From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 36BEE156C63; Fri, 2 May 2025 15:11:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746198703; cv=none; b=FU7S/wydNNyOOFNDoWqIsL2m+Os8TdnCAp0pqVE0DKN0zXGkSLVg1Yq0JiCfjvcBxKCIh2ghPs77DWWVGbxR3gTS26jkyrpgqpka4m4XobqED5OLO33yNEfkEAqxG/dS6pz7lwAKnrld+vMJ5XaLEA2E+wdd56Z6E4PTXVT7gtU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746198703; c=relaxed/simple; bh=U+YSNzUnply29Hjd9uH9yUM2wuQsFaLy2qkKb05i3KE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qemMMqO3IfmCaWgzwt2araf4Fnj3saw7b11q9IUlLh/NQOvgL8T0uV6A8kCEKnVvGp2R9dukhOCIU/HNp4HaH8nZhCyK+VJ1Y9ywn0wGaMULr6TNQ8v0KmKY316yw+xSnwYbfohw+bfRKjIv6dFpX0uMh9/WfiDnduUxfYyYG6U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 52B951688; Fri, 2 May 2025 08:11:26 -0700 (PDT) Received: from [10.1.196.40] (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 86C713F66E; Fri, 2 May 2025 08:11:28 -0700 (PDT) Message-ID: <4b2f7c31-c61b-45d8-b32e-16bb91c4289b@arm.com> Date: Fri, 2 May 2025 16:11:26 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v8 11/14] tee: add tee_shm_alloc_cma_phys_mem() To: Jens Wiklander , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, op-tee@lists.trustedfirmware.org, linux-arm-kernel@lists.infradead.org Cc: Olivier Masse , Thierry Reding , Yong Wu , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T . J . Mercier" , =?UTF-8?Q?Christian_K=C3=B6nig?= , Sumit Garg , Matthias Brugger , AngeloGioacchino Del Regno , azarrabi@qti.qualcomm.com, Simona Vetter , Daniel Stone , Rouven Czerwinski References: <20250502100049.1746335-1-jens.wiklander@linaro.org> <20250502100049.1746335-12-jens.wiklander@linaro.org> From: Robin Murphy Content-Language: en-GB In-Reply-To: <20250502100049.1746335-12-jens.wiklander@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 02/05/2025 10:59 am, Jens Wiklander wrote: > Add tee_shm_alloc_cma_phys_mem() to allocate a physical memory using > from the default CMA pool. The memory is represented by a tee_shm object > using the new flag TEE_SHM_CMA_BUF to identify it as physical memory > from CMA. If and when it's possible to dynamically delegate any old kernel memory to the TEE, it's far from clear why that should involve poking around in CMA internals... > Signed-off-by: Jens Wiklander > --- > drivers/tee/tee_shm.c | 55 ++++++++++++++++++++++++++++++++++++++-- > include/linux/tee_core.h | 4 +++ > 2 files changed, 57 insertions(+), 2 deletions(-) > > diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c > index e1ed52ee0a16..faaa0a87bb18 100644 > --- a/drivers/tee/tee_shm.c > +++ b/drivers/tee/tee_shm.c > @@ -3,8 +3,11 @@ > * Copyright (c) 2015-2017, 2019-2021 Linaro Limited > */ > #include > +#include > #include > #include > +#include > +#include > #include > #include > #include > @@ -13,7 +16,6 @@ > #include > #include > #include > -#include > #include "tee_private.h" > > static void shm_put_kernel_pages(struct page **pages, size_t page_count) > @@ -49,7 +51,14 @@ static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) > struct tee_shm *parent_shm = NULL; > void *p = shm; > > - if (shm->flags & TEE_SHM_DMA_BUF) { > + if (shm->flags & TEE_SHM_CMA_BUF) { > +#if IS_ENABLED(CONFIG_CMA) > + struct page *page = phys_to_page(shm->paddr); > + struct cma *cma = dev_get_cma_area(&shm->ctx->teedev->dev); If you want dma_contiguous_default_area as the commit message implies, use dma_contiguous_default_area. Appearing to support per-device CMA pools but relying on the device not having one is pretty yucky. But again, why? If you want page-backed DMA-able memory, with all the other assumptions being made here, you may as well just rely on dma_alloc_pages(DMA_ATTR_SKIP_CPU_SYNC) doing what you want, while also being potentially more flexible for !CMA and non-invasive. Or at the very least, could the TEE delegation not be composed on top of the existing CMA heap allocator? Thanks, Robin. > + > + cma_release(cma, page, shm->size / PAGE_SIZE); > +#endif > + } else if (shm->flags & TEE_SHM_DMA_BUF) { > struct tee_shm_dmabuf_ref *ref; > > ref = container_of(shm, struct tee_shm_dmabuf_ref, shm); > @@ -306,6 +315,48 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) > } > EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); > > +struct tee_shm *tee_shm_alloc_cma_phys_mem(struct tee_context *ctx, > + size_t page_count, size_t align) > +{ > +#if IS_ENABLED(CONFIG_CMA) > + struct tee_device *teedev = ctx->teedev; > + struct cma *cma = dev_get_cma_area(&teedev->dev); > + struct tee_shm *shm; > + struct page *page; > + > + if (!tee_device_get(teedev)) > + return ERR_PTR(-EINVAL); > + > + page = cma_alloc(cma, page_count, align, true/*no_warn*/); > + if (!page) > + goto err_put_teedev; > + > + shm = kzalloc(sizeof(*shm), GFP_KERNEL); > + if (!shm) > + goto err_cma_crelease; > + > + refcount_set(&shm->refcount, 1); > + shm->ctx = ctx; > + shm->paddr = page_to_phys(page); > + shm->size = page_count * PAGE_SIZE; > + shm->flags = TEE_SHM_CMA_BUF; > + > + teedev_ctx_get(ctx); > + > + return shm; > + > +err_cma_crelease: > + cma_release(cma, page, page_count); > +err_put_teedev: > + tee_device_put(teedev); > + > + return ERR_PTR(-ENOMEM); > +#else > + return ERR_PTR(-EINVAL); > +#endif > +} > +EXPORT_SYMBOL_GPL(tee_shm_alloc_cma_phys_mem); > + > int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align, > int (*shm_register)(struct tee_context *ctx, > struct tee_shm *shm, > diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h > index 02c07f661349..3a4e1b00fcc7 100644 > --- a/include/linux/tee_core.h > +++ b/include/linux/tee_core.h > @@ -29,6 +29,7 @@ > #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */ > #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */ > #define TEE_SHM_DMA_BUF BIT(4) /* Memory with dma-buf handle */ > +#define TEE_SHM_CMA_BUF BIT(5) /* CMA allocated memory */ > > #define TEE_DEVICE_FLAG_REGISTERED 0x1 > #define TEE_MAX_DEV_NAME_LEN 32 > @@ -310,6 +311,9 @@ void *tee_get_drvdata(struct tee_device *teedev); > */ > struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size); > > +struct tee_shm *tee_shm_alloc_cma_phys_mem(struct tee_context *ctx, > + size_t page_count, size_t align); > + > int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align, > int (*shm_register)(struct tee_context *ctx, > struct tee_shm *shm,