From 3acf4223bd662dc1698cedfeebfca452bbddf874 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 11 Nov 2019 12:16:40 +0000 Subject: [PATCH] FROMLIST: drivers/iommu: Allow IOMMU bus ops to be unregistered 'bus_set_iommu()' allows IOMMU drivers to register their ops for a given bus type. Unfortunately, it then doesn't allow them to be removed, which is necessary for modular drivers to shutdown cleanly so that they can be reloaded later on. Allow 'bus_set_iommu()' to take a NULL 'ops' argument, which clear the ops pointer for the selected bus_type. Signed-off-by: Will Deacon Bug: 140290589 Link: https://lore.kernel.org/lkml/20191121114918.2293-7-will@kernel.org/ Signed-off-by: Will Deacon Change-Id: Ia89fa2df61d2a9ad04901d4c2e71e293c4c6171d --- drivers/iommu/iommu.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 4bfecfbbe2cf..e99704c2e06b 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1558,6 +1558,11 @@ int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops) { int err; + if (ops == NULL) { + bus->iommu_ops = NULL; + return 0; + } + if (bus->iommu_ops != NULL) return -EBUSY;