| Message ID | 1369911913-10934-2-git-send-email-mst@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, May 30, 2013 at 02:07:16PM +0300, Michael S. Tsirkin wrote: > Sometimes we need to pass ranges around, add a > handy structure for this purpose. > > Note: memory.c defines its own concept of AddrRange structure for > working with 128 addresses. It's necessary there for doing range math. > This is not needed for most users: struct Range is > much simpler, and is only used for passing the range around. > > Cc: Peter Maydell <peter.maydell@linaro.org> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > include/qemu/range.h | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/include/qemu/range.h b/include/qemu/range.h > index 3502372..b76cc0d 100644 > --- a/include/qemu/range.h > +++ b/include/qemu/range.h > @@ -1,6 +1,22 @@ > #ifndef QEMU_RANGE_H > #define QEMU_RANGE_H > > +#include <inttypes.h> > + > +/* > + * Operations on 64 bit address ranges. > + * Notes: > + * - ranges must not wrap around 0, but can include the last byte ~0x0LL. > + * - this can not represent a full 0 to ~0x0LL range. > + */ > + > +/* A structure representing a range of addresses. */ > +struct Range { > + uint64_t begin; /* First byte of the range, or 0 if empty. */ I don't understand, can't a range start from 0? > + uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */ How to tell from the two? Instead I suggest this be a length field, whereas 0 means empty. > +}; > +typedef struct Range Range; > + > /* Get last byte of a range from offset + length. > * Undefined for ranges that wrap around 0. */ > static inline uint64_t range_get_last(uint64_t offset, uint64_t len) > -- > MST >
diff --git a/include/qemu/range.h b/include/qemu/range.h index 3502372..b76cc0d 100644 --- a/include/qemu/range.h +++ b/include/qemu/range.h @@ -1,6 +1,22 @@ #ifndef QEMU_RANGE_H #define QEMU_RANGE_H +#include <inttypes.h> + +/* + * Operations on 64 bit address ranges. + * Notes: + * - ranges must not wrap around 0, but can include the last byte ~0x0LL. + * - this can not represent a full 0 to ~0x0LL range. + */ + +/* A structure representing a range of addresses. */ +struct Range { + uint64_t begin; /* First byte of the range, or 0 if empty. */ + uint64_t end; /* 1 + the last byte. 0 if range empty or ends at ~0x0LL. */ +}; +typedef struct Range Range; + /* Get last byte of a range from offset + length. * Undefined for ranges that wrap around 0. */ static inline uint64_t range_get_last(uint64_t offset, uint64_t len)
Sometimes we need to pass ranges around, add a handy structure for this purpose. Note: memory.c defines its own concept of AddrRange structure for working with 128 addresses. It's necessary there for doing range math. This is not needed for most users: struct Range is much simpler, and is only used for passing the range around. Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- include/qemu/range.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)