From patchwork Fri Feb 4 17:44:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Lucas De Marchi X-Patchwork-Id: 12735375 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 2F5A4C43217 for ; Fri, 4 Feb 2022 17:45:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E6ACC10EEEC; Fri, 4 Feb 2022 17:45:11 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5D3DB10E8C5; Fri, 4 Feb 2022 17:45:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643996710; x=1675532710; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5ETlEkJotXscY1acR0RRNJRgVVqgQwciPhVqY20Tn/w=; b=ZPgz1ng2mkIgpeLoGS0i46+9wt0WMWlIdmk7wEL5f7K0sQAvlAHKspeV iRDB5ZI9WgWzP2PTAM1Ru4EkSTrPL5laCuaZbIjGYa8Lunetko395BO7a 0XM0catD2P73eIwOE49v5UKn4jqTM74/e2bRlyjUVF3ZoWZVhu8qD4rkz jV3dooJItgVWKlSetoInv0QI/0x5EcUtNWmTOwU+gUy7YPU8l+nf/fH/f pZw5j98fC8Tg/M+uF45pdbZz8QvWJ84osEUP+1TsYWF1iTxxSDuzZOe6D kbFy3YbBAqscNHsQlAtAssG4Yd0LPEBx8G7Rfb7vMQgIRH2EgqXDTohfj w==; X-IronPort-AV: E=McAfee;i="6200,9189,10248"; a="247242171" X-IronPort-AV: E=Sophos;i="5.88,343,1635231600"; d="scan'208";a="247242171" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2022 09:45:09 -0800 X-IronPort-AV: E=Sophos;i="5.88,343,1635231600"; d="scan'208";a="539240793" Received: from lucas-s2600cw.jf.intel.com ([10.165.21.202]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2022 09:45:08 -0800 From: Lucas De Marchi To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH 03/19] iosys-map: Add a few more helpers Date: Fri, 4 Feb 2022 09:44:20 -0800 Message-Id: <20220204174436.830121-4-lucas.demarchi@intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220204174436.830121-1-lucas.demarchi@intel.com> References: <20220204174436.830121-1-lucas.demarchi@intel.com> 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: Matthew Brost , =?utf-8?q?Thomas_Hellstr=C3=B6m?= , Lucas De Marchi , linux-kernel@vger.kernel.org, Daniele Ceraolo Spurio , Thomas Zimmermann , =?utf-8?q?Christian_K=C3=B6nig?= , John Harrison Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" First the simplest ones: - iosys_map_memset(): when abstracting system and I/O memory, just like the memcpy() use case, memset() also has dedicated functions to be called for using IO memory. - iosys_map_memcpy_from(): we may need to copy data from I/O memory, not only to. 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. As a pre-requisite for the implementation, add iosys_map_memcpy_from() to be the equivalent of iosys_map_memcpy_to(), but in the other direction. Then add 2 pairs of macros: - iosys_map_rd() / iosys_map_wr() - iosys_map_rd_field() / iosys_map_wr_field() The first pair takes the C-type and offset to read/write. The second pair uses a struct describing the layout of the mapping in order to calculate the offset and size being read/written. 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. Finally, in order to use the above macros with a map derived from another, add another initializer: IOSYS_MAP_INIT_OFFSET(). Cc: Sumit Semwal Cc: Christian König Cc: Thomas Zimmermann Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Lucas De Marchi --- include/linux/iosys-map.h | 154 +++++++++++++++++++++++++++++++++++++- 1 file changed, 153 insertions(+), 1 deletion(-) diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h index edd7fa3be9e9..96f8b61ac6fb 100644 --- a/include/linux/iosys-map.h +++ b/include/linux/iosys-map.h @@ -6,6 +6,7 @@ #ifndef __IOSYS_MAP_H__ #define __IOSYS_MAP_H__ +#include #include #include @@ -133,6 +134,45 @@ static inline void iosys_map_set_vaddr(struct iosys_map *map, void *vaddr) map->is_iomem = false; } +/** + * IOSYS_MAP_INIT_OFFSET - Initializes struct iosys_map from another iosys_map + * @map_: The dma-buf mapping structure to copy from + * @offset_: Offset to add to the other mapping + * + * Initializes a new iosys_map struct based on another passed as argument. It + * does a shallow copy of the struct so it's possible to update the back storage + * without changing where the original map points to. It is the equivalent of + * doing: + * + * .. code-block: c + * + * iosys_map map = other_map; + * iosys_map_incr(&map, &offset); + * + * Example usage: + * + * .. code-block: c + * + * void foo(struct device *dev, struct iosys_map *base_map) + * { + * ... + * struct iosys_map map = IOSYS_MAP_INIT_OFFSET(base_map, FIELD_OFFSET); + * ... + * } + * + * The advantage of using the initializer over just increasing the offset with + * ``iosys_map_incr()`` like above is that the new map will always point to the + * right place of the buffer during its scope. It reduces the risk of updating + * the wrong part of the buffer and having no compiler warning about that. If + * the assignment to IOSYS_MAP_INIT_OFFSET() is forgotten, the compiler can warn + * using a uninitialized variable. + */ +#define IOSYS_MAP_INIT_OFFSET(map_, offset_) (struct iosys_map) \ + { \ + .vaddr = (map_)->vaddr + (offset_), \ + .is_iomem = (map_)->is_iomem, \ + } + /** * iosys_map_set_vaddr_iomem - Sets a iosys mapping structure to an address in I/O memory * @map: The iosys_map structure @@ -220,7 +260,7 @@ static inline void iosys_map_clear(struct iosys_map *map) } /** - * iosys_map_memcpy_to_offset - Memcpy into offset of iosys_map + * iosys_map_memcpy_to - Memcpy into iosys_map * @dst: The iosys_map structure * @dst_offset: The offset from which to copy * @src: The source buffer @@ -239,6 +279,26 @@ static inline void iosys_map_memcpy_to(struct iosys_map *dst, size_t dst_offset, memcpy(dst->vaddr + dst_offset, src, len); } +/** + * iosys_map_memcpy_from - Memcpy from iosys_map into system memory + * @dst: Destination in system memory + * @src: The iosys_map structure + * @src_offset: The offset from which to copy + * @len: The number of byte in src + * + * Copies data from a iosys_map 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 iosys_map_memcpy_from(void *dst, const struct iosys_map *src, + size_t src_offset, size_t len) +{ + if (src->is_iomem) + memcpy_fromio(dst, src->vaddr_iomem + src_offset, len); + else + memcpy(dst, src->vaddr + src_offset, len); +} + /** * iosys_map_incr - Increments the address stored in a iosys mapping * @map: The iosys_map structure @@ -255,4 +315,96 @@ static inline void iosys_map_incr(struct iosys_map *map, size_t incr) map->vaddr += incr; } +/** + * iosys_map_memset - Memset iosys_map + * @dst: The iosys_map structure + * @offset: Offset from dst where to start setting value + * @value: The value to set + * @len: The number of bytes to set in dst + * + * Set value in iosys_map. Depending on the buffer's location, the helper + * picks the correct method of accessing the memory. + */ +static inline void iosys_map_memset(struct iosys_map *dst, size_t offset, + int value, size_t len) +{ + if (dst->is_iomem) + memset_io(dst->vaddr_iomem + offset, value, len); + else + memset(dst->vaddr + offset, value, len); +} + +/** + * iosys_map_rd - Read a C-type value from the iosys_map + * + * @map__: The iosys_map structure + * @offset__: The offset from which to read + * @type__: Type of the value being read + * + * Read a C type value from iosys_map, handling possible un-aligned accesses to + * the mapping. + * + * Returns: + * The value read from the mapping. + */ +#define iosys_map_rd(map__, offset__, type__) ({ \ + type__ val; \ + iosys_map_memcpy_from(&val, map__, offset__, sizeof(val)); \ + val; \ +}) + +/** + * iosys_map_wr - Write a C-type value to the iosys_map + * + * @map__: The iosys_map structure + * @offset__: The offset from the mapping to write to + * @type__: Type of the value being written + * @val__: Value to write + * + * Write a C-type value to the iosys_map, handling possible un-aligned accesses + * to the mapping. + */ +#define iosys_map_wr(map__, offset__, type__, val__) ({ \ + type__ val = (val__); \ + iosys_map_memcpy_to(map__, offset__, &val, sizeof(val)); \ +}) + +/** + * iosys_map_rd_field - Read a member from a struct in the iosys_map + * + * @map__: The iosys_map structure + * @struct_type__: The struct describing the layout of the mapping + * @field__: Member of the struct to read + * + * Read a value from iosys_map assuming its layout is described by a struct, + * passed as argument. The offset and size to the struct member is calculated + * and possible un-aligned accesses to the mapping handled. + * + * Returns: + * The value read from the mapping. + */ +#define iosys_map_rd_field(map__, struct_type__, field__) ({ \ + struct_type__ *s; \ + iosys_map_rd(map__, offsetof(struct_type__, field__), \ + typeof(s->field__)); \ +}) + +/** + * iosys_map_wr_field - Write to a member of a struct in the iosys_map + * + * @map__: The iosys_map structure + * @struct_type__: The struct describing the layout of the mapping + * @field__: Member of the struct to read + * @val__: Value to write + * + * Write a value to the iosys_map assuming its layout is described by a struct, + * passed as argument. The offset and size to the struct member is calculated + * and possible un-aligned accesses to the mapping handled. + */ +#define iosys_map_wr_field(map__, struct_type__, field__, val__) ({ \ + struct_type__ *s; \ + iosys_map_wr(map__, offsetof(struct_type__, field__), \ + typeof(s->field__), val__); \ +}) + #endif /* __IOSYS_MAP_H__ */