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[23.128.96.18]) by mx.google.com with ESMTP id e1si227763ejm.628.2022.01.26.14.41.17; Wed, 26 Jan 2022 14:41:43 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=ER21pQAQ; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231152AbiAZUgf (ORCPT + 99 others); Wed, 26 Jan 2022 15:36:35 -0500 Received: from mga01.intel.com ([192.55.52.88]:9978 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230222AbiAZUgc (ORCPT ); Wed, 26 Jan 2022 15:36:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643229392; x=1674765392; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=fT5raPuy4gQlCWtdlnkOy0l3+TfxT0XyYHiwiGiH8uo=; b=ER21pQAQNixZZr51HDoE8m6yU0dITAoM0LXdE6OFvk7mrPzN7W2ZYZpl BnuVHyoIa3f6DgiI3lddIyGRYCXFGAptWFXuxqs3IxBvNSq/n/eaVeAP0 4oupsKQgfyDQNqVGGWJ4h0b/7M4bVd4H210/l5M8B3sRgrIs1fZb6rIci qs1x+unukHL4aS7fIML0kFOAaHPUXxzG3yaX3ddcpjlVOmReE+sJDnERf URgNdjVlJe57hzRdTJuujSn8vS8L/jmaeELNFLzsyeKS/6rQd7jDanoGf EUoNC8vGGXILqp8+h7EqkQqDMZ+IFPZ4n8ZkNSf5FpEQB5m+luHdU5qvE g==; X-IronPort-AV: E=McAfee;i="6200,9189,10239"; a="271098463" X-IronPort-AV: E=Sophos;i="5.88,319,1635231600"; d="scan'208";a="271098463" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 12:36:22 -0800 X-IronPort-AV: E=Sophos;i="5.88,319,1635231600"; d="scan'208";a="581221490" Received: from lucas-s2600cw.jf.intel.com ([10.165.21.202]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2022 12:36:22 -0800 From: Lucas De Marchi To: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org, Matt Roper , Sumit Semwal , =?UTF-8?q?Christian=20K=C3=B6nig?= , linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH 01/19] dma-buf-map: Add read/write helpers Date: Wed, 26 Jan 2022 12:36:44 -0800 Message-Id: <20220126203702.1784589-2-lucas.demarchi@intel.com> X-Mailer: git-send-email 2.35.0 In-Reply-To: <20220126203702.1784589-1-lucas.demarchi@intel.com> References: <20220126203702.1784589-1-lucas.demarchi@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In certain situations it's useful to be able to read or write to an offset that is calculated by having the memory layout given by a struct declaration. Usually we are going to read/write a u8, u16, u32 or u64. Add a pair of macros dma_buf_map_read_field()/dma_buf_map_write_field() to calculate the offset of a struct member and memcpy the data from/to the dma_buf_map. We could use readb, readw, readl, readq and the write* counterparts, however due to alignment issues this may not work on all architectures. If alignment needs to be checked to call the right function, it's not possible to decide at compile-time which function to call: so just leave the decision to the memcpy function that will do exactly that on IO memory or dereference the pointer. Cc: Sumit Semwal Cc: Christian König Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi --- include/linux/dma-buf-map.h | 81 +++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h index 19fa0b5ae5ec..65e927d9ce33 100644 --- a/include/linux/dma-buf-map.h +++ b/include/linux/dma-buf-map.h @@ -6,6 +6,7 @@ #ifndef __DMA_BUF_MAP_H__ #define __DMA_BUF_MAP_H__ +#include #include #include @@ -229,6 +230,46 @@ static inline void dma_buf_map_clear(struct dma_buf_map *map) } } +/** + * dma_buf_map_memcpy_to_offset - Memcpy into offset of dma-buf mapping + * @dst: The dma-buf mapping structure + * @offset: The offset from which to copy + * @src: The source buffer + * @len: The number of byte in src + * + * Copies data into a dma-buf mapping with an offset. The source buffer is in + * system memory. Depending on the buffer's location, the helper picks the + * correct method of accessing the memory. + */ +static inline void dma_buf_map_memcpy_to_offset(struct dma_buf_map *dst, size_t offset, + const void *src, size_t len) +{ + if (dst->is_iomem) + memcpy_toio(dst->vaddr_iomem + offset, src, len); + else + memcpy(dst->vaddr + offset, src, len); +} + +/** + * dma_buf_map_memcpy_from_offset - Memcpy from offset of dma-buf mapping into system memory + * @dst: Destination in system memory + * @src: The dma-buf mapping structure + * @src: The offset from which to copy + * @len: The number of byte in src + * + * Copies data from a dma-buf mapping with an offset. The dest buffer is in + * system memory. Depending on the mapping location, the helper picks the + * correct method of accessing the memory. + */ +static inline void dma_buf_map_memcpy_from_offset(void *dst, const struct dma_buf_map *src, + size_t offset, size_t len) +{ + if (src->is_iomem) + memcpy_fromio(dst, src->vaddr_iomem + offset, len); + else + memcpy(dst, src->vaddr + offset, len); +} + /** * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping * @dst: The dma-buf mapping structure @@ -263,4 +304,44 @@ static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr) map->vaddr += incr; } +/** + * dma_buf_map_read_field - Read struct member from dma-buf mapping with + * arbitrary size and handling un-aligned accesses + * + * @map__: The dma-buf mapping structure + * @type__: The struct to be used containing the field to read + * @field__: Member from struct we want to read + * + * Read a value from dma-buf mapping calculating the offset and size: this assumes + * the dma-buf mapping is aligned with a a struct type__. A single u8, u16, u32 + * or u64 can be read, based on the offset and size of type__.field__. + */ +#define dma_buf_map_read_field(map__, type__, field__) ({ \ + type__ *t__; \ + typeof(t__->field__) val__; \ + dma_buf_map_memcpy_from_offset(&val__, map__, offsetof(type__, field__), \ + sizeof(t__->field__)); \ + val__; \ +}) + +/** + * dma_buf_map_write_field - Write struct member to the dma-buf mapping with + * arbitrary size and handling un-aligned accesses + * + * @map__: The dma-buf mapping structure + * @type__: The struct to be used containing the field to write + * @field__: Member from struct we want to write + * @val__: Value to be written + * + * Write a value to the dma-buf mapping calculating the offset and size. + * A single u8, u16, u32 or u64 can be written based on the offset and size of + * type__.field__. + */ +#define dma_buf_map_write_field(map__, type__, field__, val__) ({ \ + type__ *t__; \ + typeof(t__->field__) val____ = val__; \ + dma_buf_map_memcpy_to_offset(map__, offsetof(type__, field__), \ + &val____, sizeof(t__->field__)); \ +}) + #endif /* __DMA_BUF_MAP_H__ */ -- 2.35.0