amd_pmf_init_smart_pc() calls out to amd_pmf_get_bios_buffer() but
the error handling flow doesn't clean everything up allocated
memory.
As amd_pmf_get_bios_buffer() is only called by amd_pmf_init_smart_pc(),
fold it into the function and add labels to clean up any step that
can fail along the way. Explicitly set everything allocated to NULL as
there are other features that may access some of the same variables.
Fixes: 7c45534afa ("platform/x86/amd/pmf: Add support for PMF Policy Binary")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20240217014107.113749-3-mario.limonciello@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
PMF driver based on the output actions from the TA can request to update
the system states like entering s0i3, lock screen etc. by generating
an uevent. Based on the udev rules set in the userspace the event id
matching the uevent shall get updated accordingly using the systemctl.
Sample udev rules under Documentation/admin-guide/pmf.rst.
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20231212014705.2017474-9-Shyam-sundar.S-k@amd.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
PMF Policy binary is a encrypted and signed binary that will be part
of the BIOS. PMF driver via the ACPI interface checks the existence
of Smart PC bit. If the advertised bit is found, PMF driver walks
the acpi namespace to find out the policy binary size and the address
which has to be passed to the TA during the TA init sequence.
The policy binary is comprised of inputs (or the events) and outputs
(or the actions). With the PMF ecosystem, OEMs generate the policy
binary (or could be multiple binaries) that contains a supported set
of inputs and outputs which could be specifically carved out for each
usage segment (or for each user also) that could influence the system
behavior either by enriching the user experience or/and boost/throttle
power limits.
Once the TA init command succeeds, the PMF driver sends the changing
events in the current environment to the TA for a constant sampling
frequency time (the event here could be a lid close or open) and
if the policy binary has corresponding action built within it, the
TA sends the action for it in the subsequent enact command.
If the inputs sent to the TA has no output defined in the policy
binary generated by OEMs, there will be no action to be performed
by the PMF driver.
Example policies:
1) if slider is performance ; set the SPL to 40W
Here PMF driver registers with the platform profile interface and
when the slider position is changed, PMF driver lets the TA know
about this. TA sends back an action to update the Sustained
Power Limit (SPL). PMF driver updates this limit via the PMFW mailbox.
2) if user_away ; then lock the system
Here PMF driver hooks to the AMD SFH driver to know the user presence
and send the inputs to TA and if the condition is met, the TA sends
the action of locking the system. PMF driver generates a uevent and
based on the udev rule in the userland the system gets locked with
systemctl.
The intent here is to provide the OEM's to make a policy to lock the
system when the user is away ; but the userland can make a choice to
ignore it.
The OEMs will have an utility to create numerous such policies and
the policies shall be reviewed by AMD before signing and encrypting
them. Policies are shared between operating systems to have seemless user
experience.
Since all this action has to happen via the "amdtee" driver, currently
there is no caller for it in the kernel which can load the amdtee driver.
Without amdtee driver loading onto the system the "tee" calls shall fail
from the PMF driver. Hence an explicit MODULE_SOFTDEP has been added
to address this.
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20231212014705.2017474-5-Shyam-sundar.S-k@amd.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
PMF TA (Trusted Application) loads via the TEE environment into the
AMD ASP.
PMF-TA supports two commands:
1) Init: Initialize the TA with the PMF Smart PC policy binary and
start the policy engine. A policy is a combination of inputs and
outputs, where;
- the inputs are the changing dynamics of the system like the user
behaviour, system heuristics etc.
- the outputs, which are the actions to be set on the system which
lead to better power management and enhanced user experience.
PMF driver acts as a central manager in this case to supply the
inputs required to the TA (either by getting the information from
the other kernel subsystems or from userland)
2) Enact: Enact the output actions from the TA. The action could be
applying a new thermal limit to boost/throttle the power limits or
change system behavior.
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20231212014705.2017474-3-Shyam-sundar.S-k@amd.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
