Hi Joe, On Fri, Nov 16, 2018 at 12:55 AM Joe Perches <j...@perches.com> wrote: > > On Thu, 2018-11-15 at 23:29 +0530, Sabyasachi Gupta wrote: > > On Mon, Nov 5, 2018 at 8:58 AM Sabyasachi Gupta > > <sabyasachi.li...@gmail.com> wrote: > > > Replaced dma_alloc_coherent + memset with dma_zalloc_coherent > > > > > > Signed-off-by: Sabyasachi Gupta <sabyasachi.li...@gmail.com> > > > > Any comment on this patch? > > It's obviously correct. > > You might realign the arguments on the next lines > to the open parenthesis. > > Perhaps there should be new function calls > added for symmetry to the other alloc functions > for multiplication overflow protection. > > Perhaps: > > void *dma_alloc_array_coherent() > void *dma_calloc_coherent() > > Something like > --- > include/linux/dma-mapping.h | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 15bd41447025..95bebf8883b1 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -565,6 +565,25 @@ static inline void *dma_alloc_coherent(struct device > *dev, size_t size, > (gfp & __GFP_NOWARN) ? DMA_ATTR_NO_WARN : 0); > } > > +static inline void *dma_alloc_array_coherent(struct device *dev, > + size_t n, size_t size, > + dma_addr_t *dma_handle, gfp_t > gfp) > +{ > + size_t bytes; > + > + if (unlikely(check_mul_overflow(n, size, &bytes))) > + return NULL; > + return dma_alloc_coherent(dev, bytes, dma_handle, gfp); > +} > + > +static inline void *dma_calloc_coherent(struct device *dev, > + size_t n, size_t size, > + dma_addr_t *dma_handle, gfp_t gfp) > +{ > + return dma_alloc_array_coherent(dev, n, size, dma_handle, > + gfp | __GFP_ZERO); > +} > +
If I understood correctly, you are talking about adding these 2 new inline functions. We can do that. Can you please help to understand the consumers of these 2 new inline ? > static inline void dma_free_coherent(struct device *dev, size_t size, > void *cpu_addr, dma_addr_t dma_handle) > { > > --- > > > diff --git a/arch/powerpc/platforms/pasemi/dma_lib.c > > > b/arch/powerpc/platforms/pasemi/dma_lib.c > [] > > > @@ -255,15 +255,13 @@ int pasemi_dma_alloc_ring(struct pasemi_dmachan > > > *chan, int ring_size) > > > > > > chan->ring_size = ring_size; > > > > > > - chan->ring_virt = dma_alloc_coherent(&dma_pdev->dev, > > > + chan->ring_virt = dma_zalloc_coherent(&dma_pdev->dev, > > > ring_size * sizeof(u64), > > > &chan->ring_dma, GFP_KERNEL); > > > en > > > if (!chan->ring_virt) > > > return -ENOMEM; > > > > > > - memset(chan->ring_virt, 0, ring_size * sizeof(u64)); > > > - > > > return 0; > > > } > > > EXPORT_SYMBOL(pasemi_dma_alloc_ring); > >