From patchwork Tue Jun 20 10:48:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sui Jingfeng X-Patchwork-Id: 13285614 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 32F14EB64D7 for ; Tue, 20 Jun 2023 10:48:21 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3007910E2B0; Tue, 20 Jun 2023 10:48:20 +0000 (UTC) Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by gabe.freedesktop.org (Postfix) with ESMTP id BFD3D10E2CA for ; Tue, 20 Jun 2023 10:48:17 +0000 (UTC) Received: from loongson.cn (unknown [10.20.42.43]) by gateway (Coremail) with SMTP id _____8Cxd+nvg5FkgiwHAA--.12833S3; Tue, 20 Jun 2023 18:48:15 +0800 (CST) Received: from openarena.loongson.cn (unknown [10.20.42.43]) by localhost.localdomain (Coremail) with SMTP id AQAAf8CxCOXmg5FklJghAA--.28448S9; Tue, 20 Jun 2023 18:48:15 +0800 (CST) From: Sui Jingfeng To: Lucas Stach Subject: [PATCH v10 07/11] drm/etnaviv: Add support for the dma coherent device Date: Tue, 20 Jun 2023 18:48:02 +0800 Message-Id: <20230620104806.2236666-8-suijingfeng@loongson.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230620104806.2236666-1-suijingfeng@loongson.cn> References: <20230620104806.2236666-1-suijingfeng@loongson.cn> MIME-Version: 1.0 X-CM-TRANSID: AQAAf8CxCOXmg5FklJghAA--.28448S9 X-CM-SenderInfo: xvxlyxpqjiv03j6o00pqjv00gofq/ X-Coremail-Antispam: 1Uk129KBj93XoW3Gw15tw1rKw47GrWrJr4rCrX_yoWfJr4kpF s3AFyYyrW8ZFyj9w1xAFn5ZFy3Kw1xWFWFkasrtwn0v3y5tr18try0kFn8CF98Jr1fWrWa qr1qyry3GF1UArXCm3ZEXasCq-sJn29KB7ZKAUJUUUU5529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUk2b4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r126r13M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv6xkF7I0E14v2 6F4UJVW0owAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07AIYIkI8VC2zVCFFI0UMc 02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWrXVW3AwAv7VC2z280aVAF wI0_Cr0_Gr1UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVW5JVW7JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF 04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26F4j6r4UJwCI42IY6I8E87Iv6x kF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU4hF4DUUUU 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: Bjorn Helgaas , dri-devel@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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 compiled 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 | 35 +++++++++++++++++++++ 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, 70 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c index 0a365e96d371..d8e788aa16cb 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 @@ -24,6 +26,34 @@ #include "etnaviv_pci_drv.h" #include "etnaviv_perfmon.h" +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: */ @@ -52,6 +82,11 @@ etnaviv_alloc_private(struct device *dev, struct drm_device *drm) return ERR_PTR(-ENOMEM); } + priv->dma_coherent = etnaviv_is_dma_coherent(dev); + + if (priv->dma_coherent) + 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 d6a21e97feb1..d99ac675ce8b 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