From 4dbc30fb27ac4e647e6efadb382ff7d38c3d368e Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 11 May 2005 11:37:00 -0700 Subject: [PATCH] [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/pci_iommu.c | 165 +++++++++++++------------------- arch/sparc64/kernel/sbus.c | 31 ++++-- 2 files changed, 88 insertions(+), 108 deletions(-) diff --git a/arch/sparc64/kernel/pci_iommu.c b/arch/sparc64/kernel/pci_iommu.c index 292983413ae..f009b1b4550 100644 --- a/arch/sparc64/kernel/pci_iommu.c +++ b/arch/sparc64/kernel/pci_iommu.c @@ -8,6 +8,7 @@ #include #include #include +#include #include @@ -379,6 +380,54 @@ bad: return PCI_DMA_ERROR_CODE; } +static void pci_strbuf_flush(struct pci_strbuf *strbuf, struct pci_iommu *iommu, u32 vaddr, unsigned long ctx, unsigned long npages) +{ + int limit; + + PCI_STC_FLUSHFLAG_INIT(strbuf); + if (strbuf->strbuf_ctxflush && + iommu->iommu_ctxflush) { + unsigned long matchreg, flushreg; + + flushreg = strbuf->strbuf_ctxflush; + matchreg = PCI_STC_CTXMATCH_ADDR(strbuf, ctx); + + limit = 10000; + do { + pci_iommu_write(flushreg, ctx); + udelay(10); + limit--; + if (!limit) + break; + } while(((long)pci_iommu_read(matchreg)) < 0L); + if (!limit) + printk(KERN_WARNING "pci_strbuf_flush: ctx flush " + "timeout vaddr[%08x] ctx[%lx]\n", + vaddr, ctx); + } else { + unsigned long i; + + for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE) + pci_iommu_write(strbuf->strbuf_pflush, vaddr); + } + + pci_iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa); + (void) pci_iommu_read(iommu->write_complete_reg); + + limit = 10000; + while (!PCI_STC_FLUSHFLAG_SET(strbuf)) { + limit--; + if (!limit) + break; + udelay(10); + membar("#LoadLoad"); + } + if (!limit) + printk(KERN_WARNING "pci_strbuf_flush: flushflag timeout " + "vaddr[%08x] ctx[%lx] npages[%ld]\n", + vaddr, ctx, npages); +} + /* Unmap a single streaming mode DMA translation. */ void pci_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int direction) { @@ -386,7 +435,7 @@ void pci_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int struct pci_iommu *iommu; struct pci_strbuf *strbuf; iopte_t *base; - unsigned long flags, npages, i, ctx; + unsigned long flags, npages, ctx; if (direction == PCI_DMA_NONE) BUG(); @@ -414,29 +463,8 @@ void pci_unmap_single(struct pci_dev *pdev, dma_addr_t bus_addr, size_t sz, int ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL; /* Step 1: Kick data out of streaming buffers if necessary. */ - if (strbuf->strbuf_enabled) { - u32 vaddr = bus_addr; - - PCI_STC_FLUSHFLAG_INIT(strbuf); - if (strbuf->strbuf_ctxflush && - iommu->iommu_ctxflush) { - unsigned long matchreg, flushreg; - - flushreg = strbuf->strbuf_ctxflush; - matchreg = PCI_STC_CTXMATCH_ADDR(strbuf, ctx); - do { - pci_iommu_write(flushreg, ctx); - } while(((long)pci_iommu_read(matchreg)) < 0L); - } else { - for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE) - pci_iommu_write(strbuf->strbuf_pflush, vaddr); - } - - pci_iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa); - (void) pci_iommu_read(iommu->write_complete_reg); - while (!PCI_STC_FLUSHFLAG_SET(strbuf)) - membar("#LoadLoad"); - } + if (strbuf->strbuf_enabled) + pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages); /* Step 2: Clear out first TSB entry. */ iopte_make_dummy(iommu, base); @@ -647,29 +675,8 @@ void pci_unmap_sg(struct pci_dev *pdev, struct scatterlist *sglist, int nelems, ctx = (iopte_val(*base) & IOPTE_CONTEXT) >> 47UL; /* Step 1: Kick data out of streaming buffers if necessary. */ - if (strbuf->strbuf_enabled) { - u32 vaddr = (u32) bus_addr; - - PCI_STC_FLUSHFLAG_INIT(strbuf); - if (strbuf->strbuf_ctxflush && - iommu->iommu_ctxflush) { - unsigned long matchreg, flushreg; - - flushreg = strbuf->strbuf_ctxflush; - matchreg = PCI_STC_CTXMATCH_ADDR(strbuf, ctx); - do { - pci_iommu_write(flushreg, ctx); - } while(((long)pci_iommu_read(matchreg)) < 0L); - } else { - for (i = 0; i < npages; i++, vaddr += IO_PAGE_SIZE) - pci_iommu_write(strbuf->strbuf_pflush, vaddr); - } - - pci_iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa); - (void) pci_iommu_read(iommu->write_complete_reg); - while (!PCI_STC_FLUSHFLAG_SET(strbuf)) - membar("#LoadLoad"); - } + if (strbuf->strbuf_enabled) + pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages); /* Step 2: Clear out first TSB entry. */ iopte_make_dummy(iommu, base); @@ -715,28 +722,7 @@ void pci_dma_sync_single_for_cpu(struct pci_dev *pdev, dma_addr_t bus_addr, size } /* Step 2: Kick data out of streaming buffers. */ - PCI_STC_FLUSHFLAG_INIT(strbuf); - if (iommu->iommu_ctxflush && - strbuf->strbuf_ctxflush) { - unsigned long matchreg, flushreg; - - flushreg = strbuf->strbuf_ctxflush; - matchreg = PCI_STC_CTXMATCH_ADDR(strbuf, ctx); - do { - pci_iommu_write(flushreg, ctx); - } while(((long)pci_iommu_read(matchreg)) < 0L); - } else { - unsigned long i; - - for (i = 0; i < npages; i++, bus_addr += IO_PAGE_SIZE) - pci_iommu_write(strbuf->strbuf_pflush, bus_addr); - } - - /* Step 3: Perform flush synchronization sequence. */ - pci_iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa); - (void) pci_iommu_read(iommu->write_complete_reg); - while (!PCI_STC_FLUSHFLAG_SET(strbuf)) - membar("#LoadLoad"); + pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages); spin_unlock_irqrestore(&iommu->lock, flags); } @@ -749,7 +735,8 @@ void pci_dma_sync_sg_for_cpu(struct pci_dev *pdev, struct scatterlist *sglist, i struct pcidev_cookie *pcp; struct pci_iommu *iommu; struct pci_strbuf *strbuf; - unsigned long flags, ctx; + unsigned long flags, ctx, npages, i; + u32 bus_addr; pcp = pdev->sysdata; iommu = pcp->pbm->iommu; @@ -772,36 +759,14 @@ void pci_dma_sync_sg_for_cpu(struct pci_dev *pdev, struct scatterlist *sglist, i } /* Step 2: Kick data out of streaming buffers. */ - PCI_STC_FLUSHFLAG_INIT(strbuf); - if (iommu->iommu_ctxflush && - strbuf->strbuf_ctxflush) { - unsigned long matchreg, flushreg; - - flushreg = strbuf->strbuf_ctxflush; - matchreg = PCI_STC_CTXMATCH_ADDR(strbuf, ctx); - do { - pci_iommu_write(flushreg, ctx); - } while (((long)pci_iommu_read(matchreg)) < 0L); - } else { - unsigned long i, npages; - u32 bus_addr; - - bus_addr = sglist[0].dma_address & IO_PAGE_MASK; - - for(i = 1; i < nelems; i++) - if (!sglist[i].dma_length) - break; - i--; - npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) - bus_addr) >> IO_PAGE_SHIFT; - for (i = 0; i < npages; i++, bus_addr += IO_PAGE_SIZE) - pci_iommu_write(strbuf->strbuf_pflush, bus_addr); - } - - /* Step 3: Perform flush synchronization sequence. */ - pci_iommu_write(strbuf->strbuf_fsync, strbuf->strbuf_flushflag_pa); - (void) pci_iommu_read(iommu->write_complete_reg); - while (!PCI_STC_FLUSHFLAG_SET(strbuf)) - membar("#LoadLoad"); + bus_addr = sglist[0].dma_address & IO_PAGE_MASK; + for(i = 1; i < nelems; i++) + if (!sglist[i].dma_length) + break; + i--; + npages = (IO_PAGE_ALIGN(sglist[i].dma_address + sglist[i].dma_length) + - bus_addr) >> IO_PAGE_SHIFT; + pci_strbuf_flush(strbuf, iommu, bus_addr, ctx, npages); spin_unlock_irqrestore(&iommu->lock, flags); } 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); } -- 2.41.0