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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Emulation of enough SCSI commands to find and read from a unit
*
* Copyright 2022 Google LLC
* Written by Simon Glass <sjg@chromium.org>
*
* implementations of SCSI functions required so that CONFIG_SCSI can be enabled
* for sandbox
*/
#ifndef __scsi_emul_h
#define __scsi_emul_h
/**
* struct scsi_emul_info - information for emulating a SCSI device
*
* @vendor: Vendor name
* @product: Product name
* @block_size: Block size of device in bytes (normally 512)
* @file_size: Size of the backing file for this emulator, in bytes
* @seek_block: Seek position for file (block number)
*
* @phase: Current SCSI phase
* @buff_used: Number of bytes ready to transfer back to host
* @read_len: Number of bytes of data left in the current read command
* @alloc_len: Allocation length from the last incoming command
* @transfer_len: Transfer length from CBW header
* @buff: Data buffer for outgoing data
*/
struct scsi_emul_info {
/* provided by the caller: */
void *buff;
const char *vendor;
const char *product;
int block_size;
loff_t file_size;
int seek_block;
/* state maintained by the emulator: */
enum scsi_cmd_phase phase;
int buff_used;
int read_len;
int write_len;
uint seek_pos;
int alloc_len;
uint transfer_len;
};
/**
* Return value from sb_scsi_emul_command() indicates that a read or write is
* being started
*/
enum {
SCSI_EMUL_DO_READ = 1,
SCSI_EMUL_DO_WRITE = 2,
};
/**
* sb_scsi_emul_command() - Process a SCSI command
*
* This sets up the response in info->buff and updates various other values
* in info.
*
* If SCSI_EMUL_DO_READ is returned then the caller should set up so that the
* backing file can be read, or return an error status if there is no file.
*
* @info: Emulation information
* @req: Request to process
* @len: Length of request in bytes
* @return SCSI_EMUL_DO_READ if a read has started, SCSI_EMUL_DO_WRITE if a
* write has started, 0 if some other operation has started, -ve if there
* was an error
*/
int sb_scsi_emul_command(struct scsi_emul_info *info,
const struct scsi_cmd *req, int len);
#endif