From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (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 1888F3168EE for ; Mon, 17 Aug 2026 04:48:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786942104; cv=none; b=jQ+xMEv9bwQxeAF0vvr2jj/tLdAU9ZwBaK46W/SsS0TKMRkB6BqbK+hRIEOBmOqBaXWNMIgEGHp18NJyvve8Vbiabm5EYOiKYnnJK06FBydfxWA4Z8DBkCTjFNJK/46k3k8Ha8PPZOV2eQCwwUUXNkbxatAGtYxd9/Q66MgnxCw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786942104; c=relaxed/simple; bh=hIrbWmJD0ELmEoKWXa2F2uGx8rOTlGvAJu1hlS5UQzk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=g5+0TuqCID4J9lZODh7v694Jd0g38J+7jaRp7TRnPRFBA+o8LcKXPK4VDE8ST++br1x3zmJPe1OfrdW6Di5SRt4+lmuWKsI8stLOIoSKLB30B5SYWwqQVxrShb2/G83KJ5ESi1WT2x+5LE2ocYI52hyyNWzCIYrhFeC+M2s8FCc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=OpZXLdGi; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=ebUK+ijZ; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="OpZXLdGi"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="ebUK+ijZ" Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67GLCuFe4058882 for ; Mon, 17 Aug 2026 04:48:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= 5sD4xExdiA0Vnoacy0mh+mqYbupmmmaZLz3mIlSwgrI=; b=OpZXLdGiOJ6Aku3W /MbHH2UpHpVxMLw7n/qEVrdY7mOnSDdWOgGSsVQMckcVQANmKDI26etWyN9rpFh8 zg/N2NiCow0BBhhG0VJDITiFh1Xmk1H2k2lWczgYs2J92zC7MzoUs2Odr85QUEeA S8JzHreU+SvuQ6FF/b4Ecexl6oigcmcM987RgM9BJC4KJ+NbsQUlpdb81PYlT4yg fAG2YMsIw8Z9N0fqiii67P1xq8xcKtzjVIvjrL6v5yxl6mAiqDqMGehn6Ez2XG6Q PIwEYboDzgzLaIVzwZsFiWJhg3J/jyhlTdRSlRBCs0NXBc4hE/Uyh55Dp84k6+Ih SL2VBA== Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4g2hd7w1vx-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Mon, 17 Aug 2026 04:48:22 +0000 (GMT) Received: by mail-pf1-f197.google.com with SMTP id d2e1a72fcca58-8488ac68185so6147277b3a.2 for ; Sun, 16 Aug 2026 21:48:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1786942102; x=1787546902; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=5sD4xExdiA0Vnoacy0mh+mqYbupmmmaZLz3mIlSwgrI=; b=ebUK+ijZAUwCRLIFG3ywEtObZWzxjYdGA/hNxkb4XmaUM7q9ocBkJVaIHy6rztxy3I hI8HS70WBzOqPlAgEsBPjBaBzggxDpphCMeG0fsuyUC4L8NEwV0ZLOH3Ul9cnaBDawgl KeEkxDCkCVci51ZRMIiIZ/cJG+yfv/ydiZMIrcaNe+Uuobnx5k6GEgoa+56VBuLTFjl6 MHdVGxxHDqJ5nn9MIfi58VkYc4m8OQsRl3Cgcx06vlxPIQ3G4wmQmHgKLSsTVbPPpV/C rl8/V5C+aDCsSGjT/WHCB3/VZs+ytfB1luTGgGQzGl4chHPa16Flxgw61UiBsGvnztec S2iQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786942102; x=1787546902; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=5sD4xExdiA0Vnoacy0mh+mqYbupmmmaZLz3mIlSwgrI=; b=iS3k0I8+gvc4zQueBdH8BEd9B71tRd6EJVs8Ltcim2v1NP+AIWvaYJBqspwBfX6FPW HrQXw3SKtGvPl2vSkKWSGZ0t1BpdzSCG+O7Y8S0sFhSNgeY1/WZWoDuDrBAUkLbnqjfn iLWBPOMkW9/ZJzD4/IkzC4nwScPxfTW8plgJtO6GIUXYbXtKJTD+Vp9+IZRDlYssAwFz suurbSfJ5almWfcqADc1z5jfwW7dcA408/W01UD8VXUrWQFtoM9wwmEXkjkv9XmucmOg htl7nmwknSJFiBaxHxg7jiTUyDhenAocb1jQBUI1F2a6ORITkXtld2m/PsC9RYtQlKNA HyjA== X-Forwarded-Encrypted: i=1; AHgh+Rqc+BNvxzi4fesd+dwVKKt+11De8wb88J4C+T/HxiKsoTJIc7vd54Z1YBnkIdd5egUUWbK+4Kf6XtGb610=@vger.kernel.org X-Gm-Message-State: AOJu0YxoFr3gq8F1Vaf2X3D7QoHN6JEgyJ/R4Cua8yJC3ijfzAM3wwEg LAO+4Y3ME3hQ6uXfiryq8bhTz2Y8ip8yx7Z8XuQkDPEHlBagFMucGeTTq2loBrdsfHK7hRShrqy /CI+k7/ssL5Qn4VR1hxPs+Xy62bakuxOkV2GuxbBNI4ZJWtsBH8ytGfHF5lMnJcH3qWA= X-Gm-Gg: AR+sD10+1I4gXRJ6ui6T3vKsJ7BYI0UmBxS3jfrP2aMCSplglLJDN16bQGh2nOzfNzf GS/WO86NU1/MkjdrEy6j4XKuaPbHTaob+nulQP4dHFdkGJv7/rYu/KLcbVu5zkEdT1u2ykTn/i7 XpwLCro5uSdhXTTsDtixCyBiD5vbvB6O2HIGRY4axsH03rBsYPOht6v0ivp79OJyM7C71MkslsZ aABnS5flL9Nymy0x+3QhmZZ8y2CiUlBzMKJh9RygBa4c1QkyPHV1hSaSPTkrkxfwvwkPQ/KHQvH V/D+OR6fuicAm83Lo6w7e39zYYRHveHAaQ+Fg2912wmS141IaL1cVlIekZ6p0qYqtiGiPO3Nogm WUHGMxhyHdsOYCWT/nc9McicOvuezdGfG X-Received: by 2002:a05:6a00:f86:b0:847:8504:9946 with SMTP id d2e1a72fcca58-84fde2e8c72mr22514543b3a.25.1786942101546; Sun, 16 Aug 2026 21:48:21 -0700 (PDT) X-Received: by 2002:a05:6a00:f86:b0:847:8504:9946 with SMTP id d2e1a72fcca58-84fde2e8c72mr22514485b3a.25.1786942101065; Sun, 16 Aug 2026 21:48:21 -0700 (PDT) Received: from hu-ekangupt-hyd.qualcomm.com ([202.46.23.25]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-8517d046638sm2149250b3a.27.2026.08.16.21.48.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 16 Aug 2026 21:48:20 -0700 (PDT) From: Ekansh Gupta Date: Mon, 17 Aug 2026 10:17:39 +0530 Subject: [PATCH v2 04/15] accel/qda: Add compute bus for QDA context banks Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260817-qda-v2-v2-4-69a02e9090d4@oss.qualcomm.com> References: <20260817-qda-v2-v2-0-69a02e9090d4@oss.qualcomm.com> In-Reply-To: <20260817-qda-v2-v2-0-69a02e9090d4@oss.qualcomm.com> To: Oded Gabbay , Jonathan Corbet , Shuah Khan , Randy Dunlap , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= Cc: Bharath Kumar , Chenna Kesava Raju , srinivas.kandagatla@oss.qualcomm.com, dmitry.baryshkov@oss.qualcomm.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org, llvm@lists.linux.dev, iommu@lists.linux.dev, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, Ekansh Gupta X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1786942058; l=6606; i=ekansh.gupta@oss.qualcomm.com; s=20260223; h=from:subject:message-id; bh=hIrbWmJD0ELmEoKWXa2F2uGx8rOTlGvAJu1hlS5UQzk=; b=O2xo35ZfWnWAz0OLd+pRlGnuzFMigKI6sN4E66Oi933RmI69+04Ylda9tdZKP33nz5sbGtaBv qqJSz+e5gCUCZEbjcHI8VGSfdLsMX0ZGvZvGJE1JJhG9qS2SCwELQ2P X-Developer-Key: i=ekansh.gupta@oss.qualcomm.com; a=ed25519; pk=n0SepARizye+pYjhjg1RA5J+Nq4+IJbyRcBybU+/ERQ= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODE3MDAzMyBTYWx0ZWRfX165B5rzNVlBM xIzMzA0GDqdb7Fw6oh23uWif6rA7hUJD5dULw5haWH1Ed6zBK795UQ6bUxVdcus2R1YNA90R24f MpaO62x1wRlJLQ69Jk+LXmJYfh7VOOdszjZEGi8VM6ZeYWtPZq0XKpsp2C2gGlc92GYkfQrc6T7 SGOS6ks2q6MldYs7lRXFqr3vCbJ5tSooF1vGCGcvLM6UT96WcGOqY5QqrM8+Ra81rokkTyESdOR AGN5/UKG9VaJvx1+j4jeP4s3Gn33/M4np/fibSA20kbUX4of4tuLxkS+5jpWgqDasacCWVC7auY N3dzS+k9G2Em3VtjBhd66zlqYVrpxwZtkkqBRW+UsniyqmnC2A0IWmRxfbdEhKHGXOTWE7yH4NQ N5dIMiVoWNTpNO2IaTwyJzK4Q4mmop/xYbiazW4rhGrs2K7ha+FLQkCZhgXEHlpq1FkYKLRzns1 E3eFoUsVhHu8n3EHzdQ== X-Proofpoint-GUID: sgSu_j-QY1NeaLGH63iiyUBQIyYeuFKj X-Authority-Analysis: v=2.4 cv=Ja2Ma0KV c=1 sm=1 tr=0 ts=6a829296 cx=c_pps a=rEQLjTOiSrHUhVqRoksmgQ==:117 a=ZePRamnt/+rB5gQjfz0u9A==:17 a=IkcTkHD0fZMA:10 a=Sv0fKeRqtYgA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=YMgV9FUhrdKAYTUUvYB2:22 a=EUspDBNiAAAA:8 a=DAPPgmGbAxSwGNae-agA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 a=2VI0MkxyNR6bbpdq8BZq:22 X-Proofpoint-ORIG-GUID: sgSu_j-QY1NeaLGH63iiyUBQIyYeuFKj X-Proofpoint-Spam-Info: AW1haW4tMjYwODE3MDAzMyBTYWx0ZWRfX7cpRT0emIWF6 ihdCKTlJTK5f+tLr+a7m2aX99jw6w3KWWT1hN1wQPkl4W0q8YJaxLdqLDuJI9y9bHpCZ6IroRcH e27VBvEybhEbMGdBN5/A3bTIe/IXoco= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-16_06,2026-08-12_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 spamscore=0 suspectscore=0 adultscore=0 bulkscore=0 impostorscore=0 clxscore=1015 phishscore=0 lowpriorityscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608170033 Introduce a custom virtual bus (qda-compute-cb) for managing IOMMU context bank (CB) devices used by the QDA driver. IOMMU context banks are synthetic constructs — they are not real platform devices and do not appear as children of a platform bus node in the device tree. Using a platform driver to represent them was therefore incorrect and introduced a probe-ordering race: device nodes were created before the RPMsg channel resources were fully initialized, and because probe runs asynchronously, user-space could open a CB device and attempt to start a session before the underlying transport was ready. The qda-compute-cb bus solves this by allowing the main QDA driver to create CB devices explicitly and under its own control, making their lifetime strictly subordinate to the parent qda_dev. The bus provides a dma_configure callback that calls of_dma_configure() so that each CB device gets its own IOMMU domain derived from its device-tree node, enabling per-session memory isolation. The bus type and the CB device constructor (create_qda_cb_device) are exported for use by the QDA memory manager. A hidden Kconfig symbol (DRM_ACCEL_QDA_COMPUTE_BUS) is introduced and automatically selected by DRM_ACCEL_QDA so that the bus initialisation runs via postcore_initcall before any QDA device probes. Assisted-by: Claude:claude-sonnet-5 Reviewed-by: Dmitry Baryshkov Signed-off-by: Ekansh Gupta --- drivers/accel/Makefile | 1 + drivers/accel/qda/Kconfig | 4 ++ drivers/accel/qda/Makefile | 2 + drivers/accel/qda/qda_compute_bus.c | 80 +++++++++++++++++++++++++++++++++++++ include/linux/qda_compute_bus.h | 33 +++++++++++++++ 5 files changed, 120 insertions(+) diff --git a/drivers/accel/Makefile b/drivers/accel/Makefile index 58c08dd5f389..9ed843cd293f 100644 --- a/drivers/accel/Makefile +++ b/drivers/accel/Makefile @@ -6,4 +6,5 @@ obj-$(CONFIG_DRM_ACCEL_HABANALABS) += habanalabs/ obj-$(CONFIG_DRM_ACCEL_IVPU) += ivpu/ obj-$(CONFIG_DRM_ACCEL_QAIC) += qaic/ obj-$(CONFIG_DRM_ACCEL_QDA) += qda/ +obj-$(CONFIG_DRM_ACCEL_QDA_COMPUTE_BUS) += qda/ obj-$(CONFIG_DRM_ACCEL_ROCKET) += rocket/ \ No newline at end of file diff --git a/drivers/accel/qda/Kconfig b/drivers/accel/qda/Kconfig index e679cd00f092..e288458b63ab 100644 --- a/drivers/accel/qda/Kconfig +++ b/drivers/accel/qda/Kconfig @@ -3,11 +3,15 @@ # Qualcomm DSP accelerator driver # +config DRM_ACCEL_QDA_COMPUTE_BUS + bool + config DRM_ACCEL_QDA tristate "Qualcomm DSP accelerator" depends on DRM_ACCEL depends on ARCH_QCOM || COMPILE_TEST depends on RPMSG + select DRM_ACCEL_QDA_COMPUTE_BUS help Enables the DRM-based accelerator driver for Qualcomm's Hexagon DSPs. This driver provides a standardized interface for offloading computational diff --git a/drivers/accel/qda/Makefile b/drivers/accel/qda/Makefile index dbe809067a8b..424176f652a5 100644 --- a/drivers/accel/qda/Makefile +++ b/drivers/accel/qda/Makefile @@ -8,3 +8,5 @@ obj-$(CONFIG_DRM_ACCEL_QDA) := qda.o qda-y := \ qda_drv.o \ qda_rpmsg.o + +obj-$(CONFIG_DRM_ACCEL_QDA_COMPUTE_BUS) += qda_compute_bus.o diff --git a/drivers/accel/qda/qda_compute_bus.c b/drivers/accel/qda/qda_compute_bus.c new file mode 100644 index 000000000000..69ba3c1396b5 --- /dev/null +++ b/drivers/accel/qda/qda_compute_bus.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. +#include +#include +#include +#include +#include +#include +#include + +static int qda_cb_bus_dma_configure(struct device *dev) +{ + return of_dma_configure(dev, dev->of_node, true); +} + +const struct bus_type qda_cb_bus_type = { + .name = "qda-compute-cb", + .dma_configure = qda_cb_bus_dma_configure, +}; +EXPORT_SYMBOL_GPL(qda_cb_bus_type); + +static void release_qda_cb_device(struct device *dev) +{ + of_node_put(dev->of_node); + kfree(dev); +} + +struct device *qda_cb_device_create(struct device *parent_device, u64 dma_mask, + struct device_node *of_node, const char *fmt, ...) +{ + struct device *dev; + va_list args; + char *name; + int ret; + + va_start(args, fmt); + name = kvasprintf(GFP_KERNEL, fmt, args); + va_end(args); + if (!name) + return ERR_PTR(-ENOMEM); + + dev = kzalloc_obj(*dev); + if (!dev) { + kfree(name); + return ERR_PTR(-ENOMEM); + } + + dev->release = release_qda_cb_device; + dev->bus = &qda_cb_bus_type; + dev->parent = parent_device; + dev->coherent_dma_mask = dma_mask; + dev->dma_mask = &dev->coherent_dma_mask; + dev->of_node = of_node_get(of_node); + + dev_set_name(dev, "%s", name); + kfree(name); + + ret = device_register(dev); + if (ret) { + put_device(dev); + return ERR_PTR(ret); + } + + return dev; +} +EXPORT_SYMBOL_GPL(qda_cb_device_create); + +static int __init qda_cb_bus_init(void) +{ + int err; + + err = bus_register(&qda_cb_bus_type); + if (err < 0) { + pr_err("qda-compute-cb bus registration failed: %d\n", err); + return err; + } + return 0; +} + +postcore_initcall(qda_cb_bus_init); diff --git a/include/linux/qda_compute_bus.h b/include/linux/qda_compute_bus.h new file mode 100644 index 000000000000..cf7913b79741 --- /dev/null +++ b/include/linux/qda_compute_bus.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + */ + +#ifndef __QDA_COMPUTE_BUS_H__ +#define __QDA_COMPUTE_BUS_H__ + +#include + +/* + * Custom bus type for QDA compute context bank (CB) devices + * + * This bus type is used for manually created CB devices that represent + * IOMMU context banks. The custom bus allows proper IOMMU configuration + * and device management for these virtual devices. + */ +#ifdef CONFIG_DRM_ACCEL_QDA_COMPUTE_BUS +extern const struct bus_type qda_cb_bus_type; + +struct device *qda_cb_device_create(struct device *parent_device, u64 dma_mask, + struct device_node *of_node, const char *fmt, ...) +#else +static inline struct device *qda_cb_device_create(struct device *parent_device, + u64 dma_mask, + struct device_node *of_node, + const char *fmt, ...) +{ + return ERR_PTR(-ENODEV); +} +#endif + +#endif /* __QDA_COMPUTE_BUS_H__ */ -- 2.34.1