From nobody Mon Feb 9 18:19:27 2026 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 6173432825F for ; Mon, 5 Jan 2026 08:58:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767603541; cv=none; b=hyP6K+j8YBprNfY9Oj7Lg3y56v8/lY25pLbsHelck/wEDayxrOy0ACpZSMkQ+ViacprlqBMlq9Us3L3+pvYsFn1p2T/ZeWalluQtcp/rKnjUMf5PFIPcu/8cmQWrdVNmIFkMdW0hVcsuAjAKhUhHGAyHPfpFe87uAxDTWEJGPhk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767603541; c=relaxed/simple; bh=6RtZPZvZXGOqvBVDi0FRjwT5s9+REfOXDSWFSwoOvFg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=a1pFTXmcey7eD8+CRyiMoygGNpY/JdZ99vE7O5b0WtXiOiLOCO5XtbnWtZ6R2TTCqoqBviT7u7cyrUn5+NlNW1kxqsaIO7ET6//2SYyXsYOc/qF92I6hdJD9THYLlU3WXD3tIljni3lEvVVPJac+G2QJT7UXFs1HyVwbBDQN+u4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=wQcwRw7D; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="wQcwRw7D" Received: from mail.ideasonboard.com (unknown [223.190.87.50]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 65A8F22A; Mon, 5 Jan 2026 09:58:37 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1767603517; bh=6RtZPZvZXGOqvBVDi0FRjwT5s9+REfOXDSWFSwoOvFg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=wQcwRw7D/WygBqUQ3w9ISEIm/KKOclyY3ppmpHUEJrm8DcnKECP/9NsudsdEzktal CegKtn2Xb9YxO54bWYwUEzBxwavEbQ46P/7yRMpz0A3GRrI5WJq3m5EdGDR7rfcAuO xvgnDMBZnlgAYcTMmeU0oBEOmy0J5WEP0w3trZjk= From: Jai Luthra Date: Mon, 05 Jan 2026 14:26:50 +0530 Subject: [PATCH v2 4/6] platform/raspberrypi: vchiq-mmal: Use vc-sm-cma to support zero copy 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: quoted-printable Message-Id: <20260105-b4-vc-sm-cma-v2-4-4daea749ced9@ideasonboard.com> References: <20260105-b4-vc-sm-cma-v2-0-4daea749ced9@ideasonboard.com> In-Reply-To: <20260105-b4-vc-sm-cma-v2-0-4daea749ced9@ideasonboard.com> To: Florian Fainelli , Raspberry Pi Kernel Maintenance , bcm-kernel-feedback-list@broadcom.com, Greg Kroah-Hartman , Dave Stevenson Cc: Phil Elwell , Stefan Wahren , Laurent Pinchart , Kieran Bingham , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, Jai Luthra X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=6593; i=jai.luthra@ideasonboard.com; h=from:subject:message-id; bh=hqfrNactmquArSqRZATD0fAov0xH3TdcLOnTetjVoaM=; b=owEBbQKS/ZANAwAKAUPekfkkmnFFAcsmYgBpW3z8kih5ZAwdVO2VeEo2acysdpr7MFYyxCopU i24a5eYC1mJAjMEAAEKAB0WIQRN4NgY5dV16NRar8VD3pH5JJpxRQUCaVt8/AAKCRBD3pH5JJpx Rab/D/0ZK9vBf9thC8OHZJjXID6nBqSP4RmaG8vhbqbGdA/kSB6gpFCmBOgqWat3ofvJI26r8Ew kIndk+GNHtS9ICc0J1D7BVPOgKcTmej2VFD8eFihuMT2s5Zcuu8iJaVSsShgfjX5XJEha2njJ9z Swi9PSYBdxF/WIKZGQct1nqfzDG9eWW4vymsrRtdWmXfluVzWXJDaJGIPtlM7rhNuBQt5Qa1xmt xFcHGCbVcVMh+bPnbmE/uOHXH71uAy/0BNtfbtJ/SipcEfY+PClC51WcdObDzJQHLbvf+cmTh6x b6isW7EewzJ1BxatpWuGy2gYtARTESimK+v8ahbTd2h8UrMmNf0px6vupcxQoTiHH4Jk3YMvVTh GUptfWbuulvxSjr5yz7hBjIZKQkb7y3Szb0VtdmzDmGEuurfoFkxfHlv1PGSQ1KLOrrO2iq+frQ ZuOy/qZX2CMApk0ndZZIOG2TOfxkuGU/+IAx5uTbw9kfYomt0KRMbAwmVyP6/pS77xsmvV9wjZp DDDim3tRNJRXlB6fz7/yUAOnO0jf2VfkMk+jPaA/xk72LKYGP6JfmijlAt7R3/UXCQsvygKMMHM 3kLJ29uGlgiwNNx6XKcUADuB/xe9td0LUdbjsUx6EPX6ufe5iey5cJ/K/S09b1LYmDzymSVBsjN /MP6BtYCn1Y/nVw== X-Developer-Key: i=jai.luthra@ideasonboard.com; a=openpgp; fpr=4DE0D818E5D575E8D45AAFC543DE91F9249A7145 From: Dave Stevenson With the vc-sm-cma driver we can support zero copy of buffers between the kernel and VPU. Add this support to mmal-vchiq. Signed-off-by: Dave Stevenson Signed-off-by: Jai Luthra --- drivers/platform/raspberrypi/vchiq-mmal/Kconfig | 3 +- .../platform/raspberrypi/vchiq-mmal/mmal-common.h | 4 ++ .../platform/raspberrypi/vchiq-mmal/mmal-vchiq.c | 65 ++++++++++++++++++= ++-- .../platform/raspberrypi/vchiq-mmal/mmal-vchiq.h | 1 + 4 files changed, 68 insertions(+), 5 deletions(-) diff --git a/drivers/platform/raspberrypi/vchiq-mmal/Kconfig b/drivers/plat= form/raspberrypi/vchiq-mmal/Kconfig index c99525a0bb4525d497c74984b8b44a9079279b6f..5df9198cdab1786353aeab287f8= 3ea7f0630b317 100644 --- a/drivers/platform/raspberrypi/vchiq-mmal/Kconfig +++ b/drivers/platform/raspberrypi/vchiq-mmal/Kconfig @@ -1,6 +1,7 @@ config BCM2835_VCHIQ_MMAL tristate "BCM2835 MMAL VCHIQ service" - depends on BCM2835_VCHIQ + select BCM2835_VCHIQ + select BCM_VC_SM_CMA help Enables the MMAL API over VCHIQ interface as used for the majority of the multimedia services on VideoCore. diff --git a/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h b/driver= s/platform/raspberrypi/vchiq-mmal/mmal-common.h index b33129403a30347fe762d0377cacbda77434c211..6c5092a68b99594a0234f56b48b= 785fbc611bf5a 100644 --- a/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h +++ b/drivers/platform/raspberrypi/vchiq-mmal/mmal-common.h @@ -50,6 +50,10 @@ struct mmal_buffer { =20 struct mmal_msg_context *msg_context; =20 + struct dma_buf *dma_buf;/* Exported dmabuf fd from videobuf2 */ + void *vcsm_handle; /* VCSM handle having imported the dmabuf */ + u32 vc_handle; /* VC handle to that dmabuf */ + unsigned long length; u32 mmal_flags; s64 dts; diff --git a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c b/drivers= /platform/raspberrypi/vchiq-mmal/mmal-vchiq.c index e76551948bd9c4f60bef1138280fe8dd9d32477b..fe6fb571b745e04545d2d7fe7f3= 7a486792d398f 100644 --- a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c +++ b/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.c @@ -23,12 +23,13 @@ #include #include #include +#include +#include #include #include =20 -#include - #include "mmal-common.h" +#include "mmal-parameters.h" #include "mmal-vchiq.h" #include "mmal-msg.h" =20 @@ -422,8 +423,12 @@ buffer_from_host(struct vchiq_mmal_instance *instance, =20 /* buffer header */ m.u.buffer_from_host.buffer_header.cmd =3D 0; - m.u.buffer_from_host.buffer_header.data =3D - (u32)(unsigned long)buf->buffer; + if (port->zero_copy) + m.u.buffer_from_host.buffer_header.data =3D buf->vc_handle; + else + m.u.buffer_from_host.buffer_header.data =3D + (u32)(unsigned long)buf->buffer; + m.u.buffer_from_host.buffer_header.alloc_size =3D buf->buffer_size; m.u.buffer_from_host.buffer_header.length =3D 0; /* nothing used yet */ m.u.buffer_from_host.buffer_header.offset =3D 0; /* no offset */ @@ -484,6 +489,20 @@ static void buffer_to_host_cb(struct vchiq_mmal_instan= ce *instance, =20 msg_context->u.bulk.status =3D msg->h.status; =20 + } else if (msg->u.buffer_from_host.is_zero_copy) { + /* + * Zero copy buffer, so nothing to do. + * Copy buffer info and make callback. + */ + msg_context->u.bulk.buffer_used =3D + msg->u.buffer_from_host.buffer_header.length; + msg_context->u.bulk.mmal_flags =3D + msg->u.buffer_from_host.buffer_header.flags; + msg_context->u.bulk.dts =3D + msg->u.buffer_from_host.buffer_header.dts; + msg_context->u.bulk.pts =3D + msg->u.buffer_from_host.buffer_header.pts; + } else if (msg->u.buffer_from_host.buffer_header.length =3D=3D 0) { /* empty buffer */ if (msg->u.buffer_from_host.buffer_header.flags & @@ -1431,6 +1450,9 @@ int vchiq_mmal_port_parameter_set(struct vchiq_mmal_i= nstance *instance, =20 mutex_unlock(&instance->vchiq_mutex); =20 + if (parameter =3D=3D MMAL_PARAMETER_ZERO_COPY && !ret) + port->zero_copy =3D !!(*(bool *)value); + return ret; } EXPORT_SYMBOL_GPL(vchiq_mmal_port_parameter_set); @@ -1599,6 +1621,31 @@ int vchiq_mmal_submit_buffer(struct vchiq_mmal_insta= nce *instance, unsigned long flags =3D 0; int ret; =20 + /* + * We really want to do this in mmal_vchi_buffer_init but can't as + * videobuf2 won't let us have the dmabuf there. + */ + if (port->zero_copy && buffer->dma_buf && !buffer->vcsm_handle) { + pr_debug("%s: import dmabuf %p\n", __func__, buffer->dma_buf); + ret =3D vc_sm_cma_import_dmabuf(buffer->dma_buf, + &buffer->vcsm_handle); + if (ret) { + pr_err("%s: vc_sm_import_dmabuf_fd failed, ret %d\n", + __func__, ret); + return ret; + } + + buffer->vc_handle =3D vc_sm_cma_int_handle(buffer->vcsm_handle); + if (!buffer->vc_handle) { + pr_err("%s: vc_sm_int_handle failed %d\n", + __func__, ret); + vc_sm_cma_free(buffer->vcsm_handle); + return ret; + } + pr_debug("%s: import dmabuf %p - got vc handle %08X\n", + __func__, buffer->dma_buf, buffer->vc_handle); + } + ret =3D buffer_from_host(instance, port, buffer); if (ret =3D=3D -EINVAL) { /* Port is disabled. Queue for when it is enabled. */ @@ -1632,6 +1679,16 @@ int mmal_vchi_buffer_cleanup(struct mmal_buffer *buf) release_msg_context(msg_context); buf->msg_context =3D NULL; =20 + if (buf->vcsm_handle) { + int ret; + + pr_debug("%s: vc_sm_cma_free on handle %p\n", __func__, + buf->vcsm_handle); + ret =3D vc_sm_cma_free(buf->vcsm_handle); + if (ret) + pr_err("%s: vcsm_free failed, ret %d\n", __func__, ret); + buf->vcsm_handle =3D 0; + } return 0; } EXPORT_SYMBOL_GPL(mmal_vchi_buffer_cleanup); diff --git a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h b/drivers= /platform/raspberrypi/vchiq-mmal/mmal-vchiq.h index 8c3959f6f97fb21bcaf2f21589ef291e754e7c19..9d31816f5be54d74bfdf42381b3= 8e340279ffee4 100644 --- a/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h +++ b/drivers/platform/raspberrypi/vchiq-mmal/mmal-vchiq.h @@ -49,6 +49,7 @@ typedef void (*vchiq_mmal_buffer_cb)(struct vchiq_mmal_in= stance *instance, =20 struct vchiq_mmal_port { bool enabled; + u32 zero_copy:1; u32 handle; u32 type; /* port type, cached to use on port info set */ u32 index; /* port index, cached to use on port info set */ --=20 2.52.0