iommu: apple-dart: Allow mismatched bypass support

This is needed by ISP, which has DART0 with bypass and DART1/2 without.

Signed-off-by: Hector Martin <marcan@marcan.st>

Author: marcan

drivers/iommu/apple-dart.c

@@ -293,6 +293,9 @@ struct apple_dart_domain {
  * @streams: streams for this device
  */
 struct apple_dart_master_cfg {
+	/* Union of DART capabilitles */
+	u32 supports_bypass : 1;
+
 	struct apple_dart_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
 };
 
@@ -887,7 +890,7 @@ static int apple_dart_attach_dev_identity(struct iommu_domain *domain,
 	struct apple_dart_stream_map *stream_map;
 	int i;
 
-	if (!cfg->stream_maps[0].dart->supports_bypass)
+	if (!cfg->supports_bypass)
 		return -EINVAL;
 
 	if (cfg->stream_maps[0].dart->locked)
@@ -1018,20 +1021,25 @@ static int apple_dart_of_xlate(struct device *dev,
 		return -EINVAL;
 	sid = args->args[0];
 
-	if (!cfg)
+	if (!cfg) {
 		cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+
+		/* Will be ANDed with DART capabilities */
+		cfg->supports_bypass = true;
+	}
 	if (!cfg)
 		return -ENOMEM;
 	dev_iommu_priv_set(dev, cfg);
 
 	cfg_dart = cfg->stream_maps[0].dart;
 	if (cfg_dart) {
-		if (cfg_dart->supports_bypass != dart->supports_bypass)
-			return -EINVAL;
 		if (cfg_dart->pgsize != dart->pgsize)
 			return -EINVAL;
 	}
 
+	if (!dart->supports_bypass)
+		cfg->supports_bypass = false;
+
 	for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
 		if (cfg->stream_maps[i].dart == dart) {
 			set_bit(sid, cfg->stream_maps[i].sidmap);
@@ -1171,7 +1179,7 @@ static int apple_dart_def_domain_type(struct device *dev)
 
 	if (cfg->stream_maps[0].dart->pgsize > PAGE_SIZE)
 		return IOMMU_DOMAIN_IDENTITY;
-	if (!cfg->stream_maps[0].dart->supports_bypass)
+	if (!cfg->supports_bypass)
 		return IOMMU_DOMAIN_DMA;
 	if (cfg->stream_maps[0].dart->locked)
 		return IOMMU_DOMAIN_DMA;