Commands which causes PUNIT writes, store them and restore them on system
resume. The driver stores all such requests in a hash table and stores the
the latest mailbox request parameters. On resume these commands mail box
commands are executed again. There are only 5 such mail box commands which
will trigger such processing so a very low overhead in store and execute
on resume. Also there is no order requirement for mail box commands for
these write/set commands. There is one MSR request for changing turbo
ratio limits, this also stored and get restored on resume and cpu online.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
While using new non arhitectural features using PUNIT Mailbox and MMIO
read/write interface, still there is need to operate using MSRs to
control PUNIT. User space could have used user user-space MSR interface for
this, but when user space MSR access is disabled, then it can't. Here only
limited number of MSRs are allowed using this new interface.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Add an IOCTL to send mailbox commands to PUNIT using PUNIT PCI device.
A limited set of mailbox commands can be sent to PUNIT.
This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and control Intel Speed Select features.
The MBOX commands ids and semantics of the message can be checked from
the source code of the tool.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Added MMIO interface to read/write specific offsets in PUNIT PCI device
which export core priortization. This MMIO interface can be used using
ioctl interface on /dev/isst_interface using IOCTL ISST_IF_IO_CMD.
This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and set core priority. The MMIO offsets and
semantics of the message can be checked from the source code of the tool.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Add processing for IOCTL command ISST_IF_GET_PHY_ID. This converts from the
Linux logical CPU to PUNIT CPU numbering scheme.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
There are two per CPU data needs to be stored and cached to avoid repeated
MSR readings for accessing them later:
- Physical to logical CPU conversion
The PUNIT uses a different CPU numbering scheme which is not APIC id based.
So we need to establish relationship between PUNIT CPU number and Linux
logical CPU numbering which is based on APIC id. There is an MSR 0x53
(MSR_THREAD_ID), which gets physical CPU number for the local CPU where it
is read. Also the CPU mask in some messages will inform which CPUs needs
to be online/offline for a TDP level. During TDP switch if user offlined
some CPUs, then the physical CPU mask can't be converted as we can't
read MSR on an offlined CPU to go to a lower TDP level by onlining more
CPUs. So the mapping needs to be established at the boot up time.
- Bus number corresponding to a CPU
A group of CPUs are in a control of a PUNIT. The PUNIT device is exported
as PCI device. To do operation on a PUNIT for a CPU, we need to find out
to which PCI device it is related to. This is done by reading MSR 0x128
(MSR_CPU_BUS_NUMBER).
So during CPU online stages the above MSRs are read and stored. Later
this stored information is used to process IOCTLs request from the user
space.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Encapsulate common functions which all Intel Speed Select Technology
interface drivers can use. This creates API to register misc device for
user kernel communication and handle all common IOCTLs. As part of the
registry it allows a callback which is to handle domain specific ioctl
processing.
There can be multiple drivers register for services, which can be built
as modules. So this driver handle contention during registry and as well
as during removal. Once user space opened the misc device, the registered
driver will be prevented from removal. Also once misc device is opened by
the user space new client driver can't register, till the misc device is
closed.
There are two types of client drivers, one to handle mail box interface
and the other is to allow direct read/write to some specific MMIO space.
This common driver implements IOCTL ISST_IF_GET_PLATFORM_INFO.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Srinivas Pandruvada