From 6fb5ee7cec06266a29f25ecc01a23b9d107f64e1 Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Tue, 28 Jun 2022 12:10:16 -0700 Subject: [PATCH] iosys-map: Add per-word write MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Like was done for read, provide the equivalent for write. Even if current users are not in the hot path, this should future-proof it. v2: - Remove default from _Generic() - callers wanting to write more than u64 should use iosys_map_memcpy_to() - Add WRITE_ONCE() cases dereferencing the pointer when using system memory v3: - Fix precedence issue when casting inside WRITE_ONCE(). By not using () around vaddr__ the offset was not part of the cast, but rather added to it, producing a wrong address - Remove compiletime_assert() as WRITE_ONCE() already contains it Signed-off-by: Lucas De Marchi Reviewed-by: Reviewed-by: Christian König # v1 Reviewed-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-2-lucas.demarchi@intel.com --- include/linux/iosys-map.h | 38 +++++++++++++++++++++++++++++--------- 1 file changed, 29 insertions(+), 9 deletions(-) diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h index d19977e..a533cae 100644 --- a/include/linux/iosys-map.h +++ b/include/linux/iosys-map.h @@ -337,9 +337,13 @@ static inline void iosys_map_memset(struct iosys_map *dst, size_t offset, #ifdef CONFIG_64BIT #define __iosys_map_rd_io_u64_case(val_, vaddr_iomem_) \ u64: val_ = readq(vaddr_iomem_) +#define __iosys_map_wr_io_u64_case(val_, vaddr_iomem_) \ + u64: writeq(val_, vaddr_iomem_) #else #define __iosys_map_rd_io_u64_case(val_, vaddr_iomem_) \ u64: memcpy_fromio(&(val_), vaddr_iomem_, sizeof(u64)) +#define __iosys_map_wr_io_u64_case(val_, vaddr_iomem_) \ + u64: memcpy_toio(vaddr_iomem_, &(val_), sizeof(u64)) #endif #define __iosys_map_rd_io(val__, vaddr_iomem__, type__) _Generic(val__, \ @@ -351,6 +355,15 @@ static inline void iosys_map_memset(struct iosys_map *dst, size_t offset, #define __iosys_map_rd_sys(val__, vaddr__, type__) \ val__ = READ_ONCE(*(type__ *)(vaddr__)) +#define __iosys_map_wr_io(val__, vaddr_iomem__, type__) _Generic(val__, \ + u8: writeb(val__, vaddr_iomem__), \ + u16: writew(val__, vaddr_iomem__), \ + u32: writel(val__, vaddr_iomem__), \ + __iosys_map_wr_io_u64_case(val__, vaddr_iomem__)) + +#define __iosys_map_wr_sys(val__, vaddr__, type__) \ + WRITE_ONCE(*(type__ *)(vaddr__), val__) + /** * iosys_map_rd - Read a C-type value from the iosys_map * @@ -383,12 +396,17 @@ static inline void iosys_map_memset(struct iosys_map *dst, size_t offset, * @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. + * Write a C type value (u8, u16, u32 and u64) to the iosys_map. For other types + * or if pointer may be unaligned (and problematic for the architecture + * supported), use iosys_map_memcpy_to() */ -#define iosys_map_wr(map__, offset__, type__, val__) ({ \ - type__ val = (val__); \ - iosys_map_memcpy_to(map__, offset__, &val, sizeof(val)); \ +#define iosys_map_wr(map__, offset__, type__, val__) ({ \ + type__ val = (val__); \ + if ((map__)->is_iomem) { \ + __iosys_map_wr_io(val, (map__)->vaddr_iomem + (offset__), type__);\ + } else { \ + __iosys_map_wr_sys(val, (map__)->vaddr + (offset__), type__); \ + } \ }) /** @@ -469,10 +487,12 @@ static inline void iosys_map_memset(struct iosys_map *dst, size_t offset, * @field__: Member of the struct to read * @val__: Value to write * - * Write a value to the iosys_map considering its layout is described by a C struct - * starting at @struct_offset__. The field offset and size is calculated and the - * @val__ is written handling possible un-aligned memory accesses. Refer to - * iosys_map_rd_field() for expected usage and memory layout. + * Write a value to the iosys_map considering its layout is described by a C + * struct starting at @struct_offset__. The field offset and size is calculated + * and the @val__ is written. If the field access would incur in un-aligned + * access, then either iosys_map_memcpy_to() needs to be used or the + * architecture must support it. Refer to iosys_map_rd_field() for expected + * usage and memory layout. */ #define iosys_map_wr_field(map__, struct_offset__, struct_type__, field__, val__) ({ \ struct_type__ *s; \ -- 2.7.4