diff options
Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/arch/i386/include/gpxe/x86_io.h')
| -rw-r--r-- | contrib/syslinux-4.02/gpxe/src/arch/i386/include/gpxe/x86_io.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/arch/i386/include/gpxe/x86_io.h b/contrib/syslinux-4.02/gpxe/src/arch/i386/include/gpxe/x86_io.h new file mode 100644 index 0000000..beb5b22 --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/arch/i386/include/gpxe/x86_io.h @@ -0,0 +1,153 @@ +#ifndef _GPXE_X86_IO_H +#define _GPXE_X86_IO_H + +/** @file + * + * gPXE I/O API for x86 + * + * i386 uses direct pointer dereferences for accesses to memory-mapped + * I/O space, and the inX/outX instructions for accesses to + * port-mapped I/O space. + * + * 64-bit atomic accesses (readq() and writeq()) use MMX instructions, + * and will crash original Pentium and earlier CPUs. Fortunately, no + * hardware that requires atomic 64-bit accesses will physically fit + * into a machine with such an old CPU anyway. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#ifdef IOAPI_X86 +#define IOAPI_PREFIX_x86 +#else +#define IOAPI_PREFIX_x86 __x86_ +#endif + +/* + * Memory space mappings + * + */ + +/* + * Physical<->Bus and Bus<->I/O address mappings + * + */ + +static inline __always_inline unsigned long +IOAPI_INLINE ( x86, phys_to_bus ) ( unsigned long phys_addr ) { + return phys_addr; +} + +static inline __always_inline unsigned long +IOAPI_INLINE ( x86, bus_to_phys ) ( unsigned long bus_addr ) { + return bus_addr; +} + +static inline __always_inline void * +IOAPI_INLINE ( x86, ioremap ) ( unsigned long bus_addr, size_t len __unused ) { + return phys_to_virt ( bus_addr ); +} + +static inline __always_inline void +IOAPI_INLINE ( x86, iounmap ) ( volatile const void *io_addr __unused ) { + /* Nothing to do */ +} + +static inline __always_inline unsigned long +IOAPI_INLINE ( x86, io_to_bus ) ( volatile const void *io_addr ) { + return virt_to_phys ( io_addr ); +} + +/* + * MMIO reads and writes up to 32 bits + * + */ + +#define X86_READX( _api_func, _type ) \ +static inline __always_inline _type \ +IOAPI_INLINE ( x86, _api_func ) ( volatile _type *io_addr ) { \ + return *io_addr; \ +} +X86_READX ( readb, uint8_t ); +X86_READX ( readw, uint16_t ); +X86_READX ( readl, uint32_t ); + +#define X86_WRITEX( _api_func, _type ) \ +static inline __always_inline void \ +IOAPI_INLINE ( x86, _api_func ) ( _type data, \ + volatile _type *io_addr ) { \ + *io_addr = data; \ +} +X86_WRITEX ( writeb, uint8_t ); +X86_WRITEX ( writew, uint16_t ); +X86_WRITEX ( writel, uint32_t ); + +/* + * PIO reads and writes up to 32 bits + * + */ + +#define X86_INX( _insn_suffix, _type, _reg_prefix ) \ +static inline __always_inline _type \ +IOAPI_INLINE ( x86, in ## _insn_suffix ) ( volatile _type *io_addr ) { \ + _type data; \ + __asm__ __volatile__ ( "in" #_insn_suffix " %w1, %" _reg_prefix "0" \ + : "=a" ( data ) : "Nd" ( io_addr ) ); \ + return data; \ +} \ +static inline __always_inline void \ +IOAPI_INLINE ( x86, ins ## _insn_suffix ) ( volatile _type *io_addr, \ + _type *data, \ + unsigned int count ) { \ + unsigned int discard_D; \ + __asm__ __volatile__ ( "rep ins" #_insn_suffix \ + : "=D" ( discard_D ) \ + : "d" ( io_addr ), "c" ( count ), \ + "0" ( data ) ); \ +} +X86_INX ( b, uint8_t, "b" ); +X86_INX ( w, uint16_t, "w" ); +X86_INX ( l, uint32_t, "k" ); + +#define X86_OUTX( _insn_suffix, _type, _reg_prefix ) \ +static inline __always_inline void \ +IOAPI_INLINE ( x86, out ## _insn_suffix ) ( _type data, \ + volatile _type *io_addr ) { \ + __asm__ __volatile__ ( "out" #_insn_suffix " %" _reg_prefix "0, %w1" \ + : : "a" ( data ), "Nd" ( io_addr ) ); \ +} \ +static inline __always_inline void \ +IOAPI_INLINE ( x86, outs ## _insn_suffix ) ( volatile _type *io_addr, \ + const _type *data, \ + unsigned int count ) { \ + unsigned int discard_S; \ + __asm__ __volatile__ ( "rep outs" #_insn_suffix \ + : "=S" ( discard_S ) \ + : "d" ( io_addr ), "c" ( count ), \ + "0" ( data ) ); \ +} +X86_OUTX ( b, uint8_t, "b" ); +X86_OUTX ( w, uint16_t, "w" ); +X86_OUTX ( l, uint32_t, "k" ); + +/* + * Slow down I/O + * + */ + +static inline __always_inline void +IOAPI_INLINE ( x86, iodelay ) ( void ) { + __asm__ __volatile__ ( "outb %al, $0x80" ); +} + +/* + * Memory barrier + * + */ + +static inline __always_inline void +IOAPI_INLINE ( x86, mb ) ( void ) { + __asm__ __volatile__ ( "lock; addl $0, 0(%%esp)" : : : "memory" ); +} + +#endif /* _GPXE_X86_IO_H */ |