From f49db805a978015936f40ad5ba859181def8acbe Mon Sep 17 00:00:00 2001 From: Isaku Yamahata Date: Fri, 30 Oct 2009 21:21:19 +0900 Subject: [PATCH] pci: add helper functions to check ranges overlap. add helper function to check ranges overlap suggested by Michael S. Tsirkin . 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 Signed-off-by: Isaku Yamahata Signed-off-by: Anthony Liguori --- hw/pci.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/hw/pci.h b/hw/pci.h index 8e5d64aa68..7991bfdf49 100644 --- a/hw/pci.h +++ b/hw/pci.h @@ -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