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author | Isaku Yamahata <yamahata@valinux.co.jp> | 2009-10-30 21:21:19 +0900 |
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committer | Anthony Liguori <aliguori@us.ibm.com> | 2009-11-09 08:43:09 -0600 |
commit | f49db805a978015936f40ad5ba859181def8acbe (patch) | |
tree | 422c283fa6e076f8e24a3a0d5c242bb00855566f /hw/pci.h | |
parent | a9f49946113262f9449890ed918ab99ef73dace8 (diff) | |
download | hqemu-f49db805a978015936f40ad5ba859181def8acbe.zip hqemu-f49db805a978015936f40ad5ba859181def8acbe.tar.gz |
pci: add helper functions to check ranges overlap.
add helper function to check ranges overlap suggested by
Michael S. Tsirkin <mst@redhat.com>.
His original suggestion was to use [first, last], however I chosen
to use offset, length pair, i.e. [offset, offset + length)
because pci configuration space related functions all uses offset and length
pair, so it helps to avoid to type constant twice.
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw/pci.h')
-rw-r--r-- | hw/pci.h | 29 |
1 files changed, 29 insertions, 0 deletions
@@ -406,4 +406,33 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base, PCIBus *sh_pci_register_bus(pci_set_irq_fn set_irq, pci_map_irq_fn map_irq, void *pic, int devfn_min, int nirq); +/* These are not pci specific. Should move into a separate header. + * Only pci.c uses them, so keep them here for now. + */ + +/* 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) +{ + return offset + len - 1; +} + +/* Check whether a given range covers a given byte. */ +static inline int range_covers_byte(uint64_t offset, uint64_t len, + uint64_t byte) +{ + return offset <= byte && byte <= range_get_last(offset, len); +} + +/* Check whether 2 given ranges overlap. + * Undefined if ranges that wrap around 0. */ +static inline int ranges_overlap(uint64_t first1, uint64_t len1, + uint64_t first2, uint64_t len2) +{ + uint64_t last1 = range_get_last(first1, len1); + uint64_t last2 = range_get_last(first2, len2); + + return !(last2 < first1 || last1 < first2); +} + #endif |