iommu/vt-d: Use put_pages_list

page->freelist is for the use of slab.  We already have the ability
to free a list of pages in the core mm, but it requires the use of a
list_head and for the pages to be chained together through page->lru.
Switch the Intel IOMMU and IOVA code over to using free_pages_list().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
[rm: split from original patch, cosmetic tweaks, fix fq entries]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/2115b560d9a0ce7cd4b948bd51a2b7bde8fdfd59.1639753638.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 9 insertions, 17 deletions

diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index bbf642940988..962614c7afbb 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -96,7 +96,7 @@ static void free_iova_flush_queue(struct iova_domain *iovad)
 int init_iova_flush_queue(struct iova_domain *iovad, struct iommu_domain *fq_domain)
 {
 	struct iova_fq __percpu *queue;
-	int cpu;
+	int i, cpu;
 
 	atomic64_set(&iovad->fq_flush_start_cnt,  0);
 	atomic64_set(&iovad->fq_flush_finish_cnt, 0);
@@ -113,6 +113,9 @@ int init_iova_flush_queue(struct iova_domain *iovad, struct iommu_domain *fq_dom
 		fq->tail = 0;
 
 		spin_lock_init(&fq->lock);
+
+		for (i = 0; i < IOVA_FQ_SIZE; i++)
+			INIT_LIST_HEAD(&fq->entries[i].freelist);
 	}
 
 	iovad->fq_domain = fq_domain;
@@ -543,16 +546,6 @@ free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
 }
 EXPORT_SYMBOL_GPL(free_iova_fast);
 
-static void fq_entry_dtor(struct page *freelist)
-{
-	while (freelist) {
-		unsigned long p = (unsigned long)page_address(freelist);
-
-		freelist = freelist->freelist;
-		free_page(p);
-	}
-}
-
 #define fq_ring_for_each(i, fq) \
 	for ((i) = (fq)->head; (i) != (fq)->tail; (i) = ((i) + 1) % IOVA_FQ_SIZE)
 
@@ -585,7 +578,7 @@ static void fq_ring_free(struct iova_domain *iovad, struct iova_fq *fq)
 		if (fq->entries[idx].counter >= counter)
 			break;
 
-		fq_entry_dtor(fq->entries[idx].freelist);
+		put_pages_list(&fq->entries[idx].freelist);
 		free_iova_fast(iovad,
 			       fq->entries[idx].iova_pfn,
 			       fq->entries[idx].pages);
@@ -607,15 +600,14 @@ static void fq_destroy_all_entries(struct iova_domain *iovad)
 
 	/*
 	 * This code runs when the iova_domain is being detroyed, so don't
-	 * bother to free iovas, just call the entry_dtor on all remaining
-	 * entries.
+	 * bother to free iovas, just free any remaining pagetable pages.
 	 */
 	for_each_possible_cpu(cpu) {
 		struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu);
 		int idx;
 
 		fq_ring_for_each(idx, fq)
-			fq_entry_dtor(fq->entries[idx].freelist);
+			put_pages_list(&fq->entries[idx].freelist);
 	}
 }
 
@@ -640,7 +632,7 @@ static void fq_flush_timeout(struct timer_list *t)
 
 void queue_iova(struct iova_domain *iovad,
 		unsigned long pfn, unsigned long pages,
-		struct page *freelist)
+		struct list_head *freelist)
 {
 	struct iova_fq *fq;
 	unsigned long flags;
@@ -674,8 +666,8 @@ void queue_iova(struct iova_domain *iovad,
 
 	fq->entries[idx].iova_pfn = pfn;
 	fq->entries[idx].pages    = pages;
-	fq->entries[idx].freelist = freelist;
 	fq->entries[idx].counter  = atomic64_read(&iovad->fq_flush_start_cnt);
+	list_splice(freelist, &fq->entries[idx].freelist);
 
 	spin_unlock_irqrestore(&fq->lock, flags);