Hi Shameer,
On Thu, Nov 02, 2017 at 12:49:32PM +0000, Shameerali Kolothum Thodi wrote:
> We had a go with this series on HiSIlicon D05 platform which doesn't have
> support for ssids/ATS/PRI, to make sure it generally works.
>
> But observed the below crash on boot,
>
> [ 16.009084] WARNING: CPU: 59 PID: 391 at mm/page_alloc.c:3883 __alloc_pages_nodemask+0x19c/0xc48
> [ 16.026797] Modules linked in:
> [ 16.032944] CPU: 59 PID: 391 Comm: kworker/59:1 Not tainted 4.14.0-rc1-159539-ge42aca3 #236
> [...]
> [ 16.068206] Workqueue: events deferred_probe_work_func
> [ 16.078557] task: ffff8017d38a0000 task.stack: ffff00000b198000
> [ 16.090486] PC is at __alloc_pages_nodemask+0x19c/0xc48
> [ 16.101013] LR is at __alloc_pages_nodemask+0xe0/0xc48
> [ 16.469220] [<ffff000008186b94>] __alloc_pages_nodemask+0x19c/0xc48
> [ 16.481854] [<ffff0000081d65b0>] alloc_pages_current+0x80/0xcc
> [ 16.493607] [<ffff000008182be8>] __get_free_pages+0xc/0x38
> [ 16.504661] [<ffff0000083c4d58>] swiotlb_alloc_coherent+0x64/0x190
> [ 16.517117] [<ffff00000809824c>] __dma_alloc+0x110/0x204
> [ 16.527820] [<ffff00000858e850>] dmam_alloc_coherent+0x88/0xf0
> [ 16.539575] [<ffff000008568884>] arm_smmu_domain_finalise_s1+0x60/0x248
> [ 16.552909] [<ffff00000856c104>] arm_smmu_attach_dev+0x264/0x300
> [ 16.565013] [<ffff00000855d40c>] __iommu_attach_device+0x48/0x5c
> [ 16.577117] [<ffff00000855e698>] iommu_group_add_device+0x144/0x3a4
> [ 16.589746] [<ffff00000855ed18>] iommu_group_get_for_dev+0x70/0xf8
> [ 16.602201] [<ffff00000856a314>] arm_smmu_add_device+0x1a4/0x418
> [ 16.614308] [<ffff00000849dfcc>] iort_iommu_configure+0xf0/0x16c
> [ 16.626416] [<ffff000008468c50>] acpi_dma_configure+0x30/0x70
> [ 16.637994] [<ffff00000858f00c>] dma_configure+0xa8/0xd4
> [ 16.648695] [<ffff00000857706c>] driver_probe_device+0x1a4/0x2dc
> [ 16.673081] [<ffff0000085752c8>] bus_for_each_drv+0x54/0x94
> [ 16.684307] [<ffff000008576db0>] __device_attach+0xc4/0x12c
> [ 16.695533] [<ffff000008577350>] device_initial_probe+0x10/0x18
> [ 16.707462] [<ffff0000085762b4>] bus_probe_device+0x90/0x98
>
> After a bit of debug it looks like on platforms where ssid is not supported,
> s1_cfg.num_contexts is set to zero and it eventually results in this crash
> in,
> arm_smmu_domain_finalise_s1() -->arm_smmu_alloc_cd_tables()-->
> arm_smmu_alloc_cd_leaf_table() as num_leaf_entries is zero.
>
> With the below fix, it works on D05 now,
>
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 8ad90e2..51f5821 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2433,7 +2433,10 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain,
> domain->min_pasid = 1;
> domain->max_pasid = master->num_ssids - 1;
> smmu_domain->s1_cfg.num_contexts = master->num_ssids;
> + } else {
> + smmu_domain->s1_cfg.num_contexts = 1;
> }
> +
> smmu_domain->s1_cfg.can_stall = master->ste.can_stall;
> break;
> case ARM_SMMU_DOMAIN_NESTED:
>
>
> I am not sure this is right place do this. Please take a look.
Thanks for testing the series and reporting the bug. I added the
following patch to branch svm/current, does it work for you?
Thanks,
Jean
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 42c8378624ed..edda466adc81 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -3169,9 +3169,7 @@ static int arm_smmu_add_device(struct device *dev)
}
}
- if (smmu->ssid_bits)
- master->num_ssids = 1 << min(smmu->ssid_bits,
- fwspec->num_pasid_bits);
+ master->num_ssids = 1 << min(smmu->ssid_bits, fwspec->num_pasid_bits);
if (fwspec->can_stall && smmu->features & ARM_SMMU_FEAT_STALLS) {
master->can_fault = true;
--
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