From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 2 Apr 2019 07:59:25 -0700 From: Moritz Fischer Subject: Re: [PATCH 14/17] fpga: dfl: fme: add thermal management support Message-ID: <20190402145925.GA15773@archbook> References: <1553483264-5379-1-git-send-email-hao.wu@intel.com> <1553483264-5379-15-git-send-email-hao.wu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1553483264-5379-15-git-send-email-hao.wu@intel.com> To: Wu Hao Cc: atull@kernel.org, mdf@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Luwei Kang , Russ Weight , Xu Yilun List-ID: Hi Wu, On Mon, Mar 25, 2019 at 11:07:41AM +0800, Wu Hao wrote: > This patch adds support to thermal management private feature for DFL > FPGA Management Engine (FME). As thermal throttling is handled by > hardware automatically per pre-defined thresholds, this private > feature driver only provides read-only sysfs interfaces for user > to read temperature, thresholds, threshold policy and other info. > > Signed-off-by: Luwei Kang > Signed-off-by: Russ Weight > Signed-off-by: Xu Yilun > Signed-off-by: Wu Hao > --- > Documentation/ABI/testing/sysfs-platform-dfl-fme | 56 +++++++ > drivers/fpga/dfl-fme-main.c | 202 +++++++++++++++++++++++ > 2 files changed, 258 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-platform-dfl-fme b/Documentation/ABI/testing/sysfs-platform-dfl-fme > index b8327e9..d3aeb88 100644 > --- a/Documentation/ABI/testing/sysfs-platform-dfl-fme > +++ b/Documentation/ABI/testing/sysfs-platform-dfl-fme > @@ -44,3 +44,59 @@ Description: Read-only. It returns socket_id to indicate which socket > this FPGA belongs to, only valid for integrated solution. > User only needs this information, in case standard numa node > can't provide correct information. > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/temperature > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. It returns temperature (in Celsius) of this FPGA > + device. > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/threshold1 > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. Read this file to get the temperature threshold1 > + (in Celsius). > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/threshold2 > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. Read this file to get the temperature threshold2 > + (in Celsius). > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/trip_threshold > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. It returns trip threshold (in Celsius), once FPGA > + temperature reaches trip threshold, it triggers a fatal event > + to board management controller (BMC) to shutdown FPGA. > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/threshold1_status > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. It returns 1 if temperature reaches threshold1, > + otherwise 0. Once temperature reaches threshold1, hardware > + will automatically enter throttling state (AP1 - 50% > + or AP2 - 90% throttling, see 'threshold1_policy'). > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/threshold2_status > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. It returns 1 if temperature reaches threshold2, > + otherwise 0. Once temperature reaches threshold2, hardware > + will automatically enter the deepest throttling state (AP6 > + - 100% throttling). > + > +What: /sys/bus/platform/devices/dfl-fme.0/thermal_mgmt/threshold1_policy > +Date: March 2019 > +KernelVersion: 5.2 > +Contact: Wu Hao > +Description: Read-only. Read this file to get the policy of temperature > + threshold1. It only supports two value (policy): > + 0 - AP2 state (90% throttling) > + 1 - AP1 state (50% throttling) These look like they could directly map to the linux thermal framework, any reason you can't use the thermal framework? The trip stuff literally maps 1:1 to what a thermal driver does, I think that's something you'd wanna consider. Cheers, Moritz