Hi Jean, > -----Original Message----- > From: linux-arm-kernel [mailto:linux-arm-kernel-bounces@xxxxxxxxxxxxxxxxxxx] > On Behalf Of Jean-Philippe Brucker > Sent: Friday, October 06, 2017 2:32 PM > To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; linux- > acpi@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; iommu@lists.linux- > foundation.org > Cc: mark.rutland@xxxxxxx; xieyisheng (A) <xieyisheng1@xxxxxxxxxx>; > Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>; catalin.marinas@xxxxxxx; > will.deacon@xxxxxxx; okaya@xxxxxxxxxxxxxx; yi.l.liu@xxxxxxxxx; > lorenzo.pieralisi@xxxxxxx; ashok.raj@xxxxxxxxx; tn@xxxxxxxxxxxx; > joro@xxxxxxxxxx; rfranz@xxxxxxxxxx; lenb@xxxxxxxxxx; > jacob.jun.pan@xxxxxxxxxxxxxxx; alex.williamson@xxxxxxxxxx; > robh+dt@xxxxxxxxxx; Leizhen (ThunderTown) <thunder.leizhen@xxxxxxxxxx>; > bhelgaas@xxxxxxxxxx; dwmw2@xxxxxxxxxxxxx; liubo (CU) > <liubo95@xxxxxxxxxx>; rjw@xxxxxxxxxxxxx; robdclark@xxxxxxxxx; > hanjun.guo@xxxxxxxxxx; sudeep.holla@xxxxxxx; robin.murphy@xxxxxxx; > nwatters@xxxxxxxxxxxxxx > 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
