[SCSI] sgiwd93: use cached memory access to make driver work on IP28

SGI IP28 machines would need special treatment (enable adding addtional
wait states) when accessing memory uncached. To avoid this pain I
changed the driver to use only cached access to memory.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 40 insertions, 26 deletions

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 3e161cd66463..14fc7f39e83e 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -345,7 +345,7 @@ config ISCSI_TCP
 
 config SGIWD93_SCSI
         tristate "SGI WD93C93 SCSI Driver"
-        depends on SGI_IP22 && SCSI
+        depends on SGI_HAS_WD93 && SCSI
         help
           If you have a Western Digital WD93 SCSI controller on
           an SGI MIPS system, say Y.  Otherwise, say N.
diff --git a/drivers/scsi/sgiwd93.c b/drivers/scsi/sgiwd93.c
index d4ebe8c67ba9..26cfc56c7091 100644
--- a/drivers/scsi/sgiwd93.c
+++ b/drivers/scsi/sgiwd93.c
@@ -33,10 +33,9 @@
 
 struct ip22_hostdata {
         struct WD33C93_hostdata wh;
-        struct hpc_data {
-                dma_addr_t      dma;
-                void            *cpu;
-        } hd;
+        dma_addr_t dma;
+        void *cpu;
+        struct device *dev;
 };
 
 #define host_to_hostdata(host) ((struct ip22_hostdata *)((host)->hostdata))
@@ -46,6 +45,11 @@ struct hpc_chunk {
         u32 _padding;   /* align to quadword boundary */
 };
 
+/* space for hpc dma descriptors */
+#define HPC_DMA_SIZE   PAGE_SIZE
+
+#define DMA_DIR(d)   ((d == DATA_OUT_DIR) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
+
 static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
 {
         struct Scsi_Host * host = dev_id;
@@ -59,15 +63,17 @@ static irqreturn_t sgiwd93_intr(int irq, void *dev_id)
 }
 
 static inline
-void fill_hpc_entries(struct hpc_chunk *hcp, struct scsi_cmnd *cmd, int datainp)
+void fill_hpc_entries(struct ip22_hostdata *hd, struct scsi_cmnd *cmd, int din)
 {
         unsigned long len = cmd->SCp.this_residual;
         void *addr = cmd->SCp.ptr;
         dma_addr_t physaddr;
         unsigned long count;
+        struct hpc_chunk *hcp;
 
-        physaddr = dma_map_single(NULL, addr, len, cmd->sc_data_direction);
+        physaddr = dma_map_single(hd->dev, addr, len, DMA_DIR(din));
         cmd->SCp.dma_handle = physaddr;
+        hcp = hd->cpu;
 
         while (len) {
                 /*
@@ -89,6 +95,9 @@ void fill_hpc_entries(struct hpc_chunk *hcp, struct scsi_cmnd *cmd, int datainp)
          */
         hcp->desc.pbuf = 0;
         hcp->desc.cntinfo = HPCDMA_EOX;
+        dma_cache_sync(hd->dev, hd->cpu,
+                       (unsigned long)(hcp + 1) - (unsigned long)hd->cpu,
+                       DMA_TO_DEVICE);
 }
 
 static int dma_setup(struct scsi_cmnd *cmd, int datainp)
@@ -96,9 +105,8 @@ static int dma_setup(struct scsi_cmnd *cmd, int datainp)
         struct ip22_hostdata *hdata = host_to_hostdata(cmd->device->host);
         struct hpc3_scsiregs *hregs =
                 (struct hpc3_scsiregs *) cmd->device->host->base;
-        struct hpc_chunk *hcp = (struct hpc_chunk *) hdata->hd.cpu;
 
-        pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hcp);
+        pr_debug("dma_setup: datainp<%d> hcp<%p> ", datainp, hdata->cpu);
 
         hdata->wh.dma_dir = datainp;
 
@@ -111,12 +119,12 @@ static int dma_setup(struct scsi_cmnd *cmd, int datainp)
         if (cmd->SCp.ptr == NULL || cmd->SCp.this_residual == 0)
                 return 1;
 
-        fill_hpc_entries(hcp, cmd, datainp);
+        fill_hpc_entries(hdata, cmd, datainp);
 
         pr_debug(" HPCGO\n");
 
         /* Start up the HPC. */
-        hregs->ndptr = hdata->hd.dma;
+        hregs->ndptr = hdata->dma;
         if (datainp)
                 hregs->ctrl = HPC3_SCTRL_ACTIVE;
         else
@@ -134,6 +142,9 @@ static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
         if (!SCpnt)
                 return;
 
+        if (SCpnt->SCp.ptr == NULL || SCpnt->SCp.this_residual == 0)
+                return;
+
         hregs = (struct hpc3_scsiregs *) SCpnt->device->host->base;
 
         pr_debug("dma_stop: status<%d> ", status);
@@ -145,8 +156,9 @@ static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
                         barrier();
         }
         hregs->ctrl = 0;
-        dma_unmap_single(NULL, SCpnt->SCp.dma_handle, SCpnt->SCp.this_residual,
-                         SCpnt->sc_data_direction);
+        dma_unmap_single(hdata->dev, SCpnt->SCp.dma_handle,
+                         SCpnt->SCp.this_residual,
+                         DMA_DIR(hdata->wh.dma_dir));
 
         pr_debug("\n");
 }
@@ -161,22 +173,23 @@ void sgiwd93_reset(unsigned long base)
 }
 EXPORT_SYMBOL_GPL(sgiwd93_reset);
 
-static inline void init_hpc_chain(struct hpc_data *hd)
+static inline void init_hpc_chain(struct ip22_hostdata *hdata)
 {
-        struct hpc_chunk *hcp = (struct hpc_chunk *) hd->cpu;
-        struct hpc_chunk *dma = (struct hpc_chunk *) hd->dma;
+        struct hpc_chunk *hcp = (struct hpc_chunk *)hdata->cpu;
+        dma_addr_t dma = hdata->dma;
         unsigned long start, end;
 
         start = (unsigned long) hcp;
-        end = start + PAGE_SIZE;
+        end = start + HPC_DMA_SIZE;
         while (start < end) {
-                hcp->desc.pnext = (u32) (dma + 1);
+                hcp->desc.pnext = (u32) (dma + sizeof(struct hpc_chunk));
                 hcp->desc.cntinfo = HPCDMA_EOX;
-                hcp++; dma++;
+                hcp++;
+                dma += sizeof(struct hpc_chunk);
                 start += sizeof(struct hpc_chunk);
         };
         hcp--;
-        hcp->desc.pnext = hd->dma;
+        hcp->desc.pnext = hdata->dma;
 }
 
 static int sgiwd93_bus_reset(struct scsi_cmnd *cmd)
@@ -235,16 +248,17 @@ static int __init sgiwd93_probe(struct platform_device *pdev)
         host->irq = irq;
 
         hdata = host_to_hostdata(host);
-        hdata->hd.cpu = dma_alloc_coherent(&pdev->dev, PAGE_SIZE,
-                                           &hdata->hd.dma, GFP_KERNEL);
-        if (!hdata->hd.cpu) {
+        hdata->dev = &pdev->dev;
+        hdata->cpu = dma_alloc_noncoherent(&pdev->dev, HPC_DMA_SIZE,
+                                           &hdata->dma, GFP_KERNEL);
+        if (!hdata->cpu) {
                 printk(KERN_WARNING "sgiwd93: Could not allocate memory for "
                        "host %d buffer.\n", unit);
                 err = -ENOMEM;
                 goto out_put;
         }
 
-        init_hpc_chain(&hdata->hd);
+        init_hpc_chain(hdata);
 
         regs.SASR = wdregs + 3;
         regs.SCMD = wdregs + 7;
@@ -274,7 +288,7 @@ static int __init sgiwd93_probe(struct platform_device *pdev)
 out_irq:
         free_irq(irq, host);
 out_free:
-        dma_free_coherent(NULL, PAGE_SIZE, hdata->hd.cpu, hdata->hd.dma);
+        dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
 out_put:
         scsi_host_put(host);
 out:
@@ -290,7 +304,7 @@ static void __exit sgiwd93_remove(struct platform_device *pdev)
 
         scsi_remove_host(host);
         free_irq(pd->irq, host);
-        dma_free_coherent(&pdev->dev, PAGE_SIZE, hdata->hd.cpu, hdata->hd.dma);
+        dma_free_noncoherent(&pdev->dev, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
         scsi_host_put(host);
 }