From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4] iommu/arm-smmu: avoid calling request_irq in atomic context
Date: Thu, 31 Jul 2014 14:22:50 +0100 [thread overview]
Message-ID: <20140731132250.GU26853@arm.com> (raw)
In-Reply-To: <1406743093-17227-1-git-send-email-mitchelh@codeaurora.org>
On Wed, Jul 30, 2014 at 06:58:13PM +0100, Mitchel Humpherys wrote:
> request_irq shouldn't be called from atomic context since it might
> sleep, but we're calling it with a spinlock held, resulting in:
>
> [ 9.172202] BUG: sleeping function called from invalid context at kernel/mm/slub.c:926
> [ 9.182989] in_atomic(): 1, irqs_disabled(): 128, pid: 1, name: swapper/0
> [ 9.189762] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 3.10.40-gbc1b510b-38437-g55831d3bd9-dirty #97
> [ 9.199757] [<c020c448>] (unwind_backtrace+0x0/0x11c) from [<c02097d0>] (show_stack+0x10/0x14)
> [ 9.208346] [<c02097d0>] (show_stack+0x10/0x14) from [<c0301d74>] (kmem_cache_alloc_trace+0x3c/0x210)
> [ 9.217543] [<c0301d74>] (kmem_cache_alloc_trace+0x3c/0x210) from [<c0276a48>] (request_threaded_irq+0x88/0x11c)
> [ 9.227702] [<c0276a48>] (request_threaded_irq+0x88/0x11c) from [<c0931ca4>] (arm_smmu_attach_dev+0x188/0x858)
> [ 9.237686] [<c0931ca4>] (arm_smmu_attach_dev+0x188/0x858) from [<c0212cd8>] (arm_iommu_attach_device+0x18/0xd0)
> [ 9.247837] [<c0212cd8>] (arm_iommu_attach_device+0x18/0xd0) from [<c093314c>] (arm_smmu_test_probe+0x68/0xd4)
> [ 9.257823] [<c093314c>] (arm_smmu_test_probe+0x68/0xd4) from [<c05aadd0>] (driver_probe_device+0x12c/0x330)
> [ 9.267629] [<c05aadd0>] (driver_probe_device+0x12c/0x330) from [<c05ab080>] (__driver_attach+0x68/0x8c)
> [ 9.277090] [<c05ab080>] (__driver_attach+0x68/0x8c) from [<c05a92d4>] (bus_for_each_dev+0x70/0x84)
> [ 9.286118] [<c05a92d4>] (bus_for_each_dev+0x70/0x84) from [<c05aa3b0>] (bus_add_driver+0x100/0x244)
> [ 9.295233] [<c05aa3b0>] (bus_add_driver+0x100/0x244) from [<c05ab5d0>] (driver_register+0x9c/0x124)
> [ 9.304347] [<c05ab5d0>] (driver_register+0x9c/0x124) from [<c0933088>] (arm_smmu_test_init+0x14/0x38)
> [ 9.313635] [<c0933088>] (arm_smmu_test_init+0x14/0x38) from [<c0200618>] (do_one_initcall+0xb8/0x160)
> [ 9.322926] [<c0200618>] (do_one_initcall+0xb8/0x160) from [<c1200b7c>] (kernel_init_freeable+0x108/0x1cc)
> [ 9.332564] [<c1200b7c>] (kernel_init_freeable+0x108/0x1cc) from [<c0b924b0>] (kernel_init+0xc/0xe4)
> [ 9.341675] [<c0b924b0>] (kernel_init+0xc/0xe4) from [<c0205e38>] (ret_from_fork+0x14/0x3c)
>
> Fix this by moving the request_irq out of the critical section. This
> should be okay since smmu_domain->smmu is still being protected by the
> critical section. Also, we still don't program the Stream Match Register
> until after registering our interrupt handler so we shouldn't be missing
> any interrupts.
>
> Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
> ---
> Changelog:
>
> - v4: some cleanup suggested by Will
> - v3: rework irq request code to avoid requesting the irq every
> time a master is added to the domain
> - v2: return error code from request_irq on failure
> ---
> drivers/iommu/arm-smmu.c | 49 +++++++++++++++++++++++++-----------------------
> 1 file changed, 26 insertions(+), 23 deletions(-)
Great, thanks Mitch. I'll queue this for 3.18.
Will
next prev parent reply other threads:[~2014-07-31 13:22 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-30 17:58 [PATCH v4] iommu/arm-smmu: avoid calling request_irq in atomic context Mitchel Humpherys
2014-07-31 13:22 ` Will Deacon [this message]
2014-07-31 18:30 ` Will Deacon
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