From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1C1DACA5FAE for ; Tue, 29 Sep 2026 03:47:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Q1UoDLaUSVrQDcp8js+xQqVPvK9lSKlk7fepU02SFQA=; b=xtDIgQU9aGSv9XI6l/2TJagjdg Gxg0ctgwLj9D1obmx7RHy2o1FDDxBcmQC7L3N2FBuNTqGhSY/hqIYKjpVH2nqjmwiit5DUhu40rm/ bilr9sLfWgIm2hjvKgu43ENFymil//ttj//WmWEQcA7D/xcBnqZ73ZZuEhcnFxyFSEJYqQKXpdian vKiyVGa/T5q1Ck+4pDdfxU+F9Fv8YUBNo+8TXgCsHzdkpNjRpFS3FuF+CgKyJQGpTBHAc0nQl+wrc aoiNbk7791s+i2RMV087YfDaw7XtsRKp3Y7eYEjnuMo9cC6C+LQ96BmEq0wGk85/dxVyG1kAa0/nO 3ou7SaDA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBOnt-00000002Gw9-0CFw; Tue, 29 Sep 2026 03:46:53 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBOmy-00000002GQo-2oE6 for linux-arm-kernel@bombadil.infradead.org; Tue, 29 Sep 2026 03:45:56 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:Cc:To:From:Subject: Message-ID:References:Mime-Version:In-Reply-To:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Q1UoDLaUSVrQDcp8js+xQqVPvK9lSKlk7fepU02SFQA=; b=rOO8Bri1AGZmkT/mrgYCmAtxVt w5lavTjD02taBMeH/eYKbFSjALBce8kPCekFDqnEXxg/nPOL4SaPn0NqfNjlDyPutRUT6SpdZb3fK 2tY+dybbntQ9NjFz3pKuc51Kyx1rfLhxS1tj7Zdd5HjnSUk48Xp1MMHPnByfCQ6oT3aPgoPnxnl5f hF2We0cB6HHr6M9GVhCB1/k9CT3fpBrhtKEFFoJ6jzFFPWyitYc1ziyd0+BMzJVr6JjnN8AI0er8O 6K3tIVm5Ve+z1AKmhqfJKtu7GoK1YpeQCSLxzRDITtJo3/uzEHjCPRIk3v95tDqu1GQpl+SQGBT95 Nh/uJaqQ==; Received: from mail-pg1-x546.google.com ([2607:f8b0:4864:20::546]) by desiato.infradead.org with esmtps (Exim 4.99.2 #2 (Red Hat Linux)) id 1xBOmt-000000029R8-2xUt for linux-arm-kernel@lists.infradead.org; Tue, 29 Sep 2026 03:45:54 +0000 Received: by mail-pg1-x546.google.com with SMTP id 41be03b00d2f7-cc1ca15334cso4175693a12.1 for ; Mon, 28 Sep 2026 20:45:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790653549; x=1791258349; darn=lists.infradead.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=Q1UoDLaUSVrQDcp8js+xQqVPvK9lSKlk7fepU02SFQA=; b=FxRSkjH8p6wU9aX6opK+FGnZCqvE76sLt5isrRYSIrFJ6HnODEF0dZvFlDLSmnDnDk yGtU7OqUd1ZQRfzyVDUlUDBLoMtC4pyk2kNhHLo//GuMML8hj2VzAmN2P/ZsgO3FZJjC gKAjJ0qkugzrZF1N3Ggahe7Z6t7yS4jZcK2Sk3EN+P4aV2uLQO/IL5IEqNP7m84swQr+ duHVm7rvq/8KzUMfhKqreEeOjMlUJII5XrjR8WKlkiUYcNYwcd9gaFdZjs9HZXggsQ39 4L/BQM0eHyvR4OvWOatXBGA/MuoF9tqC59UWBLuC+tIujlTMQ4iOY3vkZYqHt0F3w4yn ayQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790653549; x=1791258349; 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=Q1UoDLaUSVrQDcp8js+xQqVPvK9lSKlk7fepU02SFQA=; b=aypMHSETjuJXTe2KHGCU9Th9/cVzYPijdLZ+nsRMYmN0JMe8Ox6RTqTB0Lj0UJ1ovM WXbUEESe4Ivt2w+sjj0Rtw61xIjFov7cRfxi6qjDp0vogpXrq7DXnjcyUS2otyxg9BU5 gOWeYHBeh5sc7+ZGzAQTzxhZgvedmvBDlpcLWD43OuKlkxEfD+ORXuaifoO2bFOxdQoH JnZbGxt1TUG4MdS+t3Vdo5+AldjIDZYWtWrZrTBn4RNFaBuBqOWbfmd3BDUdDWlxJ1eg lKtJ0yRApSJhRtIg7F3sK7z1t3P8i8QN5G6JuDKjvYVrvs4XeaCznYpZhAAc5vqwvzrH Rzzg== X-Forwarded-Encrypted: i=1; AKwUvBx7on4Z/N+jWL66SVg5KEmDYk7FMV+0mX0RNLI4tN3llRxBvjTuTvK/z4BQDVD9DWo5ucVEnHBkFDGIqACyZzMH@lists.infradead.org X-Gm-Message-State: AFuF++k4NDGkpPy7q4jO0W6jorSYDGlIhrLcttHrG+0CtIrWDDXvbxDZ yL5C/G7xU2ZoqoXixC9HwQUKamn7ZsNStqo3F75LjZyiGN4zFOaFhUC+o8o3xQlYn/325FQ4iHj 7cg== X-Received: from pgww22.prod.google.com ([2002:a05:6a02:2c96:b0:cc7:ade4:5f77]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:c90a:b0:3dd:85a9:55a9 with SMTP id adf61e73a8af0-3de26db3254mr10142499637.34.1790653549063; Mon, 28 Sep 2026 20:45:49 -0700 (PDT) Date: Tue, 29 Sep 2026 03:45:06 +0000 In-Reply-To: <20260929034510.2023173-1-praan@google.com> 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: <20260929034510.2023173-13-praan@google.com> Subject: [PATCH v11 12/16] iommu/tegra241-cmdqv: Add a helper to quiesce VCMDQs 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 Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260929_044552_959188_43636144 X-CRM114-Status: GOOD ( 26.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The tegra241-cmdqv driver supports vCMDQs which need to be quiesced using the STOP_FLAG. The current driver implementation only uses VINTF0 for vCMDQs owned by the kernel which need to be stopped. Add a helper that sets the CMDQ_PROD_STOP_FLAG on these vCMDQs. Consolidate this logic by renaming the implementation hook to quiesce_and_drain_queues and ensuring that the tegra241-cmdqv driver gates all active local virtual queues before starting the drain loop. Additionally, clear the STOP_FLAG in tegra241_vcmdq_hw_init() as a part of tegra241_cmdqv_hw_reset(). Suggested-by: Nicolin Chen Signed-off-by: Pranjal Shrivastava --- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 4 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 +- .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 77 ++++++++++++++++++- 3 files changed, 76 insertions(+), 7 deletions(-) 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 7f89e2306942..89a4e756ff17 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -1077,8 +1077,8 @@ static int __maybe_unused arm_smmu_drain_cmdqs(struct arm_smmu_device *smmu) 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 (smmu->impl_ops && smmu->impl_ops->quiesce_and_drain_queues) { + err = smmu->impl_ops->quiesce_and_drain_queues(smmu); if (err) ret = err; } diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index 794b258550dd..0a841441cc44 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -896,7 +896,7 @@ struct arm_smmu_impl_ops { size_t (*get_viommu_size)(enum iommu_viommu_type viommu_type); int (*vsmmu_init)(struct arm_vsmmu *vsmmu, const struct iommu_user_data *user_data); - int (*drain_queues)(struct arm_smmu_device *smmu); + int (*quiesce_and_drain_queues)(struct arm_smmu_device *smmu); }; /* An SMMUv3 instance */ diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c index c7989fcd2c62..61847f2802a3 100644 --- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c +++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c @@ -447,6 +447,54 @@ tegra241_cmdqv_get_cmdq(struct arm_smmu_device *smmu, return &vcmdq->cmdq; } +static void tegra241_cmdqv_quiesce_vintf0_lvcmdqs(struct arm_smmu_device *smmu) +{ + struct tegra241_cmdqv *cmdqv = + container_of(smmu, struct tegra241_cmdqv, smmu); + struct tegra241_vintf *vintf = cmdqv->vintfs[0]; + u16 lidx; + + if (!READ_ONCE(vintf->enabled)) + return; + + for (lidx = 0; lidx < cmdqv->num_lvcmdqs_per_vintf; lidx++) { + struct tegra241_vcmdq *vcmdq = vintf->lvcmdqs[lidx]; + + if (!vcmdq || !READ_ONCE(vcmdq->enabled)) + continue; + + atomic_or(CMDQ_PROD_STOP_FLAG, &vcmdq->cmdq.q.llq.atomic.prod); + } +} + +static void tegra241_vcmdq_wait_quiescent(struct arm_smmu_device *smmu, + struct tegra241_vcmdq *vcmdq) +{ + u32 target = READ_ONCE(vcmdq->cmdq.q.llq.prod) & CMDQ_PROD_IDX_MASK; + int timeout = ARM_SMMU_POLL_TIMEOUT_US; + + /* Wait for the last committed owner to reach the hardware */ + while (atomic_read(&vcmdq->cmdq.owner_prod) != target && timeout) { + udelay(1); + timeout--; + } + + if (!timeout) + dev_err(smmu->dev, "vintf0 lvcmdq%u owner wait timeout\n", + vcmdq->lidx); + + /* Wait for queue lock to be released */ + timeout = ARM_SMMU_POLL_TIMEOUT_US; + while (atomic_read(&vcmdq->cmdq.lock) != 0 && timeout) { + udelay(1); + timeout--; + } + + if (!timeout) + dev_err(smmu->dev, "vintf0 lvcmdq%u lock wait timeout\n", + vcmdq->lidx); +} + static int tegra241_cmdqv_drain_vintf0_lvcmdqs(struct arm_smmu_device *smmu) { struct tegra241_cmdqv *cmdqv = @@ -467,6 +515,21 @@ static int tegra241_cmdqv_drain_vintf0_lvcmdqs(struct arm_smmu_device *smmu) if (!READ_ONCE(vintf->enabled)) return 0; + /* + * Gate all vCMDQs by setting the STOP_FLAG in a separate, + * initial loop to ensure no new commands can be submitted + * to any secondary queue while we are waiting to drain them. + * + * Client devices are suspended at this point due to devlinks, + * ensuring no concurrent command submissions race with this + * drain sequence. + */ + tegra241_cmdqv_quiesce_vintf0_lvcmdqs(smmu); + + /* Ensure all CPUs observe the STOP_FLAG before draining */ + smp_mb(); + + /* Now that all queues are safely gated, drain them sequentially. */ for (lidx = 0; lidx < cmdqv->num_lvcmdqs_per_vintf; lidx++) { struct tegra241_vcmdq *vcmdq = vintf->lvcmdqs[lidx]; int rc; @@ -474,6 +537,9 @@ static int tegra241_cmdqv_drain_vintf0_lvcmdqs(struct arm_smmu_device *smmu) if (!vcmdq || !READ_ONCE(vcmdq->enabled)) continue; + /* Wait for the last committed owner to reach the hardware */ + tegra241_vcmdq_wait_quiescent(smmu, vcmdq); + rc = arm_smmu_drain_queue(smmu, &vcmdq->cmdq.q, true); if (rc) { /* @@ -489,7 +555,7 @@ static int tegra241_cmdqv_drain_vintf0_lvcmdqs(struct arm_smmu_device *smmu) } /* Avoid consuming stale commands on resume */ - vcmdq->cmdq.q.llq.cons = vcmdq->cmdq.q.llq.prod; + vcmdq->cmdq.q.llq.cons = vcmdq->cmdq.q.llq.prod & CMDQ_PROD_IDX_MASK; } return ret; @@ -566,7 +632,6 @@ static int tegra241_vcmdq_hw_init(struct tegra241_vcmdq *vcmdq) /* Configure and enable VCMDQ */ writeq_relaxed(vcmdq->cmdq.q.q_base, REG_VCMDQ_PAGE1(vcmdq, BASE)); - /* * HW Registers reset to 0 when power-cycled. Restore them from their * SW copies to prevent executing stale/ghost commands after resume. @@ -574,7 +639,8 @@ static int tegra241_vcmdq_hw_init(struct tegra241_vcmdq *vcmdq) * to the Guests since the relevant frameworks (IOMMUFD / VFIO) hold * active PM references preventing suspend while VMs are active. */ - writel_relaxed(vcmdq->cmdq.q.llq.prod, REG_VCMDQ_PAGE0(vcmdq, PROD)); + writel_relaxed(vcmdq->cmdq.q.llq.prod & CMDQ_PROD_IDX_MASK, + REG_VCMDQ_PAGE0(vcmdq, PROD)); writel_relaxed(vcmdq->cmdq.q.llq.cons, REG_VCMDQ_PAGE0(vcmdq, CONS)); ret = vcmdq_write_config(vcmdq, VCMDQ_EN); @@ -587,6 +653,9 @@ static int tegra241_vcmdq_hw_init(struct tegra241_vcmdq *vcmdq) return ret; } + /* Clear the CMDQ_PROD_STOP_FLAG */ + atomic_andnot(CMDQ_PROD_STOP_FLAG, &vcmdq->cmdq.q.llq.atomic.prod); + dev_dbg(vcmdq->cmdqv->dev, "%sinited\n", h); return 0; } @@ -963,7 +1032,7 @@ static struct arm_smmu_impl_ops tegra241_cmdqv_impl_ops = { .device_reset = tegra241_cmdqv_hw_reset, .device_disable = tegra241_cmdqv_hw_disable, .device_remove = tegra241_cmdqv_remove, - .drain_queues = tegra241_cmdqv_drain_vintf0_lvcmdqs, + .quiesce_and_drain_queues = tegra241_cmdqv_drain_vintf0_lvcmdqs, /* For user-space use */ .hw_info = tegra241_cmdqv_hw_info, .get_viommu_size = tegra241_cmdqv_get_vintf_size, -- 2.56.0.rc1.315.gc6ed9934b7-goog