_idle", @@ -29,9 +30,11 @@ struct cpuidle_driver powernv_idle_driver = { static int max_idle_state; static struct cpuidle_state *cpuidle_state_table; + +static u64 stop_psscr_table[MAX_POWERNV_IDLE_STATES]; + static u64 snooze_timeout; static bool snooze_timeout_en; - static int snooze_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) @@ -139,6 +142,15 @@ static struct notifier_block setup_hotplug_notifier = { .notifier_call = powernv_cpuidle_add_cpu_notifier, }; +static int stop_loop(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + ppc64_runlatch_off(); + power_stop(stop_psscr_table[index]); + ppc64_runlatch_on(); + return index; +} /* * powernv_cpuidle_driver_init() */ @@ -169,6 +181,8 @@ static int powernv_add_idle_states(void) int nr_idle_states = 1; /* Snooze */ int dt_idle_states; u32 *latency_ns, *residency_ns, *flags; + u64 *psscr_val = NULL; + const char *names[MAX_POWERNV_IDLE_STATES]; int i, rc; /* Currently we have snooze statically defined */ @@ -201,6 +215,23 @@ static int powernv_add_idle_states(void) goto out_free_latency; } + rc = of_property_read_string_array(power_mgt, + "ibm,cpu-idle-state-names", names, dt_idle_states); + if (rc < -1) { + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-names in DT\n"); + goto out_free_latency; + } + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + psscr_val = kcalloc(dt_idle_states, sizeof(*psscr_val), + GFP_KERNEL); + rc = of_property_read_u64_array(power_mgt, + "ibm,cpu-idle-state-psscr", psscr_val, dt_idle_states); + if (rc < -1) { + pr_warn("cpuidle-powernv: missing ibm,cpu-idle-states-psscr in DT\n"); + goto out_free_psscr; + } + } residency_ns = kzalloc(sizeof(*residency_ns) * dt_idle_states, GFP_KERNEL); rc = of_property_read_u32_array(power_mgt, "ibm,cpu-idle-state-residency-ns", residency_ns, dt_idle_states); @@ -218,6 +249,16 @@ static int powernv_add_idle_states(void) powernv_states[nr_idle_states].flags = 0; powernv_states[nr_idle_states].target_residency = 100; powernv_states[nr_idle_states].enter = &nap_loop; + } else if ((flags[i] & OPAL_PM_STOP_INST_FAST) && + !(flags[i] & OPAL_PM_TIMEBASE_STOP)) { + strncpy(powernv_states[nr_idle_states].name, + (char *)names[i], MAX_IDLE_STATE_NAME_LEN); + strncpy(powernv_states[nr_idle_states].desc, + (char *)names[i], MAX_IDLE_STATE_NAME_LEN); + powernv_states[nr_idle_states].flags = 0; + + powernv_states[nr_idle_states].enter = &stop_loop; + stop_psscr_table[nr_idle_states] = psscr_val[i]; } /* @@ -233,6 +274,18 @@ static int powernv_add_idle_states(void) powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP; powernv_states[nr_idle_states].target_residency = 300000; powernv_states[nr_idle_states].enter = &fastsleep_loop; + } else if ((flags[i] & OPAL_PM_STOP_INST_DEEP) && + (flags[i] & OPAL_PM_TIMEBASE_STOP)) { + + strncpy(powernv_states[nr_idle_states].name, + (char *)names[i], MAX_IDLE_STATE_NAME_LEN); + strncpy(powernv_states[nr_idle_states].desc, + (char *)names[i], MAX_IDLE_STATE_NAME_LEN); + + powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIMER_STOP; + + powernv_states[nr_idle_states].enter = &stop_loop; + stop_psscr_table[nr_idle_states] = psscr_val[i]; } #endif powernv_states[nr_idle_states].exit_latency = @@ -247,6 +300,8 @@ static int powernv_add_idle_states(void) } kfree(residency_ns); +out_free_psscr: + kfree(psscr_val); out_free_latency: kfree(latency_ns); out_free_flags: -- 2.4.11