From 14180d6221502bd4b9d96fa5f1065e7cda4bcf00 Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Fri, 26 May 2023 18:00:07 +0100 Subject: [PATCH] bswap: Add the ability to store to an unaligned 24 bit field MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Ira Weiny Signed-off-by: Jonathan Cameron Message-Id: <20230526170010.574-2-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/devel/loads-stores.rst | 2 ++ include/qemu/bswap.h | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/docs/devel/loads-stores.rst b/docs/devel/loads-stores.rst index d2cefc77a2..dab6dfa0ac 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 @@ -65,6 +66,7 @@ of size ``sz`` bytes. Regexes for git grep - ``\`` - ``\`` + - ``\`` - ``\`` - ``\`` diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h index 15a78c0db5..933a66ee87 100644 --- a/include/qemu/bswap.h +++ b/include/qemu/bswap.h @@ -8,11 +8,23 @@ #undef bswap64 #define bswap64(_x) __builtin_bswap64(_x) +static inline uint32_t bswap24(uint32_t x) +{ + 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); @@ -26,11 +38,13 @@ static inline void bswap64s(uint64_t *s) #if HOST_BIG_ENDIAN #define be_bswap(v, size) (v) #define le_bswap(v, size) glue(__builtin_bswap, size)(v) +#define le_bswap24(v) bswap24(v) #define be_bswaps(v, size) #define le_bswaps(p, size) \ do { *p = glue(__builtin_bswap, size)(*p); } while (0) #else #define le_bswap(v, size) (v) +#define le_bswap24(v) (v) #define be_bswap(v, size) glue(__builtin_bswap, size)(v) #define le_bswaps(v, size) #define be_bswaps(p, size) \ @@ -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_bswap24(v)); +} + static inline void stl_le_p(void *ptr, uint32_t v) { stl_he_p(ptr, le_bswap(v, 32)); -- 2.11.0