linux-mips
[Top] [All Lists]

[UPDATED PATCH] SGIWD93: use cached memory access to make driver work on

To: linux-scsi@vger.kernel.org, linux-mips@linux-mips.org
Subject: [UPDATED PATCH] SGIWD93: use cached memory access to make driver work on IP28
From: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Date: Mon, 26 Nov 2007 18:41:15 +0100
Cc: ralf@linux-mips.org, James.Bottomley@HansenPartnership.com
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
Changes to last version:
- no additional padding of hpc descriptor
- one dma_cache_sync after hpc descriptors are setup is enough

Thomas.

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>
---




 drivers/scsi/sgiwd93.c |   64 +++++++++++++++++++++++++++++------------------
 1 files changed, 39 insertions(+), 25 deletions(-)

diff --git a/drivers/scsi/sgiwd93.c b/drivers/scsi/sgiwd93.c
index eef8275..e64ddee 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;
+       void *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");
 }
@@ -160,22 +172,23 @@ void sgiwd93_reset(unsigned long base)
        hregs->ctrl = 0;
 }
 
-static inline void init_hpc_chain(struct hpc_data *hd)
+static inline void init_hpc_chain(void *dev, 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)
@@ -234,16 +247,17 @@ 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(&pdev->dev, hdata);
 
        regs.SASR = wdregs + 3;
        regs.SCMD = wdregs + 7;
@@ -273,7 +287,7 @@ 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(NULL, HPC_DMA_SIZE, hdata->cpu, hdata->dma);
 out_put:
        scsi_host_put(host);
 out:
@@ -289,7 +303,7 @@ 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);
 }
 

<Prev in Thread] Current Thread [Next in Thread>
  • [UPDATED PATCH] SGIWD93: use cached memory access to make driver work on IP28, Thomas Bogendoerfer <=