From 4dbc30fb27ac4e647e6efadb382ff7d38c3d368e Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 11 May 2005 11:37:00 -0700 Subject: [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 --- arch/sparc64/kernel/sbus.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) (limited to 'arch/sparc64/kernel/sbus.c') diff --git a/arch/sparc64/kernel/sbus.c b/arch/sparc64/kernel/sbus.c index 14d9c3a21b9..d3eca98e1fe 100644 --- a/arch/sparc64/kernel/sbus.c +++ b/arch/sparc64/kernel/sbus.c @@ -117,19 +117,34 @@ 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) { + 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 @@ 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); spin_unlock_irqrestore(&iommu->lock, flags); } @@ -569,7 +584,7 @@ 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); spin_unlock_irqrestore(&iommu->lock, flags); } @@ -581,7 +596,7 @@ 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); spin_unlock_irqrestore(&iommu->lock, flags); } @@ -605,7 +620,7 @@ 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); spin_unlock_irqrestore(&iommu->lock, flags); } -- cgit v1.2.3