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 #include <linux/version.h> 34 35 char kernel_version[] = UTS_RELEASE; 36 37 int init_module(void) { /* */ 38 driver_template.usage_count = &mod_use_count_; 39 scsi_register_module(MODULE_SCSI_HA, &driver_template); 40 return (driver_template.present == 0); 41 } 42 43 void cleanup_module( void) { /* */ 44 if (MOD_IN_USE) { 45 printk(KERN_INFO __FILE__ ": module is in use, remove rejected\n"); 46 } 47 scsi_unregister_module(MODULE_SCSI_HA, &driver_template); 48 } 49