diff options
Diffstat (limited to 'include/scsi/scsi_host.h')
| -rw-r--r-- | include/scsi/scsi_host.h | 52 |
1 files changed, 31 insertions, 21 deletions
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 5c58d59..530ff4c 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -6,6 +6,7 @@ #include <linux/types.h> #include <linux/workqueue.h> #include <linux/mutex.h> +#include <scsi/scsi.h> struct request_queue; struct block_device; @@ -25,12 +26,15 @@ struct blk_queue_tags; * 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. + * we scatter/gather data. The value we set here is the maximum + * single element sglist. To use chained sglists, the adapter + * has to set a value beyond ALL (and correctly use the chain + * handling API. * Anything else: Indicates the maximum number of chains that can be * used in one scatter-gather request. */ #define SG_NONE 0 -#define SG_ALL 0xff +#define SG_ALL SCSI_MAX_SG_SEGMENTS #define MODE_UNKNOWN 0x00 #define MODE_INITIATOR 0x01 @@ -280,39 +284,45 @@ struct scsi_host_template { * If the host wants to be called before the scan starts, but * after the midlayer has set up ready for the scan, it can fill * in this function. + * + * Status: OPTIONAL */ void (* scan_start)(struct Scsi_Host *); /* - * fill in this function to allow the queue depth of this host - * to be changeable (on a per device basis). returns either + * Fill in this function to allow the queue depth of this host + * to be changeable (on a per device basis). Returns either * the current queue depth setting (may be different from what * was passed in) or an error. An error should only be * returned if the requested depth is legal but the driver was * unable to set it. If the requested depth is illegal, the * driver should set and return the closest legal queue depth. * + * Status: OPTIONAL */ int (* change_queue_depth)(struct scsi_device *, int); /* - * fill in this function to allow the changing of tag types + * Fill in this function to allow the changing of tag types * (this also allows the enabling/disabling of tag command * queueing). An error should only be returned if something * went wrong in the driver while trying to set the tag type. * If the driver doesn't support the requested tag type, then * it should set the closest type it does support without * returning an error. Returns the actual tag type set. + * + * Status: OPTIONAL */ int (* change_queue_type)(struct scsi_device *, int); /* - * This function determines the bios parameters for a given + * 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, list (heads, sectors, cylinders) * - * Status: OPTIONAL */ + * Status: OPTIONAL + */ int (* bios_param)(struct scsi_device *, struct block_device *, sector_t, int []); @@ -351,7 +361,7 @@ struct scsi_host_template { /* * This determines if we will use a non-interrupt driven - * or an interrupt driven scheme, It is set to the maximum number + * or an interrupt driven scheme. It is set to the maximum number * of simultaneous commands a given host adapter will accept. */ int can_queue; @@ -372,12 +382,12 @@ struct scsi_host_template { unsigned short sg_tablesize; /* - * If the host adapter has limitations beside segment count + * Set this if the host adapter has limitations beside segment count. */ unsigned short max_sectors; /* - * dma scatter gather segment boundary limit. a segment crossing this + * DMA scatter gather segment boundary limit. A segment crossing this * boundary will be split in two. */ unsigned long dma_boundary; @@ -386,7 +396,7 @@ struct scsi_host_template { * This specifies "machine infinity" for host templates which don't * limit the transfer size. Note this limit represents an absolute * maximum, and may be over the transfer limits allowed for - * individual devices (e.g. 256 for SCSI-1) + * individual devices (e.g. 256 for SCSI-1). */ #define SCSI_DEFAULT_MAX_SECTORS 1024 @@ -413,12 +423,12 @@ struct scsi_host_template { unsigned supported_mode:2; /* - * true if this host adapter uses unchecked DMA onto an ISA bus. + * 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. + * 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 @@ -428,7 +438,7 @@ struct scsi_host_template { unsigned use_clustering:1; /* - * True for emulated SCSI host adapters (e.g. ATAPI) + * True for emulated SCSI host adapters (e.g. ATAPI). */ unsigned emulated:1; @@ -438,12 +448,12 @@ struct scsi_host_template { unsigned skip_settle_delay:1; /* - * ordered write support + * True if we are using ordered write support. */ unsigned ordered_tag:1; /* - * Countdown for host blocking with no commands outstanding + * Countdown for host blocking with no commands outstanding. */ unsigned int max_host_blocked; @@ -522,8 +532,8 @@ struct Scsi_Host { struct scsi_transport_template *transportt; /* - * area to keep a shared tag map (if needed, will be - * NULL if not) + * Area to keep a shared tag map (if needed, will be + * NULL if not). */ struct blk_queue_tag *bqt; @@ -596,16 +606,16 @@ struct Scsi_Host { /* * Host uses correct SCSI ordering not PC ordering. The bit is * set for the minority of drivers whose authors actually read - * the spec ;) + * the spec ;). */ unsigned reverse_ordering:1; /* - * ordered write support + * Ordered write support */ unsigned ordered_tag:1; - /* task mgmt function in progress */ + /* Task mgmt function in progress */ unsigned tmf_in_progress:1; /* Asynchronous scan in progress */ |
