This series introduces the new functions pci_epc_mem_map() and pci_epc_mem_unmap() to improve handling of the PCI address mapping alignment constraints of endpoint controllers in a controller independent manner. The issue fixed is that the fixed alignment defined by the "align" field of struct pci_epc_features is defined for inbound ATU entries (e.g. BARs) and is a fixed value, whereas some controllers need a PCI address alignment that depends on the PCI address itself. For instance, the rk3399 SoC controller in endpoint mode uses the lower bits of the local endpoint memory address as the lower bits for the PCI addresses for data transfers. That is, when mapping local memory, one must take into account the number of bits of the RC PCI address that change from the start address of the mapping. To fix this, the new endpoint controller method .get_mem_map is introduced and called from the new pci_epc_mem_map() function. This method is optional and for controllers that do not define it, it is assumed that the controller has no PCI address constraint. The functions pci_epc_mem_map() is a helper function which obtains the mapping information, allocates endpoint controller memory according to the mapping size obtained and maps the memory. pci_epc_mem_unmap() unmaps and frees the endpoint memory. This series is organized as follows: - Patch 1 introduces a small helper to clean up the epc core code - Patch 2 improves pci_epc_mem_alloc_addr() - Patch 3 introduce the new get_mem_map endpoint controller method and the epc functions pci_epc_mem_map() and pci_epc_mem_unmap(). - Patch 4 documents these new functions. - Patch 5 modifies the test endpoint function driver to use pci_epc_mem_map() and pci_epc_mem_unmap() to illustrate the use of these functions. - Finally, patch 6 implements the RK3588 endpoint controller driver .get_mem_map operation to satisfy that controller PCI address alignment constraint. This patch series was tested using the pci endpoint test driver (as-is and a modified version removing memory allocation alignment on the host side) as well as with a prototype NVMe endpoint function driver (where data transfers use addresses that are never aligned to any specific boundary). Changes from v4: - Removed the patch adding the pci_epc_map_align() function. The former .map_align controller operation is now introduced in patch 3 as "get_mem_map()" and used directly in the new pci_epf_mem_map() function. - Modified the documentation patch 4 to reflect the previous change. - Changed patch 6 title and modified it to rename map_align to get_mem_map in accordance with the new patch 3. - Added review tags Changes from v3: - Addressed Niklas comments (improved patch 2 commit message, added comments in the pci_epc_map_align() function in patch 3, typos and improvements in patch 5, patch 7 commit message). - Added review tags Changes from v2: - Dropped all patches for the rockchip-ep. These patches will be sent later as a separate series. - Added patch 2 and 5 - Added review tags to patch 1 Changes from v1: - Changed pci_epc_check_func() to pci_epc_function_is_valid() in patch 1. - Removed patch "PCI: endpoint: Improve pci_epc_mem_alloc_addr()" (former patch 2 of v1) - Various typos cleanups all over. Also fixed some blank space indentation. - Added review tags Damien Le Moal (6): PCI: endpoint: Introduce pci_epc_function_is_valid() PCI: endpoint: Improve pci_epc_mem_alloc_addr() PCI: endpoint: Introduce pci_epc_mem_map()/unmap() PCI: endpoint: Update documentation PCI: endpoint: test: Use pci_epc_mem_map/unmap() PCI: dwc: endpoint: Implement the pci_epc_ops::get_mem_map() operation Documentation/PCI/endpoint/pci-endpoint.rst | 29 ++ .../pci/controller/dwc/pcie-designware-ep.c | 15 + drivers/pci/endpoint/functions/pci-epf-test.c | 372 +++++++++--------- drivers/pci/endpoint/pci-epc-core.c | 205 +++++++--- drivers/pci/endpoint/pci-epc-mem.c | 9 +- include/linux/pci-epc.h | 39 ++ 6 files changed, 439 insertions(+), 230 deletions(-) -- 2.47.0
