ANDROID: iommu/io-pgtable-arm: Fix existing/missing mapping hooks

Fix one hook that is called in the wrong place and add 2 missing calls,
also remove the return from arm_lpae_unmap_empty() as it is not used.

Bug: 357781595
Bug: 384432312
Change-Id: I62cb848b0421c295a144660511bf4389f4e6ffd6
Signed-off-by: Mostafa Saleh <smostafa@google.com>

drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm.c

@@ -25,9 +25,8 @@ int arm_lpae_map_exists(void)
 	return -EEXIST;
 }
 
-int arm_lpae_unmap_empty(void)
+void arm_lpae_unmap_empty(void)
 {
-	return -EEXIST;
 }
 
 void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,

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

@@ -231,7 +231,7 @@ static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
 		cptep = iopte_deref(pte, data);
 	} else if (iopte_valid(pte)) {
 		/* We require an unmap first */
-		return arm_lpae_unmap_empty();
+		return arm_lpae_map_exists();
 	}
 
 	/* Rinse, repeat */
@@ -428,8 +428,10 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
 	unmap_idx_start = ARM_LPAE_LVL_IDX(iova, lvl, data);
 	ptep += unmap_idx_start;
 	pte = READ_ONCE(*ptep);
-	if (WARN_ON(!iopte_valid(pte)))
+	if (!iopte_valid(pte)) {
+		arm_lpae_unmap_empty();
 		return 0;
+	}
 
 	/* If the size matches this level, we're in the right place */
 	if (size == ARM_LPAE_BLOCK_SIZE(lvl, data)) {
@@ -439,8 +441,10 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
 		/* Find and handle non-leaf entries */
 		for (i = 0; i < num_entries; i++) {
 			pte = READ_ONCE(ptep[i]);
-			if (WARN_ON(!iopte_valid(pte)))
+			if (!iopte_valid(pte)) {
+				arm_lpae_unmap_empty();
 				break;
+			}
 
 			if (!iopte_leaf(pte, lvl, iop->fmt)) {
 				__arm_lpae_clear_pte(&ptep[i], &iop->cfg, 1);

drivers/iommu/io-pgtable-arm.c

@@ -31,10 +31,9 @@ int arm_lpae_map_exists(void)
 	return -EEXIST;
 }
 
-int arm_lpae_unmap_empty(void)
+void arm_lpae_unmap_empty(void)
 {
 	WARN_ON(!selftest_running);
-	return -EEXIST;
 }
 
 static dma_addr_t __arm_lpae_dma_addr(void *pages)

include/linux/io-pgtable-arm.h

@@ -233,5 +233,5 @@ void __arm_lpae_free_pages(void *pages, size_t size, struct io_pgtable_cfg *cfg,
 void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries,
 			 struct io_pgtable_cfg *cfg);
 int arm_lpae_map_exists(void);
-int arm_lpae_unmap_empty(void);
+void arm_lpae_unmap_empty(void);
 #endif /* IO_PGTABLE_H_ */