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[SPARC64]: Add timeouts to streaming buffer synchronization.
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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>
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David S. Miller committed May 11, 2005
1 parent e4fdee8 commit 4dbc30f
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Showing 2 changed files with 88 additions and 108 deletions.
165 changes: 65 additions & 100 deletions arch/sparc64/kernel/pci_iommu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/delay.h>

#include <asm/pbm.h>

Expand Down Expand Up @@ -379,14 +380,62 @@ dma_addr_t pci_map_single(struct pci_dev *pdev, void *ptr, size_t sz, int direct
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)
{
struct pcidev_cookie *pcp;
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();
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
}
Expand All @@ -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;
Expand All @@ -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);
}
Expand Down
31 changes: 23 additions & 8 deletions arch/sparc64/kernel/sbus.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand Down Expand Up @@ -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);
}

Expand Down Expand Up @@ -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);
}

Expand All @@ -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);
}

Expand All @@ -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);
}

Expand Down

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