[PATCH] iommu/dart: Remove iommu_flush_ops

Sven Peter
2021-09-21T15:40:16Z

apple_dart_tlb_flush_{all,walk} expect to get a struct apple_dart_domain
but instead get a struct iommu_domain right now. This breaks those two
functions and can lead to kernel panics like the one below.
DART can only invalidate the entire TLB and apple_dart_iotlb_sync will
already flush everything. There's no need to do that again inside those
two functions. Let's just drop them.

pci 0000:03:00.0: Removing from iommu group 1
Unable to handle kernel paging request at virtual address 0000000100000023
[...]
Call trace:
_raw_spin_lock_irqsave+0x54/0xbc
apple_dart_hw_stream_command.constprop.0+0x2c/0x130
apple_dart_tlb_flush_all+0x48/0x90
free_io_pgtable_ops+0x40/0x70
apple_dart_domain_free+0x2c/0x44
iommu_group_release+0x68/0xac
kobject_cleanup+0x4c/0x1fc
kobject_cleanup+0x14c/0x1fc
kobject_put+0x64/0x84
iommu_group_remove_device+0x110/0x180
iommu_release_device+0x50/0xa0
[...]

Fixes: 46d1fb072e76b161 ("iommu/dart: Add DART iommu driver")
Reported-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
drivers/iommu/apple-dart.c | 18 ------------------
1 file changed, 18 deletions(-)

diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index c37fb4790e8a..47ffe9e49abb 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -181,7 +181,6 @@ struct apple_dart_master_cfg {

static struct platform_driver apple_dart_driver;
static const struct iommu_ops apple_dart_iommu_ops;
-static const struct iommu_flush_ops apple_dart_tlb_ops;

static struct apple_dart_domain *to_dart_domain(struct iommu_domain *dom)
{
@@ -336,22 +335,6 @@ static void apple_dart_iotlb_sync_map(struct iommu_domain *domain,
apple_dart_domain_flush_tlb(to_dart_domain(domain));
}

-static void apple_dart_tlb_flush_all(void *cookie)
-{
- apple_dart_domain_flush_tlb(cookie);
-}
-
-static void apple_dart_tlb_flush_walk(unsigned long iova, size_t size,
- size_t granule, void *cookie)
-{
- apple_dart_domain_flush_tlb(cookie);
-}
-
-static const struct iommu_flush_ops apple_dart_tlb_ops = {
- .tlb_flush_all = apple_dart_tlb_flush_all,
- .tlb_flush_walk = apple_dart_tlb_flush_walk,
-};
-
static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain,
dma_addr_t iova)
{
@@ -433,7 +416,6 @@ static int apple_dart_finalize_domain(struct iommu_domain *domain,
.ias = 32,
.oas = 36,
.coherent_walk = 1,
- .tlb = &apple_dart_tlb_ops,
.iommu_dev = dart->dev,
};

--
2.25.1