Hi Michal, Thanks for the review!
On Thu, Aug 06, 2015 at 01:40:28PM +0200, Michal Nazarewicz wrote: > On Thu, Aug 06 2015, Feng Tang wrote: > > When trying to use several cma heaps on our platforms, > > we met a memory issue due to that the several cma_heaps > > are sharing the same "struct device *". > > > > As in current code base, the normal cma heap creating > > process is, one platform device is created during boot, > > and it will sequentially create cma heaps (usually passing > > its own struct device * as a parameter) > > > > For the multiple cma heaps case, there will be one "struct > > cma" created for each cma heap, and this "struct cma *" is > > saved in dev->cma_area. So the single platform device can't > > meet the requirement here. > > > > So this patch add one default device for a cma heap to avoid > > sharing the same "struct device", thus fix the issue. And it > > doesn't break existing code by only using that default device > > when no "struct device *" is passed in. > > > > Also, since the cma framework has been cleaned up, this patch > > also add a platform data member to pass the "struct cma*" to > > ion_cma_heap_create(). > > > > Signed-off-by: Feng Tang <[email protected]> > > >From CMA’s point of view: > > Acked-by: Michal Nazarewicz <[email protected]> > > > --- > > drivers/staging/android/ion/ion.h | 4 ++++ > > drivers/staging/android/ion/ion_cma_heap.c | 20 +++++++++++++++++--- > > 2 files changed, 21 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/staging/android/ion/ion.h > > b/drivers/staging/android/ion/ion.h > > index 443db84..e9af17e 100644 > > --- a/drivers/staging/android/ion/ion.h > > +++ b/drivers/staging/android/ion/ion.h > > @@ -45,6 +45,9 @@ struct ion_buffer; > > * @size: size of the heap in bytes if applicable > > * @align: required alignment in physical memory if applicable > > * @priv: private info passed from the board file > > + * @priv2: when creating CMA heap, platform device should better also > > + * pass the "struct cma *" info, so that the cma buffer request > > + * know where to go for the buffer > > * > > * Provided by the board file. > > */ > > @@ -56,6 +59,7 @@ struct ion_platform_heap { > > size_t size; > > ion_phys_addr_t align; > > void *priv; > > + void *priv2; > > Why are those void pointers anyway? Perhaps just make them struct device > *dev and struct cma *cma? Especially since priv2 is a bit awkward name. My initial thought is the same, but as there are several other kinds of ion heaps which are also using this structure for their own ion_xxx_heap_create(struct ion_platform_heap *), I gave up using the explicit "struct cma *", in case other kinds of heaps may need to use this additional priv2 in future > > + * data->priv for cma heap is currently supposed to point > > + * to a "struct device *" > > + */ > > + if (data->priv) { > > + cma_heap->dev = data->priv; > > + } else { > > + cma_heap->dev = &cma_heap->default_dma_dev; > > + cma_heap->dev->coherent_dma_mask = DMA_BIT_MASK(32); > > + cma_heap->dev->dma_mask = &dev->coherent_dma_mask; > > + } > > + > > + /* data->priv2 contains a pointer to struct cma */ > > + dev_set_cma_area(cma_heap->dev, data->priv2); > > Perhaps: > > + if (data->priv2) > + dev_set_cma_area(cma_heap->dev, data->priv2); Yes, this looks more logical, even though the cma_heap structure is kzalloced. Thanks, Feng -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
