Commit 6fb5ee7c authored by Lucas De Marchi's avatar Lucas De Marchi
Browse files

iosys-map: Add per-word write 



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: default avatarLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Reviewed-by: Christian König <christian.koenig@amd.com> # v1
Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220628191016.3899428-2-lucas.demarchi@intel.com
parent 5f278dbd

include/linux/iosys-map.h

+29 −9
Original line number Diff line number Diff line
@@ -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));	\

	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;								\