From patchwork Fri Dec 6 13:04:05 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frederic Weisbecker X-Patchwork-Id: 848006 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18C82206F1F; Fri, 6 Dec 2024 13:04:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733490263; cv=none; b=tldVqpcC5yudQaFXAjZLC+I9FBb24+FTxbkdrXN3acvDBnS+HO63dBERIcSnRDskoHON8o07XX36pJxCz2rSPeIS7vqt44aHMbqOZp03AUiZjJCEgk3j895l72zqliwsC3OvBC/X5eaqx7IPs/KS0b0105aHLzos8patTFXzRAM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733490263; c=relaxed/simple; bh=vnlbtpQU0ZM/p6oSUAtyreorxH4BApB8/i74FdQ9nU0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iuvYde0+qKHNJcYwl8eunnk8IKmCht87VnyDBZT9lRIeN8I6M2LGGgWxH5R+fHt5efrI2GwkfykpKOoqLgeULuDHAhUFeWTRSkIOUHKzVNpugLCFE8KA0c5pUeMWrvlA3TWAH62//Ndxm2rBQsG2qNGmGCiovIGYiBkJlHaUdDg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O6R3V9ZK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O6R3V9ZK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F33BC4CEE2; Fri, 6 Dec 2024 13:04:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733490262; bh=vnlbtpQU0ZM/p6oSUAtyreorxH4BApB8/i74FdQ9nU0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O6R3V9ZKuAK4GNNEeN5z54qY1XiCDLI7dWdmQd9l4a8L+JgvAxQxRxHxaDeLbB9j/ WZojL8el2aMp2iZbVRZC/iMlNEehQThDHTg2CpWr608lUVLlDfVd945t8PfynrGwZP ltPOOYO2/MyALttdoL1jjuVTuvHq+oprhyC0cvjrZhji8p7ZQLZZFpxqf0uGrLtFhk Wf79c6J0Sx4krmaPBvGAICVKCxFFlk+ErJHdwoyJo7Mgn4mbQQmDvLaUEdkExis6wg bYO78iUqspc4EJlmJ7kuZBoHXXV3DiXFJwzObazdYT63kOvYgCCGcSNbsiFESMrJq7 hkKaC+QA9rMfA== From: Frederic Weisbecker To: LKML Cc: Peter Zijlstra , "Rafael J . Wysocki" , Daniel Lezcano , linux-pm@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Frederic Weisbecker Subject: [PATCH 2/5] cpuidle: Introduce CPUIDLE_FLAG_MWAIT Date: Fri, 6 Dec 2024 14:04:05 +0100 Message-ID: <20241206130408.18690-3-frederic@kernel.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20241206130408.18690-1-frederic@kernel.org> References: <20241206130408.18690-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Peter Zijlstra Provide a way to tell the cpuidle core about states monitoring TIF_NEED_RESCHED on the hardware level, monitor/mwait users being the only examples in use. This will allow cpuidle core to manage TIF_NR_POLLING on behalf of all kinds of TIF_NEED_RESCHED watching states while keeping a necessary distinction for the governors between software loops polling on TIF_NEED_RESCHED and hardware monitored writes to thread flags. [fweisbec: _ Initialize flag from acpi_processor_setup_cstates() instead of acpi_processor_setup_lpi_states(), as the latter seem to be about arm64... _ Rename CPUIDLE_FLAG_NO_IPI to CPUIDLE_FLAG_MWAIT] Not-yet-signed-off-by: Peter Zijlstra Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) --- drivers/acpi/processor_idle.c | 3 +++ drivers/idle/intel_idle.c | 5 ++++- include/linux/cpuidle.h | 1 + 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 698897b29de2..66cb5536d91e 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -806,6 +806,9 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr) if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) drv->safe_state_index = count; + if (cx->entry_method == ACPI_CSTATE_FFH) + state->flags |= CPUIDLE_FLAG_MWAIT; + /* * Halt-induced C1 is not good for ->enter_s2idle, because it * re-enables interrupts on exit. Moreover, C1 is generally not diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index ac4d8faa3886..d52723fbeb04 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1787,7 +1787,8 @@ static void __init intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) if (cx->type > ACPI_STATE_C1) state->target_residency *= 3; - state->flags = MWAIT2flg(cx->address); + state->flags = MWAIT2flg(cx->address) | CPUIDLE_FLAG_MWAIT; + if (cx->type > ACPI_STATE_C2) state->flags |= CPUIDLE_FLAG_TLB_FLUSHED; @@ -2072,6 +2073,8 @@ static bool __init intel_idle_verify_cstate(unsigned int mwait_hint) static void state_update_enter_method(struct cpuidle_state *state, int cstate) { + state->flags |= CPUIDLE_FLAG_MWAIT; + if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) { /* * Combining with XSTATE with IBRS or IRQ_ENABLE flags diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index a9ee4fe55dcf..b8084617aa27 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -85,6 +85,7 @@ struct cpuidle_state { #define CPUIDLE_FLAG_OFF BIT(4) /* disable this state by default */ #define CPUIDLE_FLAG_TLB_FLUSHED BIT(5) /* idle-state flushes TLBs */ #define CPUIDLE_FLAG_RCU_IDLE BIT(6) /* idle-state takes care of RCU */ +#define CPUIDLE_FLAG_MWAIT BIT(7) /* hardware need_resched() monitoring */ struct cpuidle_device_kobj; struct cpuidle_state_kobj;