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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5be25464-bbc5-4b84-0f90-08dd578e903c X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Feb 2025 00:26:37.5658 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 9zjex/YbpZQW1AM7BNgtGxfX1aBzZtzWMocqLjh90e+nrP/9BwgtjQUqf4i8qc4I X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR12MB7433 Userspace will need to know some details about the fwctl interface being used to locate the correct userspace code to communicate with the kernel. Provide a simple device_type enum indicating what the kernel driver is. Allow the device to provide a device specific info struct that contains any additional information that the driver may need to provide to userspace. Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Tested-by: Dave Jiang Reviewed-by: Shannon Nelson Tested-by: Shannon Nelson Signed-off-by: Jason Gunthorpe --- drivers/fwctl/main.c | 55 ++++++++++++++++++++++++++++++++++++++ include/linux/fwctl.h | 12 +++++++++ include/uapi/fwctl/fwctl.h | 31 +++++++++++++++++++++ 3 files changed, 98 insertions(+) diff --git a/drivers/fwctl/main.c b/drivers/fwctl/main.c index 4bba6109712e42..bd84c4e5b3b92e 100644 --- a/drivers/fwctl/main.c +++ b/drivers/fwctl/main.c @@ -27,8 +27,62 @@ struct fwctl_ucmd { u32 user_size; }; +static int ucmd_respond(struct fwctl_ucmd *ucmd, size_t cmd_len) +{ + if (copy_to_user(ucmd->ubuffer, ucmd->cmd, + min_t(size_t, ucmd->user_size, cmd_len))) + return -EFAULT; + return 0; +} + +static int copy_to_user_zero_pad(void __user *to, const void *from, + size_t from_len, size_t user_len) +{ + size_t copy_len; + + copy_len = min(from_len, user_len); + if (copy_to_user(to, from, copy_len)) + return -EFAULT; + if (copy_len < user_len) { + if (clear_user(to + copy_len, user_len - copy_len)) + return -EFAULT; + } + return 0; +} + +static int fwctl_cmd_info(struct fwctl_ucmd *ucmd) +{ + struct fwctl_device *fwctl = ucmd->uctx->fwctl; + struct fwctl_info *cmd = ucmd->cmd; + size_t driver_info_len = 0; + + if (cmd->flags) + return -EOPNOTSUPP; + + if (!fwctl->ops->info && cmd->device_data_len) { + if (clear_user(u64_to_user_ptr(cmd->out_device_data), + cmd->device_data_len)) + return -EFAULT; + } else if (cmd->device_data_len) { + void *driver_info __free(kfree) = + fwctl->ops->info(ucmd->uctx, &driver_info_len); + if (IS_ERR(driver_info)) + return PTR_ERR(driver_info); + + if (copy_to_user_zero_pad(u64_to_user_ptr(cmd->out_device_data), + driver_info, driver_info_len, + cmd->device_data_len)) + return -EFAULT; + } + + cmd->out_device_type = fwctl->ops->device_type; + cmd->device_data_len = driver_info_len; + return ucmd_respond(ucmd, sizeof(*cmd)); +} + /* On stack memory for the ioctl structs */ union fwctl_ucmd_buffer { + struct fwctl_info info; }; struct fwctl_ioctl_op { @@ -48,6 +102,7 @@ struct fwctl_ioctl_op { .execute = _fn, \ } static const struct fwctl_ioctl_op fwctl_ioctl_ops[] = { + IOCTL_OP(FWCTL_INFO, fwctl_cmd_info, struct fwctl_info, out_device_data), }; static long fwctl_fops_ioctl(struct file *filp, unsigned int cmd, diff --git a/include/linux/fwctl.h b/include/linux/fwctl.h index faa4b2c780e0c6..700a5be940e365 100644 --- a/include/linux/fwctl.h +++ b/include/linux/fwctl.h @@ -7,6 +7,7 @@ #include #include #include +#include struct fwctl_device; struct fwctl_uctx; @@ -19,6 +20,10 @@ struct fwctl_uctx; * it will block device hot unplug and module unloading. */ struct fwctl_ops { + /** + * @device_type: The drivers assigned device_type number. This is uABI. + */ + enum fwctl_device_type device_type; /** * @uctx_size: The size of the fwctl_uctx struct to allocate. The first * bytes of this memory will be a fwctl_uctx. The driver can use the @@ -35,6 +40,13 @@ struct fwctl_ops { * is closed. */ void (*close_uctx)(struct fwctl_uctx *uctx); + /** + * @info: Implement FWCTL_INFO. Return a kmalloc() memory that is copied + * to out_device_data. On input length indicates the size of the user + * buffer on output it indicates the size of the memory. The driver can + * ignore length on input, the core code will handle everything. + */ + void *(*info)(struct fwctl_uctx *uctx, size_t *length); }; /** diff --git a/include/uapi/fwctl/fwctl.h b/include/uapi/fwctl/fwctl.h index 8f5fe821cf286e..4052df63f66dc6 100644 --- a/include/uapi/fwctl/fwctl.h +++ b/include/uapi/fwctl/fwctl.h @@ -4,6 +4,9 @@ #ifndef _UAPI_FWCTL_H #define _UAPI_FWCTL_H +#include +#include + #define FWCTL_TYPE 0x9A /** @@ -33,6 +36,34 @@ */ enum { FWCTL_CMD_BASE = 0, + FWCTL_CMD_INFO = 0, }; +enum fwctl_device_type { + FWCTL_DEVICE_TYPE_ERROR = 0, +}; + +/** + * struct fwctl_info - ioctl(FWCTL_INFO) + * @size: sizeof(struct fwctl_info) + * @flags: Must be 0 + * @out_device_type: Returns the type of the device from enum fwctl_device_type + * @device_data_len: On input the length of the out_device_data memory. On + * output the size of the kernel's device_data which may be larger or + * smaller than the input. Maybe 0 on input. + * @out_device_data: Pointer to a memory of device_data_len bytes. Kernel will + * fill the entire memory, zeroing as required. + * + * Returns basic information about this fwctl instance, particularly what driver + * is being used to define the device_data format. + */ +struct fwctl_info { + __u32 size; + __u32 flags; + __u32 out_device_type; + __u32 device_data_len; + __aligned_u64 out_device_data; +}; +#define FWCTL_INFO _IO(FWCTL_TYPE, FWCTL_CMD_INFO) + #endif