When PCI_IOBASE is not defined, it is set to 0 such that it is ignored in calls to the readX/writeX primitives. This triggers clang's -Wnull-pointer-arithmetic warning and will result in illegal accesses on platforms that do not support I/O ports. Make things explicit and silence the warning by letting inb() and friends fail with WARN_ONCE() and a 0xff... return in case PCI_IOBASE is not defined. Link: https://lore.kernel.org/lkml/20210421111759.2059976-1-schnelle@xxxxxxxxxxxxx/ Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> --- v5 -> v6: - Added memset to insb()/insw()/insl() in WARN_ONCE() case to prevent access to uninitalized memory v4 -> v5: - Added Link to commit message (Arnd) v3 -> v4: - Changed the subject to better reflect the actual change - Added asm/bug.h so WARN_ONCE() is always available v2 -> v3: - Added ifdefs to ioport_map() and __pci_ioport_map() since apparently at least test configs enable CONFIG_HAS_IOPORT_MAP even on architectures which leave PCI_IOBASE unset (kernel test robot for nds32 and ARC). v1 -> v2: - Instead of working around the warning with a uintptr_t PCI_IOBASE make inb() and friends explicitly WARN_ONCE() and return 0xff... (Arnd) include/asm-generic/io.h | 68 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 64 insertions(+), 4 deletions(-) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index e93375c710b9..4a3af97a832d 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -8,6 +8,7 @@ #define __ASM_GENERIC_IO_H #include <asm/page.h> /* I/O is all done through memory accesses */ +#include <linux/bug.h> #include <linux/string.h> /* for memset() and memcpy() */ #include <linux/types.h> @@ -440,10 +441,6 @@ static inline void writesq(volatile void __iomem *addr, const void *buffer, #endif #endif /* CONFIG_64BIT */ -#ifndef PCI_IOBASE -#define PCI_IOBASE ((void __iomem *)0) -#endif - #ifndef IO_SPACE_LIMIT #define IO_SPACE_LIMIT 0xffff #endif @@ -458,12 +455,17 @@ static inline void writesq(volatile void __iomem *addr, const void *buffer, #define _inb _inb static inline u8 _inb(unsigned long addr) { +#ifdef PCI_IOBASE u8 val; __io_pbr(); val = __raw_readb(PCI_IOBASE + addr); __io_par(val); return val; +#else + WARN_ONCE(1, "No I/O port support\n"); + return ~0; +#endif } #endif @@ -471,12 +473,17 @@ static inline u8 _inb(unsigned long addr) #define _inw _inw static inline u16 _inw(unsigned long addr) { +#ifdef PCI_IOBASE u16 val; __io_pbr(); val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); __io_par(val); return val; +#else + WARN_ONCE(1, "No I/O port support\n"); + return ~0; +#endif } #endif @@ -484,12 +491,17 @@ static inline u16 _inw(unsigned long addr) #define _inl _inl static inline u32 _inl(unsigned long addr) { +#ifdef PCI_IOBASE u32 val; __io_pbr(); val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); __io_par(val); return val; +#else + WARN_ONCE(1, "No I/O port support\n"); + return ~0; +#endif } #endif @@ -497,9 +509,13 @@ static inline u32 _inl(unsigned long addr) #define _outb _outb static inline void _outb(u8 value, unsigned long addr) { +#ifdef PCI_IOBASE __io_pbw(); __raw_writeb(value, PCI_IOBASE + addr); __io_paw(); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -507,9 +523,13 @@ static inline void _outb(u8 value, unsigned long addr) #define _outw _outw static inline void _outw(u16 value, unsigned long addr) { +#ifdef PCI_IOBASE __io_pbw(); __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); __io_paw(); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -517,9 +537,13 @@ static inline void _outw(u16 value, unsigned long addr) #define _outl _outl static inline void _outl(u32 value, unsigned long addr) { +#ifdef PCI_IOBASE __io_pbw(); __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); __io_paw(); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -606,7 +630,12 @@ static inline void outl_p(u32 value, unsigned long addr) #define insb insb static inline void insb(unsigned long addr, void *buffer, unsigned int count) { +#ifdef PCI_IOBASE readsb(PCI_IOBASE + addr, buffer, count); +#else + memset(buffer, 0xff, count); + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -614,7 +643,12 @@ static inline void insb(unsigned long addr, void *buffer, unsigned int count) #define insw insw static inline void insw(unsigned long addr, void *buffer, unsigned int count) { +#ifdef PCI_IOBASE readsw(PCI_IOBASE + addr, buffer, count); +#else + memset(buffer, 0xff, count); + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -622,7 +656,12 @@ static inline void insw(unsigned long addr, void *buffer, unsigned int count) #define insl insl static inline void insl(unsigned long addr, void *buffer, unsigned int count) { +#ifdef PCI_IOBASE readsl(PCI_IOBASE + addr, buffer, count); +#else + memset(buffer, 0xff, count); + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -631,7 +670,11 @@ static inline void insl(unsigned long addr, void *buffer, unsigned int count) static inline void outsb(unsigned long addr, const void *buffer, unsigned int count) { +#ifdef PCI_IOBASE writesb(PCI_IOBASE + addr, buffer, count); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -640,7 +683,11 @@ static inline void outsb(unsigned long addr, const void *buffer, static inline void outsw(unsigned long addr, const void *buffer, unsigned int count) { +#ifdef PCI_IOBASE writesw(PCI_IOBASE + addr, buffer, count); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -649,7 +696,11 @@ static inline void outsw(unsigned long addr, const void *buffer, static inline void outsl(unsigned long addr, const void *buffer, unsigned int count) { +#ifdef PCI_IOBASE writesl(PCI_IOBASE + addr, buffer, count); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif @@ -1020,18 +1071,27 @@ static inline void __iomem *ioremap_np(phys_addr_t offset, size_t size) #define ioport_map ioport_map static inline void __iomem *ioport_map(unsigned long port, unsigned int nr) { +#ifdef PCI_IOBASE port &= IO_SPACE_LIMIT; return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port; +#else + WARN_ONCE(1, "No I/O port support\n"); + return NULL; +#endif } #define __pci_ioport_unmap __pci_ioport_unmap static inline void __pci_ioport_unmap(void __iomem *p) { +#ifdef PCI_IOBASE uintptr_t start = (uintptr_t) PCI_IOBASE; uintptr_t addr = (uintptr_t) p; if (addr >= start && addr < start + IO_SPACE_LIMIT) return; iounmap(p); +#else + WARN_ONCE(1, "No I/O port support\n"); +#endif } #endif -- 2.25.1
