cciss: factor out cciss_p600_dma_prefetch_quirk()

cciss: factor out cciss_p600_dma_prefetch_quirk()

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index b4264bcda618..e1c2bf1c6d64 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -4120,6 +4120,24 @@ static inline void cciss_enable_scsi_prefetch(ctlr_info_t *h)
 #endif
 }
 
+/* Disable DMA prefetch for the P600.  Otherwise an ASIC bug may result
+ * in a prefetch beyond physical memory.
+ */
+static inline void cciss_p600_dma_prefetch_quirk(ctlr_info_t *h)
+{
+        u32 dma_prefetch;
+        __u32 dma_refetch;
+
+        if (h->board_id != 0x3225103C)
+                return;
+        dma_prefetch = readl(h->vaddr + I2O_DMA1_CFG);
+        dma_prefetch |= 0x8000;
+        writel(dma_prefetch, h->vaddr + I2O_DMA1_CFG);
+        pci_read_config_dword(h->pdev, PCI_COMMAND_PARITY, &dma_refetch);
+        dma_refetch |= 0x1;
+        pci_write_config_dword(h->pdev, PCI_COMMAND_PARITY, dma_refetch);
+}
+
 static int __devinit cciss_pci_init(ctlr_info_t *c)
 {
         int prod_index, err;
@@ -4182,24 +4200,7 @@ static int __devinit cciss_pci_init(ctlr_info_t *c)
                 goto err_out_free_res;
         }
         cciss_enable_scsi_prefetch(c);
-        /* Disabling DMA prefetch and refetch for the P600.
-         * An ASIC bug may result in accesses to invalid memory addresses.
-         * We've disabled prefetch for some time now. Testing with XEN
-         * kernels revealed a bug in the refetch if dom0 resides on a P600.
-         */
-        if (c->board_id == 0x3225103C) {
-                __u32 dma_prefetch;
-                __u32 dma_refetch;
-                dma_prefetch = readl(c->vaddr + I2O_DMA1_CFG);
-                dma_prefetch |= 0x8000;
-                writel(dma_prefetch, c->vaddr + I2O_DMA1_CFG);
-                pci_read_config_dword(c->pdev, PCI_COMMAND_PARITY,
-                        &dma_refetch);
-                dma_refetch |= 0x1;
-                pci_write_config_dword(c->pdev, PCI_COMMAND_PARITY,
-                        dma_refetch);
-        }
-
+        cciss_p600_dma_prefetch_quirk(c);
 #ifdef CCISS_DEBUG
         printk(KERN_WARNING "Trying to put board into Performant mode\n");
 #endif                          /* CCISS_DEBUG */