Introduce the helper function pci_epf_align_addr() to adjust addresses according to PCI BAR alignment requirements, converting addresses into base and offset values. Signed-off-by: Frank Li <Frank.Li@xxxxxxx> --- change from v6 to v7 - new patch --- drivers/pci/endpoint/pci-epf-core.c | 39 +++++++++++++++++++++++++++++++++++++ include/linux/pci-epf.h | 13 +++++++++++++ 2 files changed, 52 insertions(+) diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 8fa2797d4169a..a3f172cc786e9 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -464,6 +464,45 @@ struct pci_epf *pci_epf_create(const char *name) } EXPORT_SYMBOL_GPL(pci_epf_create); +/** + * pci_epf_align_addr() - Get base address and offset that match bar's + * alignment requirement + * @epf: the EPF device + * @addr: the address of the memory + * @bar: the BAR number corresponding to map addr + * @base: return base address, which match BAR's alignment requirement, nothing + * return if NULL + * @off: return offset, nothing return if NULL + * + * Helper function to convert input 'addr' to base and offset, which match + * BAR's alignment requirement. + */ +int pci_epf_align_addr(struct pci_epf *epf, enum pci_barno bar, u64 addr, u64 *base, size_t *off) +{ + const struct pci_epc_features *epc_features; + u64 align; + + epc_features = pci_epc_get_features(epf->epc, epf->func_no, epf->vfunc_no); + if (!epc_features) { + dev_err(&epf->dev, "epc_features not implemented\n"); + return -EOPNOTSUPP; + } + + align = epc_features->align; + align = align ? align : 128; + if (epc_features->bar[bar].type == BAR_FIXED) + align = max(epc_features->bar[bar].fixed_size, align); + + if (base) + *base = round_down(addr, align); + + if (off) + *off = addr & (align - 1); + + return 0; +} +EXPORT_SYMBOL_GPL(pci_epf_align_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 5374e6515ffa0..20f4f31ba9b36 100644 --- a/include/linux/pci-epf.h +++ b/include/linux/pci-epf.h @@ -238,6 +238,19 @@ 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_addr(struct pci_epf *epf, enum pci_barno bar, u64 addr, u64 *base, size_t *off); +static inline int pci_epf_align_addr_lo_hi(struct pci_epf *epf, enum pci_barno bar, + u32 low, u32 high, u64 *base, size_t *off) +{ + u64 addr = high; + + addr <<= 32; + addr |= low; + + return pci_epf_align_addr(epf, bar, addr, base, 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); -- 2.34.1