Import of Linux/MIPS 2.1.14.2

1 files changed, 246 insertions, 0 deletions

diff --git a/drivers/scsi/sgiwd93.c b/drivers/scsi/sgiwd93.c
new file mode 100644
index 000000000..83affefb6
--- /dev/null
+++ b/drivers/scsi/sgiwd93.c
@@ -0,0 +1,246 @@
+/* $Id: sgiwd93.c,v 1.7 1996/07/23 09:00:16 dm Exp $
+ * sgiwd93.c: SGI WD93 scsi driver.
+ *
+ * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
+ *
+ * (In all truth, Jed Schimmel wrote all this code.)
+ */
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/blk.h>
+#include <linux/version.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/sgi.h>
+#include <asm/sgialib.h>
+#include <asm/sgimc.h>
+#include <asm/sgihpc.h>
+#include <asm/sgint23.h>
+#include <asm/irq.h>
+
+#include "scsi.h"
+#include "hosts.h"
+#include "wd33c93.h"
+#include "sgiwd93.h"
+
+#include <linux/stat.h>
+
+struct hpc_chunk {
+	struct hpc_dma_desc desc;
+	unsigned long padding;
+};
+
+struct proc_dir_entry proc_scsi_sgiwd93 = {
+	PROC_SCSI_SGIWD93, 5, "SGIWD93",
+	S_IFDIR | S_IRUGO | S_IXUGO, 2
+};
+
+struct Scsi_Host *sgiwd93_host = NULL;
+
+/* Wuff wuff, wuff, wd33c93.c, wuff wuff, object oriented, bow wow. */
+static inline void write_wd33c93_count(wd33c93_regs *regp, unsigned long value)
+{
+	regp->SASR = WD_TRANSFER_COUNT_MSB;
+	regp->SCMD = ((value >> 16) & 0xff);
+	regp->SCMD = ((value >>  8) & 0xff);
+	regp->SCMD = ((value >>  0) & 0xff);
+}
+
+static inline unsigned long read_wd33c93_count(wd33c93_regs *regp)
+{
+	unsigned long value;
+
+	regp->SASR = WD_TRANSFER_COUNT_MSB;
+	value =  ((regp->SCMD & 0xff) << 16);
+	value |= ((regp->SCMD & 0xff) <<  8);
+	value |= ((regp->SCMD & 0xff) <<  0);
+	return value;
+}
+
+/* XXX woof! */
+static void sgiwd93_intr(int irq, void *dev_id, struct pt_regs *regs)
+{
+	wd33c93_intr(sgiwd93_host);
+}
+
+#undef DEBUG_DMA
+
+static int dma_setup(Scsi_Cmnd *cmd, int datainp)
+{
+	struct WD33C93_hostdata *hdata = CMDHOSTDATA(cmd);
+	wd33c93_regs *regp = hdata->regp;
+	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) cmd->host->base;
+	struct hpc_chunk *hcp = (struct hpc_chunk *) hdata->dma_bounce_buffer;
+
+#ifdef DEBUG_DMA
+	printk("dma_setup: datainp<%d> hcp<%p> ",
+	       datainp, hcp);
+#endif
+
+	hdata->dma_dir = datainp;
+
+	if(cmd->use_sg) {
+		struct scatterlist *slp = cmd->SCp.buffer;
+		int i, totlen = 0;
+
+#ifdef DEBUG_DMA
+		printk("SCLIST<");
+#endif
+		for(i = 0; i <= (cmd->use_sg - 1); i++, hcp++) {
+#ifdef DEBUG_DMA
+			printk("[%p,%d]", slp[i].address, slp[i].length);
+#endif
+			flush_page_to_ram((unsigned long)slp[i].address);
+			hcp->desc.pbuf = PHYSADDR(slp[i].address);
+			hcp->desc.cntinfo = (slp[i].length & HPCDMA_BCNT);
+			totlen += slp[i].length;
+		}
+#ifdef DEBUG_DMA
+		printk(">tlen<%d>", totlen);
+#endif
+		hdata->dma_bounce_len = totlen; /* a trick... */
+		write_wd33c93_count(regp, totlen);
+	} else {
+		/* Non-scattered dma. */
+#ifdef DEBUG_DMA
+		printk("ONEBUF<%p,%d>", cmd->SCp.ptr, cmd->SCp.this_residual);
+#endif
+		flush_page_to_ram((unsigned long)cmd->SCp.ptr);
+		hcp->desc.pbuf = PHYSADDR(cmd->SCp.ptr);
+		hcp->desc.cntinfo = (cmd->SCp.this_residual & HPCDMA_BCNT);
+		hcp++;
+		write_wd33c93_count(regp, 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
+	 * descriptor at the end of the chain.
+	 */
+	hcp->desc.pbuf = 0;
+	hcp->desc.cntinfo = (HPCDMA_EOX);
+
+#ifdef DEBUG_DMA
+	printk(" HPCGO\n");
+#endif
+
+	/* Start up the HPC. */
+	hregs->ndptr = PHYSADDR(hdata->dma_bounce_buffer);
+	if(datainp)
+		hregs->ctrl = (HPC3_SCTRL_ACTIVE);
+	else
+		hregs->ctrl = (HPC3_SCTRL_ACTIVE | HPC3_SCTRL_DIR);
+	return 0;
+}
+
+static void dma_stop(struct Scsi_Host *instance, Scsi_Cmnd *SCpnt,
+		     int status)
+{
+	struct WD33C93_hostdata *hdata = INSTHOSTDATA(instance);
+	wd33c93_regs *regp = hdata->regp;
+	struct hpc3_scsiregs *hregs = (struct hpc3_scsiregs *) SCpnt->host->base;
+
+#ifdef DEBUG_DMA
+	printk("dma_stop: status<%d> ", status);
+#endif
+
+	/* First stop the HPC and flush it's FIFO. */
+	if(hdata->dma_dir) {
+		hregs->ctrl |= HPC3_SCTRL_FLUSH;
+		while(hregs->ctrl & HPC3_SCTRL_ACTIVE)
+			barrier();
+	}
+	hregs->ctrl = 0;
+
+	/* See how far we got and update scatterlist state if necessary. */
+	if(SCpnt->use_sg) {
+		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(regp);
+		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->use_sg - 1); 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->use_sg - 1);
+		}
+		SCpnt->SCp.buffer = &slp[i];
+		SCpnt->SCp.buffers_residual = (SCpnt->use_sg - 1 - i);
+		SCpnt->SCp.ptr = (char *) slp[i].address;
+		SCpnt->SCp.this_residual = slp[i].length;
+	}
+#ifdef DEBUG_DMA
+	printk("\n");
+#endif
+}
+
+static inline void init_hpc_chain(uchar *buf)
+{
+	struct hpc_chunk *hcp = (struct hpc_chunk *) buf;
+	unsigned long start, end;
+
+	start = (unsigned long) buf;
+	end = start + PAGE_SIZE;
+	while(start < end) {
+		hcp->desc.pnext = PHYSADDR((hcp + 1));
+		hcp->desc.cntinfo = HPCDMA_EOX;
+		hcp++;
+		start += sizeof(struct hpc_chunk);
+	};
+	hcp--;
+	hcp->desc.pnext = PHYSADDR(buf);
+}
+
+int sgiwd93_detect(Scsi_Host_Template *HPsUX)
+{
+	static unsigned char called = 0;
+	struct hpc3_scsiregs *hregs = &hpc3c0->scsi_chan0;
+	struct WD33C93_hostdata *hdata;
+	uchar *buf;
+
+	if(called)
+		return 0; /* Should bitch on the console about this... */
+
+	HPsUX->proc_dir = &proc_scsi_sgiwd93;
+
+	sgiwd93_host = scsi_register(HPsUX, sizeof(struct WD33C93_hostdata));
+	sgiwd93_host->base = (unsigned char *) hregs;
+
+	buf = (uchar *) get_free_page(GFP_KERNEL);
+	init_hpc_chain(buf);
+	flush_page_to_ram((unsigned long) buf);
+
+	wd33c93_init(sgiwd93_host, (wd33c93_regs *) 0xbfbc0003,
+		     dma_setup, dma_stop, WD33C93_FS_16_20);
+
+	hdata = INSTHOSTDATA(sgiwd93_host);
+	hdata->no_sync = 0;
+	hdata->dma_bounce_buffer = (uchar *) (KSEG1ADDR(buf));
+	flush_page_to_ram((unsigned long) buf);
+
+	request_irq(1, sgiwd93_intr, 0, "SGI WD93", (void *) sgiwd93_host);
+	called = 1;
+
+	return 1; /* Found one. */
+}