Files
linux-nv-oot/drivers/net
Aniruddha Paul d01b6a3a2b nvethernet: Create pool per Rx DMA channel
Existing implementation uses a single page_pool
for all Rx DMA channels. As by default all irqs
are on CPU 0, this does not cause any issue.
Routing an irq to some other CPU causes race
conditon for page allocation from page_pool which
leads to random memory corruption.

[  158.416637] Call trace:
[  158.416644]  arm_lpae_map_pages+0xb4/0x1e0
[  158.416649]  arm_smmu_map_pages+0x8c/0x160
[  158.416661]  __iommu_map+0xf8/0x2b0
[  158.416677]  iommu_map_atomic+0x58/0xb0
[  158.416683]  __iommu_dma_map+0xac/0x150
[  158.416687]  iommu_dma_map_page+0xf4/0x220
[  158.416690]  dma_map_page_attrs+0x1e8/0x260
[  158.416727]  page_pool_dma_map+0x48/0xd0
[  158.416750]  __page_pool_alloc_pages_slow+0xc4/0x390
[  158.416757]  page_pool_alloc_pages+0x64/0x90
[  158.416762]  ether_padctrl_mii_rx_pins+0x164/0x9d0 [nvethernet]
[  158.416807]  ether_padctrl_mii_rx_pins+0x478/0x9d0 [nvethernet]
[  158.416822]  osi_process_rx_completions+0x284/0x4d0 [nvethernet]
[  158.416832]  0xffffa26218b8f71c
[  158.416855]  __napi_poll+0x48/0x230
[  158.416871]  net_rx_action+0xf4/0x290
[  158.416875]  __do_softirq+0x130/0x3e8
[  158.416889]  __irq_exit_rcu+0xe8/0x110

This change creates a page_pool per Rx DMA channel.
This ensures there is no race conditon for page
alloc/dealloc from each DMA napi context.

Bug 4541158

Change-Id: I12668ee7d824fd30d54a874bbbdf190d02943478
Signed-off-by: Aniruddha Paul <anpaul@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3093534
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
2024-03-14 03:54:09 -07:00
..
2024-03-09 03:40:00 -08:00