[PATCH] hack imm.c to work in highmem machines

Currently imm uses page_address() which can crash on highmem. It's not
directly doable to map the pages properly, at least not without
changing some code. In lack of a ->bounce_highio member in the scsi
host template, just set ->unchecked_isa_dma which will just bounce
everything for us. imm isn't performance critical by any stretch of
the imagination, so...

Usually I'd not encourage such a silly hack, but in lack of hardware for
testing (who has it??), this should suffice as it is obviously correct.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/imm.c

@@ -1140,6 +1140,10 @@ static struct scsi_host_template imm_template = {
 	.use_clustering		= ENABLE_CLUSTERING,
 	.can_queue		= 1,
 	.slave_alloc		= imm_adjust_queue,
+	.unchecked_isa_dma	= 1, /* imm cannot deal with highmem, so
+				      * this is an easy trick to ensure
+				      * all io pages for this host reside
+				      * in low memory */
 };
 
 /***************************************************************************