| Message ID | 20240330041928.1555578-4-dlemoal@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Improve PCI memory mapping API | expand |
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@gmail.com>. > Adding 'Co-developed-by && Signed-off-by' tags would give the due credit. > Signed-off-by: Damien Le Moal <dlemoal@kernel.org> > --- > 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 >
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@gmail.com>. > > Signed-off-by: Damien Le Moal <dlemoal@kernel.org> > --- > 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 > + * @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 > + * region, taking into account the controller physical address mapping > + * constraints (if any). Returns the effective size of the mapping, which may > + * 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); > + 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; map->pci_size is of type size_t. pci_epc_mem_map returns a type of ssize_t. This means that on ILP32 you will truncate the result, and will only be able to map a region of max size 2GB. Could we perhaps change this function to return an int instead? (0 on success). The mapped size can still be accessed in map->pci_size. Kind regards, Niklas > +} > +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 >
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 + * @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 + * region, taking into account the controller physical address mapping + * constraints (if any). Returns the effective size of the mapping, which may + * 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); + 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 */
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@gmail.com>. Signed-off-by: Damien Le Moal <dlemoal@kernel.org> --- drivers/pci/endpoint/pci-epc-core.c | 68 +++++++++++++++++++++++++++++ include/linux/pci-epc.h | 6 +++ 2 files changed, 74 insertions(+)