| Message ID | 20200817234033.442511-4-leobras.c@gmail.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | DDW indirect mapping | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (97a94d178e5876ad49482c42b13b7296cd6803de) |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 15 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
On 18/08/2020 09:40, Leonardo Bras wrote: > As of today, doing iommu_range_alloc() only for !largealloc (npages <= 15) > will only be able to use 3/4 of the available pages, given pages on > largepool not being available for !largealloc. > > This could mean some drivers not being able to fully use all the available > pages for the DMA window. > > Add pages on largepool as a last resort for !largealloc, making all pages > of the DMA window available. > > Signed-off-by: Leonardo Bras <leobras.c@gmail.com> > --- > arch/powerpc/kernel/iommu.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c > index d7086087830f..7f603d4e62d4 100644 > --- a/arch/powerpc/kernel/iommu.c > +++ b/arch/powerpc/kernel/iommu.c > @@ -261,6 +261,15 @@ static unsigned long iommu_range_alloc(struct device *dev, > pass++; > goto again; > > + } else if (pass == tbl->nr_pools + 1) { > + /* Last resort: try largepool */ > + spin_unlock(&pool->lock); > + pool = &tbl->large_pool; > + spin_lock(&pool->lock); > + pool->hint = pool->start; > + pass++; > + goto again; > + A nit: unnecessary new line. Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> > } else { > /* Give up */ > spin_unlock_irqrestore(&(pool->lock), flags); >
On Sat, 2020-08-22 at 20:09 +1000, Alexey Kardashevskiy wrote: > > + goto again; > > + > > A nit: unnecessary new line. I was following the pattern used above. There is a newline after every "goto again" in this 'if'. > Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Thank you!
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index d7086087830f..7f603d4e62d4 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -261,6 +261,15 @@ static unsigned long iommu_range_alloc(struct device *dev, pass++; goto again; + } else if (pass == tbl->nr_pools + 1) { + /* Last resort: try largepool */ + spin_unlock(&pool->lock); + pool = &tbl->large_pool; + spin_lock(&pool->lock); + pool->hint = pool->start; + pass++; + goto again; + } else { /* Give up */ spin_unlock_irqrestore(&(pool->lock), flags);
As of today, doing iommu_range_alloc() only for !largealloc (npages <= 15) will only be able to use 3/4 of the available pages, given pages on largepool not being available for !largealloc. This could mean some drivers not being able to fully use all the available pages for the DMA window. Add pages on largepool as a last resort for !largealloc, making all pages of the DMA window available. Signed-off-by: Leonardo Bras <leobras.c@gmail.com> --- arch/powerpc/kernel/iommu.c | 9 +++++++++ 1 file changed, 9 insertions(+)