lkml.org 
[lkml]   [2018]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[RFC 0/2] iommu/arm-smmu-v3: Support software retention for pm_resume
Date
- Backgroud:
Hisilicon's implement of smmuv3 do not support hardware retention if system
do power gating when system suspend, however for embed system, we do need
to do power gating at trust zone for lower power comsume. So software
retention is need.

- Implement:
From the process of smmu probe, it will get the feature of smmu from IDR
registers and keep the status in struct arm_smmu_device, then
arm_smmu_device_reset() will initial(set) most of the registers according
to it. So we can use arm_smmu_device_reset() to re-initial the smmuv3
device to make it can works again.

To achieve this, patch 1 move the bypass parameter from arm_smmu_device_reset()
to struct arm_smmu_device to make arm_smmu_device_reset() re-usable. Patch 2
introduces probed parameter for struct arm_smmu_device, so once smmuv3 is probed
we can avoid request irqs once more. It also introduce a struct arm_smmu_msi_val
to keep the value of smmuv3's msi register which can be restore when reset device
after probed.

Yisheng Xie (2):
iommu/arm-smmu-v3: Remove bypass in arm_smmu_reset_device
iommu/arm-smmu-v3: Support software retention for pm_resume

drivers/iommu/arm-smmu-v3.c | 80 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 72 insertions(+), 8 deletions(-)

--
1.7.12.4

\
 
 \ /
  Last update: 2018-04-23 13:57    [W:0.062 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site