| Message ID | 1372227662-28302-1-git-send-email-aik@ozlabs.ru (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
Ben, please ignore this. Need some more code there. On 06/26/2013 04:21 PM, Alexey Kardashevskiy wrote: > VFIO IOMMU driver for sPAPR TCE locks the whole DMA window by setting > ones to iommu_table.it_map. However this was not protected by the locks > which other clients of iommu_table use. > > The patch fixes this. > > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > > v1->v2: > * Fixed a potential warning from lockdep. > > --- > arch/powerpc/kernel/iommu.c | 25 +++++++++++++++++++++++-- > 1 file changed, 23 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c > index b20ff17..5c1fc89 100644 > --- a/arch/powerpc/kernel/iommu.c > +++ b/arch/powerpc/kernel/iommu.c > @@ -1076,25 +1076,42 @@ EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode); > int iommu_take_ownership(struct iommu_table *tbl) > { > unsigned long sz = (tbl->it_size + 7) >> 3; > + unsigned long i, flags; > + int ret = 0; > + > + spin_lock_irqsave(&tbl->large_pool.lock, flags); > + for (i = 0; i < tbl->nr_pools; i++) > + spin_lock(&tbl->pools[i].lock); > > if (tbl->it_offset == 0) > clear_bit(0, tbl->it_map); > > if (!bitmap_empty(tbl->it_map, tbl->it_size)) { > pr_err("iommu_tce: it_map is not empty"); > - return -EBUSY; > + ret = -EBUSY; > + goto unlock_exit; > } > > memset(tbl->it_map, 0xff, sz); > iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); > > - return 0; > +unlock_exit: > + for (i = 0; i < tbl->nr_pools; i++) > + spin_unlock(&tbl->pools[i].lock); > + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); > + > + return ret; > } > EXPORT_SYMBOL_GPL(iommu_take_ownership); > > void iommu_release_ownership(struct iommu_table *tbl) > { > unsigned long sz = (tbl->it_size + 7) >> 3; > + unsigned long i, flags; > + > + spin_lock_irqsave(&tbl->large_pool.lock, flags); > + for (i = 0; i < tbl->nr_pools; i++) > + spin_lock(&tbl->pools[i].lock); > > iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); > memset(tbl->it_map, 0, sz); > @@ -1102,6 +1119,10 @@ void iommu_release_ownership(struct iommu_table *tbl) > /* Restore bit#0 set by iommu_init_table() */ > if (tbl->it_offset == 0) > set_bit(0, tbl->it_map); > + > + for (i = 0; i < tbl->nr_pools; i++) > + spin_unlock(&tbl->pools[i].lock); > + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); > } > EXPORT_SYMBOL_GPL(iommu_release_ownership); > >
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index b20ff17..5c1fc89 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1076,25 +1076,42 @@ EXPORT_SYMBOL_GPL(iommu_put_tce_user_mode); int iommu_take_ownership(struct iommu_table *tbl) { unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long i, flags; + int ret = 0; + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); if (tbl->it_offset == 0) clear_bit(0, tbl->it_map); if (!bitmap_empty(tbl->it_map, tbl->it_size)) { pr_err("iommu_tce: it_map is not empty"); - return -EBUSY; + ret = -EBUSY; + goto unlock_exit; } memset(tbl->it_map, 0xff, sz); iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); - return 0; +unlock_exit: + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); + + return ret; } EXPORT_SYMBOL_GPL(iommu_take_ownership); void iommu_release_ownership(struct iommu_table *tbl) { unsigned long sz = (tbl->it_size + 7) >> 3; + unsigned long i, flags; + + spin_lock_irqsave(&tbl->large_pool.lock, flags); + for (i = 0; i < tbl->nr_pools; i++) + spin_lock(&tbl->pools[i].lock); iommu_clear_tces_and_put_pages(tbl, tbl->it_offset, tbl->it_size); memset(tbl->it_map, 0, sz); @@ -1102,6 +1119,10 @@ void iommu_release_ownership(struct iommu_table *tbl) /* Restore bit#0 set by iommu_init_table() */ if (tbl->it_offset == 0) set_bit(0, tbl->it_map); + + for (i = 0; i < tbl->nr_pools; i++) + spin_unlock(&tbl->pools[i].lock); + spin_unlock_irqrestore(&tbl->large_pool.lock, flags); } EXPORT_SYMBOL_GPL(iommu_release_ownership);
VFIO IOMMU driver for sPAPR TCE locks the whole DMA window by setting ones to iommu_table.it_map. However this was not protected by the locks which other clients of iommu_table use. The patch fixes this. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> --- v1->v2: * Fixed a potential warning from lockdep. --- arch/powerpc/kernel/iommu.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)