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>
The current SMN index used for the driver probe seems to be meant
for the BIOS pair and there are potential concurrency problems that can
occur with an inopportune SMI.
It is been advised to use SMN_INDEX_0 instead of SMN_INDEX_2, which is
what amd_nb.c provides and this function has protections to ensure that
only one caller can use it at a time.
Fixes: da5ce22df5 ("platform/x86/amd/pmf: Add support for PMF core layer")
Co-developed-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Patil Rajesh Reddy <Patil.Reddy@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20230406164807.50969-4-Shyam-sundar.S-k@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
It is reported that amd_pmf driver is missing "depends on" for
CONFIG_POWER_SUPPLY causing the following build error.
ld: drivers/platform/x86/amd/pmf/core.o: in function `amd_pmf_remove':
core.c:(.text+0x10): undefined reference to `power_supply_unreg_notifier'
ld: drivers/platform/x86/amd/pmf/core.o: in function `amd_pmf_probe':
core.c:(.text+0x38f): undefined reference to `power_supply_reg_notifier'
make[1]: *** [scripts/Makefile.vmlinux:34: vmlinux] Error 1
make: *** [Makefile:1248: vmlinux] Error 2
Add this to the Kconfig file.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217028
Fixes: c5258d39fc ("platform/x86/amd/pmf: Add helper routine to update SPS thermals")
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://lore.kernel.org/r/20230213121457.1764463-1-Shyam-sundar.S-k@amd.com
Cc: stable@vger.kernel.org
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Its reported that amd-pmf driver when built with config which does not
have ACPI_PLATFORM_PROFILE set/enabled throws a undefined references to
symbols used.
ld: vmlinux.o: in function `amd_pmf_init_sps':
drivers/platform/x86/amd/pmf/sps.c:132: undefined reference to `platform_profile_register'
ld: vmlinux.o: in function `amd_pmf_deinit_sps':
drivers/platform/x86/amd/pmf/sps.c:142: undefined reference to `platform_profile_remove'
Fix it by adding a "select" to the Kconfig.
Fixes: da5ce22df5 ("platform/x86/amd/pmf: Add support for PMF core layer")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20220819083858.3987590-1-Shyam-sundar.S-k@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
