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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [drivers/] [scsi/] [hosts.h] - Rev 1765
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/* * hosts.h Copyright (C) 1992 Drew Eckhardt * Copyright (C) 1993, 1994, 1995, 1998, 1999 Eric Youngdale * * mid to low-level SCSI driver interface header * Initial versions: Drew Eckhardt * Subsequent revisions: Eric Youngdale * * <drew@colorado.edu> * * Modified by Eric Youngdale eric@andante.org to * add scatter-gather, multiple outstanding request, and other * enhancements. * * Further modified by Eric Youngdale to support multiple host adapters * of the same type. * * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli */ #ifndef _HOSTS_H #define _HOSTS_H /* $Header: /home/marcus/revision_ctrl_test/oc_cvs/cvs/or1k/linux/linux-2.4/drivers/scsi/hosts.h,v 1.1.1.1 2004-04-15 02:12:49 phoenix Exp $ */ #include <linux/config.h> #include <linux/proc_fs.h> #include <linux/pci.h> /* It is senseless to set SG_ALL any higher than this - the performance * does not get any better, and it wastes memory */ #define SG_NONE 0 #define SG_ALL 0xff #define DISABLE_CLUSTERING 0 #define ENABLE_CLUSTERING 1 /* The various choices mean: * NONE: Self evident. Host adapter is not capable of scatter-gather. * ALL: Means that the host adapter module can do scatter-gather, * and that there is no limit to the size of the table to which * we scatter/gather data. * Anything else: Indicates the maximum number of chains that can be * used in one scatter-gather request. */ /* * The Scsi_Host_Template type has all that is needed to interface with a SCSI * host in a device independent matter. There is one entry for each different * type of host adapter that is supported on the system. */ typedef struct scsi_disk Disk; typedef struct SHT { /* Used with loadable modules so we can construct a linked list. */ struct SHT * next; /* Used with loadable modules so that we know when it is safe to unload */ struct module * module; /* The pointer to the /proc/scsi directory entry */ struct proc_dir_entry *proc_dir; /* proc-fs info function. * Can be used to export driver statistics and other infos to the world * outside the kernel ie. userspace and it also provides an interface * to feed the driver with information. Check eata_dma_proc.c for reference */ int (*proc_info)(char *, char **, off_t, int, int, int); /* * The name pointer is a pointer to the name of the SCSI * device detected. */ const char *name; /* * The detect function shall return non zero on detection, * indicating the number of host adapters of this particular * type were found. It should also * initialize all data necessary for this particular * SCSI driver. It is passed the host number, so this host * knows where the first entry is in the scsi_hosts[] array. * * Note that the detect routine MUST not call any of the mid level * functions to queue commands because things are not guaranteed * to be set up yet. The detect routine can send commands to * the host adapter as long as the program control will not be * passed to scsi.c in the processing of the command. Note * especially that scsi_malloc/scsi_free must not be called. */ int (* detect)(struct SHT *); int (*revoke)(Scsi_Device *); /* Used with loadable modules to unload the host structures. Note: * there is a default action built into the modules code which may * be sufficient for most host adapters. Thus you may not have to supply * this at all. */ int (*release)(struct Scsi_Host *); /* * The info function will return whatever useful * information the developer sees fit. If not provided, then * the name field will be used instead. */ const char *(* info)(struct Scsi_Host *); /* * ioctl interface */ int (*ioctl)(Scsi_Device *dev, int cmd, void *arg); /* * The command function takes a target, a command (this is a SCSI * command formatted as per the SCSI spec, nothing strange), a * data buffer pointer, and data buffer length pointer. The return * is a status int, bit fielded as follows : * Byte What * 0 SCSI status code * 1 SCSI 1 byte message * 2 host error return. * 3 mid level error return */ int (* command)(Scsi_Cmnd *); /* * The QueueCommand function works in a similar manner * to the command function. It takes an additional parameter, * void (* done)(int host, int code) which is passed the host * # and exit result when the command is complete. * Host number is the POSITION IN THE hosts array of THIS * host adapter. * * The done() function must only be called after QueueCommand() * has returned. */ int (* queuecommand)(Scsi_Cmnd *, void (*done)(Scsi_Cmnd *)); /* * This is an error handling strategy routine. You don't need to * define one of these if you don't want to - there is a default * routine that is present that should work in most cases. For those * driver authors that have the inclination and ability to write their * own strategy routine, this is where it is specified. Note - the * strategy routine is *ALWAYS* run in the context of the kernel eh * thread. Thus you are guaranteed to *NOT* be in an interrupt handler * when you execute this, and you are also guaranteed to *NOT* have any * other commands being queued while you are in the strategy routine. * When you return from this function, operations return to normal. * * See scsi_error.c scsi_unjam_host for additional comments about what * this function should and should not be attempting to do. */ int (*eh_strategy_handler)(struct Scsi_Host *); int (*eh_abort_handler)(Scsi_Cmnd *); int (*eh_device_reset_handler)(Scsi_Cmnd *); int (*eh_bus_reset_handler)(Scsi_Cmnd *); int (*eh_host_reset_handler)(Scsi_Cmnd *); /* * Since the mid level driver handles time outs, etc, we want to * be able to abort the current command. Abort returns 0 if the * abortion was successful. The field SCpnt->abort reason * can be filled in with the appropriate reason why we wanted * the abort in the first place, and this will be used * in the mid-level code instead of the host_byte(). * If non-zero, the code passed to it * will be used as the return code, otherwise * DID_ABORT should be returned. * * Note that the scsi driver should "clean up" after itself, * resetting the bus, etc. if necessary. * * NOTE - this interface is depreciated, and will go away. Use * the eh_ routines instead. */ int (* abort)(Scsi_Cmnd *); /* * The reset function will reset the SCSI bus. Any executing * commands should fail with a DID_RESET in the host byte. * The Scsi_Cmnd is passed so that the reset routine can figure * out which host adapter should be reset, and also which command * within the command block was responsible for the reset in * the first place. Some hosts do not implement a reset function, * and these hosts must call scsi_request_sense(SCpnt) to keep * the command alive. * * NOTE - this interface is depreciated, and will go away. Use * the eh_ routines instead. */ int (* reset)(Scsi_Cmnd *, unsigned int); /* * This function is used to select synchronous communications, * which will result in a higher data throughput. Not implemented * yet. */ int (* slave_attach)(int, int); /* * This function determines the bios parameters for a given * harddisk. These tend to be numbers that are made up by * the host adapter. Parameters: * size, device number, list (heads, sectors, cylinders) */ int (* bios_param)(Disk *, kdev_t, int []); /* * Used to set the queue depth for a specific device. */ void (*select_queue_depths)(struct Scsi_Host *, Scsi_Device *); /* * This determines if we will use a non-interrupt driven * or an interrupt driven scheme, It is set to the maximum number * of simultaneous commands a given host adapter will accept. */ int can_queue; /* * In many instances, especially where disconnect / reconnect are * supported, our host also has an ID on the SCSI bus. If this is * the case, then it must be reserved. Please set this_id to -1 if * your setup is in single initiator mode, and the host lacks an * ID. */ int this_id; /* * This determines the degree to which the host adapter is capable * of scatter-gather. */ short unsigned int sg_tablesize; /* * if the host adapter has limitations beside segment count */ short unsigned int max_sectors; /* * True if this host adapter can make good use of linked commands. * This will allow more than one command to be queued to a given * unit on a given host. Set this to the maximum number of command * blocks to be provided for each device. Set this to 1 for one * command block per lun, 2 for two, etc. Do not set this to 0. * You should make sure that the host adapter will do the right thing * before you try setting this above 1. */ short cmd_per_lun; /* * present contains counter indicating how many boards of this * type were found when we did the scan. */ unsigned char present; /* * true if this host adapter uses unchecked DMA onto an ISA bus. */ unsigned unchecked_isa_dma:1; /* * true if this host adapter can make good use of clustering. * I originally thought that if the tablesize was large that it * was a waste of CPU cycles to prepare a cluster list, but * it works out that the Buslogic is faster if you use a smaller * number of segments (i.e. use clustering). I guess it is * inefficient. */ unsigned use_clustering:1; /* * True if this driver uses the new error handling code. This flag is * really only temporary until all of the other drivers get converted * to use the new error handling code. */ unsigned use_new_eh_code:1; /* * True for emulated SCSI host adapters (e.g. ATAPI) */ unsigned emulated:1; /* * True for drivers that can do I/O from highmem */ unsigned highmem_io:1; /* * Name of proc directory */ char *proc_name; } Scsi_Host_Template; /* * The scsi_hosts array is the array containing the data for all * possible <supported> scsi hosts. This is similar to the * Scsi_Host_Template, except that we have one entry for each * actual physical host adapter on the system, stored as a linked * list. Note that if there are 2 aha1542 boards, then there will * be two Scsi_Host entries, but only 1 Scsi_Host_Template entry. */ struct Scsi_Host { /* private: */ /* * This information is private to the scsi mid-layer. Wrapping it in a * struct private is a way of marking it in a sort of C++ type of way. */ struct Scsi_Host * next; Scsi_Device * host_queue; struct task_struct * ehandler; /* Error recovery thread. */ struct semaphore * eh_wait; /* The error recovery thread waits on this. */ struct semaphore * eh_notify; /* wait for eh to begin */ struct semaphore * eh_action; /* Wait for specific actions on the host. */ unsigned int eh_active:1; /* Indicates the eh thread is awake and active if this is true. */ wait_queue_head_t host_wait; Scsi_Host_Template * hostt; atomic_t host_active; /* commands checked out */ volatile unsigned short host_busy; /* commands actually active on low-level */ volatile unsigned short host_failed; /* commands that failed. */ /* public: */ unsigned short extra_bytes; unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ int resetting; /* if set, it means that last_reset is a valid value */ unsigned long last_reset; /* * These three parameters can be used to allow for wide scsi, * and for host adapters that support multiple busses * The first two should be set to 1 more than the actual max id * or lun (i.e. 8 for normal systems). */ unsigned int max_id; unsigned int max_lun; unsigned int max_channel; /* These parameters should be set by the detect routine */ unsigned long base; unsigned long io_port; unsigned char n_io_port; unsigned char dma_channel; unsigned int irq; /* * This is a unique identifier that must be assigned so that we * have some way of identifying each detected host adapter properly * and uniquely. For hosts that do not support more than one card * in the system at one time, this does not need to be set. It is * initialized to 0 in scsi_register. */ unsigned int unique_id; /* * The rest can be copied from the template, or specifically * initialized, as required. */ /* * The maximum length of SCSI commands that this host can accept. * Probably 12 for most host adapters, but could be 16 for others. * For drivers that don't set this field, a value of 12 is * assumed. I am leaving this as a number rather than a bit * because you never know what subsequent SCSI standards might do * (i.e. could there be a 20 byte or a 24-byte command a few years * down the road?). */ unsigned char max_cmd_len; int this_id; int can_queue; short cmd_per_lun; short unsigned int sg_tablesize; short unsigned int max_sectors; unsigned in_recovery:1; unsigned unchecked_isa_dma:1; unsigned use_clustering:1; unsigned highmem_io:1; /* * True if this host was loaded as a loadable module */ unsigned loaded_as_module:1; /* * Host has rejected a command because it was busy. */ unsigned host_blocked:1; /* * Host has requested that no further requests come through for the * time being. */ unsigned host_self_blocked:1; /* * Host uses correct SCSI ordering not PC ordering. The bit is * set for the minority of drivers whose authors actually read the spec ;) */ unsigned reverse_ordering:1; /* * Indicates that one or more devices on this host were starved, and * when the device becomes less busy that we need to feed them. */ unsigned some_device_starved:1; void (*select_queue_depths)(struct Scsi_Host *, Scsi_Device *); /* * For SCSI hosts which are PCI devices, set pci_dev so that * we can do BIOS EDD 3.0 mappings */ struct pci_dev *pci_dev; /* * We should ensure that this is aligned, both for better performance * and also because some compilers (m68k) don't automatically force * alignment to a long boundary. */ unsigned long hostdata[0] /* Used for storage of host specific stuff */ __attribute__ ((aligned (sizeof(unsigned long)))); }; /* * These two functions are used to allocate and free a pseudo device * which will connect to the host adapter itself rather than any * physical device. You must deallocate when you are done with the * thing. This physical pseudo-device isn't real and won't be available * from any high-level drivers. */ extern void scsi_free_host_dev(Scsi_Device * SDpnt); extern Scsi_Device * scsi_get_host_dev(struct Scsi_Host * SHpnt); extern void scsi_unblock_requests(struct Scsi_Host * SHpnt); extern void scsi_block_requests(struct Scsi_Host * SHpnt); extern void scsi_report_bus_reset(struct Scsi_Host * SHpnt, int channel); typedef struct SHN { struct SHN * next; char * name; unsigned short host_no; unsigned short host_registered; unsigned loaded_as_module; } Scsi_Host_Name; extern Scsi_Host_Name * scsi_host_no_list; extern struct Scsi_Host * scsi_hostlist; extern struct Scsi_Device_Template * scsi_devicelist; extern Scsi_Host_Template * scsi_hosts; extern void build_proc_dir_entries(Scsi_Host_Template *); /* * scsi_init initializes the scsi hosts. */ extern int next_scsi_host; unsigned int scsi_init(void); extern struct Scsi_Host * scsi_register(Scsi_Host_Template *, int j); extern void scsi_unregister(struct Scsi_Host * i); extern void scsi_register_blocked_host(struct Scsi_Host * SHpnt); extern void scsi_deregister_blocked_host(struct Scsi_Host * SHpnt); static inline void scsi_set_pci_device(struct Scsi_Host *SHpnt, struct pci_dev *pdev) { SHpnt->pci_dev = pdev; } /* * Prototypes for functions/data in scsi_scan.c */ extern void scan_scsis(struct Scsi_Host *shpnt, uint hardcoded, uint hchannel, uint hid, uint hlun); extern void scsi_mark_host_reset(struct Scsi_Host *Host); #define BLANK_HOST {"", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} struct Scsi_Device_Template { struct Scsi_Device_Template * next; const char * name; const char * tag; struct module * module; /* Used for loadable modules */ unsigned char scsi_type; unsigned int major; unsigned int min_major; /* Minimum major in range. */ unsigned int max_major; /* Maximum major in range. */ unsigned int nr_dev; /* Number currently attached */ unsigned int dev_noticed; /* Number of devices detected. */ unsigned int dev_max; /* Current size of arrays */ unsigned blk:1; /* 0 if character device */ int (*detect)(Scsi_Device *); /* Returns 1 if we can attach this device */ int (*init)(void); /* Sizes arrays based upon number of devices * detected */ void (*finish)(void); /* Perform initialization after attachment */ int (*attach)(Scsi_Device *); /* Attach devices to arrays */ void (*detach)(Scsi_Device *); int (*init_command)(Scsi_Cmnd *); /* Used by new queueing code. Selects command for blkdevs */ }; void scsi_initialize_queue(Scsi_Device * SDpnt, struct Scsi_Host * SHpnt); int scsi_register_device(struct Scsi_Device_Template * sdpnt); void scsi_deregister_device(struct Scsi_Device_Template * tpnt); /* These are used by loadable modules */ extern int scsi_register_module(int, void *); extern int scsi_unregister_module(int, void *); /* The different types of modules that we can load and unload */ #define MODULE_SCSI_HA 1 #define MODULE_SCSI_CONST 2 #define MODULE_SCSI_IOCTL 3 #define MODULE_SCSI_DEV 4 /* * This is an ugly hack. If we expect to be able to load devices at run time, * we need to leave extra room in some of the data structures. Doing a * realloc to enlarge the structures would be riddled with race conditions, * so until a better solution is discovered, we use this crude approach * * Even bigger hack for SparcSTORAGE arrays. Those are at least 6 disks, but * usually up to 30 disks, so everyone would need to change this. -jj * * Note: These things are all evil and all need to go away. My plan is to * tackle the character devices first, as there aren't any locking implications * in the block device layer. The block devices will require more work. * * The generics driver has been updated to resize as required. So as the tape * driver. Two down, two more to go. */ #ifndef CONFIG_SD_EXTRA_DEVS #define CONFIG_SD_EXTRA_DEVS 2 #endif #ifndef CONFIG_SR_EXTRA_DEVS #define CONFIG_SR_EXTRA_DEVS 2 #endif #define SD_EXTRA_DEVS CONFIG_SD_EXTRA_DEVS #define SR_EXTRA_DEVS CONFIG_SR_EXTRA_DEVS #endif /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically * adjust the settings for this buffer only. This must remain at the end * of the file. * --------------------------------------------------------------------------- * Local variables: * c-indent-level: 4 * c-brace-imaginary-offset: 0 * c-brace-offset: -4 * c-argdecl-indent: 4 * c-label-offset: -4 * c-continued-statement-offset: 4 * c-continued-brace-offset: 0 * indent-tabs-mode: nil * tab-width: 8 * End: */