diff options
| author | Vladimir Murzin <vladimir.murzin@arm.com> | 2014-08-08 10:31:47 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2014-09-01 16:48:57 +0100 |
| commit | 93b14135cf24668b45eb57348312b627a8539bc4 (patch) | |
| tree | a7fa504b041e608adc44012a51c5e3049cf537e1 /drivers | |
| parent | 1fc870c7efa364862c3bc792cfbdb38afea26742 (diff) | |
| download | lwn-93b14135cf24668b45eb57348312b627a8539bc4.tar.gz lwn-93b14135cf24668b45eb57348312b627a8539bc4.zip | |
iommu/arm-smmu: remove pgtable_page_{c,d}tor()
If split page table lock for PTE tables is enabled (CONFIG_SPLIT_PTLOCK_CPUS
<=NR_CPUS) pgtable_page_ctor() leads to non-atomic allocation for ptlock with
a spinlock held, resulting in:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 466 at kernel/locking/lockdep.c:2742 lockdep_trace_alloc+0xd8/0xf4()
DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
Modules linked in:
CPU: 0 PID: 466 Comm: dma0chan0-copy0 Not tainted 3.16.0-3d47efb-clean-pl330-dma_test-ve-a15-a32-slr-m
c-on-3+ #55
[<80014748>] (unwind_backtrace) from [<80011640>] (show_stack+0x10/0x14)
[<80011640>] (show_stack) from [<802bf864>] (dump_stack+0x80/0xb4)
[<802bf864>] (dump_stack) from [<8002385c>] (warn_slowpath_common+0x64/0x88)
[<8002385c>] (warn_slowpath_common) from [<80023914>] (warn_slowpath_fmt+0x30/0x40)
[<80023914>] (warn_slowpath_fmt) from [<8005d818>] (lockdep_trace_alloc+0xd8/0xf4)
[<8005d818>] (lockdep_trace_alloc) from [<800d3d78>] (kmem_cache_alloc+0x24/0x144)
[<800d3d78>] (kmem_cache_alloc) from [<800bfae4>] (ptlock_alloc+0x18/0x2c)
[<800bfae4>] (ptlock_alloc) from [<802b1ec0>] (arm_smmu_handle_mapping+0x4c0/0x690)
[<802b1ec0>] (arm_smmu_handle_mapping) from [<802b0cd8>] (iommu_map+0xe0/0x148)
[<802b0cd8>] (iommu_map) from [<80019098>] (arm_coherent_iommu_map_page+0x160/0x278)
[<80019098>] (arm_coherent_iommu_map_page) from [<801f4d78>] (dmatest_func+0x60c/0x1098)
[<801f4d78>] (dmatest_func) from [<8003f8ac>] (kthread+0xcc/0xe8)
[<8003f8ac>] (kthread) from [<8000e868>] (ret_from_fork+0x14/0x2c)
---[ end trace ce0d27e6f434acf8 ]--
Split page tables lock is not used in the driver. In fact, page tables are
guarded with domain lock, so remove calls to pgtable_page_{c,d}tor().
Cc: <stable@vger.kernel.org>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/iommu/arm-smmu.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 1f10ac0d4135..398802ad9d2d 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -984,7 +984,6 @@ static void arm_smmu_free_ptes(pmd_t *pmd) { pgtable_t table = pmd_pgtable(*pmd); - pgtable_page_dtor(table); __free_page(table); } @@ -1253,10 +1252,6 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd, return -ENOMEM; arm_smmu_flush_pgtable(smmu, page_address(table), PAGE_SIZE); - if (!pgtable_page_ctor(table)) { - __free_page(table); - return -ENOMEM; - } pmd_populate(NULL, pmd, table); arm_smmu_flush_pgtable(smmu, pmd, sizeof(*pmd)); } |