┌────────────┐ ┌───────────────────────────────────┐ ┌────────────────┐ │ │ │ │ │ │ │ │ │ PCI Endpoint │ │ PCI Host │ │ │ │ │ │ │ │ │◄──┤ 1.platform_msi_domain_alloc_irqs()│ │ │ │ │ │ │ │ │ │ MSI ├──►│ 2.write_msi_msg() ├──►├─BAR<n> │ │ Controller │ │ update doorbell register address│ │ │ │ │ │ for BAR │ │ │ │ │ │ │ │ 3. Write BAR<n>│ │ │◄──┼───────────────────────────────────┼───┤ │ │ │ │ │ │ │ │ ├──►│ 4.Irq Handle │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └────────────┘ └───────────────────────────────────┘ └────────────────┘ This patches based on old https://lore.kernel.org/imx/20221124055036.1630573-1-Frank.Li@xxxxxxx/ Original patch only target to vntb driver. But actually it is common method. This patches add new API to pci-epf-core, so any EP driver can use it. The key point is comments from Thomas Gleixner, who suggest use new PCI/IMS. But arm platform change still not be merged yet. git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git devmsi-v2-arm So I still use existed method implement RC to EP doorbell. If Thomas Gleixner want to continue work on devmsi-v2-arm, I can help test and update this patch. Frank Li (3): PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller misc: pci_endpoint_test: Add doorbell test case tools: PCI: Add 'B' option for test doorbell drivers/misc/pci_endpoint_test.c | 41 +++++++++++ drivers/pci/endpoint/pci-epf-core.c | 109 ++++++++++++++++++++++++++++ include/linux/pci-epf.h | 16 ++++ include/uapi/linux/pcitest.h | 1 + tools/pci/pcitest.c | 16 +++- 5 files changed, 182 insertions(+), 1 deletion(-) -- 2.34.1
