| Message ID | 20211202113553.238011-1-manivannan.sadhasivam@linaro.org |
|---|---|
| Headers | show |
| Series | Add initial support for MHI endpoint stack | expand |
On 12/2/21 5:35 AM, Manivannan Sadhasivam wrote: > Hello, > > This series adds initial support for the Qualcomm specific Modem Host Interface > (MHI) bus in endpoint devices like SDX55 modems. The MHI bus in endpoint devices > communicates with the MHI bus in host machines like x86 over any physical bus > like PCIe for data connectivity. The MHI host support is already in mainline [1] > and been used by PCIe based modems and WLAN devices running vendor code > (downstream). Today I'm offering some initial review comments on this series. I told you offline I had quite a few comments. When I looked at the code a week or two ago I looked at the end result... So my notes didn't line up well with the way you built it up incrementally. (Still, the way you did it is generally good for review.) I got through patch 9 and kind of petered out. I can look at the rest tomorrow and/or can give you a chance to update before I review more. I'll let you decide... -Alex > Overview > ======== > > This series aims at adding the MHI support in the endpoint devices with the goal > of getting data connectivity using the mainline kernel running on the modems. > Modems here refer to the combination of an APPS processor (Cortex A grade) and > a baseband processor (DSP). The MHI bus is located in the APPS processor and it > transfers data packets from the baseband processor to the host machine. > > The MHI Endpoint (MHI EP) stack proposed here is inspired by the downstream > code written by Qualcomm. But the complete stack is mostly re-written to adapt > to the "bus" framework and made it modular so that it can work with the upstream > subsystems like "PCI Endpoint". The code structure of the MHI endpoint stack > follows the MHI host stack to maintain uniformity. > > With this initial MHI EP stack (along with few other drivers), we can establish > the network interface between host and endpoint over the MHI software channels > (IP_SW0) and can do things like IP forwarding, SSH, etc... . . .
Hello, This series adds initial support for the Qualcomm specific Modem Host Interface (MHI) bus in endpoint devices like SDX55 modems. The MHI bus in endpoint devices communicates with the MHI bus in host machines like x86 over any physical bus like PCIe for data connectivity. The MHI host support is already in mainline [1] and been used by PCIe based modems and WLAN devices running vendor code (downstream). Overview ======== This series aims at adding the MHI support in the endpoint devices with the goal of getting data connectivity using the mainline kernel running on the modems. Modems here refer to the combination of an APPS processor (Cortex A grade) and a baseband processor (DSP). The MHI bus is located in the APPS processor and it transfers data packets from the baseband processor to the host machine. The MHI Endpoint (MHI EP) stack proposed here is inspired by the downstream code written by Qualcomm. But the complete stack is mostly re-written to adapt to the "bus" framework and made it modular so that it can work with the upstream subsystems like "PCI Endpoint". The code structure of the MHI endpoint stack follows the MHI host stack to maintain uniformity. With this initial MHI EP stack (along with few other drivers), we can establish the network interface between host and endpoint over the MHI software channels (IP_SW0) and can do things like IP forwarding, SSH, etc... Stack Organization ================== The MHI EP stack has the concept of controller and device drivers as like the MHI host stack. The MHI EP controller driver can be a PCI Endpoint Function driver and the MHI device driver can be a MHI EP Networking driver or QRTR driver. The MHI EP controller driver is tied to the PCI Endpoint subsystem and handles all bus related activities like mapping the host memory, raising IRQ, passing link specific events etc... The MHI EP networking driver is tied to the Networking stack and handles all networking related activities like sending/receiving the SKBs from netdev, statistics collection etc... This series only contains the MHI EP code, whereas the PCIe EPF driver and MHI EP Networking drivers are not yet submitted and can be found here [2]. Though the MHI EP stack doesn't have the build time dependency, it cannot function without them. Test setup ========== This series has been tested on Telit FN980 TLB board powered by Qualcomm SDX55 (a.k.a X55 modem) interfaced to the 96Boards Poplar board (ARM64 host) over PCIe. Limitations =========== We are not _yet_ there to get the data packets from the modem as that involves the Qualcomm IP Accelerator (IPA) integration with MHI endpoint stack. But we are planning to add support for it in the coming days. References ========== MHI bus: https://www.kernel.org/doc/html/latest/mhi/mhi.html Linaro connect presentation around this topic: https://connect.linaro.org/resources/lvc21f/lvc21f-222/ Thanks, Mani [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/bus/mhi [2] https://git.linaro.org/landing-teams/working/qualcomm/kernel.git/log/?h=tracking-qcomlt-sdx55-drivers Manivannan Sadhasivam (20): bus: mhi: Move host MHI code to "host" directory bus: mhi: Move common MHI definitions out of host directory bus: mhi: Make mhi_state_str[] array static const and move to common.h bus: mhi: Cleanup the register definitions used in headers bus: mhi: ep: Add support for registering MHI endpoint controllers bus: mhi: ep: Add support for registering MHI endpoint client drivers bus: mhi: ep: Add support for creating and destroying MHI EP devices bus: mhi: ep: Add support for managing MMIO registers bus: mhi: ep: Add support for ring management bus: mhi: ep: Add support for sending events to the host bus: mhi: ep: Add support for managing MHI state machine bus: mhi: ep: Add support for processing MHI endpoint interrupts bus: mhi: ep: Add support for powering up the MHI endpoint stack bus: mhi: ep: Add support for powering down the MHI endpoint stack bus: mhi: ep: Add support for handling MHI_RESET bus: mhi: ep: Add support for handling SYS_ERR condition bus: mhi: ep: Add support for processing command and TRE rings bus: mhi: ep: Add support for queueing SKBs over MHI bus bus: mhi: ep: Add support for suspending and resuming channels bus: mhi: ep: Add uevent support for module autoloading drivers/bus/Makefile | 2 +- drivers/bus/mhi/Kconfig | 28 +- drivers/bus/mhi/Makefile | 9 +- drivers/bus/mhi/common.h | 284 ++++ drivers/bus/mhi/ep/Kconfig | 10 + drivers/bus/mhi/ep/Makefile | 2 + drivers/bus/mhi/ep/internal.h | 237 +++ drivers/bus/mhi/ep/main.c | 1674 +++++++++++++++++++++ drivers/bus/mhi/ep/mmio.c | 303 ++++ drivers/bus/mhi/ep/ring.c | 316 ++++ drivers/bus/mhi/ep/sm.c | 181 +++ drivers/bus/mhi/host/Kconfig | 31 + drivers/bus/mhi/{core => host}/Makefile | 4 +- drivers/bus/mhi/{core => host}/boot.c | 0 drivers/bus/mhi/{core => host}/debugfs.c | 0 drivers/bus/mhi/{core => host}/init.c | 12 - drivers/bus/mhi/{core => host}/internal.h | 436 ++---- drivers/bus/mhi/{core => host}/main.c | 0 drivers/bus/mhi/{ => host}/pci_generic.c | 0 drivers/bus/mhi/{core => host}/pm.c | 0 include/linux/mhi_ep.h | 289 ++++ include/linux/mod_devicetable.h | 2 + scripts/mod/file2alias.c | 10 + 23 files changed, 3448 insertions(+), 382 deletions(-) create mode 100644 drivers/bus/mhi/common.h create mode 100644 drivers/bus/mhi/ep/Kconfig create mode 100644 drivers/bus/mhi/ep/Makefile create mode 100644 drivers/bus/mhi/ep/internal.h create mode 100644 drivers/bus/mhi/ep/main.c create mode 100644 drivers/bus/mhi/ep/mmio.c create mode 100644 drivers/bus/mhi/ep/ring.c create mode 100644 drivers/bus/mhi/ep/sm.c create mode 100644 drivers/bus/mhi/host/Kconfig rename drivers/bus/mhi/{core => host}/Makefile (54%) rename drivers/bus/mhi/{core => host}/boot.c (100%) rename drivers/bus/mhi/{core => host}/debugfs.c (100%) rename drivers/bus/mhi/{core => host}/init.c (99%) rename drivers/bus/mhi/{core => host}/internal.h (51%) rename drivers/bus/mhi/{core => host}/main.c (100%) rename drivers/bus/mhi/{ => host}/pci_generic.c (100%) rename drivers/bus/mhi/{core => host}/pm.c (100%) create mode 100644 include/linux/mhi_ep.h