From: Pavan Chebbi Date: Sat, 14 Mar 2026 15:16:05 +0000 (-0700) Subject: fwctl/bnxt_fwctl: Add documentation entries X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=44230bb342ffba040d56b0dc24c478797aad9b38;p=thirdparty%2Fkernel%2Flinux.git fwctl/bnxt_fwctl: Add documentation entries Add bnxt_fwctl to the driver and fwctl documentation pages. Link: https://patch.msgid.link/r/20260314151605.932749-6-pavan.chebbi@broadcom.com Reviewed-by: Andy Gospodarek Reviewed-by: Dave Jiang Signed-off-by: Pavan Chebbi Signed-off-by: Jason Gunthorpe --- diff --git a/Documentation/userspace-api/fwctl/bnxt_fwctl.rst b/Documentation/userspace-api/fwctl/bnxt_fwctl.rst new file mode 100644 index 0000000000000..97c9b095cf21c --- /dev/null +++ b/Documentation/userspace-api/fwctl/bnxt_fwctl.rst @@ -0,0 +1,74 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +fwctl bnxt driver +================= + +:Author: Pavan Chebbi + +Overview +======== + +BNXT driver makes a fwctl service available through an auxiliary_device. +The bnxt_fwctl driver binds to this device and registers itself with the +fwctl subsystem. + +The bnxt_fwctl driver is agnostic to the device firmware internals. It +uses the Upper Layer Protocol (ULP) conduit provided by bnxt to send +HardWare Resource Manager (HWRM) commands to firmware. + +These commands can query or change firmware driven device configurations +and read/write registers that are useful for debugging. + +bnxt_fwctl User API +=================== + +Each RPC request contains the HWRM input structure in the fwctl_rpc +'in' buffer while 'out' will contain the response. + +A typical user application can send a FWCTL_INFO command using ioctl() +to discover bnxt_fwctl's RPC capabilities as shown below: + + ioctl(fd, FWCTL_INFO, &fwctl_info_msg); + +where fwctl_info_msg (of type struct fwctl_info) describes bnxt_info_msg +(of type struct fwctl_info_bnxt). fwctl_info_msg is set up as follows: + + size = sizeof(struct fwctl_info); + flags = 0; + device_data_len = sizeof(bnxt_info_msg); + out_device_data = (__aligned_u64)&bnxt_info_msg; + +The uctx_caps of bnxt_info_msg represents the capabilities as described +in fwctl_bnxt_commands of include/uapi/fwctl/bnxt.h + +The FW RPC itself, FWCTL_RPC can be sent using ioctl() as: + + ioctl(fd, FWCTL_RPC, &fwctl_rpc_msg); + +where fwctl_rpc_msg (of type struct fwctl_rpc) carries the HWRM command +in its 'in' buffer. The HWRM input structures are described in +include/linux/bnxt/hsi.h. An example for HWRM_VER_GET is shown below: + + struct hwrm_ver_get_output resp; + struct fwctl_rpc fwctl_rpc_msg; + struct hwrm_ver_get_input req; + + req.req_type = HWRM_VER_GET; + req.hwrm_intf_maj = HWRM_VERSION_MAJOR; + req.hwrm_intf_min = HWRM_VERSION_MINOR; + req.hwrm_intf_upd = HWRM_VERSION_UPDATE; + req.cmpl_ring = -1; + req.target_id = -1; + + fwctl_rpc_msg.size = sizeof(struct fwctl_rpc); + fwctl_rpc_msg.scope = FWCTL_RPC_DEBUG_READ_ONLY; + fwctl_rpc_msg.in_len = sizeof(req); + fwctl_rpc_msg.out_len = sizeof(resp); + fwctl_rpc_msg.in = (__aligned_u64)&req; + fwctl_rpc_msg.out = (__aligned_u64)&resp; + +An example python3 program that can exercise this interface can be found in +the following git repository: + +https://github.com/Broadcom/fwctl-tools diff --git a/Documentation/userspace-api/fwctl/fwctl.rst b/Documentation/userspace-api/fwctl/fwctl.rst index a74eab8d14c61..826817bfd54db 100644 --- a/Documentation/userspace-api/fwctl/fwctl.rst +++ b/Documentation/userspace-api/fwctl/fwctl.rst @@ -148,6 +148,7 @@ area resulting in clashes will be resolved in favour of a kernel implementation. fwctl User API ============== +.. kernel-doc:: include/uapi/fwctl/bnxt.h .. kernel-doc:: include/uapi/fwctl/fwctl.h .. kernel-doc:: include/uapi/fwctl/mlx5.h .. kernel-doc:: include/uapi/fwctl/pds.h diff --git a/Documentation/userspace-api/fwctl/index.rst b/Documentation/userspace-api/fwctl/index.rst index 316ac456ad3b5..8062f76296543 100644 --- a/Documentation/userspace-api/fwctl/index.rst +++ b/Documentation/userspace-api/fwctl/index.rst @@ -10,5 +10,6 @@ to securely construct and execute RPCs inside device firmware. :maxdepth: 1 fwctl + bnxt_fwctl fwctl-cxl pds_fwctl