From patchwork Mon Nov 18 13:02:11 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matt Coster X-Patchwork-Id: 13878527 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 101E4D49219 for ; Mon, 18 Nov 2024 13:03:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3439710E4CD; Mon, 18 Nov 2024 13:02:58 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=imgtec.com header.i=@imgtec.com header.b="NVqweKVO"; dkim-atps=neutral Received: from mx07-00376f01.pphosted.com (mx07-00376f01.pphosted.com [185.132.180.163]) by gabe.freedesktop.org (Postfix) with ESMTPS id D9A0310E4C5 for ; Mon, 18 Nov 2024 13:02:54 +0000 (UTC) Received: from pps.filterd (m0168889.ppops.net [127.0.0.1]) by mx07-00376f01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4AICK2Ao027968; Mon, 18 Nov 2024 13:02:45 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=imgtec.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=dk201812; bh=d N2ozmFtvCmmLHAMUe5XTS6v38AloNcoMRiCPfNJqO4=; b=NVqweKVOXUWy34I3u LAPCRRdeP4WoR0LKdgGcKqEsOPLcJAgJ87mPuukBkv+u+YbEfYyUdCfjnEbCzypg UKCce0X/S2au/F811sRLDzRuIpst+v8vgI4Eqvv0aZ9CUaAOTxZ8JhOXgGEKhSCX QvLfKUC7+PDMF3R8E82tB9sDa7d8n7hJ0cxkB7GStyfyfLgRvV9cXCEhJXI3qaoy q4sZtoFQ3WdSJY7HQYmqhFnuDb0zHqZ/aClE8v3iNhSWkDwSsHca7LdVsNpUHud8 oDEM+O7nqt9nn63d3lzX6jyzKXEwAe1/gD1cQol1SiC5Vl7gM3rMDGThwLI7Iq66 K+3gQ== Received: from hhmail05.hh.imgtec.org (83-244-153-141.cust-83.exponential-e.net [83.244.153.141]) by mx07-00376f01.pphosted.com (PPS) with ESMTPS id 42xmc1hmj6-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Mon, 18 Nov 2024 13:02:45 +0000 (GMT) Received: from 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa (172.25.16.114) by HHMAIL05.hh.imgtec.org (10.100.10.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.37; Mon, 18 Nov 2024 13:02:44 +0000 From: Matt Coster Date: Mon, 18 Nov 2024 13:02:11 +0000 Subject: [PATCH v2 19/21] drm/imagination: Add device_memory_force_cpu_cached override MIME-Version: 1.0 Message-ID: <20241118-sets-bxs-4-64-patch-v1-v2-19-3fd45d9fb0cf@imgtec.com> References: <20241118-sets-bxs-4-64-patch-v1-v2-0-3fd45d9fb0cf@imgtec.com> In-Reply-To: <20241118-sets-bxs-4-64-patch-v1-v2-0-3fd45d9fb0cf@imgtec.com> To: Frank Binns , Matt Coster , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Nishanth Menon , "Vignesh Raghavendra" , Tero Kristo CC: , , , , Randolph Sapp , Darren Etheridge X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=7048; i=matt.coster@imgtec.com; h=from:subject:message-id; bh=cB8Xf2NvNov9ZHbtNEv9xGMvJyEWiDLKefTxZkGcESs=; b=owGbwMvMwCFWuUfy8817WRsYT6slMaRbWz3bWq1zq8XKtzDkPMvajiNTV+x+k/q6/tnTvauLd nOcWpb9tKOUhUGMg0FWTJFlxwrLFWp/1LQkbvwqhpnDygQyhIGLUwAmIjyX4X+Bo/m+jTLXuBn+ lMVc+ry1v3nrqXj+yonPv4rVeMXklLUz/DPYsftd8bnoC685du/3udFf1abAJrBv/rbL+ZNjF4m cS2YFAA== X-Developer-Key: i=matt.coster@imgtec.com; a=openpgp; fpr=05A40CFCE7269D61D97100A1747F0A9036F90DFA X-Originating-IP: [172.25.16.114] X-EXCLAIMER-MD-CONFIG: 15a78312-3e47-46eb-9010-2e54d84a9631 X-Proofpoint-ORIG-GUID: SNuPUNGDYeQdHQI_KDsgBwNMblS5mBmg X-Authority-Analysis: v=2.4 cv=E4efprdl c=1 sm=1 tr=0 ts=673b3af5 cx=c_pps a=AKOq//PuzOIrVTIF9yBwbA==:117 a=AKOq//PuzOIrVTIF9yBwbA==:17 a=hzDjp0mCheYA:10 a=IkcTkHD0fZMA:10 a=VlfZXiiP6vEA:10 a=VwQbUJbxAAAA:8 a=r_1tXGB3AAAA:8 a=ZhBkjoDcyXaoxMow2pUA:9 a=QEXdDO2ut3YA:10 a=t8nPyN_e6usw4ciXM-Pk:22 X-Proofpoint-GUID: SNuPUNGDYeQdHQI_KDsgBwNMblS5mBmg 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The TI k3-j721s2 platform has a bug relating to cache snooping on the AXI ACE-Lite interface. Disabling cache snooping altogether would also resolve the issue, but is considered more of a performance hit. Given the platform is dma-coherent, forcing all device-accessible memory allocations through the CPU cache is the preferred solution. Implement this workaround so that it can later be enabled for the TI k3-j721s2 platform. Signed-off-by: Matt Coster --- Changes in v2: - None - Link to v1: https://lore.kernel.org/r/20241105-sets-bxs-4-64-patch-v1-v1-19-4ed30e865892@imgtec.com --- drivers/gpu/drm/imagination/pvr_device.c | 11 ++++++++++- drivers/gpu/drm/imagination/pvr_device.h | 11 +++++++++++ drivers/gpu/drm/imagination/pvr_drv.c | 2 +- drivers/gpu/drm/imagination/pvr_gem.c | 3 +++ drivers/gpu/drm/imagination/pvr_gem.h | 7 +++++-- drivers/gpu/drm/imagination/pvr_mmu.c | 7 ++++++- 6 files changed, 36 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c index 2ce46b9a8ab7609faebeeb4e7820751b00047806..ffc177c383c1be16061eff0290c347918b0991f7 100644 --- a/drivers/gpu/drm/imagination/pvr_device.c +++ b/drivers/gpu/drm/imagination/pvr_device.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -635,6 +636,7 @@ bool pvr_device_overrides_validate(struct pvr_device *pvr_dev, const struct pvr_device_overrides *overrides) { + struct drm_device *drm_dev = from_pvr_device(pvr_dev); bool ret = true; /* @@ -643,7 +645,14 @@ pvr_device_overrides_validate(struct pvr_device *pvr_dev, * * Note that this function may be called early during device initialization * so it should not be assumed that @pvr_dev is ready for normal use yet. - */ + */ + + if (overrides->device_memory_force_cpu_cached && + device_get_dma_attr(drm_dev->dev) != DEV_DMA_COHERENT) { + drm_err(drm_dev, + "Specifying device_memory_force_cpu_cached override without dma-coherent attribute is unsupported."); + ret = false; + } return ret; } diff --git a/drivers/gpu/drm/imagination/pvr_device.h b/drivers/gpu/drm/imagination/pvr_device.h index ad0a02a37154099542247dfc62f411c10f4e41f4..7ae14899db24f4c747e8cf4d61d252eb403713f4 100644 --- a/drivers/gpu/drm/imagination/pvr_device.h +++ b/drivers/gpu/drm/imagination/pvr_device.h @@ -60,8 +60,19 @@ struct pvr_fw_version { /** * struct pvr_device_overrides - Hardware-level overrides loaded from * MODULE_DEVICE_TABLE() or similar. + * + * @device_memory_force_cpu_cached: By default, all device memory buffer objects + * are mapped write-combined on the CPU (see %PVR_BO_CPU_CACHED) including MMU + * page table backing pages which do not use the regular device memory objects. + * This override forces all CPU mappings to be mapped cached instead. Since this + * could require additional cache maintenance operations to be performed, + * pvr_device_overrides_validate() ensures that the dma-coherent attribute is + * set when this override is specified. Required on some TI platforms where a + * bug causes device-to-cpu cache snooping to behave incorrectly when + * interacting with cpu-uncached memory. */ struct pvr_device_overrides { + bool device_memory_force_cpu_cached; }; /** diff --git a/drivers/gpu/drm/imagination/pvr_drv.c b/drivers/gpu/drm/imagination/pvr_drv.c index b56ee2cda9b54c4388a6eef38b0ff81acdb05874..e074cfb0d2055b5387dbb142ca972108977f9854 100644 --- a/drivers/gpu/drm/imagination/pvr_drv.c +++ b/drivers/gpu/drm/imagination/pvr_drv.c @@ -1490,7 +1490,7 @@ static void pvr_remove(struct platform_device *plat_dev) pvr_power_domains_fini(pvr_dev); } -static const struct pvr_device_overrides pvr_device_overrides_default = {}; +static const struct pvr_device_overrides pvr_device_overrides_default = { 0 }; /* * Always specify &pvr_device_overrides_default instead of %NULL for &struct of_device_id->data so diff --git a/drivers/gpu/drm/imagination/pvr_gem.c b/drivers/gpu/drm/imagination/pvr_gem.c index 6a8c81fe8c1e85c2130a4fe90fce35b6a2be35aa..c67c30518f89af3de2e617a9b65e5cd78870fa2c 100644 --- a/drivers/gpu/drm/imagination/pvr_gem.c +++ b/drivers/gpu/drm/imagination/pvr_gem.c @@ -345,6 +345,9 @@ pvr_gem_object_create(struct pvr_device *pvr_dev, size_t size, u64 flags) if (size == 0 || !pvr_gem_object_flags_validate(flags)) return ERR_PTR(-EINVAL); + if (PVR_HAS_OVERRIDE(pvr_dev, device_memory_force_cpu_cached)) + flags |= PVR_BO_CPU_CACHED; + shmem_obj = drm_gem_shmem_create(from_pvr_device(pvr_dev), size); if (IS_ERR(shmem_obj)) return ERR_CAST(shmem_obj); diff --git a/drivers/gpu/drm/imagination/pvr_gem.h b/drivers/gpu/drm/imagination/pvr_gem.h index e0e5ea509a2e88a437b8d241ea13c7bab2220f56..9b3cbcbe48dfbbc8be211a8a409699a43452e178 100644 --- a/drivers/gpu/drm/imagination/pvr_gem.h +++ b/drivers/gpu/drm/imagination/pvr_gem.h @@ -44,8 +44,11 @@ struct pvr_file; * Bits not defined anywhere are "undefined". * * CPU mapping options - * :PVR_BO_CPU_CACHED: By default, all GEM objects are mapped write-combined on the CPU. Set this - * flag to override this behaviour and map the object cached. + * :PVR_BO_CPU_CACHED: By default, all GEM objects are mapped write-combined on the CPU. Set + * this flag to override this behaviour and map the object cached. If + * &struct pvr_device_overrides->device_memory_force_cpu_cached is specified, all allocations + * will be mapped as if this flag was set. This does not require any additional consideration + * at allocation time since the override is only valid if the dma-coherent attribute is set. * * Firmware options * :PVR_BO_FW_NO_CLEAR_ON_RESET: By default, all FW objects are cleared and reinitialised on hard diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c index 4fe70610ed94cf707e631f8148af081a94f97327..7c7deb29b735308eaed26900f2f54a838382c255 100644 --- a/drivers/gpu/drm/imagination/pvr_mmu.c +++ b/drivers/gpu/drm/imagination/pvr_mmu.c @@ -259,6 +259,7 @@ pvr_mmu_backing_page_init(struct pvr_mmu_backing_page *page, struct device *dev = from_pvr_device(pvr_dev)->dev; struct page *raw_page; + pgprot_t prot; int err; dma_addr_t dma_addr; @@ -268,7 +269,11 @@ pvr_mmu_backing_page_init(struct pvr_mmu_backing_page *page, if (!raw_page) return -ENOMEM; - host_ptr = vmap(&raw_page, 1, VM_MAP, pgprot_writecombine(PAGE_KERNEL)); + prot = PAGE_KERNEL; + if (!PVR_HAS_OVERRIDE(pvr_dev, device_memory_force_cpu_cached)) + prot = pgprot_writecombine(prot); + + host_ptr = vmap(&raw_page, 1, VM_MAP, prot); if (!host_ptr) { err = -ENOMEM; goto err_free_page;