drivers/scsi/scsi_module.c

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 1 /*
 2  * scsi_module.c Copyright (1994, 1995) Eric Youngdale.
 3  *
 4  * Support for loading low-level scsi drivers using the linux kernel loadable
 5  * module interface.
 6  *
 7  * To use, the host adapter should first define and initialize the variable
 8  * driver_template (datatype Scsi_Host_Template), and then include this file.
 9  * This should also be wrapped in a #ifdef MODULE/#endif.
 10  *
 11  * The low -level driver must also define a release function which will
 12  * free any irq assignments, release any dma channels, release any I/O
 13  * address space that might be reserved, and otherwise clean up after itself.
 14  * The idea is that the same driver should be able to be reloaded without
 15  * any difficulty. This makes debugging new drivers easier, as you should
 16  * be able to load the driver, test it, unload, modify and reload.
 17  *
 18  * One *very* important caveat. If the driver may need to do DMA on the
 19  * ISA bus, you must have unchecked_isa_dma set in the device template,
 20  * even if this might be changed during the detect routine. This is
 21  * because the shpnt structure will be allocated in a special way so that
 22  * it will be below the appropriate DMA limit - thus if your driver uses
 23  * the hostdata field of shpnt, and the board must be able to access this
 24  * via DMA, the shpnt structure must be in a DMA accessible region of
 25  * memory. This comment would be relevant for something like the buslogic
 26  * driver where there are many boards, only some of which do DMA onto the
 27  * ISA bus. There is no convenient way of specifying whether the host
 28  * needs to be in a ISA DMA accessible region of memory when you call
 29  * scsi_register.
 30  */
 31
 32 #include <linux/module.h>
 33
 34 intinit_module(void)
 35 {
 36  driver_template.module = &__this_module;
 37 scsi_register_module(MODULE_SCSI_HA, &driver_template);
 38 if(driver_template.present)
 39 return0;
 40
 41 scsi_unregister_module(MODULE_SCSI_HA, &driver_template);
 42 return-1;
 43 }
 44
 45 voidcleanup_module(void)
 46 {
 47 scsi_unregister_module(MODULE_SCSI_HA, &driver_template);
 48 }
 49
 50 /*
 51  * Overrides for Emacs so that we almost follow Linus's tabbing style.
 52  * Emacs will notice this stuff at the end of the file and automatically
 53  * adjust the settings for this buffer only. This must remain at the end
 54  * of the file.
 55  * ---------------------------------------------------------------------------
 56  * Local variables:
 57  * c-indent-level: 4
 58  * c-brace-imaginary-offset: 0
 59  * c-brace-offset: -4
 60  * c-argdecl-indent: 4
 61  * c-label-offset: -4
 62  * c-continued-statement-offset: 4
 63  * c-continued-brace-offset: 0
 64  * indent-tabs-mode: nil
 65  * tab-width: 8
 66  * End:
 67  */