From patchwork Mon Aug 1 17:04:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rob Clark X-Patchwork-Id: 594795 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 88193C00144 for ; Mon, 1 Aug 2022 17:04:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232395AbiHAREf (ORCPT ); Mon, 1 Aug 2022 13:04:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232156AbiHAREc (ORCPT ); Mon, 1 Aug 2022 13:04:32 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B9393336D; Mon, 1 Aug 2022 10:04:31 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id w10so11065337plq.0; Mon, 01 Aug 2022 10:04:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=TkCavpnUSJ7vycAkcy6P7E6qdN3Z1ej/wDjztPEV1Xs=; b=mcZ6MXoEnw1JToD2hyRhIZ7pGnefjHTTti+cjwuy9wEhPI6rOCmXGKRxCCyNgpQVGQ 8ESBynZewyeP+SZ1jLeB8wARO2Qg6Ez0lCcZ4hW5Ad8Ij6Gv9RiSk4lnu4tQPos6Vs8t Wvq0L05TVB+4rbq4F2Qbli+EVXlKvq50rJMQBYzqGnXZ4V7U37sqyIGaTCR+TY+fWwKF OOkDDbKQsUeSAysdawliNu53PRsS1Ms5xw86ZQOU9y+IdzyNh61KweuH7ZDuCKbTwsxq HD4OvuUg7ZP692EA+mU+yv7FDvEb1AXFoMHE+NNT9MVfirvSgmZL52BvG/lfo29jqZoD uHkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=TkCavpnUSJ7vycAkcy6P7E6qdN3Z1ej/wDjztPEV1Xs=; b=5V9KOejNftjF02X6AyPWYfFXr2q47bCy2Rf4zHxq5DaJxAc9/EYMiZnhWzDGdC4zx9 Vrscv6THvK138YETVwlsXaiCzaElmRplwOmVmPVEm/Xu3hF9RN4hc+dmdS3TFOO96haK e05tEA2yWRmP7Ej9osrbdusoItnj2s7XFHNDjyS4dYV/l/jZG/hMWmJvUyLkQHwlbLHF a8SQFByAnE0+6a/FgxIv2X0tsetKv5iylqpEkIo40h3mZTuSdi+5XuZcwqZbKsFoIWvK YqMjjkcBTOdOsKLr7yaH316G8dcTj5Vgmhi9I0dknYolNfA7kWquMAFlF7Mu6qAHPI7F c1pg== X-Gm-Message-State: ACgBeo2Sqii70qw3+0C3rWNVrnz8CV9TrR0Qlt8MG3/h4MrgHMKPyPKe 3FvcbOtOh+GX+mRs2a/wSOq9ZlIeoXI= X-Google-Smtp-Source: AA6agR52MvgLOLsM9cuZ5dMaC0PMt05gnbIz5aCroJo5wVmxWfOtz0BXNBd1TvyuExGOeaD5YCdI6Q== X-Received: by 2002:a17:903:22cb:b0:16e:e31f:5197 with SMTP id y11-20020a17090322cb00b0016ee31f5197mr7430704plg.23.1659373470488; Mon, 01 Aug 2022 10:04:30 -0700 (PDT) Received: from localhost ([2a00:79e1:abd:4a00:2703:3c72:eb1a:cffd]) by smtp.gmail.com with ESMTPSA id f13-20020a170902ce8d00b0016d5626af4fsm10105279plg.21.2022.08.01.10.04.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Aug 2022 10:04:29 -0700 (PDT) From: Rob Clark To: dri-devel@lists.freedesktop.org Cc: freedreno@lists.freedesktop.org, Rob Clark , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= , =?utf-8?b?SsOp?= =?utf-8?b?csO0bWUgUG91aWxsZXI=?= , linux-media@vger.kernel.org (open list:DMA BUFFER SHARING FRAMEWORK), linaro-mm-sig@lists.linaro.org (moderated list:DMA BUFFER SHARING FRAMEWORK), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 1/3] dma-buf: Add ioctl to query mmap info Date: Mon, 1 Aug 2022 10:04:55 -0700 Message-Id: <20220801170459.1593706-2-robdclark@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220801170459.1593706-1-robdclark@gmail.com> References: <20220801170459.1593706-1-robdclark@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Rob Clark This is a fairly narrowly focused interface, providing a way for a VMM in userspace to tell the guest kernel what pgprot settings to use when mapping a buffer to guest userspace. For buffers that get mapped into guest userspace, virglrenderer returns a dma-buf fd to the VMM (crosvm or qemu). In addition to mapping the pages into the guest VM, it needs to report to drm/virtio in the guest the cache settings to use for guest userspace. In particular, on some architectures, creating aliased mappings with different cache attributes is frowned upon, so it is important that the guest mappings have the same cache attributes as any potential host mappings. Signed-off-by: Rob Clark --- v2. fix compiler warning drivers/dma-buf/dma-buf.c | 26 ++++++++++++++++++++++++++ include/linux/dma-buf.h | 7 +++++++ include/uapi/linux/dma-buf.h | 28 ++++++++++++++++++++++++++++ 3 files changed, 61 insertions(+) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 32f55640890c..87c52f080274 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -326,6 +326,29 @@ static long dma_buf_set_name(struct dma_buf *dmabuf, const char __user *buf) return 0; } +static long dma_buf_info(struct dma_buf *dmabuf, void __user *uarg) +{ + struct dma_buf_info arg; + + if (copy_from_user(&arg, uarg, sizeof(arg))) + return -EFAULT; + + switch (arg.param) { + case DMA_BUF_INFO_VM_PROT: + if (!dmabuf->ops->mmap_info) + return -ENOSYS; + arg.value = dmabuf->ops->mmap_info(dmabuf); + break; + default: + return -EINVAL; + } + + if (copy_to_user(uarg, &arg, sizeof(arg))) + return -EFAULT; + + return 0; +} + static long dma_buf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -369,6 +392,9 @@ static long dma_buf_ioctl(struct file *file, case DMA_BUF_SET_NAME_B: return dma_buf_set_name(dmabuf, (const char __user *)arg); + case DMA_BUF_IOCTL_INFO: + return dma_buf_info(dmabuf, (void __user *)arg); + default: return -ENOTTY; } diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 71731796c8c3..6f4de64a5937 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -283,6 +283,13 @@ struct dma_buf_ops { */ int (*mmap)(struct dma_buf *, struct vm_area_struct *vma); + /** + * @mmap_info: + * + * Return mmapping info for the buffer. See DMA_BUF_INFO_VM_PROT. + */ + int (*mmap_info)(struct dma_buf *); + int (*vmap)(struct dma_buf *dmabuf, struct iosys_map *map); void (*vunmap)(struct dma_buf *dmabuf, struct iosys_map *map); }; diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h index b1523cb8ab30..a41adac0f46a 100644 --- a/include/uapi/linux/dma-buf.h +++ b/include/uapi/linux/dma-buf.h @@ -85,6 +85,32 @@ struct dma_buf_sync { #define DMA_BUF_NAME_LEN 32 + +/** + * struct dma_buf_info - Query info about the buffer. + */ +struct dma_buf_info { + +#define DMA_BUF_INFO_VM_PROT 1 +# define DMA_BUF_VM_PROT_WC 0 +# define DMA_BUF_VM_PROT_CACHED 1 + + /** + * @param: Which param to query + * + * DMA_BUF_INFO_BM_PROT: + * Query the access permissions of userspace mmap's of this buffer. + * Returns one of DMA_BUF_VM_PROT_x + */ + __u32 param; + __u32 pad; + + /** + * @value: Return value of the query. + */ + __u64 value; +}; + #define DMA_BUF_BASE 'b' #define DMA_BUF_IOCTL_SYNC _IOW(DMA_BUF_BASE, 0, struct dma_buf_sync) @@ -95,4 +121,6 @@ struct dma_buf_sync { #define DMA_BUF_SET_NAME_A _IOW(DMA_BUF_BASE, 1, __u32) #define DMA_BUF_SET_NAME_B _IOW(DMA_BUF_BASE, 1, __u64) +#define DMA_BUF_IOCTL_INFO _IOWR(DMA_BUF_BASE, 2, struct dma_buf_info) + #endif