qcom-io-pgtable-arm: Implement the unmap_pages() callback

Implement the unmap_pages() for the qcom-io-pgtable-arm format
code.

Change-Id: I2e94b25c736cdc5ee1346941f986c5ddeca30ba4
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>

drivers/iommu/qcom-io-pgtable-arm.c

@@ -47,6 +47,9 @@
 #define ARM_LPAE_PGD_SIZE(d)						\
 	(sizeof(arm_lpae_iopte) << (d)->pgd_bits)
 
+#define ARM_LPAE_PTES_PER_TABLE(d)					\
+	(ARM_LPAE_GRANULE(d) >> ilog2(sizeof(arm_lpae_iopte)))
+
 /*
  * Calculate the index at level l used to map virtual address a using the
  * pagetable in d.
@@ -323,8 +326,8 @@ static void __arm_lpae_set_pte(arm_lpae_iopte *ptep, arm_lpae_iopte pte,
 
 static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
 			       struct iommu_iotlb_gather *gather,
-			       unsigned long iova, size_t size, int lvl,
+			       unsigned long iova, size_t size, size_t pgcount,
-			       arm_lpae_iopte *ptep);
+			       int lvl, arm_lpae_iopte *ptep);
 
 static void __arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
 				phys_addr_t paddr, arm_lpae_iopte prot,
@@ -800,14 +803,15 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
 				       struct iommu_iotlb_gather *gather,
 				       unsigned long iova, size_t size,
 				       arm_lpae_iopte blk_pte, int lvl,
-				       arm_lpae_iopte *ptep)
+				       arm_lpae_iopte *ptep, size_t pgcount)
 {
 	struct io_pgtable_cfg *cfg = &data->iop.cfg;
 	arm_lpae_iopte pte, *tablep;
 	phys_addr_t blk_paddr;
 	size_t tablesz = ARM_LPAE_GRANULE(data);
 	size_t split_sz = ARM_LPAE_BLOCK_SIZE(lvl, data);
-	int i, unmap_idx = -1;
+	int ptes_per_table = ARM_LPAE_PTES_PER_TABLE(data);
+	int i, unmap_idx_start = -1, num_entries = 0, max_entries;
 	void *cookie = data->iop.cookie;
 	int child_cnt = 0;
 
@@ -818,15 +822,18 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
 	if (!tablep)
 		return 0; /* Bytes unmapped */
 
-	if (size == split_sz)
+	if (size == split_sz) {
-		unmap_idx = ARM_LPAE_LVL_IDX(iova, lvl, data);
+		unmap_idx_start = ARM_LPAE_LVL_IDX(iova, lvl, data);
+		max_entries = ptes_per_table - unmap_idx_start;
+		num_entries = min_t(int, pgcount, max_entries);
+	}
 
 	blk_paddr = iopte_to_paddr(blk_pte, data);
 	pte = iopte_prot(blk_pte);
 
-	for (i = 0; i < tablesz / sizeof(pte); i++, blk_paddr += split_sz) {
+	for (i = 0; i < ptes_per_table; i++, blk_paddr += split_sz) {
 		/* Unmap! */
-		if (i == unmap_idx)
+		if (i >= unmap_idx_start && i < (unmap_idx_start + num_entries))
 			continue;
 
 		__arm_lpae_init_pte(data, blk_paddr, pte, lvl, 1, &tablep[i], true);
@@ -845,33 +852,38 @@ static size_t arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
 			return 0;
 
 		tablep = iopte_deref(pte, data);
-	} else if (unmap_idx >= 0) {
+	} else if (unmap_idx_start >= 0) {
-		return size;
+		return num_entries * size;
 	}
 
-	return __arm_lpae_unmap(data, gather, iova, size, lvl, tablep);
+	return __arm_lpae_unmap(data, gather, iova, size, pgcount, lvl, tablep);
 }
 
 static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
 			       struct iommu_iotlb_gather *gather,
-			       unsigned long iova, size_t size, int lvl,
+			       unsigned long iova, size_t size, size_t pgcount,
-			       arm_lpae_iopte *ptep)
+			       int lvl, arm_lpae_iopte *ptep)
 {
 	arm_lpae_iopte pte;
 	struct io_pgtable *iop = &data->iop;
+	int ptes_per_table = ARM_LPAE_PTES_PER_TABLE(data);
+	int num_entries, max_entries, unmap_idx_start;
 
 	/* Something went horribly wrong and we ran out of page table */
 	if (WARN_ON(lvl == ARM_LPAE_MAX_LEVELS))
 		return 0;
 
-	ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+	unmap_idx_start = ARM_LPAE_LVL_IDX(iova, lvl, data);
+	ptep += unmap_idx_start;
 	pte = READ_ONCE(*ptep);
 	if (WARN_ON(!pte))
 		return 0;
 
 	/* If the size matches this level, we're in the right place */
 	if (size == ARM_LPAE_BLOCK_SIZE(lvl, data)) {
-		__arm_lpae_set_pte(ptep, 0, 1, &iop->cfg);
+		max_entries = ptes_per_table - unmap_idx_start;
+		num_entries = min_t(int, pgcount, max_entries);
+		__arm_lpae_set_pte(ptep, 0, num_entries, &iop->cfg);
 
 		if (!iopte_leaf(pte, lvl, iop->fmt)) {
 			ptep = iopte_deref(pte, data);
@@ -885,15 +897,17 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
 			smp_wmb();
 		}
 
-		return size;
+		return num_entries * size;
 	} else if ((lvl == ARM_LPAE_MAX_LEVELS - 2) && !iopte_leaf(pte, lvl,
 								   iop->fmt)) {
 		arm_lpae_iopte *table = iopte_deref(pte, data);
 		arm_lpae_iopte *entry = table + ARM_LPAE_LVL_IDX(iova, lvl + 1, data);
 
-		__arm_lpae_set_pte(entry, 0, 1, &iop->cfg);
+		max_entries = ptes_per_table - unmap_idx_start;
+		num_entries = min_t(int, pgcount, max_entries);
+		__arm_lpae_set_pte(entry, 0, num_entries, &iop->cfg);
 
-		iopte_tblcnt_sub(ptep, 1);
+		iopte_tblcnt_sub(ptep, num_entries);
 		if (!iopte_tblcnt(*ptep)) {
 			size_t block_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
 			/*
@@ -909,32 +923,33 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
 				block_size);
 		}
 
-		return size;
+		return num_entries * size;
 	} else if (iopte_leaf(pte, lvl, iop->fmt)) {
 		/*
 		 * Insert a table at the next level to map the old region,
 		 * minus the part we want to unmap
 		 */
 		return arm_lpae_split_blk_unmap(data, gather, iova, size, pte,
-						lvl + 1, ptep);
+						lvl + 1, ptep, pgcount);
 	}
 
 	/* Keep on walkin' */
 	ptep = iopte_deref(pte, data);
-	return __arm_lpae_unmap(data, gather, iova, size, lvl + 1, ptep);
+	return __arm_lpae_unmap(data, gather, iova, size, pgcount, lvl + 1, ptep);
 }
 
-static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
+static size_t arm_lpae_unmap_pages(struct io_pgtable_ops *ops, unsigned long iova,
-			     size_t size, struct iommu_iotlb_gather *gather)
+				   size_t pgsize, size_t pgcount,
+				   struct iommu_iotlb_gather *gather)
 {
 	struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
 	struct io_pgtable_cfg *cfg = &data->iop.cfg;
 	arm_lpae_iopte *ptep = data->pgd;
 	long iaext = (s64)iova >> cfg->ias;
+	size_t unmapped;
 	unsigned long flags;
-	size_t ret;
 
-	if (WARN_ON(!size || (size & cfg->pgsize_bitmap) != size))
+	if (WARN_ON(!pgsize || (pgsize & cfg->pgsize_bitmap) != pgsize || !pgcount))
 		return 0;
 
 	if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_TTBR1)
@@ -943,9 +958,17 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
 		return 0;
 
 	spin_lock_irqsave(&data->lock, flags);
-	ret = __arm_lpae_unmap(data, gather, iova, size, data->start_level, ptep);
+	unmapped = __arm_lpae_unmap(data, gather, iova, pgsize, pgcount,
+				    data->start_level, ptep);
 	spin_unlock_irqrestore(&data->lock, flags);
-	return ret;
+
+	return unmapped;
+}
+
+static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
+			     size_t size, struct iommu_iotlb_gather *gather)
+{
+	return arm_lpae_unmap_pages(ops, iova, size, 1, gather);
 }
 
 static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
@@ -1068,6 +1091,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
 		.map		= arm_lpae_map,
 		.map_sg		= arm_lpae_map_sg,
 		.unmap		= arm_lpae_unmap,
+		.unmap_pages	= arm_lpae_unmap_pages,
 		.iova_to_phys	= arm_lpae_iova_to_phys,
 	};