[PATCH 07/36] cpuidle,tegra: Push RCU-idle into driver
From: Peter Zijlstra <peterz@infradead.org>
Date: 2022-06-08 14:49:30
Also in:
linux-acpi, linux-alpha, linux-arch, linux-arm-msm, linux-clk, linux-m68k, linux-mips, linux-omap, linux-perf-users, linux-pm, linux-riscv, linux-s390, linux-sh, linux-tegra, linux-um, lkml, rcu, sparclinux, virtualization, xen-devel
, Arnd Bergmann [off-list ref], ulli.kroll@googlemail.com, vgupta@kernel.org, linux-clk@vger.kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, bcain@quicinc.com, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, sudeep.holla@arm.com, shawnguo@kernel.org, davem@davemloft.net, dalias@libc.org, tony@atomide.com, amakhalov@vmware.com, bjorn.andersson@linaro.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, anton.ivanov@cambridgegreys.com, jonas@southpole.se, yury.norov@gmail.com, richard@nod.at, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, aou@eecs.berkeley.edu, paulmck@kernel.org, hca@linux.ibm.com, stefan.kristiansson@saunalahti.fi, openrisc@lists.librecores.org, paul.walmsley@sifive.com, linux-tegra@vger.kernel.org, namhyung@kernel.org, andriy.shevchenko@linux.intel.com, jpoimboe@kernel.org, jgross@suse.com, monstr@monstr.eu, linux-mips@vger.kernel.org, palmer@dab belt.com, anup@brainfault.org, ink@jurassic.park.msu.ru, johannes@sipsolutions.net, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" [off-list ref] Doing RCU-idle outside the driver, only to then temporarily enable it again, at least twice, before going idle is daft. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- drivers/cpuidle/cpuidle-tegra.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
--- a/drivers/cpuidle/cpuidle-tegra.c
+++ b/drivers/cpuidle/cpuidle-tegra.c@@ -180,9 +180,11 @@ static int tegra_cpuidle_state_enter(str } local_fiq_disable(); - RCU_NONIDLE(tegra_pm_set_cpu_in_lp2()); + tegra_pm_set_cpu_in_lp2(); cpu_pm_enter(); + rcu_idle_enter(); + switch (index) { case TEGRA_C7: err = tegra_cpuidle_c7_enter();
@@ -197,8 +199,10 @@ static int tegra_cpuidle_state_enter(str break; } + rcu_idle_exit(); + cpu_pm_exit(); - RCU_NONIDLE(tegra_pm_clear_cpu_in_lp2()); + tegra_pm_clear_cpu_in_lp2(); local_fiq_enable(); return err ?: index;
@@ -226,6 +230,7 @@ static int tegra_cpuidle_enter(struct cp struct cpuidle_driver *drv, int index) { + bool do_rcu = drv->states[index].flags & CPUIDLE_FLAG_RCU_IDLE; unsigned int cpu = cpu_logical_map(dev->cpu); int ret;
@@ -233,9 +238,13 @@ static int tegra_cpuidle_enter(struct cp if (dev->states_usage[index].disable) return -1; - if (index == TEGRA_C1) + if (index == TEGRA_C1) { + if (do_rcu) + rcu_idle_enter(); ret = arm_cpuidle_simple_enter(dev, drv, index); - else + if (do_rcu) + rcu_idle_exit(); + } else ret = tegra_cpuidle_state_enter(dev, index, cpu); if (ret < 0) {
@@ -285,7 +294,8 @@ static struct cpuidle_driver tegra_idle_ .exit_latency = 2000, .target_residency = 2200, .power_usage = 100, - .flags = CPUIDLE_FLAG_TIMER_STOP, + .flags = CPUIDLE_FLAG_TIMER_STOP | + CPUIDLE_FLAG_RCU_IDLE, .name = "C7", .desc = "CPU core powered off", },
@@ -295,6 +305,7 @@ static struct cpuidle_driver tegra_idle_ .target_residency = 10000, .power_usage = 0, .flags = CPUIDLE_FLAG_TIMER_STOP | + CPUIDLE_FLAG_RCU_IDLE | CPUIDLE_FLAG_COUPLED, .name = "CC6", .desc = "CPU cluster powered off",