Hi Jean,
> -----Original Message-----
> From: linux-arm-kernel [mailto:[email protected]]
> On Behalf Of Jean-Philippe Brucker
> Sent: Friday, October 06, 2017 2:32 PM
> To: [email protected]; [email protected]; linux-
> [email protected]; [email protected]; [email protected]
> foundation.org
> Cc: [email protected]; xieyisheng (A) <[email protected]>;
> Gabriele Paoloni <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; Leizhen (ThunderTown) <[email protected]>;
> [email protected]; [email protected]; liubo (CU)
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]
> Subject: [RFCv2 PATCH 14/36] iommu/arm-smmu-v3: Add support for
> Substream IDs
>
> At the moment, the SMMUv3 driver offers only one stage-1 or stage-2
> address space to each device. SMMUv3 allows to associate multiple address
> spaces per device. In addition to the Stream ID (SID), that identifies a
> device, we can now have Substream IDs (SSID) identifying an address space.
> In PCIe lingo, SID is called Requester ID (RID) and SSID is called Process
> Address-Space ID (PASID).
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,
Shameer
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