[PATCH] Put sgiwd93.c back in sync with 2.4

drivers/scsi/sgiwd93.c

@@ -4,10 +4,13 @@
  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
  *		 1999 Andrew R. Baker (andrewb@uab.edu)
  *		      - Support for 2nd SCSI controller on Indigo2
+ *		 2001 Florian Lohoff (flo@rfc822.org)
+ *		      - Delete HPC scatter gather (Read corruption on 
+ *		        multiple disks)
+ *		      - Cleanup wback cache handling
  * 
  * (In all truth, Jed Schimmel wrote all this code.)
  *
- * $Id: sgiwd93.c,v 1.19 2000/02/04 07:40:47 ralf Exp $
  */
 #include <linux/init.h>
 #include <linux/types.h>
@@ -36,32 +39,13 @@
 
 struct hpc_chunk {
 	struct hpc_dma_desc desc;
-	unsigned long padding;
+	u32 _padding;	/* align to quadword boundary */
 };
 
 struct Scsi_Host *sgiwd93_host = NULL;
 struct Scsi_Host *sgiwd93_host1 = NULL;
 
 /* Wuff wuff, wuff, wd33c93.c, wuff wuff, object oriented, bow wow. */
-static inline void write_wd33c93_count(const wd33c93_regs regs,
-				       unsigned long value)
-{
-	*regs.SASR = WD_TRANSFER_COUNT_MSB;
-	*regs.SCMD = ((value >> 16) & 0xff);
-	*regs.SCMD = ((value >>  8) & 0xff);
-	*regs.SCMD = ((value >>  0) & 0xff);
-}
-
-static inline unsigned long read_wd33c93_count(const wd33c93_regs regs)
-{
-	unsigned long value;
-
-	*regs.SASR = WD_TRANSFER_COUNT_MSB;
-	value =  (*regs.SCMD << 16);
-	value |= (*regs.SCMD <<  8);
-	value |= (*regs.SCMD <<  0);
-	return value;
-}
 
 /* XXX woof! */
 static void sgiwd93_intr(int irq, void *dev_id, struct pt_regs *regs)
@@ -82,7 +66,6 @@ void fill_hpc_entries (struct hpc_chunk **hcp, char *addr, unsigned long len)
 	unsigned long physaddr;
 	unsigned long count;
 	
-	dma_cache_wback_inv((unsigned long)addr,len);
 	physaddr = PHYSADDR(addr);
 	while (len) {
 		/*
@@ -101,7 +84,6 @@ void fill_hpc_entries (struct hpc_chunk **hcp, char *addr, unsigned long len)
 static int dma_setup(Scsi_Cmnd *cmd, int datainp)
 {
 	struct WD33C93_hostdata *hdata = (struct WD33C93_hostdata *)cmd->host->hostdata;
-	const wd33c93_regs regs = hdata->regs;
 	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) cmd->host->base;
 	struct hpc_chunk *hcp = (struct hpc_chunk *) hdata->dma_bounce_buffer;
 
@@ -112,46 +94,17 @@ static int dma_setup(Scsi_Cmnd *cmd, int datainp)
 
 	hdata->dma_dir = datainp;
 
-	if(cmd->SCp.buffers_residual) {
-		struct scatterlist *slp = cmd->SCp.buffer;
-		int i, totlen = 0;
+	/*
+	 * wd33c93 shouldn't pass us bogus dma_setups, but
+	 * it does:-( The other wd33c93 drivers deal with
+	 * it the same way (which isn't that obvious).
+	 * IMHO a better fix would be, not to do these
+	 * dma setups in the first place
+	 */
+	if (cmd->SCp.ptr == NULL)
+		return 1;
 
-#ifdef DEBUG_DMA
-		printk("SCLIST<");
-#endif
-		for(i = 0; i <= cmd->SCp.buffers_residual; i++) {
-#ifdef DEBUG_DMA
-			printk("[%p,%d]",
-			       page_address(slp[i].page) + slp[i].offset,
-			       slp[i].length);
-#endif
-			fill_hpc_entries (&hcp,
-					  page_address(slp[i].page) + slp[i].offset,
-					  slp[i].length);
-			totlen += slp[i].length;
-		}
-#ifdef DEBUG_DMA
-		printk(">tlen<%d>", totlen);
-#endif
-		hdata->dma_bounce_len = totlen; /* a trick... */
-		write_wd33c93_count(regs, totlen);
-	} else {
-		/* Non-scattered dma. */
-#ifdef DEBUG_DMA
-		printk("ONEBUF<%p,%d>", cmd->SCp.ptr, cmd->SCp.this_residual);
-#endif
-		/*
-		 * wd33c93 shouldn't pass us bogus dma_setups, but
-		 * it does:-( The other wd33c93 drivers deal with
-		 * it the same way (which isn't that obvious).
-		 * IMHO a better fix would be, not to do these
-		 * dma setups in the first place
-		 */
-		if (cmd->SCp.ptr == NULL)
-			return 1;
-		fill_hpc_entries (&hcp, cmd->SCp.ptr,cmd->SCp.this_residual);
-		write_wd33c93_count(regs, cmd->SCp.this_residual);
-	}
+	fill_hpc_entries (&hcp, cmd->SCp.ptr,cmd->SCp.this_residual);
 
 	/* To make sure, if we trip an HPC bug, that we transfer
 	 * every single byte, we tag on an extra zero length dma
@@ -166,10 +119,14 @@ static int dma_setup(Scsi_Cmnd *cmd, int datainp)
 
 	/* Start up the HPC. */
 	hregs->ndptr = PHYSADDR(hdata->dma_bounce_buffer);
-	if(datainp)
+	if(datainp) {
+		dma_cache_inv((unsigned long) cmd->SCp.ptr, cmd->SCp.this_residual);
 		hregs->ctrl = (HPC3_SCTRL_ACTIVE);
-	else
+	} else {
+		dma_cache_wback_inv((unsigned long) cmd->SCp.ptr, cmd->SCp.this_residual);
 		hregs->ctrl = (HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR);
+	}
+
 	return 0;
 }
 
@@ -177,7 +134,6 @@ static void dma_stop(struct Scsi_Host *instance, Scsi_Cmnd *SCpnt,
 		     int status)
 {
 	struct WD33C93_hostdata *hdata = (struct WD33C93_hostdata *)instance->hostdata;
-	const wd33c93_regs regs = hdata->regs;
 	struct hpc3_scsiregs *hregs;
 
 	if (!SCpnt)
@@ -197,44 +153,6 @@ static void dma_stop(struct Scsi_Host *instance, Scsi_Cmnd *SCpnt,
 	}
 	hregs->ctrl = 0;
 
-	/* See how far we got and update scatterlist state if necessary. */
-	if(SCpnt->SCp.buffers_residual) {
-		struct scatterlist *slp = SCpnt->SCp.buffer;
-		int totlen, wd93_residual, transferred, i;
-
-		/* Yep, we were doing the scatterlist thang. */
-		totlen = hdata->dma_bounce_len;
-		wd93_residual = read_wd33c93_count(regs);
-		transferred = totlen - wd93_residual;
-
-#ifdef DEBUG_DMA
-		printk("tlen<%d>resid<%d>transf<%d> ",
-		       totlen, wd93_residual, transferred);
-#endif
-
-		/* Avoid long winded partial-transfer search for common case. */
-		if(transferred != totlen) {
-			/* This is the nut case. */
-#ifdef DEBUG_DMA
-			printk("Jed was here...");
-#endif
-			for(i = 0; i <= SCpnt->SCp.buffers_residual; i++) {
-				if(slp[i].length >= transferred)
-					break;
-				transferred -= slp[i].length;
-			}
-		} else {
-			/* This is the common case. */
-#ifdef DEBUG_DMA
-			printk("did it all...");
-#endif
-			i = SCpnt->SCp.buffers_residual;
-		}
-		SCpnt->SCp.buffer = &slp[i];
-		SCpnt->SCp.buffers_residual = SCpnt->SCp.buffers_residual - i;
-		SCpnt->SCp.ptr = (char *) page_address(slp[i].page) + slp[i].offset;
-		SCpnt->SCp.this_residual = slp[i].length;
-	}
 #ifdef DEBUG_DMA
 	printk("\n");
 #endif
@@ -264,6 +182,9 @@ static inline void init_hpc_chain(uchar *buf)
 	};
 	hcp--;
 	hcp->desc.pnext = PHYSADDR(buf);
+
+	/* Force flush to memory */
+	dma_cache_wback_inv((unsigned long) buf, PAGE_SIZE);
 }
 
 int __init sgiwd93_detect(Scsi_Host_Template *SGIblows)
@@ -273,8 +194,8 @@ int __init sgiwd93_detect(Scsi_Host_Template *SGIblows)
 	struct hpc3_scsiregs *hregs1 = &hpc3c0->scsi_chan1;
 	struct WD33C93_hostdata *hdata;
 	struct WD33C93_hostdata *hdata1;
-	uchar *buf;
 	wd33c93_regs regs;
+	uchar *buf;
 	
 	if(called)
 		return 0; /* Should bitch on the console about this... */
@@ -294,10 +215,10 @@ int __init sgiwd93_detect(Scsi_Host_Template *SGIblows)
 		return 0;
 	}
 	init_hpc_chain(buf);
-	dma_cache_wback_inv((unsigned long) buf, PAGE_SIZE);
+	
 	/* HPC_SCSI_REG0 | 0x03 | KSEG1 */
-	regs.SASR = (volatile unsigned char *)KSEG1ADDR (0x1fbc0003);
-	regs.SCMD = (volatile unsigned char *)KSEG1ADDR (0x1fbc0007);
+	regs.SASR = (unsigned char*) KSEG1ADDR (0x1fbc0003);
+	regs.SCMD = (unsigned char*) KSEG1ADDR (0x1fbc0007);
 	wd33c93_init(sgiwd93_host, regs, dma_setup, dma_stop, WD33C93_FS_16_20);
 
 	hdata = (struct WD33C93_hostdata *)sgiwd93_host->hostdata;
@@ -329,17 +250,16 @@ int __init sgiwd93_detect(Scsi_Host_Template *SGIblows)
 				return 1; /* We registered host0 so return success*/
 			}
 			init_hpc_chain(buf);
-			dma_cache_wback_inv((unsigned long) buf, PAGE_SIZE);
+
 			/* HPC_SCSI_REG1 | 0x03 | KSEG1 */
-			regs.SASR = (volatile unsigned char *)KSEG1ADDR (0x1fbc8003);
-			regs.SCMD = (volatile unsigned char *)KSEG1ADDR (0x1fbc8007);
+			regs.SASR = (unsigned char*) KSEG1ADDR(0x1fbc8003);
+			regs.SCMD = (unsigned char*) KSEG1ADDR(0x1fbc8007);
 			wd33c93_init(sgiwd93_host1, regs, dma_setup, dma_stop,
-				     WD33C93_FS_16_20);
+			             WD33C93_FS_16_20);
 	
 			hdata1 = (struct WD33C93_hostdata *)sgiwd93_host1->hostdata;
 			hdata1->no_sync = 0;
 			hdata1->dma_bounce_buffer = (uchar *) (KSEG1ADDR(buf));
-			dma_cache_wback_inv((unsigned long) buf, PAGE_SIZE);
 	
 			if (request_irq(SGI_WD93_1_IRQ, sgiwd93_intr, 0, "SGI WD93", (void *) sgiwd93_host1)) {
 				printk(KERN_WARNING "sgiwd93: Could not allocate irq %d (for host1).\n", SGI_WD93_1_IRQ);