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>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20250307-isp-dart-v3-2-684fe4489591@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index edb2fb22333506d7c64ad1b6321df00ebfd07747..13ccb801f52a4d34f6653f78e92787af7dfed1bc 100644 (file)
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -277,6 +277,9 @@ struct apple_dart_domain {
  * @streams: streams for this device
  */
 struct apple_dart_master_cfg {
+       /* Intersection of DART capabilitles */
+       u32 supports_bypass : 1;
+
        struct apple_dart_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
 };
 
@@ -684,7 +687,7 @@ 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;
 
        for_each_stream_map(i, cfg, stream_map)
@@ -792,20 +795,24 @@ 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;
        }
 
+       cfg->supports_bypass &= dart->supports_bypass;
+
        for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
                if (cfg->stream_maps[i].dart == dart) {
                        set_bit(sid, cfg->stream_maps[i].sidmap);
@@ -945,7 +952,7 @@ 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;
 
        return 0;