1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Emulation of enough SCSI commands to find and read from a unit 4 * 5 * Copyright 2022 Google LLC 6 * Written by Simon Glass <sjg@chromium.org> 7 * 8 * implementations of SCSI functions required so that CONFIG_SCSI can be enabled 9 * for sandbox 10 */ 11 12 #ifndef __scsi_emul_h 13 #define __scsi_emul_h 14 15 /** 16 * struct scsi_emul_info - information for emulating a SCSI device 17 * 18 * @vendor: Vendor name 19 * @product: Product name 20 * @block_size: Block size of device in bytes (normally 512) 21 * @file_size: Size of the backing file for this emulator, in bytes 22 * @seek_block: Seek position for file (block number) 23 * 24 * @phase: Current SCSI phase 25 * @buff_used: Number of bytes ready to transfer back to host 26 * @read_len: Number of bytes of data left in the current read command 27 * @alloc_len: Allocation length from the last incoming command 28 * @transfer_len: Transfer length from CBW header 29 * @buff: Data buffer for outgoing data 30 */ 31 struct scsi_emul_info { 32 /* provided by the caller: */ 33 void *buff; 34 const char *vendor; 35 const char *product; 36 int block_size; 37 loff_t file_size; 38 int seek_block; 39 40 /* state maintained by the emulator: */ 41 enum scsi_cmd_phase phase; 42 int buff_used; 43 int read_len; 44 int write_len; 45 uint seek_pos; 46 int alloc_len; 47 uint transfer_len; 48 }; 49 50 /** 51 * Return value from sb_scsi_emul_command() indicates that a read or write is 52 * being started 53 */ 54 enum { 55 SCSI_EMUL_DO_READ = 1, 56 SCSI_EMUL_DO_WRITE = 2, 57 }; 58 59 /** 60 * sb_scsi_emul_command() - Process a SCSI command 61 * 62 * This sets up the response in info->buff and updates various other values 63 * in info. 64 * 65 * If SCSI_EMUL_DO_READ is returned then the caller should set up so that the 66 * backing file can be read, or return an error status if there is no file. 67 * 68 * @info: Emulation information 69 * @req: Request to process 70 * @len: Length of request in bytes 71 * @return SCSI_EMUL_DO_READ if a read has started, SCSI_EMUL_DO_WRITE if a 72 * write has started, 0 if some other operation has started, -ve if there 73 * was an error 74 */ 75 int sb_scsi_emul_command(struct scsi_emul_info *info, 76 const struct scsi_cmd *req, int len); 77 78 #endif 79