| Message ID | 1298584085-13129-2-git-send-email-aliguori@us.ibm.com |
|---|---|
| State | New |
| Headers | show |
On 02/24/2011 11:48 PM, Anthony Liguori wrote: > Signed-off-by: Anthony Liguori<aliguori@us.ibm.com> > > diff --git a/lib/x86/io.h b/lib/x86/io.h > new file mode 100644 > index 0000000..bd6341c > --- /dev/null > +++ b/lib/x86/io.h > @@ -0,0 +1,40 @@ > +#ifndef IO_H > +#define IO_H > + > +static inline unsigned char inb(unsigned short port) > +{ > + unsigned char value; > + asm volatile("inb %w1, %0" : "=a" (value) : "Nd" (port)); > + return value; > +} Are those %[wb] really needed? gcc should do the right thing based on the argument type. Might as well put all of that into processor.h.
On 02/27/2011 06:44 AM, Avi Kivity wrote: > On 02/24/2011 11:48 PM, Anthony Liguori wrote: >> Signed-off-by: Anthony Liguori<aliguori@us.ibm.com> >> >> diff --git a/lib/x86/io.h b/lib/x86/io.h >> new file mode 100644 >> index 0000000..bd6341c >> --- /dev/null >> +++ b/lib/x86/io.h >> @@ -0,0 +1,40 @@ >> +#ifndef IO_H >> +#define IO_H >> + >> +static inline unsigned char inb(unsigned short port) >> +{ >> + unsigned char value; >> + asm volatile("inb %w1, %0" : "=a" (value) : "Nd" (port)); >> + return value; >> +} > > Are those %[wb] really needed? gcc should do the right thing based on > the argument type. It's just a little extra type safety. > > Might as well put all of that into processor.h. Seems reasonable. Regards, Anthony Liguori
On 02/27/2011 04:01 PM, Anthony Liguori wrote: > On 02/27/2011 06:44 AM, Avi Kivity wrote: >> On 02/24/2011 11:48 PM, Anthony Liguori wrote: >>> Signed-off-by: Anthony Liguori<aliguori@us.ibm.com> >>> >>> diff --git a/lib/x86/io.h b/lib/x86/io.h >>> new file mode 100644 >>> index 0000000..bd6341c >>> --- /dev/null >>> +++ b/lib/x86/io.h >>> @@ -0,0 +1,40 @@ >>> +#ifndef IO_H >>> +#define IO_H >>> + >>> +static inline unsigned char inb(unsigned short port) >>> +{ >>> + unsigned char value; >>> + asm volatile("inb %w1, %0" : "=a" (value) : "Nd" (port)); >>> + return value; >>> +} >> >> Are those %[wb] really needed? gcc should do the right thing based >> on the argument type. > > It's just a little extra type safety. Yeah, but those constraints aren't really documented. Linux does use them in a handful of places so they're unlikely to go away though.
diff --git a/lib/x86/io.h b/lib/x86/io.h new file mode 100644 index 0000000..bd6341c --- /dev/null +++ b/lib/x86/io.h @@ -0,0 +1,40 @@ +#ifndef IO_H +#define IO_H + +static inline unsigned char inb(unsigned short port) +{ + unsigned char value; + asm volatile("inb %w1, %0" : "=a" (value) : "Nd" (port)); + return value; +} + +static inline unsigned short inw(unsigned short port) +{ + unsigned short value; + asm volatile("inw %w1, %0" : "=a" (value) : "Nd" (port)); + return value; +} + +static inline unsigned int inl(unsigned short port) +{ + unsigned int value; + asm volatile("inl %w1, %0" : "=a" (value) : "Nd" (port)); + return value; +} + +static inline void outb(unsigned char value, unsigned short port) +{ + asm volatile("outb %b0, %w1" : : "a"(value), "Nd"(port)); +} + +static inline void outw(unsigned short value, unsigned short port) +{ + asm volatile("outw %w0, %w1" : : "a"(value), "Nd"(port)); +} + +static inline void outl(unsigned int value, unsigned short port) +{ + asm volatile("outl %0, %w1" : : "a"(value), "Nd"(port)); +} + +#endif
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>