[PATCH v2] asm-generic/io.h: Fix sparse warnings on big-endian architectures

Stafford Horne
2020-08-04T03:54:47Z

On big-endian architectures like OpenRISC, sparse outputs below warnings on
asm-generic/io.h. This is due to io statements like:

__raw_writel(cpu_to_le32(value), PCI_IOBASE + addr);

The __raw_writel() function expects native endianness, however
cpu_to_le32() returns __le32. On little-endian machines these match up
and there is no issue. However, on big-endian we get warnings, for IO
that is defined as little-endian the mismatch is expected.

The fix I propose is to __force to native endian.

Warnings:

./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
./include/asm-generic/io.h:215:22: warning: incorrect type in argument 1 (different base types)
./include/asm-generic/io.h:215:22: expected unsigned short [usertype] value
./include/asm-generic/io.h:215:22: got restricted __le16 [usertype]
./include/asm-generic/io.h:225:22: warning: incorrect type in argument 1 (different base types)
./include/asm-generic/io.h:225:22: expected unsigned int [usertype] value
./include/asm-generic/io.h:225:22: got restricted __le32 [usertype]

Signed-off-by: Stafford Horne <shorne@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
Changes since v1:
- Remove white space between casts and right hand value. That matches all of
the other casts.

include/asm-generic/io.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 30a3aab312e6..dabf8cb7203b 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -163,7 +163,7 @@ static inline u16 readw(const volatile void __iomem *addr)
u16 val;

__io_br();
- val = __le16_to_cpu(__raw_readw(addr));
+ val = __le16_to_cpu((__le16 __force)__raw_readw(addr));
__io_ar(val);
return val;
}
@@ -176,7 +176,7 @@ static inline u32 readl(const volatile void __iomem *addr)
u32 val;

__io_br();
- val = __le32_to_cpu(__raw_readl(addr));
+ val = __le32_to_cpu((__le32 __force)__raw_readl(addr));
__io_ar(val);
return val;
}
@@ -212,7 +212,7 @@ static inline void writeb(u8 value, volatile void __iomem *addr)
static inline void writew(u16 value, volatile void __iomem *addr)
{
__io_bw();
- __raw_writew(cpu_to_le16(value), addr);
+ __raw_writew((u16 __force)cpu_to_le16(value), addr);
__io_aw();
}
#endif
@@ -222,7 +222,7 @@ static inline void writew(u16 value, volatile void __iomem *addr)
static inline void writel(u32 value, volatile void __iomem *addr)
{
__io_bw();
- __raw_writel(__cpu_to_le32(value), addr);
+ __raw_writel((u32 __force)__cpu_to_le32(value), addr);
__io_aw();
}
#endif
@@ -474,7 +474,7 @@ static inline u16 _inw(unsigned long addr)
u16 val;

__io_pbr();
- val = __le16_to_cpu(__raw_readw(PCI_IOBASE + addr));
+ val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
__io_par(val);
return val;
}
@@ -487,7 +487,7 @@ static inline u32 _inl(unsigned long addr)
u32 val;

__io_pbr();
- val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr));
+ val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
__io_par(val);
return val;
}
@@ -508,7 +508,7 @@ static inline void _outb(u8 value, unsigned long addr)
static inline void _outw(u16 value, unsigned long addr)
{
__io_pbw();
- __raw_writew(cpu_to_le16(value), PCI_IOBASE + addr);
+ __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
__io_paw();
}
#endif
@@ -518,7 +518,7 @@ static inline void _outw(u16 value, unsigned long addr)
static inline void _outl(u32 value, unsigned long addr)
{
__io_pbw();
- __raw_writel(cpu_to_le32(value), PCI_IOBASE + addr);
+ __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
__io_paw();
}
#endif
--
2.26.2