Add CPU latency QoS support for ufs driver. This improves random io performance by 15% for ufs. tiotest benchmark tool io performance results on sm8550 platform: 1. Without PM QoS support Type (Speed in) | Average of 18 iterations Random Read(IPOS) | 37101.3 Random Write(IPOS) | 41065.13 2. With PM QoS support Type (Speed in) | Average of 18 iterations Random Read(IPOS) | 42943.4 Random Write(IPOS) | 46784.9 (Improvement with PM QoS = ~15%). This patch is based on below patch by Stanley Chu [1]. Moving the PM QoS code to ufshcd.c and making it generic. [1] https://lore.kernel.org/r/20220623035052.18802-8-stanley.chu@xxxxxxxxxxxx Changes from v5: - Addressed bvanassche comment to use kstrtobool instead kstrtou32 - Addressed bvanassche comment to add sys attribute into an existing group Changes from v4: - Addressed angelogioacchino's comment to update commit text - Addressed angelogioacchino's comment to code alignment Changes from v3: - Removed UFSHCD_CAP_PM_QOS capability flag from patch#2 Changes from v2: - Addressed bvanassche and mani comments - Provided sysfs interface to enable/disable PM QoS feature Changes from v1: - Addressed bvanassche comments to have the code in core ufshcd - Design is changed from per-device PM QoS to CPU latency QoS based support - Reverted existing PM QoS feature from MEDIATEK UFS driver - Added PM QoS capability for both QCOM and MEDIATEK SoCs Maramaina Naresh (2): ufs: core: Add CPU latency QoS support for ufs driver ufs: ufs-mediatek: Migrate to UFSHCD generic CPU latency PM QoS support drivers/ufs/core/ufs-sysfs.c | 49 ++++++++++++++++++++++++++++++++ drivers/ufs/core/ufshcd.c | 50 +++++++++++++++++++++++++++++++++ drivers/ufs/host/ufs-mediatek.c | 17 ----------- drivers/ufs/host/ufs-mediatek.h | 3 -- include/ufs/ufshcd.h | 6 ++++ 5 files changed, 105 insertions(+), 20 deletions(-) -- 2.17.1
