[PATCH v1] iommu/apple-dart: Report TLB flush failures from iotlb_sync_map
DORMANTno replies
From: Yuho Choi <hidden>
Date: 2026-10-22 16:33:56
Also in:
asahi, linux-iommu, lkml
Subsystem:
arm/apple machine support, iommu subsystem, the rest · Maintainers:
Sven Peter, Janne Grunau, Joerg Roedel, Will Deacon, Linus Torvalds
apple_dart_iotlb_sync_map() flushes the TLBs of every DART the domain
is attached to after a new mapping has been written. The
invalidate_tlb() callbacks return -ETIMEDOUT when the busy bit does not
clear in time, but apple_dart_domain_flush_tlb() drops the result and
the callback always returns 0, so iommu_map() reports success although
the flush did not complete.
Since commit fa4c4507099f ("iommu: Allow .iotlb_sync_map to fail and
handle s390's -ENOMEM return"), iommu_map() unmaps the range and fails
when .iotlb_sync_map() returns an error. Return the error from
apple_dart_domain_flush_tlb(), after still flushing every DART of the
domain.
Signed-off-by: Yuho Choi <redacted>
---
The unmap path is not changed, as .iotlb_sync() and
.flush_iotlb_all() cannot report a failure.
drivers/iommu/apple-dart.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index b160fb464c5f..1119769f9f51 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c@@ -494,9 +494,9 @@ static int apple_dart_hw_reset(struct apple_dart *dart) return dart->hw->invalidate_tlb(&stream_map); } -static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain) +static int apple_dart_domain_flush_tlb(struct apple_dart_domain *domain) { - int i, j; + int i, j, ret = 0; struct apple_dart_atomic_stream_map *domain_stream_map; struct apple_dart_stream_map stream_map;
@@ -506,8 +506,11 @@ static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain) for (j = 0; j < BITS_TO_LONGS(stream_map.dart->num_streams); j++) stream_map.sidmap[j] = atomic_long_read(&domain_stream_map->sidmap[j]); - stream_map.dart->hw->invalidate_tlb(&stream_map); + /* Flush every DART even if one of them fails. */ + ret = stream_map.dart->hw->invalidate_tlb(&stream_map) ?: ret; } + + return ret; } static void apple_dart_flush_iotlb_all(struct iommu_domain *domain)
@@ -524,8 +527,7 @@ static void apple_dart_iotlb_sync(struct iommu_domain *domain, static int apple_dart_iotlb_sync_map(struct iommu_domain *domain, unsigned long iova, size_t size) { - apple_dart_domain_flush_tlb(to_dart_domain(domain)); - return 0; + return apple_dart_domain_flush_tlb(to_dart_domain(domain)); } static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain,
base-commit: c03c1a14507dfaf8b856c2608f9ac216021fc222 -- 2.43.0