[PATCH v3 06/51] cpuidle,tegra: Push RCU-idle into driver
From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-01-12 20:04:12
Also in:
linux-acpi, linux-alpha, linux-arch, linux-arm-msm, linux-clk, linux-m68k, linux-mips, linux-mm, linux-omap, linux-perf-users, linux-pm, linux-riscv, linux-s390, linux-samsung-soc, linux-sh, linux-tegra, linux-trace-kernel, linux-um, lkml, loongarch, sparclinux, virtualization
Doing RCU-idle outside the driver, only to then temporarily enable it again, at least twice, before going idle is daft. Notably once implicitly through the cpu_pm_*() calls and once explicitly doing RCU_NONIDLE(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Rafael J. Wysocki <redacted> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <redacted> --- 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(); + ct_idle_enter(); + switch (index) { case TEGRA_C7: err = tegra_cpuidle_c7_enter();
@@ -197,8 +199,10 @@ static int tegra_cpuidle_state_enter(str break; } + ct_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) + ct_idle_enter(); ret = arm_cpuidle_simple_enter(dev, drv, index); - else + if (do_rcu) + ct_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",