On Thu, Aug 06, 2015 at 11:25:15PM +0800, Feng Tang wrote: > 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
No, just make it a struct cma *, as that's what it is. Having multiple void * is a sign of a very crazy interface. thanks, greg k-h -- 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/
