On Sat, Mar 30, 2024 at 01:19:13PM +0900, Damien Le Moal wrote: > Introduce the function pci_epc_mem_map() to facilitate controller memory > address allocation and mapping to a RC PCI address region in endpoint > function drivers. > > This function first uses pci_epc_map_align() to determine the controller > memory address alignment (offset and size) constraints. The result of > this function is used to allocate a controller physical memory region > using pci_epc_mem_alloc_addr() and map it to the RC PCI address > space with pci_epc_map_addr(). Since pci_epc_map_align() may indicate > that a mapping can be smaller than the requested size, pci_epc_mem_map() > may only partially map the RC PCI address region specified and return > a smaller size for the effective mapping. > > The counterpart of pci_epc_mem_map() to unmap and free the controller > memory address region is pci_epc_mem_unmap(). > > Both functions operate using struct pci_epc_map data structure which is > extended to contain the physical and virtual addresses of the allocated > controller memory. Endpoint function drivers can use struct pci_epc_map > to implement read/write accesses within the mapped RC PCI address region > using the ->virt_addr and ->size fields. > > This commit contains contributions from Rick Wertenbroek > <rick.wertenbroek@xxxxxxxxx>. > Adding 'Co-developed-by && Signed-off-by' tags would give the due credit. > Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx> > --- > drivers/pci/endpoint/pci-epc-core.c | 68 +++++++++++++++++++++++++++++ > include/linux/pci-epc.h | 6 +++ > 2 files changed, 74 insertions(+) > > diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c > index 37758ca91d7f..0095b54bdf9e 100644 > --- a/drivers/pci/endpoint/pci-epc-core.c > +++ b/drivers/pci/endpoint/pci-epc-core.c > @@ -530,6 +530,74 @@ int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > } > EXPORT_SYMBOL_GPL(pci_epc_map_addr); > > +/** > + * pci_epc_mem_map() - allocate and map CPU address to PCI address How about, 'pci_epc_alloc_map()'? I think the 'mem' prefix was added to the existing APIs since the function definitions are in pci-epc-mem driver, but not needed here. > + * @epc: the EPC device on which the CPU address is to be allocated and mapped > + * @func_no: the physical endpoint function number in the EPC device > + * @vfunc_no: the virtual endpoint function number in the physical function > + * @pci_addr: PCI address to which the CPU address should be mapped > + * @size: the number of bytes to map starting from @pci_addr > + * @map: where to return the mapping information > + * > + * Allocate a controller physical address region and map it to a RC PCI address "Allocate an EPC address space region..." > + * region, taking into account the controller physical address mapping > + * constraints (if any). Returns the effective size of the mapping, which may Return value should be specified separately for Kdoc. > + * be less than @size, or a negative error code in case of error. > + */ > +ssize_t pci_epc_mem_map(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + u64 pci_addr, size_t size, struct pci_epc_map *map) > +{ > + int ret; > + > + ret = pci_epc_map_align(epc, func_no, vfunc_no, pci_addr, size, map); > + if (ret) > + return ret; > + > + map->virt_base = pci_epc_mem_alloc_addr(epc, &map->phys_base, > + map->map_size); It'd be nice to move pci_epc_map_align() inside the existing pci_epc_mem_alloc_addr() API to make sure that the allocated memory follows the constraints of the EPC. Would that make sense? - Mani > + if (!map->virt_base) > + return -ENOMEM; > + > + map->phys_addr = map->phys_base + map->map_ofst; > + map->virt_addr = map->virt_base + map->map_ofst; > + > + ret = pci_epc_map_addr(epc, func_no, vfunc_no, map->phys_base, > + map->map_pci_addr, map->map_size); > + if (ret) { > + pci_epc_mem_free_addr(epc, map->phys_base, map->virt_base, > + map->map_size); > + return ret; > + } > + > + return map->pci_size; > +} > +EXPORT_SYMBOL_GPL(pci_epc_mem_map); > + > +/** > + * pci_epc_mem_unmap() - unmap from PCI address and free a CPU address region > + * @epc: the EPC device on which the CPU address is allocated and mapped > + * @func_no: the physical endpoint function number in the EPC device > + * @vfunc_no: the virtual endpoint function number in the physical function > + * @map: the mapping information > + * > + * Allocate and map local CPU address to a PCI address, accounting for the > + * controller local CPU address alignment constraints. > + */ > +void pci_epc_mem_unmap(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + struct pci_epc_map *map) > +{ > + if (!pci_epc_function_is_valid(epc, func_no, vfunc_no)) > + return; > + > + if (!map || !map->pci_size) > + return; > + > + pci_epc_unmap_addr(epc, func_no, vfunc_no, map->phys_base); > + pci_epc_mem_free_addr(epc, map->phys_base, map->virt_base, > + map->map_size); > +} > +EXPORT_SYMBOL_GPL(pci_epc_mem_unmap); > + > /** > * pci_epc_clear_bar() - reset the BAR > * @epc: the EPC device for which the BAR has to be cleared > diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h > index 8cfb4aaf2628..86397a500b54 100644 > --- a/include/linux/pci-epc.h > +++ b/include/linux/pci-epc.h > @@ -304,4 +304,10 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc, > phys_addr_t *phys_addr, size_t size); > void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr, > void __iomem *virt_addr, size_t size); > + > +ssize_t pci_epc_mem_map(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + u64 pci_addr, size_t size, struct pci_epc_map *map); > +void pci_epc_mem_unmap(struct pci_epc *epc, u8 func_no, u8 vfunc_no, > + struct pci_epc_map *map); > + > #endif /* __LINUX_PCI_EPC_H */ > -- > 2.44.0 > -- மணிவண்ணன் சதாசிவம்