From patchwork Tue Oct 17 14:47:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Gaignard X-Patchwork-Id: 13425304 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6A01CDB483 for ; Tue, 17 Oct 2023 14:48:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344125AbjJQOsJ (ORCPT ); Tue, 17 Oct 2023 10:48:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344105AbjJQOsI (ORCPT ); Tue, 17 Oct 2023 10:48:08 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5614F1; Tue, 17 Oct 2023 07:48:05 -0700 (PDT) Received: from benjamin-XPS-13-9310.. (unknown [IPv6:2a01:e0a:120:3210:7205:da49:a7e8:59f8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: benjamin.gaignard) by madras.collabora.co.uk (Postfix) with ESMTPSA id 4396B66072F6; Tue, 17 Oct 2023 15:48:04 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1697554084; bh=7foNNb6amO3+FMMwIl173lEOz6gYhJG/dA79F9jwpAU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DnM+rhD/8S8duXjkkh8w5r/Lh6WgtvuO8T7PkO2j1MSfgB2TDFlKvv99zmEAhCu/v o0Z7Oi0VHkw1I3uLV8fYzw5JVW5ltgX8D12pZ2Q7x2rxk60kWb7+anXwyMFrYrcPvm v/oOv/D2Vts8ZUJYm1gVYHL4sDG/hwZVEA6QDUlJM02Xw26B6+O3fXN6UPha6cTuMP S6toJW93MkTIyqOf59mHw0LNF/1SJXKfSPSjDBuSxIJ1mbn5/uzl0QQ+rcIBvSHVk2 aXmFIvZWyOG+94Tq6/1aFuPSsL1HrkEzpFB3gjnHyS4P9fkcab3VSl/HNBd4yFhzjS bPXnYd3yOIRkg== From: Benjamin Gaignard To: mchehab@kernel.org, tfiga@chromium.org, m.szyprowski@samsung.com, ming.qian@nxp.com, ezequiel@vanguardiasur.com.ar, p.zabel@pengutronix.de, gregkh@linuxfoundation.org, hverkuil-cisco@xs4all.nl, nicolas.dufresne@collabora.com Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-staging@lists.linux.dev, kernel@collabora.com, Benjamin Gaignard Subject: [PATCH v12 02/56] media: videobuf2: Rework offset 'cookie' encoding pattern Date: Tue, 17 Oct 2023 16:47:02 +0200 Message-Id: <20231017144756.34719-3-benjamin.gaignard@collabora.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231017144756.34719-1-benjamin.gaignard@collabora.com> References: <20231017144756.34719-1-benjamin.gaignard@collabora.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Change how offset 'cookie' field value is computed to make possible to use more buffers. The maximum number of buffers depends of PAGE_SHIFT value and can go up to 0x7fff when PAGE_SHIFT = 12. With this encoding pattern we know the maximum number that a queue could store so we can check it at queue init time. It also make easier and faster to find buffer and plane from using the offset field. Change __find_plane_by_offset() prototype to return the video buffer itself rather than it index. Signed-off-by: Benjamin Gaignard --- .../media/common/videobuf2/videobuf2-core.c | 73 +++++++++---------- 1 file changed, 35 insertions(+), 38 deletions(-) diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index a5e57affeb30..09be8e026044 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -31,6 +31,11 @@ #include +#define PLANE_INDEX_SHIFT (PAGE_SHIFT + 3) +#define PLANE_INDEX_MASK 0x7 +#define MAX_BUFFER_INDEX BIT_MASK(30 - PLANE_INDEX_SHIFT) +#define BUFFER_INDEX_MASK (MAX_BUFFER_INDEX - 1) + static int debug; module_param(debug, int, 0644); @@ -358,21 +363,27 @@ static void __setup_offsets(struct vb2_buffer *vb) unsigned int plane; unsigned long offset = 0; - if (vb->index) { - struct vb2_buffer *prev = q->bufs[vb->index - 1]; - struct vb2_plane *p = &prev->planes[prev->num_planes - 1]; - - offset = PAGE_ALIGN(p->m.offset + p->length); - } + /* + * The offset "cookie" value has the following constraints: + * - a buffer can have up to 8 planes. + * - v4l2 mem2mem uses bit 30 to distinguish between + * OUTPUT (aka "source", bit 30 is 0) and + * CAPTURE (aka "destination", bit 30 is 1) buffers. + * - must be page aligned + * That led to this bit mapping when PAGE_SHIFT = 12: + * |30 |29 15|14 12|11 0| + * |DST_QUEUE_OFF_BASE|buffer index|plane index| 0 | + * where there are 15 bits to store the buffer index. + * Depending on PAGE_SHIFT value we can have fewer bits + * to store the buffer index. + */ + offset = vb->index << PLANE_INDEX_SHIFT; for (plane = 0; plane < vb->num_planes; ++plane) { - vb->planes[plane].m.offset = offset; + vb->planes[plane].m.offset = offset + (plane << PAGE_SHIFT); dprintk(q, 3, "buffer %d, plane %d offset 0x%08lx\n", vb->index, plane, offset); - - offset += vb->planes[plane].length; - offset = PAGE_ALIGN(offset); } } @@ -2188,10 +2199,9 @@ EXPORT_SYMBOL_GPL(vb2_core_streamoff); * __find_plane_by_offset() - find plane associated with the given offset */ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long offset, - unsigned int *_buffer, unsigned int *_plane) + struct vb2_buffer **vb, unsigned int *plane) { - struct vb2_buffer *vb; - unsigned int buffer, plane; + unsigned int buffer; /* * Sanity checks to ensure the lock is held, MEMORY_MMAP is @@ -2209,24 +2219,15 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long offset, return -EBUSY; } - /* - * Go over all buffers and their planes, comparing the given offset - * with an offset assigned to each plane. If a match is found, - * return its buffer and plane numbers. - */ - for (buffer = 0; buffer < q->num_buffers; ++buffer) { - vb = q->bufs[buffer]; + /* Get buffer and plane from the offset */ + buffer = (offset >> PLANE_INDEX_SHIFT) & BUFFER_INDEX_MASK; + *plane = (offset >> PAGE_SHIFT) & PLANE_INDEX_MASK; - for (plane = 0; plane < vb->num_planes; ++plane) { - if (vb->planes[plane].m.offset == offset) { - *_buffer = buffer; - *_plane = plane; - return 0; - } - } - } + if (buffer >= q->num_buffers || *plane >= q->bufs[buffer]->num_planes) + return -EINVAL; - return -EINVAL; + *vb = q->bufs[buffer]; + return 0; } int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, @@ -2306,7 +2307,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) { unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; struct vb2_buffer *vb; - unsigned int buffer = 0, plane = 0; + unsigned int plane = 0; int ret; unsigned long length; @@ -2335,12 +2336,10 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) * Find the plane corresponding to the offset passed by userspace. This * will return an error if not MEMORY_MMAP or file I/O is in progress. */ - ret = __find_plane_by_offset(q, offset, &buffer, &plane); + ret = __find_plane_by_offset(q, offset, &vb, &plane); if (ret) goto unlock; - vb = q->bufs[buffer]; - /* * MMAP requires page_aligned buffers. * The buffer length was page_aligned at __vb2_buf_mem_alloc(), @@ -2368,7 +2367,7 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) if (ret) return ret; - dprintk(q, 3, "buffer %d, plane %d successfully mapped\n", buffer, plane); + dprintk(q, 3, "buffer %u, plane %d successfully mapped\n", vb->index, plane); return 0; } EXPORT_SYMBOL_GPL(vb2_mmap); @@ -2382,7 +2381,7 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q, { unsigned long offset = pgoff << PAGE_SHIFT; struct vb2_buffer *vb; - unsigned int buffer, plane; + unsigned int plane; void *vaddr; int ret; @@ -2392,12 +2391,10 @@ unsigned long vb2_get_unmapped_area(struct vb2_queue *q, * Find the plane corresponding to the offset passed by userspace. This * will return an error if not MEMORY_MMAP or file I/O is in progress. */ - ret = __find_plane_by_offset(q, offset, &buffer, &plane); + ret = __find_plane_by_offset(q, offset, &vb, &plane); if (ret) goto unlock; - vb = q->bufs[buffer]; - vaddr = vb2_plane_vaddr(vb, plane); mutex_unlock(&q->mmap_lock); return vaddr ? (unsigned long)vaddr : -EINVAL;