From patchwork Wed Jul 13 15:15:04 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: 12916888 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 CCB73C43334 for ; Wed, 13 Jul 2022 15:15:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 03C2E9B648; Wed, 13 Jul 2022 15:15:33 +0000 (UTC) Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id D664D9B647; Wed, 13 Jul 2022 15:15:31 +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=tjY9pgjQiJS2RAtlwL9+FP13c9f0g+5EtDvq+MRR/TM=; b=TF4UmVPdpY6wYbtFKLm667lcxu dVGbgrkZ+wjJP/9qFW8UAmZjLKHs43VV4bmgB82HgQoYVhBEBm8Fg22t/xXoGRNu7soLU11/2pQ1X UuDJfya76fcpml9/5uXwSapmOVJNwOpXdGGqb0OUKhQ/nOCcGM7B1I8OBcbyI8m2ndkVgsZfP6UzG zHsUlawzXhrMh9gSR1NTf29F0hDQc36M9gWOh65IDtEcA04cykpJC5eD8oUkQwF5YTpphODCkaEXD uT4amKPwX+hUHXQ6IghqRtqkOOuhO4KC3UeL5P5xOOKMmMN88id4fdQfzuv3hwe3DspABFNHmJuig 7bPerr5A==; 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 1oBe5H-00F8zV-18; Wed, 13 Jul 2022 17:15:27 +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] drm/amd/debugfs: Expose GFXOFF state to userspace Date: Wed, 13 Jul 2022 12:15:04 -0300 Message-Id: <20220713151504.7521-1-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 --- 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", }; /**