Re: [PATCH 0/5] Optimize iommu_map_sg() performance

isaacm
2021-01-11T15:13:52Z

On 2021-01-10 23:52, Sai Prakash Ranjan wrote:
> On 2021-01-11 11:52, Sai Prakash Ranjan wrote:
>> Hi Isaac,
>>
>> I gave this series a go on chromebook and saw these warnings
>> and several device probe failures, logs attached below:
>>
>> WARN corresponds to this code in arm_lpae_map_by_pgsize()
>>
>> if (WARN_ON(iaext || (paddr + size) >> cfg->oas))
>> return -ERANGE;
>>
>> Logs:
>>
>> [ 2.411391] ------------[ cut here ]------------
>> [ 2.416149] WARNING: CPU: 6 PID: 56 at
>> drivers/iommu/io-pgtable-arm.c:492 arm_lpae_map_sg+0x234/0x248
>> [ 2.425606] Modules linked in:
>> [ 2.428749] CPU: 6 PID: 56 Comm: kworker/6:1 Not tainted 5.10.5
>> #970
>> [ 2.440287] Workqueue: events deferred_probe_work_func
>> [ 2.445563] pstate: 20c00009 (nzCv daif +PAN +UAO -TCO BTYPE=--)
>> [ 2.451726] pc : arm_lpae_map_sg+0x234/0x248
>> [ 2.456112] lr : arm_lpae_map_sg+0xe0/0x248
>> [ 2.460410] sp : ffffffc010513750
>> [ 2.463820] x29: ffffffc010513790 x28: ffffffb943332000
>> [ 2.469281] x27: 0000000ffffff000 x26: ffffffb943d14900
>> [ 2.474738] x25: 0000000000001000 x24: 0000000103465000
>> [ 2.480196] x23: 0000000000000001 x22: 0000000103466000
>> [ 2.485645] x21: 0000000000000003 x20: 0000000000000a20
>> [ 2.491103] x19: ffffffc010513850 x18: 0000000000000001
>> [ 2.496562] x17: 0000000000000002 x16: 00000000ffffffff
>> [ 2.502021] x15: 0000000000000000 x14: 0000000000000000
>> [ 2.507479] x13: 0000000000000001 x12: 0000000000000000
>> [ 2.512928] x11: 0000001000000000 x10: 0000000000000000
>> [ 2.518385] x9 : 0000000000000001 x8 : 0000000040201000
>> [ 2.523844] x7 : 0000000000000a20 x6 : ffffffb943463000
>> [ 2.529302] x5 : 0000000000000003 x4 : 0000000000001000
>> [ 2.534760] x3 : 0000000000000001 x2 : ffffffb941f605a0
>> [ 2.540219] x1 : 0000000000000003 x0 : 0000000000000e40
>> [ 2.545679] Call trace:
>> [ 2.548196] arm_lpae_map_sg+0x234/0x248
>> [ 2.552225] arm_smmu_map_sg+0x80/0xc4
>> [ 2.556078] __iommu_map_sg+0x6c/0x188
>> [ 2.559931] iommu_map_sg_atomic+0x18/0x20
>> [ 2.564144] iommu_dma_alloc_remap+0x26c/0x34c
>> [ 2.568703] iommu_dma_alloc+0x9c/0x268
>> [ 2.572647] dma_alloc_attrs+0x88/0xfc
>> [ 2.576503] gsi_ring_alloc+0x50/0x144
>> [ 2.580356] gsi_init+0x2c4/0x5c4
>> [ 2.583766] ipa_probe+0x14c/0x2b4
>> [ 2.587263] platform_drv_probe+0x94/0xb4
>> [ 2.591377] really_probe+0x138/0x348
>> [ 2.595145] driver_probe_device+0x80/0xb8
>> [ 2.599358] __device_attach_driver+0x90/0xa8
>> [ 2.603829] bus_for_each_drv+0x84/0xcc
>> [ 2.607772] __device_attach+0xc0/0x148
>> [ 2.611713] device_initial_probe+0x18/0x20
>> [ 2.616012] bus_probe_device+0x38/0x94
>> [ 2.619953] deferred_probe_work_func+0x78/0xb0
>> [ 2.624611] process_one_work+0x210/0x3dc
>> [ 2.628726] worker_thread+0x284/0x3e0
>> [ 2.632578] kthread+0x148/0x1a8
>> [ 2.635891] ret_from_fork+0x10/0x18
>> [ 2.639562] ---[ end trace 9bac18cad6a9862e ]---
>> [ 2.644414] ipa 1e40000.ipa: error -12 allocating channel 0 event
>> ring
>> [ 2.651656] ipa: probe of 1e40000.ipa failed with error -12
>> [ 2.660072] dwc3 a600000.dwc3: Adding to iommu group 8
>> [ 2.668632] xhci-hcd xhci-hcd.13.auto: xHCI Host Controller
>> [ 2.674680] xhci-hcd xhci-hcd.13.auto: new USB bus registered,
>> assigned bus number 1
>>
>
> <snip>...
>
> Isaac provided a fix which he will post as v2 and no warnings were
> observed
> with that fix.
>
> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
>
> Thanks,
> Sai

Thanks for testing out the patches. I've added the fix (there was an
off-by-one error in the calculation
used to check if the IOVA/physical addresses are within limits) to
version 2 of the series:
https://lore.kernel.org/linux-iommu/1610376862-927-1-git-send-email-isaacm@codeaurora.org/T/#t

Thanks,
Isaac