drm/panfrost: Update io-pgtable API

Convert to io-pgtable's bulk {map,unmap}_pages() APIs, to help the old
single-page interfaces eventually go away. Unmapping heap BOs still
wants to be done a page at a time, but everything else can get the full
benefit of the more efficient interface.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/daef7f8c134d989c55636a5790d8c0fcaca1bae3.1661205687.git.robin.murphy@arm.com

drivers/gpu/drm/panfrost/panfrost_mmu.c

@@ -248,11 +248,15 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev)
 	mmu_write(pfdev, MMU_INT_MASK, ~0);
 }
 
-static size_t get_pgsize(u64 addr, size_t size)
+static size_t get_pgsize(u64 addr, size_t size, size_t *count)
 {
-	if (addr & (SZ_2M - 1) || size < SZ_2M)
-		return SZ_4K;
+	size_t blk_offset = -addr % SZ_2M;
 
+	if (blk_offset || size < SZ_2M) {
+		*count = min_not_zero(blk_offset, size) / SZ_4K;
+		return SZ_4K;
+	}
+	*count = size / SZ_2M;
 	return SZ_2M;
 }
 
@@ -287,12 +291,16 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
 		dev_dbg(pfdev->dev, "map: as=%d, iova=%llx, paddr=%lx, len=%zx", mmu->as, iova, paddr, len);
 
 		while (len) {
-			size_t pgsize = get_pgsize(iova | paddr, len);
-
-			ops->map(ops, iova, paddr, pgsize, prot, GFP_KERNEL);
-			iova += pgsize;
-			paddr += pgsize;
-			len -= pgsize;
+			size_t pgcount, mapped = 0;
+			size_t pgsize = get_pgsize(iova | paddr, len, &pgcount);
+
+			ops->map_pages(ops, iova, paddr, pgsize, pgcount, prot,
+				       GFP_KERNEL, &mapped);
+			/* Don't get stuck if things have gone wrong */
+			mapped = max(mapped, pgsize);
+			iova += mapped;
+			paddr += mapped;
+			len -= mapped;
 		}
 	}
 
@@ -344,15 +352,17 @@ void panfrost_mmu_unmap(struct panfrost_gem_mapping *mapping)
 		mapping->mmu->as, iova, len);
 
 	while (unmapped_len < len) {
-		size_t unmapped_page;
-		size_t pgsize = get_pgsize(iova, len - unmapped_len);
-
-		if (ops->iova_to_phys(ops, iova)) {
-			unmapped_page = ops->unmap(ops, iova, pgsize, NULL);
-			WARN_ON(unmapped_page != pgsize);
+		size_t unmapped_page, pgcount;
+		size_t pgsize = get_pgsize(iova, len - unmapped_len, &pgcount);
+
+		if (bo->is_heap)
+			pgcount = 1;
+		if (!bo->is_heap || ops->iova_to_phys(ops, iova)) {
+			unmapped_page = ops->unmap_pages(ops, iova, pgsize, pgcount, NULL);
+			WARN_ON(unmapped_page != pgsize * pgcount);
 		}
-		iova += pgsize;
-		unmapped_len += pgsize;
+		iova += pgsize * pgcount;
+		unmapped_len += pgsize * pgcount;
 	}
 
 	panfrost_mmu_flush_range(pfdev, mapping->mmu,