[SPARC64]: Add timeouts to streaming buffer synchronization.
If some hardware error occurs and the flush flag never updates,
we will hang forever in these routines. Add a timeout, and
print out a diagnostic if it is reached.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/sbus.c b/arch/sparc64/kernel/sbus.c
index 14d9c3a..d3eca98 100644
--- a/arch/sparc64/kernel/sbus.c
+++ b/arch/sparc64/kernel/sbus.c
@@ -117,19 +117,34 @@
#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)
{
+ unsigned long n;
+ int limit;
+
iommu->strbuf_flushflag = 0UL;
- while (npages--)
- upa_writeq(base + (npages << IO_PAGE_SHIFT),
+ n = npages;
+ while (n--)
+ upa_writeq(base + (n << IO_PAGE_SHIFT),
iommu->strbuf_regs + STRBUF_PFLUSH);
/* 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 = 10000;
+ while (iommu->strbuf_flushflag == 0UL) {
+ limit--;
+ if (!limit)
+ break;
+ udelay(10);
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 +421,7 @@
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);
spin_unlock_irqrestore(&iommu->lock, flags);
}
@@ -569,7 +584,7 @@
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);
spin_unlock_irqrestore(&iommu->lock, flags);
}
@@ -581,7 +596,7 @@
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);
spin_unlock_irqrestore(&iommu->lock, flags);
}
@@ -605,7 +620,7 @@
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);
spin_unlock_irqrestore(&iommu->lock, flags);
}