From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE774C47096 for ; Thu, 3 Jun 2021 21:06:24 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 84E11613BF for ; Thu, 3 Jun 2021 21:06:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 84E11613BF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C0EAE6E811; Thu, 3 Jun 2021 21:06:23 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7F5ED6E811 for ; Thu, 3 Jun 2021 21:06:22 +0000 (UTC) Received: from localhost.localdomain (unknown [IPv6:2600:8800:8c09:5500::85ac]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: alyssa) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 420B11F41B1D; Thu, 3 Jun 2021 22:06:18 +0100 (BST) From: Alyssa Rosenzweig To: dri-devel@lists.freedesktop.org Subject: [PATCH v2] drm/panfrost: Add AFBC_FEATURES parameter Date: Thu, 3 Jun 2021 17:06:09 -0400 Message-Id: <20210603210609.1420-1-alyssa.rosenzweig@collabora.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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: Alyssa Rosenzweig , Tomeu Vizoso , Steven Price Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The value of the AFBC_FEATURES register is required by userspace to determine AFBC support on Bifrost. A user on our IRC channel (#panfrost) reported a workload that raised a fault on one system's Mali G31 but worked flawlessly with another system's Mali G31. We determined the cause to be missing AFBC support on one vendor's Mali implementation -- it turns out AFBC is optional on Bifrost! Whether AFBC is supported or not is exposed in the AFBC_FEATURES register on Bifrost, which reads back as 0 on Midgard. A zero value indicates AFBC is fully supported, provided the architecture itself supports AFBC, allowing backwards-compatibility with Midgard. Bits 0 and 15 indicate that AFBC support is absent for texturing and rendering respectively. The user experiencing the fault reports that AFBC_FEATURES reads back 0x10001 on their system, confirming the architectural lack of AFBC. Userspace needs this this parameter to know to disable AFBC on that chip, and perhaps others. v2: Fix typo from copy-paste fail. Signed-off-by: Alyssa Rosenzweig Cc: Rob Herring Cc: Tomeu Vizoso Cc: Steven Price --- drivers/gpu/drm/panfrost/panfrost_device.h | 1 + drivers/gpu/drm/panfrost/panfrost_drv.c | 1 + drivers/gpu/drm/panfrost/panfrost_gpu.c | 1 + drivers/gpu/drm/panfrost/panfrost_regs.h | 1 + include/uapi/drm/panfrost_drm.h | 1 + 5 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h index 597cf1459..f614e9877 100644 --- a/drivers/gpu/drm/panfrost/panfrost_device.h +++ b/drivers/gpu/drm/panfrost/panfrost_device.h @@ -45,6 +45,7 @@ struct panfrost_features { u32 thread_max_workgroup_sz; u32 thread_max_barrier_sz; u32 coherency_features; + u32 afbc_features; u32 texture_features[4]; u32 js_features[16]; diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c index ca07098a6..3383c8200 100644 --- a/drivers/gpu/drm/panfrost/panfrost_drv.c +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c @@ -63,6 +63,7 @@ static int panfrost_ioctl_get_param(struct drm_device *ddev, void *data, struct PANFROST_FEATURE(THREAD_MAX_BARRIER_SZ, thread_max_barrier_sz); PANFROST_FEATURE(COHERENCY_FEATURES, coherency_features); + PANFROST_FEATURE(AFBC_FEATURES, afbc_features); PANFROST_FEATURE_ARRAY(TEXTURE_FEATURES, texture_features, 3); PANFROST_FEATURE_ARRAY(JS_FEATURES, js_features, 15); PANFROST_FEATURE(NR_CORE_GROUPS, nr_core_groups); diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c index 2aae636f1..0e70e27fd 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c @@ -228,6 +228,7 @@ static void panfrost_gpu_init_features(struct panfrost_device *pfdev) pfdev->features.thread_max_workgroup_sz = gpu_read(pfdev, GPU_THREAD_MAX_WORKGROUP_SIZE); pfdev->features.thread_max_barrier_sz = gpu_read(pfdev, GPU_THREAD_MAX_BARRIER_SIZE); pfdev->features.coherency_features = gpu_read(pfdev, GPU_COHERENCY_FEATURES); + pfdev->features.afbc_features = gpu_read(pfdev, GPU_AFBC_FEATURES); for (i = 0; i < 4; i++) pfdev->features.texture_features[i] = gpu_read(pfdev, GPU_TEXTURE_FEATURES(i)); diff --git a/drivers/gpu/drm/panfrost/panfrost_regs.h b/drivers/gpu/drm/panfrost/panfrost_regs.h index eddaa62ad..dc9df5457 100644 --- a/drivers/gpu/drm/panfrost/panfrost_regs.h +++ b/drivers/gpu/drm/panfrost/panfrost_regs.h @@ -82,6 +82,7 @@ #define GPU_TEXTURE_FEATURES(n) (0x0B0 + ((n) * 4)) #define GPU_JS_FEATURES(n) (0x0C0 + ((n) * 4)) +#define GPU_AFBC_FEATURES (0x4C) /* (RO) AFBC support on Bifrost */ #define GPU_SHADER_PRESENT_LO 0x100 /* (RO) Shader core present bitmap, low word */ #define GPU_SHADER_PRESENT_HI 0x104 /* (RO) Shader core present bitmap, high word */ diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h index ec19db1ee..061e700dd 100644 --- a/include/uapi/drm/panfrost_drm.h +++ b/include/uapi/drm/panfrost_drm.h @@ -171,6 +171,7 @@ enum drm_panfrost_param { DRM_PANFROST_PARAM_JS_FEATURES15, DRM_PANFROST_PARAM_NR_CORE_GROUPS, DRM_PANFROST_PARAM_THREAD_TLS_ALLOC, + DRM_PANFROST_PARAM_AFBC_FEATURES, }; struct drm_panfrost_get_param { -- 2.30.2