From patchwork Wed Jun 7 10:55:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sui Jingfeng <15330273260@189.cn> X-Patchwork-Id: 13270418 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 D55A0C7EE2E for ; Wed, 7 Jun 2023 10:56:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AF47C10E4C9; Wed, 7 Jun 2023 10:56:19 +0000 (UTC) Received: from 189.cn (ptr.189.cn [183.61.185.102]) by gabe.freedesktop.org (Postfix) with ESMTP id 9EBC210E4BA; Wed, 7 Jun 2023 10:56:15 +0000 (UTC) HMM_SOURCE_IP: 10.64.8.31:55208.1520123491 HMM_ATTACHE_NUM: 0000 HMM_SOURCE_TYPE: SMTP Received: from clientip-114.242.206.180 (unknown [10.64.8.31]) by 189.cn (HERMES) with SMTP id 9F8B41002BE; Wed, 7 Jun 2023 18:56:12 +0800 (CST) Received: from ([114.242.206.180]) by gateway-151646-dep-75648544bd-xp9j7 with ESMTP id b885828f9bb14068bdbf9132914de6b9 for l.stach@pengutronix.de; Wed, 07 Jun 2023 18:56:13 CST X-Transaction-ID: b885828f9bb14068bdbf9132914de6b9 X-Real-From: 15330273260@189.cn X-Receive-IP: 114.242.206.180 X-MEDUSA-Status: 0 From: Sui Jingfeng <15330273260@189.cn> To: Lucas Stach , Russell King , Christian Gmeiner , David Airlie , Daniel Vetter , Li Yi Subject: [PATCH v8 7/8] drm/etnaviv: add support for the dma coherent device Date: Wed, 7 Jun 2023 18:55:50 +0800 Message-Id: <20230607105551.568639-8-15330273260@189.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230607105551.568639-1-15330273260@189.cn> References: <20230607105551.568639-1-15330273260@189.cn> 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: Sui Jingfeng , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, etnaviv@lists.freedesktop.org, Bjorn Helgaas Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Sui Jingfeng Loongson CPUs maintain cache coherency by hardware, which means that the data in the CPU cache is identical to the data in main system memory. As for the peripheral device, most of Loongson chips chose to define the peripherals as DMA coherent by default, device drivers do not need to maintain the coherency between a processor and an I/O device manually. There are exceptions, for LS2K1000 SoC, part of peripheral device can be configured as DMA non-coherent. But there is no released version of such firmware exist in the market. Peripherals of older LS2K1000 is also DMA non-coherent, but they are nearly outdated. So, those are trivial cases. Nevertheless, kernel space still need to do the probe work, because vivante GPU IP has been integrated into various platform. Hence, this patch add runtime detection code to probe if a specific GPU is DMA coherent, If the answer is yes, we are going to utilize such features. On Loongson platform, When a buffer is accessed by both the GPU and the CPU, the driver should prefer ETNA_BO_CACHED over ETNA_BO_WC. This patch also add a new parameter: etnaviv_param_gpu_coherent, which allow userspace to know if such a feature is available. Because write-combined BO is still preferred in some case, especially where don't need CPU read, for example, uploading shader bin. Cc: Lucas Stach Cc: Christian Gmeiner Cc: Philipp Zabel Cc: Bjorn Helgaas Cc: Daniel Vetter Signed-off-by: Sui Jingfeng --- drivers/gpu/drm/etnaviv/etnaviv_drv.c | 34 +++++++++++++++++++++ drivers/gpu/drm/etnaviv/etnaviv_drv.h | 6 ++++ drivers/gpu/drm/etnaviv/etnaviv_gem.c | 22 ++++++++++--- drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 7 ++++- drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 4 +++ include/uapi/drm/etnaviv_drm.h | 1 + 6 files changed, 69 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c index 033afe542a3a..d7e7498826f5 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c @@ -5,7 +5,9 @@ #include #include +#include #include +#include #include #include @@ -27,6 +29,34 @@ #include "etnaviv_pci_drv.h" #endif +static struct device_node *etnaviv_of_first_available_node(void) +{ + struct device_node *core_node; + + for_each_compatible_node(core_node, NULL, "vivante,gc") { + if (of_device_is_available(core_node)) + return core_node; + } + + return NULL; +} + +static bool etnaviv_is_dma_coherent(struct device *dev) +{ + struct device_node *np; + bool coherent; + + np = etnaviv_of_first_available_node(); + if (np) { + coherent = of_dma_is_coherent(np); + of_node_put(np); + } else { + coherent = dev_is_dma_coherent(dev); + } + + return coherent; +} + /* * etnaviv private data construction and destructions: */ @@ -55,6 +85,10 @@ etnaviv_alloc_private(struct device *dev, struct drm_device *drm) return ERR_PTR(-ENOMEM); } + priv->dma_coherent = etnaviv_is_dma_coherent(dev); + + drm_info(drm, "%s is dma coherent\n", dev_name(dev)); + return priv; } diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h b/drivers/gpu/drm/etnaviv/etnaviv_drv.h index 9cd72948cfad..644e5712c050 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h @@ -46,6 +46,12 @@ struct etnaviv_drm_private { struct xarray active_contexts; u32 next_context_id; + /* + * If true, the GPU is capable of snooping cpu cache. Here, it + * also means that cache coherency is enforced by the hardware. + */ + bool dma_coherent; + /* list of GEM objects: */ struct mutex gem_lock; struct list_head gem_list; diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index b5f73502e3dd..39bdc3774f2d 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -343,6 +343,7 @@ void *etnaviv_gem_vmap(struct drm_gem_object *obj) static void *etnaviv_gem_vmap_impl(struct etnaviv_gem_object *obj) { struct page **pages; + pgprot_t prot; lockdep_assert_held(&obj->lock); @@ -350,8 +351,19 @@ static void *etnaviv_gem_vmap_impl(struct etnaviv_gem_object *obj) if (IS_ERR(pages)) return NULL; - return vmap(pages, obj->base.size >> PAGE_SHIFT, - VM_MAP, pgprot_writecombine(PAGE_KERNEL)); + switch (obj->flags) { + case ETNA_BO_CACHED: + prot = PAGE_KERNEL; + break; + case ETNA_BO_UNCACHED: + prot = pgprot_noncached(PAGE_KERNEL); + break; + case ETNA_BO_WC: + default: + prot = pgprot_writecombine(PAGE_KERNEL); + } + + return vmap(pages, obj->base.size >> PAGE_SHIFT, VM_MAP, prot); } static inline enum dma_data_direction etnaviv_op_to_dma_dir(u32 op) @@ -369,6 +381,7 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op, { struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj); struct drm_device *dev = obj->dev; + struct etnaviv_drm_private *priv = dev->dev_private; bool write = !!(op & ETNA_PREP_WRITE); int ret; @@ -395,7 +408,7 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op, return ret == 0 ? -ETIMEDOUT : ret; } - if (etnaviv_obj->flags & ETNA_BO_CACHED) { + if (!priv->dma_coherent && etnaviv_obj->flags & ETNA_BO_CACHED) { dma_sync_sgtable_for_cpu(dev->dev, etnaviv_obj->sgt, etnaviv_op_to_dma_dir(op)); etnaviv_obj->last_cpu_prep_op = op; @@ -408,8 +421,9 @@ int etnaviv_gem_cpu_fini(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; struct etnaviv_gem_object *etnaviv_obj = to_etnaviv_bo(obj); + struct etnaviv_drm_private *priv = dev->dev_private; - if (etnaviv_obj->flags & ETNA_BO_CACHED) { + if (!priv->dma_coherent && etnaviv_obj->flags & ETNA_BO_CACHED) { /* fini without a prep is almost certainly a userspace error */ WARN_ON(etnaviv_obj->last_cpu_prep_op == 0); dma_sync_sgtable_for_device(dev->dev, etnaviv_obj->sgt, diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c index 3524b5811682..754126992264 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c @@ -112,11 +112,16 @@ static const struct etnaviv_gem_ops etnaviv_gem_prime_ops = { struct drm_gem_object *etnaviv_gem_prime_import_sg_table(struct drm_device *dev, struct dma_buf_attachment *attach, struct sg_table *sgt) { + struct etnaviv_drm_private *priv = dev->dev_private; struct etnaviv_gem_object *etnaviv_obj; size_t size = PAGE_ALIGN(attach->dmabuf->size); + u32 cache_flags = ETNA_BO_WC; int ret, npages; - ret = etnaviv_gem_new_private(dev, size, ETNA_BO_WC, + if (priv->dma_coherent) + cache_flags = ETNA_BO_CACHED; + + ret = etnaviv_gem_new_private(dev, size, cache_flags, &etnaviv_gem_prime_ops, &etnaviv_obj); if (ret < 0) return ERR_PTR(ret); diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c index c5bc906936e4..fa827bd24be7 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c @@ -164,6 +164,10 @@ int etnaviv_gpu_get_param(struct etnaviv_gpu *gpu, u32 param, u64 *value) *value = gpu->identity.eco_id; break; + case ETNAVIV_PARAM_GPU_COHERENT: + *value = priv->dma_coherent; + break; + default: DBG("%s: invalid param: %u", dev_name(gpu->dev), param); return -EINVAL; diff --git a/include/uapi/drm/etnaviv_drm.h b/include/uapi/drm/etnaviv_drm.h index af024d90453d..76baf45d7158 100644 --- a/include/uapi/drm/etnaviv_drm.h +++ b/include/uapi/drm/etnaviv_drm.h @@ -77,6 +77,7 @@ struct drm_etnaviv_timespec { #define ETNAVIV_PARAM_GPU_PRODUCT_ID 0x1c #define ETNAVIV_PARAM_GPU_CUSTOMER_ID 0x1d #define ETNAVIV_PARAM_GPU_ECO_ID 0x1e +#define ETNAVIV_PARAM_GPU_COHERENT 0x1f #define ETNA_MAX_PIPES 4