On Fri, Jun 17, 2022 at 01:52:04AM -0700, Lucas De Marchi wrote:
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
Thomas, do you have any additional concern on this patch regarding your
previous review?
thanks
Lucas De Marchi
Signed-off-by: Lucas De Marchi <lucas.demar...@intel.com>
Reviewed-by: Reviewed-by: Christian König <christian.koe...@amd.com> # v1
---
include/linux/iosys-map.h | 42 ++++++++++++++++++++++++++++++---------
1 file changed, 33 insertions(+), 9 deletions(-)
diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h
index f59dd00ed202..580e14cd360c 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__,
\
@@ -354,6 +358,19 @@ static inline void iosys_map_memset(struct iosys_map *dst,
size_t offset,
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__) ({
\
+ compiletime_assert(sizeof(type__) <= sizeof(u64), \
+ "Unsupported access size for __iosys_map_wr_sys()");
\
+ WRITE_ONCE(*((type__ *)vaddr__), val__);
\
+})
+
+
/**
* iosys_map_rd - Read a C-type value from the iosys_map
*
@@ -386,12 +403,17 @@ 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__);
\
+ }
\
})
/**
@@ -472,10 +494,12 @@ 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;
\
--
2.36.1
