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s390/pci_dma: handle dma table failures

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We use lazy allocation for translation table entries but don't handle
allocation (and other) failures during translation table updates.

Handle these failures and undo translation table updates when it's
meaningful.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott
2015-10-26 11:19:13 +01:00
committed by Martin Schwidefsky
parent 4d5a6b7295
commit 66728eeea6
3 changed files with 48 additions and 17 deletions
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38
arch/s390/pci/pci_dma.c
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@@ -95,7 +95,7 @@ static unsigned long *dma_get_page_table_origin(unsigned long *entry)
return pto;
}
static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
{
unsigned long *sto, *pto;
unsigned int rtx, sx, px;
@@ -114,17 +114,8 @@ static unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr
return &pto[px];
}
void dma_update_cpu_trans(unsigned long *dma_table, void *page_addr,
dma_addr_t dma_addr, int flags)
void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
{
unsigned long *entry;
entry = dma_walk_cpu_trans(dma_table, dma_addr);
if (!entry) {
WARN_ON_ONCE(1);
return;
}
if (flags & ZPCI_PTE_INVALID) {
invalidate_pt_entry(entry);
} else {
@@ -145,18 +136,25 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
u8 *page_addr = (u8 *) (pa & PAGE_MASK);
dma_addr_t start_dma_addr = dma_addr;
unsigned long irq_flags;
unsigned long *entry;
int i, rc = 0;
if (!nr_pages)
return -EINVAL;
spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
if (!zdev->dma_table)
if (!zdev->dma_table) {
rc = -EINVAL;
goto no_refresh;
}
for (i = 0; i < nr_pages; i++) {
dma_update_cpu_trans(zdev->dma_table, page_addr, dma_addr,
flags);
entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
if (!entry) {
rc = -ENOMEM;
goto undo_cpu_trans;
}
dma_update_cpu_trans(entry, page_addr, flags);
page_addr += PAGE_SIZE;
dma_addr += PAGE_SIZE;
}
@@ -175,6 +173,18 @@ static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
nr_pages * PAGE_SIZE);
undo_cpu_trans:
if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
flags = ZPCI_PTE_INVALID;
while (i-- > 0) {
page_addr -= PAGE_SIZE;
dma_addr -= PAGE_SIZE;
entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
if (!entry)
break;
dma_update_cpu_trans(entry, page_addr, flags);
}
}
no_refresh:
spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);