lkml.org 
[lkml]   [2018]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 4/9] dma-mapping: move the arm64 ncoherent alloc/free support to common code
> > +int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot)
> > +{
> > + unsigned int pool_size_order = get_order(atomic_pool_size);
> > + unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
> > + struct page *page;
> > + void *addr;
> > + int ret;
> > +
> > + if (dev_get_cma_area(NULL))
> > + page = dma_alloc_from_contiguous(NULL, nr_pages,
> > + pool_size_order, false);
> > + else
> > + page = alloc_pages(gfp, pool_size_order);
> > + if (!page)
> > + goto out;
> > +
> > + memset(page_address(page), 0, atomic_pool_size);
>
> Note that this won't work if 'page' is a highmem page - should there
> be a check for that, or a check for the gfp flags?
>
> Also, is this memset() actually useful, or a waste of cycles - when we
> allocate from this pool (see dma_alloc_from_pool()), we always memset()
> the buffer.

Currently there is no user that supports highmem, but yes, the memset
should probably simply be removed.

\
 
 \ /
  Last update: 2018-12-04 15:22    [W:0.106 / U:0.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site