From patchwork Sun Apr 23 16:20:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 13221412 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89765C77B60 for ; Sun, 23 Apr 2023 16:21:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229535AbjDWQVp (ORCPT ); Sun, 23 Apr 2023 12:21:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229493AbjDWQVo (ORCPT ); Sun, 23 Apr 2023 12:21:44 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 188C4E74 for ; Sun, 23 Apr 2023 09:21:43 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Q4D361nJWz67QQ9; Mon, 24 Apr 2023 00:18:42 +0800 (CST) Received: from SecurePC-101-06.china.huawei.com (10.122.247.231) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Sun, 23 Apr 2023 17:21:40 +0100 From: Jonathan Cameron To: , Michael Tsirkin , Fan Ni CC: , , Ira Weiny , Alison Schofield , Michael Roth , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , Dave Jiang , Markus Armbruster , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , Eric Blake , Mike Maslenkin , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , Thomas Huth Subject: [PATCH v5 3/6] bswap: Add the ability to store to an unaligned 24 bit field Date: Sun, 23 Apr 2023 17:20:10 +0100 Message-ID: <20230423162013.4535-4-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230423162013.4535-1-Jonathan.Cameron@huawei.com> References: <20230423162013.4535-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Ira Weiny CXL has 24 bit unaligned fields which need to be stored to. CXL is specified as little endian. Define st24_le_p() and the supporting functions to store such a field from a 32 bit host native value. The use of b, w, l, q as the size specifier is limiting. So "24" was used for the size part of the function name. Reviewed-by: Fan Ni Signed-off-by: Ira Weiny Signed-off-by: Jonathan Cameron --- v5: - Added assertion that upper bits of the input parameter aren't set. - Mask value in bswap24s() - update docs --- docs/devel/loads-stores.rst | 1 + include/qemu/bswap.h | 25 +++++++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/docs/devel/loads-stores.rst b/docs/devel/loads-stores.rst index ad5dfe133e..57b4396f7a 100644 --- a/docs/devel/loads-stores.rst +++ b/docs/devel/loads-stores.rst @@ -36,6 +36,7 @@ store: ``st{size}_{endian}_p(ptr, val)`` ``size`` - ``b`` : 8 bits - ``w`` : 16 bits + - ``24`` : 24 bits - ``l`` : 32 bits - ``q`` : 64 bits diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h index 15a78c0db5..91ed9c7e2c 100644 --- a/include/qemu/bswap.h +++ b/include/qemu/bswap.h @@ -8,11 +8,25 @@ #undef bswap64 #define bswap64(_x) __builtin_bswap64(_x) +static inline uint32_t bswap24(uint32_t x) +{ + assert((x & 0xff000000U) == 0); + + return (((x & 0x000000ffU) << 16) | + ((x & 0x0000ff00U) << 0) | + ((x & 0x00ff0000U) >> 16)); +} + static inline void bswap16s(uint16_t *s) { *s = __builtin_bswap16(*s); } +static inline void bswap24s(uint32_t *s) +{ + *s = bswap24(*s & 0x00ffffffU); +} + static inline void bswap32s(uint32_t *s) { *s = __builtin_bswap32(*s); @@ -176,6 +190,7 @@ CPU_CONVERT(le, 64, uint64_t) * size is: * b: 8 bits * w: 16 bits + * 24: 24 bits * l: 32 bits * q: 64 bits * @@ -248,6 +263,11 @@ static inline void stw_he_p(void *ptr, uint16_t v) __builtin_memcpy(ptr, &v, sizeof(v)); } +static inline void st24_he_p(void *ptr, uint32_t v) +{ + __builtin_memcpy(ptr, &v, 3); +} + static inline int ldl_he_p(const void *ptr) { int32_t r; @@ -297,6 +317,11 @@ static inline void stw_le_p(void *ptr, uint16_t v) stw_he_p(ptr, le_bswap(v, 16)); } +static inline void st24_le_p(void *ptr, uint32_t v) +{ + st24_he_p(ptr, le_bswap(v, 24)); +} + static inline void stl_le_p(void *ptr, uint32_t v) { stl_he_p(ptr, le_bswap(v, 32));