From patchwork Thu Jul 14 19:17:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 12918452 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 0B1ADC43334 for ; Thu, 14 Jul 2022 19:18:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9B05F11306A; Thu, 14 Jul 2022 19:18:18 +0000 (UTC) Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id D490111306A; Thu, 14 Jul 2022 19:18:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=4hMXKYb5oQeNCFz0c5Kq84rZ4yBy2gy1pD+jGE3P3t0=; b=hzGt9vhXedFNIhMMyzDtltnFsN qHJGD1K/NmIpjvwDfx37/4PDdhVGGOYopt0A1BpHCQTMapNn6BBaNKMWNOzptlfLiaqXTOWIgcrnY SQ/6ExW/Nwtao3frIJqaWQQeG8suwTLA/l7BwenxaEJ7LPzYRazspQJ1fAJtvUToQBwFzLGMLn3hp ktgfgSwR8Vr6wqwrfHvGtwtvEhyuzpZYW6PpEHNL2srhziFui0utvITAiMzyFjSFl8fk++kJWrpUB pjR11wBisDiyG3U372KUOBEvfc8ewyv6sVSlL2ZFMd17BXuySIu/QPaq9o7v27xsJfgcDQ4/Yg8nU lXGGfS1w==; Received: from [177.139.47.106] (helo=localhost.localdomain) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1oC4Ll-00Gla6-1q; Thu, 14 Jul 2022 21:18:13 +0200 From: =?utf-8?q?Andr=C3=A9_Almeida?= To: Alex Deucher , =?utf-8?b?J0NocmlzdGlhbiBLw7Zu?= =?utf-8?b?aWcn?= , 'Pan Xinhui' , David Airlie , Daniel Vetter , Hawking Zhang , Tao Zhou , Felix Kuehling , Jack Xiao , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Tom St Denis , Rodrigo Siqueira Subject: [PATCH v2 1/2] drm/amd/debugfs: Expose GFXOFF state to userspace Date: Thu, 14 Jul 2022 16:17:44 -0300 Message-Id: <20220714191745.45512-1-andrealmeid@igalia.com> X-Mailer: git-send-email 2.37.0 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Andr=C3=A9_Almeida?= , kernel-dev@igalia.com Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" GFXOFF has two different "state" values: one to define if the GPU is allowed/disallowed to enter GFXOFF, usually called state; and another one to define if currently GFXOFF is being used, usually called status. Even when GFXOFF is allowed, GPU firmware can decide to not used it accordingly to the GPU load. Userspace can allow/disallow GPUs to enter into GFXOFF via debugfs. The kernel maintains a counter of requests for GFXOFF (gfx_off_req_count) that should be decreased to allow GFXOFF and increased to disallow. The issue with this interface is that userspace can't be sure if GFXOFF is currently allowed. Even by checking amdgpu_gfxoff file, one might get an ambiguous 2, that means that GPU is currently out of GFXOFF, but that can be either because it's currently disallowed or because it's allowed but given the current GPU load it's enabled. Then, userspace needs to rely on the fact that GFXOFF is enabled by default on boot and to track this information. To make userspace life easier and GFXOFF more reliable, return the current state of GFXOFF to userspace when reading amdgpu_gfxoff with the same semantics of writing: 0 means not allowed, not 0 means allowed. Expose the current status of GFXOFF through a new file, amdgpu_gfxoff_status. Signed-off-by: André Almeida --- Changes from v1: none drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 49 ++++++++++++++++++++- 1 file changed, 47 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c index f3b3c688e4e7..e2eec985adb3 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -1117,13 +1117,50 @@ static ssize_t amdgpu_debugfs_gfxoff_read(struct file *f, char __user *buf, } while (size) { - uint32_t value; + u32 value = adev->gfx.gfx_off_state; + + r = put_user(value, (u32 *)buf); + if (r) + goto out; + + result += 4; + buf += 4; + *pos += 4; + size -= 4; + } + + r = result; +out: + pm_runtime_mark_last_busy(adev_to_drm(adev)->dev); + pm_runtime_put_autosuspend(adev_to_drm(adev)->dev); + + return r; +} + +static ssize_t amdgpu_debugfs_gfxoff_status_read(struct file *f, char __user *buf, + size_t size, loff_t *pos) +{ + struct amdgpu_device *adev = file_inode(f)->i_private; + ssize_t result = 0; + int r; + + if (size & 0x3 || *pos & 0x3) + return -EINVAL; + + r = pm_runtime_get_sync(adev_to_drm(adev)->dev); + if (r < 0) { + pm_runtime_put_autosuspend(adev_to_drm(adev)->dev); + return r; + } + + while (size) { + u32 value; r = amdgpu_get_gfx_off_status(adev, &value); if (r) goto out; - r = put_user(value, (uint32_t *)buf); + r = put_user(value, (u32 *)buf); if (r) goto out; @@ -1206,6 +1243,12 @@ static const struct file_operations amdgpu_debugfs_gfxoff_fops = { .llseek = default_llseek }; +static const struct file_operations amdgpu_debugfs_gfxoff_status_fops = { + .owner = THIS_MODULE, + .read = amdgpu_debugfs_gfxoff_status_read, + .llseek = default_llseek +}; + static const struct file_operations *debugfs_regs[] = { &amdgpu_debugfs_regs_fops, &amdgpu_debugfs_regs2_fops, @@ -1217,6 +1260,7 @@ static const struct file_operations *debugfs_regs[] = { &amdgpu_debugfs_wave_fops, &amdgpu_debugfs_gpr_fops, &amdgpu_debugfs_gfxoff_fops, + &amdgpu_debugfs_gfxoff_status_fops, }; static const char *debugfs_regs_names[] = { @@ -1230,6 +1274,7 @@ static const char *debugfs_regs_names[] = { "amdgpu_wave", "amdgpu_gpr", "amdgpu_gfxoff", + "amdgpu_gfxoff_status", }; /**