vserver 2.0 rc7

[linux-2.6.git] / arch / sparc64 / kernel / sbus.c

diff --git a/arch/sparc64/kernel/sbus.c b/arch/sparc64/kernel/sbus.c
index 14d9c3a..89f5e01 100644 (file)
--- a/arch/sparc64/kernel/sbus.c
+++ b/arch/sparc64/kernel/sbus.c
@@ -117,19 +117,42 @@ static void iommu_flush(struct sbus_iommu *iommu, u32 base, unsigned long npages
 
 #define STRBUF_TAG_VALID       0x02UL
 
-static void strbuf_flush(struct sbus_iommu *iommu, u32 base, unsigned long npages)
+static void sbus_strbuf_flush(struct sbus_iommu *iommu, u32 base, unsigned long npages, int direction)
 {
-       iommu->strbuf_flushflag = 0UL;
-       while (npages--)
-               upa_writeq(base + (npages << IO_PAGE_SHIFT),
+       unsigned long n;
+       int limit;
+
+       n = npages;
+       while (n--)
+               upa_writeq(base + (n << IO_PAGE_SHIFT),
                           iommu->strbuf_regs + STRBUF_PFLUSH);
 
+       /* If the device could not have possibly put dirty data into
+        * the streaming cache, no flush-flag synchronization needs
+        * to be performed.
+        */
+       if (direction == SBUS_DMA_TODEVICE)
+               return;
+
+       iommu->strbuf_flushflag = 0UL;
+
        /* Whoopee cushion! */
        upa_writeq(__pa(&iommu->strbuf_flushflag),
                   iommu->strbuf_regs + STRBUF_FSYNC);
        upa_readq(iommu->sbus_control_reg);
-       while (iommu->strbuf_flushflag == 0UL)
+
+       limit = 100000;
+       while (iommu->strbuf_flushflag == 0UL) {
+               limit--;
+               if (!limit)
+                       break;
+               udelay(1);
                membar("#LoadLoad");
+       }
+       if (!limit)
+               printk(KERN_WARNING "sbus_strbuf_flush: flushflag timeout "
+                      "vaddr[%08x] npages[%ld]\n",
+                      base, npages);
 }
 
 static iopte_t *alloc_streaming_cluster(struct sbus_iommu *iommu, unsigned long npages)
@@ -406,7 +429,7 @@ void sbus_unmap_single(struct sbus_dev *sdev, dma_addr_t dma_addr, size_t size,
 
        spin_lock_irqsave(&iommu->lock, flags);
        free_streaming_cluster(iommu, dma_base, size >> IO_PAGE_SHIFT);
-       strbuf_flush(iommu, dma_base, size >> IO_PAGE_SHIFT);
+       sbus_strbuf_flush(iommu, dma_base, size >> IO_PAGE_SHIFT, direction);
        spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
@@ -569,7 +592,7 @@ void sbus_unmap_sg(struct sbus_dev *sdev, struct scatterlist *sg, int nents, int
        iommu = sdev->bus->iommu;
        spin_lock_irqsave(&iommu->lock, flags);
        free_streaming_cluster(iommu, dvma_base, size >> IO_PAGE_SHIFT);
-       strbuf_flush(iommu, dvma_base, size >> IO_PAGE_SHIFT);
+       sbus_strbuf_flush(iommu, dvma_base, size >> IO_PAGE_SHIFT, direction);
        spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
@@ -581,7 +604,7 @@ void sbus_dma_sync_single_for_cpu(struct sbus_dev *sdev, dma_addr_t base, size_t
        size = (IO_PAGE_ALIGN(base + size) - (base & IO_PAGE_MASK));
 
        spin_lock_irqsave(&iommu->lock, flags);
-       strbuf_flush(iommu, base & IO_PAGE_MASK, size >> IO_PAGE_SHIFT);
+       sbus_strbuf_flush(iommu, base & IO_PAGE_MASK, size >> IO_PAGE_SHIFT, direction);
        spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
@@ -605,7 +628,7 @@ void sbus_dma_sync_sg_for_cpu(struct sbus_dev *sdev, struct scatterlist *sg, int
        size = IO_PAGE_ALIGN(sg[i].dma_address + sg[i].dma_length) - base;
 
        spin_lock_irqsave(&iommu->lock, flags);
-       strbuf_flush(iommu, base, size >> IO_PAGE_SHIFT);
+       sbus_strbuf_flush(iommu, base, size >> IO_PAGE_SHIFT, direction);
        spin_unlock_irqrestore(&iommu->lock, flags);
 }