From: Frank Li <frank...@nxp.com> Introduce the helper function pci_epf_align_inbound_addr() to adjust addresses according to PCI BAR alignment requirements, converting addresses into base and offset values.
Signed-off-by: Frank Li <frank...@nxp.com> --- Changes in v21 - align to bar size Changes in V20 - update function kdoc comments. - 128 come from pci_epf_alloc_space() drivers/pci/endpoint/pci-epf-core.c Change from v15 to v16 - none Change from v14 to v15 - change out address type to dma_addr_t to fix below build issue | Reported-by: kernel test robot <l...@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202502082311.g1hwgggf-...@intel.com/ All errors (new ones prefixed by >>): drivers/pci/endpoint/functions/pci-epf-test.c: In function 'pci_epf_test_enable_doorbell': >> drivers/pci/endpoint/functions/pci-epf-test.c:726:42: error: passing >> argument 4 of 'pci_epf_align_inbound_addr' from incompatible pointer type >> [-Werror=incompatible-pointer-types] 726 | &epf_test->db_bar.phys_addr, &offset); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | dma_addr_t * {aka unsigned int *} In file included from include/linux/pci-epc.h:12, Change form v9 to v14 - none change from v8 to v9 - pci_epf_align_inbound_addr(), base and off must be not NULL - rm pci_epf_align_inbound_addr_lo_hi() change from v7 to v8 - change name to pci_epf_align_inbound_addr() - update comment said only need for memory, which not allocated by pci_epf_alloc_space(). change from v6 to v7 - new patch --- drivers/pci/endpoint/pci-epf-core.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/pci-epf.h | 3 +++ 2 files changed, 39 insertions(+) diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c index 577a9e490115c9dd5d7fb624c4a3001f39b97e78..2947ca52edbe8834f09313249ad3871bc7a462b1 100644 --- a/drivers/pci/endpoint/pci-epf-core.c +++ b/drivers/pci/endpoint/pci-epf-core.c @@ -477,6 +477,42 @@ 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' to base and offset, which match + * BAR's alignment requirement. + * + * The pci_epf_alloc_space() function already accounts for alignment. This is + * primarily intended for use with other memory regions not allocated by + * pci_epf_alloc_space(), such as peripheral register spaces or the trigger + * address for a platform MSI controller. + */ +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 a3b1a1d90d18356e8cda966c7004c3be93962a0d..0ca08f0d05d7439ef4043a77c204062989a27bd9 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); -- 2.34.1
