From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF84A3DA5DC for ; Tue, 29 Sep 2026 03:45:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790653529; cv=none; b=d9Qnau2WrchVEaX3IQaoN+nbarTIjIe780Rf3xUrkSLgb4nGczJASIF3ge/N+I3fm+Vsbzck6hluCxYfMrM9t0Jesy0ISWjoKX1p74zJp23PmkuRisHpRluYeaL1gGiILA5d2jb1uX6cCw5SAXJkzOLMudRlmG7SBn+qt0HpOcU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790653529; c=relaxed/simple; bh=SuJ0VJDw+vh7P8OkJfHaGZVisnLRpOyIShpAsEtDHfk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=TzftI2zN4ek7nZC1jjolIUcczHjY9dTMoJ1EzzKa/KepDUShl0p++gMLS3WNj6rlhF/n7qMM4YqPhnJNe+pjdoQsjTMj86+F0sg/aDQIFgnwFHGtHiS/IBZ9iRA36HN7IrYKxGtmj9IcnjmckTv8XKMMd8dbC4bER9l3DF2GzMo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--praan.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=fZsLWGb5; arc=none smtp.client-ip=209.85.210.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--praan.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="fZsLWGb5" Received: by mail-pf1-f200.google.com with SMTP id d2e1a72fcca58-88078ca8725so1205920b3a.1 for ; Mon, 28 Sep 2026 20:45:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790653527; x=1791258327; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=fnUSb4lP0yPlj/wu8X8ngRGHkepeNm6ppJnOg67H/0o=; b=fZsLWGb5SBP3xAu9tjSlON5tTjrRkj4mas9H5VKQCwHws7Kb1tWZb9Z1Lozbk6KP8s 33mWk17vfpGbR1RHieD0ZdTg2uf6uzHyekyuT0POSYlY0MmzwGFpo02Tln9wfPCirwiN n9+VnwAl7OA6DfJLDqVJhtSmME70onKsPHjmugT+hKFqLZL4my+TrDHEMeNzZ040dugh r6Ixt9MI+mksc/OsyDUsreQvVnGqHQAKOlzOKNKNQJLhSFr5jJmY033bsEv1S3avTIID 03figFsCbBLoK929huNVgWkjYlmwH4PECQZB1z9gcQt29WhsX8oXRBlk3Faxy7U+ACLv xxGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790653527; x=1791258327; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=fnUSb4lP0yPlj/wu8X8ngRGHkepeNm6ppJnOg67H/0o=; b=0XuZX7DNBZTE0S7Un4+/1XCyn03rI8BMmORbfKwNHPK/ZlcFh7UmtFjBjLZntrCKhI dOJqjP0I4r38YMzw6p3mjTb/fCKQ7Z4YS7mvg4yQow+GM84lyqufsfH+XoA3MIdSSoW2 9hWkGXYQg43NEoRURk2xtlycfFUz+8tNMyDKhC85TyzMu563KBi/ABDfxClPT8vv4PhW tB9gUh+qOLKOvLneQqA8SB/VQjDZABOSxZMz5FR19AEOrV84W5bxB3Dafr4BT6usQgDU NvTjYQcHsXCWrd59hhNhIAqFS99ENqdIqXoNJ+iLb8FvJ54sos43dTtBvzEOv2Jj3cd8 m4KA== X-Forwarded-Encrypted: i=1; AKwUvBxxf0ZVnF5GcOXx+3ZxhWG7hjYR7yDGWOSr9tbEkbjRt8zqlWwRUyRndWlFILSiGgEyy3Wo23nMSpwbV4A=@vger.kernel.org X-Gm-Message-State: AFuF++mNN1lFF5DllpylWus1bIODNusHaWMHNXkz+KMtUCtImLoBCDUZ rmK5zdqpqnRcBJMNwzHvI+kH2EtZnIYG5GNiXbMLZD+EHX0uh1iFtc3vqv/Xyux7zcDNVyrQrsv VMA== X-Received: from pgdh4.prod.google.com ([2002:a05:6a02:5184:b0:cc7:b470:94ff]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:2583:b0:3dd:85a9:55b8 with SMTP id adf61e73a8af0-3de0e8b481emr12791744637.35.1790653526784; Mon, 28 Sep 2026 20:45:26 -0700 (PDT) Date: Tue, 29 Sep 2026 03:44:59 +0000 In-Reply-To: <20260929034510.2023173-1-praan@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260929034510.2023173-1-praan@google.com> X-Mailer: git-send-email 2.56.0.rc1.315.gc6ed9934b7-goog Message-ID: <20260929034510.2023173-6-praan@google.com> Subject: [PATCH v11 05/16] iommu/arm-smmu-v3: Add a helper to drain cmd queues From: Pranjal Shrivastava To: iommu@lists.linux.dev Cc: Will Deacon , Joerg Roedel , Robin Murphy , Jason Gunthorpe , Mostafa Saleh , Nicolin Chen , Daniel Mentz , Ashish Mhetre , linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Radu Rendec , Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , rafael@kernel.org, Danilo Krummrich , driver-core@lists.linux.dev, Pranjal Shrivastava , Jason Gunthorpe Content-Type: text/plain; charset="UTF-8" Before we suspend SMMU, we want to ensure that all commands (especially ATC_INV) have been flushed by the CMDQ, i.e. the CMDQs are empty. Add arm_smmu_drain_cmdqs() that drains the command queue using the arm_smmu_drain_queue() helper. Reviewed-by: Nicolin Chen Reviewed-by: Jason Gunthorpe Signed-off-by: Pranjal Shrivastava --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 27 +++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c index d809b625f7fb..dc2fc02b5163 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1028,6 +1028,33 @@ int arm_smmu_drain_queue(struct arm_smmu_device *smmu, return -ETIMEDOUT; } +/* + * Lockless, the caller must ensure that no concurrent command submissions + * can happen (such as during suspend where clients are already quiesced). + * Polling until PROD == CONS ensures all pending commands in the queue have + * been consumed by the hardware. + */ +static int __maybe_unused arm_smmu_drain_cmdqs(struct arm_smmu_device *smmu) +{ + int ret, err; + + /* + * We skip cmdq locking here since this helper is only called + * from contexts (like suspend) where the caller has already + * ensured that new command submissions are fully closed. + */ + ret = arm_smmu_drain_queue(smmu, &smmu->cmdq.q, true); + + /* Drain all implementation-specific queues */ + if (smmu->impl_ops && smmu->impl_ops->drain_queues) { + err = smmu->impl_ops->drain_queues(smmu); + if (err) + ret = err; + } + + return ret; +} + static void arm_smmu_page_response(struct device *dev, struct iopf_fault *unused, struct iommu_page_response *resp) { -- 2.56.0.rc1.315.gc6ed9934b7-goog