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

[Sai Prakash Ranjan]

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@xxxxxxxxxxxxxx>

Thanks,
Sai

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