Commit 29ff744a authored Jan 07, 2022 by Puranam V G Tejaswi

msm: kgsl: Perform cache flush on the pages obtained using get_user_pages()

Consider a scenario where user allocates anonymous memory but does not
write to it. Here the physical pages are not yet allocated. Now when this
memory is requested to be imported, a list of newly allocated zero pages
is obtained using get_user_pages(). Currently cache flush is not done for
these pages and hence GPU sees stale data. Fix this by performing cache
flush on these pages.

Change-Id: Id1e8aa20e8a9de112761732ed92f30c01088840b
Signed-off-by: Puranam V G Tejaswi <quic_pvgtejas@quicinc.com>

parent 533e6782

drivers/gpu/msm/kgsl.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -2610,6 +2610,15 @@ static int memdesc_sg_virt(struct kgsl_memdesc *memdesc, unsigned long useraddr)

		ret = sg_alloc_table_from_pages(memdesc->sgt, pages, npages,
		0, memdesc->size, GFP_KERNEL);

		if (ret)
		goto out;

		ret = kgsl_cache_range_op(memdesc, 0, memdesc->size,
		KGSL_CACHE_OP_FLUSH);

		if (ret)
		sg_free_table(memdesc->sgt);
		out:
		if (ret) {
		for (i = 0; i < npages; i++)