Commit ed9178fb authored by Steve Sistare's avatar Steve Sistare Committed by Jason Gunthorpe
Browse files

iommufd: Folio subroutines 

Add subroutines for copying folios to a batch.

Link: https://patch.msgid.link/r/1729861919-234514-6-git-send-email-steven.sistare@oracle.com


Signed-off-by: default avatarSteve Sistare <steven.sistare@oracle.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent c27f0a60

drivers/iommu/iommufd/pages.c

+64 −15
Original line number Diff line number Diff line
@@ -346,25 +346,39 @@ static void batch_destroy(struct pfn_batch *batch, void *backup) 
		kfree(batch->pfns);

}



/* true if the pfn was added, false otherwise */

static bool batch_add_pfn(struct pfn_batch *batch, unsigned long pfn)

static bool batch_add_pfn_num(struct pfn_batch *batch, unsigned long pfn,

			      u32 nr)

{

	const unsigned int MAX_NPFNS = type_max(typeof(*batch->npfns));

	unsigned int end = batch->end;



	if (end && pfn == batch->pfns[end - 1] + batch->npfns[end - 1] &&

	    nr <= MAX_NPFNS - batch->npfns[end - 1]) {

		batch->npfns[end - 1] += nr;

	} else if (end < batch->array_size) {

		batch->pfns[end] = pfn;

		batch->npfns[end] = nr;

		batch->end++;

	} else {

		return false;

	}



	if (batch->end &&

	    pfn == batch->pfns[batch->end - 1] + batch->npfns[batch->end - 1] &&

	    batch->npfns[batch->end - 1] != MAX_NPFNS) {

		batch->npfns[batch->end - 1]++;

		batch->total_pfns++;

	batch->total_pfns += nr;

	return true;

}

	if (batch->end == batch->array_size)

		return false;

	batch->total_pfns++;

	batch->pfns[batch->end] = pfn;

	batch->npfns[batch->end] = 1;

	batch->end++;

	return true;



static void batch_remove_pfn_num(struct pfn_batch *batch, unsigned long nr)

{

	batch->npfns[batch->end - 1] -= nr;

	if (batch->npfns[batch->end - 1] == 0)

		batch->end--;

	batch->total_pfns -= nr;

}



/* true if the pfn was added, false otherwise */

static bool batch_add_pfn(struct pfn_batch *batch, unsigned long pfn)

{

	return batch_add_pfn_num(batch, pfn, 1);

}



/*
@@ -622,6 +636,41 @@ static void batch_from_pages(struct pfn_batch *batch, struct page **pages, 
			break;

}



static int batch_from_folios(struct pfn_batch *batch, struct folio ***folios_p,

			     unsigned long *offset_p, unsigned long npages)

{

	int rc = 0;

	struct folio **folios = *folios_p;

	unsigned long offset = *offset_p;



	while (npages) {

		struct folio *folio = *folios;

		unsigned long nr = folio_nr_pages(folio) - offset;

		unsigned long pfn = page_to_pfn(folio_page(folio, offset));



		nr = min(nr, npages);

		npages -= nr;



		if (!batch_add_pfn_num(batch, pfn, nr))

			break;

		if (nr > 1) {

			rc = folio_add_pins(folio, nr - 1);

			if (rc) {

				batch_remove_pfn_num(batch, nr);

				goto out;

			}

		}



		folios++;

		offset = 0;

	}



out:

	*folios_p = folios;

	*offset_p = offset;

	return rc;

}



static void batch_unpin(struct pfn_batch *batch, struct iopt_pages *pages,

			unsigned int first_page_off, size_t npages)

{