Commit 74014a4b authored by Jason Gunthorpe's avatar Jason Gunthorpe
Browse files

iommufd: Have pfn_reader process DMABUF iopt_pages 

Make another sub implementation of pfn_reader for DMABUF. This version
will fill the batch using the struct phys_vec recorded during the
attachment.

Link: https://patch.msgid.link/r/6-v2-b2c110338e3f+5c2-iommufd_dmabuf_jgg@nvidia.com


Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Tested-by: default avatarShuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 3114c674

drivers/iommu/iommufd/pages.c

+66 −7
Original line number Diff line number Diff line
@@ -1076,6 +1076,41 @@ static int pfn_reader_user_update_pinned(struct pfn_reader_user *user, 
	return iopt_pages_update_pinned(pages, npages, inc, user);

}



struct pfn_reader_dmabuf {

	struct dma_buf_phys_vec phys;

	unsigned long start_offset;

};



static int pfn_reader_dmabuf_init(struct pfn_reader_dmabuf *dmabuf,

				  struct iopt_pages *pages)

{

	/* Callers must not get here if the dmabuf was already revoked */

	if (WARN_ON(iopt_dmabuf_revoked(pages)))

		return -EINVAL;



	dmabuf->phys = pages->dmabuf.phys;

	dmabuf->start_offset = pages->dmabuf.start;

	return 0;

}



static int pfn_reader_fill_dmabuf(struct pfn_reader_dmabuf *dmabuf,

				  struct pfn_batch *batch,

				  unsigned long start_index,

				  unsigned long last_index)

{

	unsigned long start = dmabuf->start_offset + start_index * PAGE_SIZE;



	/*

	 * start/last_index and start are all PAGE_SIZE aligned, the batch is

	 * always filled using page size aligned PFNs just like the other types.

	 * If the dmabuf has been sliced on a sub page offset then the common

	 * batch to domain code will adjust it before mapping to the domain.

	 */

	batch_add_pfn_num(batch, PHYS_PFN(dmabuf->phys.paddr + start),

			  last_index - start_index + 1, BATCH_MMIO);

	return 0;

}



/*

 * PFNs are stored in three places, in order of preference:

 * - The iopt_pages xarray. This is only populated if there is a
@@ -1094,7 +1129,10 @@ struct pfn_reader { 
	unsigned long batch_end_index;

	unsigned long last_index;



	union {

		struct pfn_reader_user user;

		struct pfn_reader_dmabuf dmabuf;

	};

};



static int pfn_reader_update_pinned(struct pfn_reader *pfns)
@@ -1130,7 +1168,7 @@ static int pfn_reader_fill_span(struct pfn_reader *pfns) 
{

	struct interval_tree_double_span_iter *span = &pfns->span;

	unsigned long start_index = pfns->batch_end_index;

	struct pfn_reader_user *user = &pfns->user;

	struct pfn_reader_user *user;

	unsigned long npages;

	struct iopt_area *area;

	int rc;
@@ -1162,8 +1200,13 @@ static int pfn_reader_fill_span(struct pfn_reader *pfns) 
		return 0;

	}



	if (start_index >= pfns->user.upages_end) {

		rc = pfn_reader_user_pin(&pfns->user, pfns->pages, start_index,

	if (iopt_is_dmabuf(pfns->pages))

		return pfn_reader_fill_dmabuf(&pfns->dmabuf, &pfns->batch,

					      start_index, span->last_hole);



	user = &pfns->user;

	if (start_index >= user->upages_end) {

		rc = pfn_reader_user_pin(user, pfns->pages, start_index,

					 span->last_hole);

		if (rc)

			return rc;
@@ -1231,6 +1274,9 @@ static int pfn_reader_init(struct pfn_reader *pfns, struct iopt_pages *pages, 
	pfns->batch_start_index = start_index;

	pfns->batch_end_index = start_index;

	pfns->last_index = last_index;

	if (iopt_is_dmabuf(pages))

		pfn_reader_dmabuf_init(&pfns->dmabuf, pages);

	else

		pfn_reader_user_init(&pfns->user, pages);

	rc = batch_init(&pfns->batch, last_index - start_index + 1);

	if (rc)
@@ -1252,8 +1298,12 @@ static int pfn_reader_init(struct pfn_reader *pfns, struct iopt_pages *pages, 
static void pfn_reader_release_pins(struct pfn_reader *pfns)

{

	struct iopt_pages *pages = pfns->pages;

	struct pfn_reader_user *user = &pfns->user;

	struct pfn_reader_user *user;



	if (iopt_is_dmabuf(pages))

		return;



	user = &pfns->user;

	if (user->upages_end > pfns->batch_end_index) {

		/* Any pages not transferred to the batch are just unpinned */
@@ -1283,6 +1333,7 @@ static void pfn_reader_destroy(struct pfn_reader *pfns) 
	struct iopt_pages *pages = pfns->pages;



	pfn_reader_release_pins(pfns);

	if (!iopt_is_dmabuf(pfns->pages))

		pfn_reader_user_destroy(&pfns->user, pfns->pages);

	batch_destroy(&pfns->batch, NULL);

	WARN_ON(pages->last_npinned != pages->npinned);
@@ -1687,6 +1738,14 @@ static void __iopt_area_unfill_domain(struct iopt_area *area, 


	lockdep_assert_held(&pages->mutex);



	if (iopt_is_dmabuf(pages)) {

		if (WARN_ON(iopt_dmabuf_revoked(pages)))

			return;

		iopt_area_unmap_domain_range(area, domain, start_index,

					     last_index);

		return;

	}



	/*

	 * For security we must not unpin something that is still DMA mapped,

	 * so this must unmap any IOVA before we go ahead and unpin the pages.