From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (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 3BC0C4B1E64 for ; Thu, 15 May 2025 01:30:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747272655; cv=none; b=hKp0wHfzPYPaA7QBwwzY9R9N33m7/Z2ngZs6IyQOWgkQ/bRusotFPCcDinALbuXRT3X7GSN5LRJRfwspYEib4Xs0wHyTnA4u6B4rb0gsaRkntpgRo/BP5V5yuiPaqlEb3fegXbSTAr5QcUvo7oq9/56ey0gcx+dnw5EXOzGVt9o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747272655; c=relaxed/simple; bh=7d11dxMUWSlUIvsx1ISMixfrtiUXfAzjI3gLaGSALKU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Aj4pmPdFzb+tr6/WDI3iSl370CamIgo9beSMXYadAfh4x2MX9xpePhcNM7eT44aUMoTigGxCueLStrni8CjECHKNpnT9JC9Hko3p8CmWY9zN5B3gbakCmwPHrw83iRmgLpb6MR/iAewQ3OP1s6m08vpIg1MomPMTkW+le8JT0dc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=aBaWm5U+; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="aBaWm5U+" Message-ID: <7135de9f-4372-4e12-994d-ecdc234bff28@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1747272641; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ciAFAPUHoqP7kxDTaOJWSofaP2GTW0t32HqF5a7B428=; b=aBaWm5U+V54ipnws5yhyd78b0OCayavJMYV1WP4Do40m7+AZKeVhiwXPNb1Vh6DBT/FQbj vJA1nJOn4XmwrE4UwRcPtYvDzpfZFAsDpASr85yAyd7JE8fAe7Uyhq4qOCzyLLGsswApKE nnouiomU3pAY4gGj1KnCcoUmOIBCc08= Date: Thu, 15 May 2025 09:30:36 +0800 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] LoongArch: Save and restore CSR.CNTC for hibernation To: Huacai Chen , Huacai Chen Cc: loongarch@lists.linux.dev, Xuefeng Li , Guo Ren , Xuerui Wang , Jiaxun Yang , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Xianglai Li References: <20250514144643.1620870-1-chenhuacai@loongson.cn> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yanteng Si In-Reply-To: <20250514144643.1620870-1-chenhuacai@loongson.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 5/14/25 10:46 PM, Huacai Chen 写道: > Save and restore CSR.CNTC for hibernation which is similar to suspend. > > For host this is unnecessary because sched clock is ensured continuous, > but for kvm guest sched clock isn't enough because rdtime.d should also > be continuous. > > Host::rdtime.d = Host::CSR.CNTC + counter > Guest::rdtime.d = Host::CSR.CNTC + Host::CSR.GCNTC + Guest::CSR.CNTC + counter > > so, > > Guest::rdtime.d = Host::rdtime.d + Host::CSR.GCNTC + Guest::CSR.CNTC > > To ensure Guest::rdtime.d continuous, Host::rdtime.d should be at first > continuous, while Host::CSR.GCNTC / Guest::CSR.CNTC is maintained by KVM. > > Cc: stable@vger.kernel.org > Signed-off-by: Xianglai Li > Signed-off-by: Huacai Chen Reviewed-by: Yanteng Si Thanks, Yanteng > --- > arch/loongarch/kernel/time.c | 2 +- > arch/loongarch/power/hibernate.c | 3 +++ > 2 files changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c > index e2d3bfeb6366..bc75a3a69fc8 100644 > --- a/arch/loongarch/kernel/time.c > +++ b/arch/loongarch/kernel/time.c > @@ -111,7 +111,7 @@ static unsigned long __init get_loops_per_jiffy(void) > return lpj; > } > > -static long init_offset __nosavedata; > +static long init_offset; > > void save_counter(void) > { > diff --git a/arch/loongarch/power/hibernate.c b/arch/loongarch/power/hibernate.c > index 1e0590542f98..e7b7346592cb 100644 > --- a/arch/loongarch/power/hibernate.c > +++ b/arch/loongarch/power/hibernate.c > @@ -2,6 +2,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -14,6 +15,7 @@ struct pt_regs saved_regs; > > void save_processor_state(void) > { > + save_counter(); > saved_crmd = csr_read32(LOONGARCH_CSR_CRMD); > saved_prmd = csr_read32(LOONGARCH_CSR_PRMD); > saved_euen = csr_read32(LOONGARCH_CSR_EUEN); > @@ -26,6 +28,7 @@ void save_processor_state(void) > > void restore_processor_state(void) > { > + sync_counter(); > csr_write32(saved_crmd, LOONGARCH_CSR_CRMD); > csr_write32(saved_prmd, LOONGARCH_CSR_PRMD); > csr_write32(saved_euen, LOONGARCH_CSR_EUEN);