diff options
| -rw-r--r-- | drivers/pci/endpoint/pci-epf-core.c | 38 | ||||
| -rw-r--r-- | include/linux/pci-epf.h | 3 |
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 577a9e490115..09b90e1631d5 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -477,6 +477,44 @@ struct pci_epf *pci_epf_create(const char *name) } EXPORT_SYMBOL_GPL(pci_epf_create); +/** + * pci_epf_align_inbound_addr() - Align the given address based on the BAR + * alignment requirement + * @epf: the EPF device + * @addr: inbound address to be aligned + * @bar: the BAR number corresponding to the given addr + * @base: base address matching the @bar alignment requirement + * @off: offset to be added to the @base address + * + * Helper function to align input @addr based on BAR's alignment requirement. + * The aligned base address and offset are returned via @base and @off. + * + * NOTE: The pci_epf_alloc_space() function already accounts for alignment. + * This API is primarily intended for use with other memory regions not + * allocated by pci_epf_alloc_space(), such as peripheral register spaces or + * the message address of a platform MSI controller. + * + * Return: 0 on success, errno otherwise. + */ +int pci_epf_align_inbound_addr(struct pci_epf *epf, enum pci_barno bar, + u64 addr, dma_addr_t *base, size_t *off) +{ + /* + * Most EP controllers require the BAR start address to be aligned to + * the BAR size, because they mask off the lower bits. + * + * Alignment to BAR size also works for controllers that support + * unaligned addresses. + */ + u64 align = epf->bar[bar].size; + + *base = round_down(addr, align); + *off = addr & (align - 1); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_epf_align_inbound_addr); + static void pci_epf_dev_release(struct device *dev) { struct pci_epf *epf = to_pci_epf(dev); diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h index 52e07602f08e..2e85504ba2ba 100644 --- a/include/linux/pci-epf.h +++ b/include/linux/pci-epf.h @@ -241,6 +241,9 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar, enum pci_epc_interface_type type); void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar, enum pci_epc_interface_type type); + +int pci_epf_align_inbound_addr(struct pci_epf *epf, enum pci_barno bar, + u64 addr, dma_addr_t *base, size_t *off); int pci_epf_bind(struct pci_epf *epf); void pci_epf_unbind(struct pci_epf *epf); int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf); |