On Sat, 30 Sep 2023, Shyam Sundar S K wrote:
> 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.
>
> and so on.
>
> 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 "request_module" has been added
> to address this.
>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
> ---
> drivers/platform/x86/amd/pmf/Kconfig | 1 +
> drivers/platform/x86/amd/pmf/acpi.c | 37 +++++++
> drivers/platform/x86/amd/pmf/core.c | 12 +++
> drivers/platform/x86/amd/pmf/pmf.h | 135 ++++++++++++++++++++++++
> drivers/platform/x86/amd/pmf/tee-if.c | 141 +++++++++++++++++++++++++-
> 5 files changed, 324 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/amd/pmf/Kconfig b/drivers/platform/x86/amd/pmf/Kconfig
> index 3064bc8ea167..437b78c6d1c5 100644
> --- a/drivers/platform/x86/amd/pmf/Kconfig
> +++ b/drivers/platform/x86/amd/pmf/Kconfig
> @@ -9,6 +9,7 @@ config AMD_PMF
> depends on POWER_SUPPLY
> depends on AMD_NB
> select ACPI_PLATFORM_PROFILE
> + depends on AMDTEE
> help
> This driver provides support for the AMD Platform Management Framework.
> The goal is to enhance end user experience by making AMD PCs smarter,
> diff --git a/drivers/platform/x86/amd/pmf/acpi.c b/drivers/platform/x86/amd/pmf/acpi.c
> index 3fc5e4547d9f..d0512af2cd42 100644
> --- a/drivers/platform/x86/amd/pmf/acpi.c
> +++ b/drivers/platform/x86/amd/pmf/acpi.c
> @@ -286,6 +286,43 @@ int apmf_install_handler(struct amd_pmf_dev *pmf_dev)
> return 0;
> }
>
> +static acpi_status apmf_walk_resources(struct acpi_resource *res, void *data)
> +{
> + struct amd_pmf_dev *dev = data;
> +
> + switch (res->type) {
> + case ACPI_RESOURCE_TYPE_ADDRESS64:
> + dev->policy_addr = res->data.address64.address.minimum;
> + dev->policy_sz = res->data.address64.address.address_length;
> + break;
> + case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
> + dev->policy_addr = res->data.fixed_memory32.address;
> + dev->policy_sz = res->data.fixed_memory32.address_length;
> + break;
> + }
> +
> + if (!dev->policy_addr || dev->policy_sz > POLICY_BUF_MAX_SZ || dev->policy_sz == 0) {
> + pr_err("Incorrect Policy params, possibly a SBIOS bug\n");
> + return AE_ERROR;
> + }
> +
> + return AE_OK;
> +}
> +
> +int apmf_check_smart_pc(struct amd_pmf_dev *pmf_dev)
> +{
> + acpi_handle ahandle = ACPI_HANDLE(pmf_dev->dev);
> + acpi_status status;
> +
> + status = acpi_walk_resources(ahandle, METHOD_NAME__CRS, apmf_walk_resources, pmf_dev);
> + if (ACPI_FAILURE(status)) {
> + dev_err(pmf_dev->dev, "acpi_walk_resources failed\n");
> + return status;
> + }
> +
> + return 0;
> +}
> +
> void apmf_acpi_deinit(struct amd_pmf_dev *pmf_dev)
> {
> acpi_handle ahandle = ACPI_HANDLE(pmf_dev->dev);
> diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c
> index 678dce4fea08..787f25511191 100644
> --- a/drivers/platform/x86/amd/pmf/core.c
> +++ b/drivers/platform/x86/amd/pmf/core.c
> @@ -384,6 +384,18 @@ static int amd_pmf_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> dev->dev = &pdev->dev;
> + err = apmf_check_smart_pc(dev);
> + if (!err) {
> + /* in order for Smart PC solution to work it has a hard dependency
> + * on the amdtee driver to be loaded first even before the PMF driver
> + * loads. PMF ASL has a _CRS method that advertises the existence
> + * of Smart PC bit. If this information is present, use this to
> + * explicitly probe the amdtee driver, so that "tee" plumbing is done
> + * before the PMF Smart PC init happens.
> + */
But please follow no-text on /* line formatting for multiline comments.
Also start with a capital letter.
> + if (request_module("amdtee"))
Are you aware that this won't give you very strong guarantees about
anything if request_module()'s function comments is to be believed?
If that's all what you're after, MODULE_SOFTDEP("pre: amdtee"); is
probably enough (and I unfortunately don't know the answer how to do it if
you want something stronger than that when you don't directly depend on
the symbols of the other module).
> + pr_err("Failed to load amdtee. PMF Smart PC not enabled!\n");
> + }
>
> rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
> if (!rdev || !pci_match_id(pmf_pci_ids, rdev)) {
> diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
> index 3930b8ed8333..6f4b6f4ecee4 100644
> --- a/drivers/platform/x86/amd/pmf/pmf.h
> +++ b/drivers/platform/x86/amd/pmf/pmf.h
> @@ -14,6 +14,11 @@
> #include <linux/acpi.h>
> #include <linux/platform_profile.h>
>
> +#define POLICY_BUF_MAX_SZ 0x4b000
> +#define POLICY_SIGN_COOKIE 0x31535024
> +#define POLICY_COOKIE_OFFSET 0x10
> +#define POLICY_COOKIE_LEN 0x14
> +
> /* APMF Functions */
> #define APMF_FUNC_VERIFY_INTERFACE 0
> #define APMF_FUNC_GET_SYS_PARAMS 1
> @@ -59,8 +64,20 @@
> #define ARG_NONE 0
> #define AVG_SAMPLE_SIZE 3
>
> +/* Policy Actions */
> +#define PMF_POLICY_SPL 2
> +#define PMF_POLICY_SPPT 3
> +#define PMF_POLICY_FPPT 4
> +#define PMF_POLICY_SPPT_APU_ONLY 5
> +#define PMF_POLICY_STT_MIN 6
> +#define PMF_POLICY_STT_SKINTEMP_APU 7
> +#define PMF_POLICY_STT_SKINTEMP_HS2 8
> +
> /* TA macros */
> #define PMF_TA_IF_VERSION_MAJOR 1
> +#define TA_PMF_ACTION_MAX 32
> +#define TA_PMF_UNDO_MAX 8
> +#define MAX_OPERATION_PARAMS 4
>
> /* AMD PMF BIOS interfaces */
> struct apmf_verify_interface {
> @@ -183,11 +200,16 @@ struct amd_pmf_dev {
> bool cnqf_supported;
> struct notifier_block pwr_src_notifier;
> /* Smart PC solution builder */
> + unsigned char *policy_buf;
> + u32 policy_sz;
> struct tee_context *tee_ctx;
> struct tee_shm *fw_shm_pool;
> u32 session_id;
> void *shbuf;
> struct delayed_work pb_work;
> + struct pmf_action_table *prev_data;
> + u64 policy_addr;
> + void *policy_base;
> bool smart_pc_enabled;
> };
>
> @@ -399,17 +421,129 @@ struct apmf_dyn_slider_output {
> struct apmf_cnqf_power_set ps[APMF_CNQF_MAX];
> } __packed;
>
> +/* Smart PC - TA internals */
> +enum ta_slider {
> + TA_BEST_BATTERY, /* Best Battery */
> + TA_BETTER_BATTERY, /* Better Battery */
> + TA_BETTER_PERFORMANCE, /* Better Performance */
> + TA_BEST_PERFORMANCE, /* Best Performance */
Align comments.
> + TA_MAX,
> +};
> +
> /* cmd ids for TA communication */
> enum ta_pmf_command {
> TA_PMF_COMMAND_POLICY_BUILDER_INITIALIZE,
> TA_PMF_COMMAND_POLICY_BUILDER_ENACT_POLICIES,
> };
>
> +enum ta_pmf_error_type {
> + TA_PMF_TYPE_SUCCESS,
> + TA_PMF_ERROR_TYPE_GENERIC,
> + TA_PMF_ERROR_TYPE_CRYPTO,
> + TA_PMF_ERROR_TYPE_CRYPTO_VALIDATE,
> + TA_PMF_ERROR_TYPE_CRYPTO_VERIFY_OEM,
> + TA_PMF_ERROR_TYPE_POLICY_BUILDER,
> + TA_PMF_ERROR_TYPE_PB_CONVERT,
> + TA_PMF_ERROR_TYPE_PB_SETUP,
> + TA_PMF_ERROR_TYPE_PB_ENACT,
> + TA_PMF_ERROR_TYPE_ASD_GET_DEVICE_INFO,
> + TA_PMF_ERROR_TYPE_ASD_GET_DEVICE_PCIE_INFO,
> + TA_PMF_ERROR_TYPE_SYS_DRV_FW_VALIDATION,
> + TA_PMF_ERROR_TYPE_MAX,
> +};
> +
> +struct pmf_action_table {
> + unsigned long spl; /* in mW */
> + unsigned long sppt; /* in mW */
> + unsigned long sppt_apuonly; /* in mW */
> + unsigned long fppt; /* in mW */
> + unsigned long stt_minlimit; /* in mW */
> + unsigned long stt_skintemp_apu; /* in C */
> + unsigned long stt_skintemp_hs2; /* in C */
Ditto.
> +};
> +
> +/* Input conditions */
> +struct ta_pmf_condition_info {
> + u32 power_source;
> + u32 bat_percentage;
> + u32 power_slider;
> + u32 lid_state;
> + bool user_present;
> + u32 rsvd1[2];
> + u32 monitor_count;
> + u32 rsvd2[2];
> + u32 bat_design;
> + u32 full_charge_capacity;
> + int drain_rate;
> + bool user_engaged;
> + u32 device_state;
> + u32 socket_power;
> + u32 skin_temperature;
> + u32 rsvd3[5];
> + u32 ambient_light;
> + u32 length;
> + u32 avg_c0residency;
> + u32 max_c0residency;
> + u32 s0i3_entry;
> + u32 gfx_busy;
> + u32 rsvd4[7];
> + bool camera_state;
> + u32 workload_type;
> + u32 display_type;
> + u32 display_state;
> + u32 rsvd5[150];
> +};
> +
> +struct ta_pmf_load_policy_table {
> + u32 table_size;
> + u8 table[POLICY_BUF_MAX_SZ];
> +};
> +
> +/* TA initialization params */
> +struct ta_pmf_init_table {
> + u32 frequency; /* SMU sampling frequency */
> + bool validate;
> + bool sku_check;
> + bool metadata_macrocheck;
> + struct ta_pmf_load_policy_table policies_table;
> +};
> +
> +/* Everything the TA needs to Enact Policies */
> +struct ta_pmf_enact_table {
> + struct ta_pmf_condition_info ev_info;
> + u32 name;
> +};
> +
> +struct ta_pmf_action {
> + u32 action_index;
> + u32 value;
> +};
> +
> +/* output actions from TA */
> +struct ta_pmf_enact_result {
> + u32 actions_count;
> + struct ta_pmf_action actions_list[TA_PMF_ACTION_MAX];
> + u32 undo_count;
> + struct ta_pmf_action undo_list[TA_PMF_UNDO_MAX];
> +};
> +
> +union ta_pmf_input {
> + struct ta_pmf_enact_table enact_table;
> + struct ta_pmf_init_table init_table;
> +};
> +
> +union ta_pmf_output {
> + struct ta_pmf_enact_result policy_apply_table;
> + u32 rsvd[906];
This is some size (SZ_1K?) - sizeof(ta_pmf_enact_result)? I don't know if
compiler would like such a construct though in the array declaration. If
the compiler isn't complaining it would be the most informative way to
state the size but if it's not happy, a comment might be useful.
> +};
> +
> struct ta_pmf_shared_memory {
> int command_id;
> int resp_id;
> u32 pmf_result;
> u32 if_version;
> + union ta_pmf_output pmf_output;
> + union ta_pmf_input pmf_input;
> };
>
> /* Core Layer */
> @@ -460,4 +594,5 @@ extern const struct attribute_group cnqf_feature_attribute_group;
> /* Smart PC builder Layer*/
> int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev);
> void amd_pmf_deinit_smart_pc(struct amd_pmf_dev *dev);
> +int apmf_check_smart_pc(struct amd_pmf_dev *pmf_dev);
> #endif /* PMF_H */
> diff --git a/drivers/platform/x86/amd/pmf/tee-if.c b/drivers/platform/x86/amd/pmf/tee-if.c
> index 1b3985cd7c08..15aa6e6e1050 100644
> --- a/drivers/platform/x86/amd/pmf/tee-if.c
> +++ b/drivers/platform/x86/amd/pmf/tee-if.c
> @@ -42,9 +42,77 @@ static void amd_pmf_prepare_args(struct amd_pmf_dev *dev, int cmd,
> param[0].u.memref.shm_offs = 0;
> }
>
> +static void amd_pmf_apply_policies(struct amd_pmf_dev *dev, struct ta_pmf_enact_result *out)
> +{
> + unsigned long val;
> + int idx;
> +
> + for (idx = 0; idx < out->actions_count; idx++) {
> + val = out->actions_list[idx].value;
> + switch (out->actions_list[idx].action_index) {
> + case PMF_POLICY_SPL:
> + if (dev->prev_data->spl != val) {
> + amd_pmf_send_cmd(dev, SET_SPL, false, val, NULL);
> + dev_dbg(dev->dev, "update SPL : %lu\n", val);
> + dev->prev_data->spl = val;
Well, I'd have expected you to go u32 (and %u) here as isn't
out->actions_list[idx].value u32? And amd_pmf_send_cmd also takes u32.
So unsigned long looks quite inconsistent and wasteful.
> + }
> + break;
> +
> + case PMF_POLICY_SPPT:
> + if (dev->prev_data->sppt != val) {
> + amd_pmf_send_cmd(dev, SET_SPPT, false, val, NULL);
> + dev_dbg(dev->dev, "update SPPT : %lu\n", val);
> + dev->prev_data->sppt = val;
> + }
> + break;
> +
> + case PMF_POLICY_FPPT:
> + if (dev->prev_data->fppt != val) {
> + amd_pmf_send_cmd(dev, SET_FPPT, false, val, NULL);
> + dev_dbg(dev->dev, "update FPPT : %lu\n", val);
> + dev->prev_data->fppt = val;
> + }
> + break;
> +
> + case PMF_POLICY_SPPT_APU_ONLY:
> + if (dev->prev_data->sppt_apuonly != val) {
> + amd_pmf_send_cmd(dev, SET_SPPT_APU_ONLY, false, val, NULL);
> + dev_dbg(dev->dev, "update SPPT_APU_ONLY : %lu\n", val);
> + dev->prev_data->sppt_apuonly = val;
> + }
> + break;
> +
> + case PMF_POLICY_STT_MIN:
> + if (dev->prev_data->stt_minlimit != val) {
> + amd_pmf_send_cmd(dev, SET_STT_MIN_LIMIT, false, val, NULL);
> + dev_dbg(dev->dev, "update STT_MIN : %lu\n", val);
> + dev->prev_data->stt_minlimit = val;
> + }
> + break;
> +
> + case PMF_POLICY_STT_SKINTEMP_APU:
> + if (dev->prev_data->stt_skintemp_apu != val) {
> + amd_pmf_send_cmd(dev, SET_STT_LIMIT_APU, false, val, NULL);
> + dev_dbg(dev->dev, "update STT_SKINTEMP_APU : %lu\n", val);
> + dev->prev_data->stt_skintemp_apu = val;
> + }
> + break;
> +
> + case PMF_POLICY_STT_SKINTEMP_HS2:
> + if (dev->prev_data->stt_skintemp_hs2 != val) {
> + amd_pmf_send_cmd(dev, SET_STT_LIMIT_HS2, false, val, NULL);
> + dev_dbg(dev->dev, "update STT_SKINTEMP_HS2 : %lu\n", val);
> + dev->prev_data->stt_skintemp_hs2 = val;
> + }
> + break;
> + }
> + }
> +}
> +
> static int amd_pmf_invoke_cmd_enact(struct amd_pmf_dev *dev)
> {
> struct ta_pmf_shared_memory *ta_sm = NULL;
> + struct ta_pmf_enact_result *out = NULL;
> struct tee_param param[MAX_TEE_PARAM];
> struct tee_ioctl_invoke_arg arg;
> int ret = 0;
> @@ -52,7 +120,10 @@ static int amd_pmf_invoke_cmd_enact(struct amd_pmf_dev *dev)
> if (!dev->tee_ctx)
> return -ENODEV;
>
> + memset(dev->shbuf, 0, dev->policy_sz);
> ta_sm = (struct ta_pmf_shared_memory *)dev->shbuf;
> + out = &ta_sm->pmf_output.policy_apply_table;
> +
> memset(ta_sm, 0, sizeof(struct ta_pmf_shared_memory));
> ta_sm->command_id = TA_PMF_COMMAND_POLICY_BUILDER_ENACT_POLICIES;
> ta_sm->if_version = PMF_TA_IF_VERSION_MAJOR;
> @@ -65,6 +136,12 @@ static int amd_pmf_invoke_cmd_enact(struct amd_pmf_dev *dev)
> return -EINVAL;
> }
>
> + if (ta_sm->pmf_result == TA_PMF_TYPE_SUCCESS && out->actions_count) {
> + dev_dbg(dev->dev, "action count:%u result:%x\n", out->actions_count,
> + ta_sm->pmf_result);
> + amd_pmf_apply_policies(dev, out);
> + }
> +
> return 0;
> }
>
> @@ -72,6 +149,7 @@ static int amd_pmf_invoke_cmd_init(struct amd_pmf_dev *dev)
> {
> struct ta_pmf_shared_memory *ta_sm = NULL;
> struct tee_param param[MAX_TEE_PARAM];
> + struct ta_pmf_init_table *in = NULL;
> struct tee_ioctl_invoke_arg arg;
> int ret = 0;
>
> @@ -80,10 +158,20 @@ static int amd_pmf_invoke_cmd_init(struct amd_pmf_dev *dev)
> return -ENODEV;
> }
>
> + dev_dbg(dev->dev, "Policy Binary size: %u bytes\n", dev->policy_sz);
> + memset(dev->shbuf, 0, dev->policy_sz);
> ta_sm = (struct ta_pmf_shared_memory *)dev->shbuf;
> + in = &ta_sm->pmf_input.init_table;
> +
> ta_sm->command_id = TA_PMF_COMMAND_POLICY_BUILDER_INITIALIZE;
> ta_sm->if_version = PMF_TA_IF_VERSION_MAJOR;
> + in->metadata_macrocheck = false;
> + in->sku_check = false;
> + in->validate = true;
> + in->frequency = pb_actions_ms;
> + in->policies_table.table_size = dev->policy_sz;
>
> + memcpy(in->policies_table.table, dev->policy_buf, dev->policy_sz);
> amd_pmf_prepare_args(dev, TA_PMF_COMMAND_POLICY_BUILDER_INITIALIZE, &arg, param);
>
> ret = tee_client_invoke_func(dev->tee_ctx, &arg, param);
> @@ -103,6 +191,47 @@ static void amd_pmf_invoke_cmd(struct work_struct *work)
> schedule_delayed_work(&dev->pb_work, msecs_to_jiffies(pb_actions_ms));
> }
>
> +static int amd_pmf_start_policy_engine(struct amd_pmf_dev *dev)
> +{
> + u32 cookie, length;
> + int res;
> +
> + cookie = readl(dev->policy_buf + POLICY_COOKIE_OFFSET);
> + length = readl(dev->policy_buf + POLICY_COOKIE_LEN);
> +
> + if (cookie != POLICY_SIGN_COOKIE || !length)
> + return -EINVAL;
> +
> + /* update the actual length */
> + dev->policy_sz = length + 512;
> + res = amd_pmf_invoke_cmd_init(dev);
> + if (res == TA_PMF_TYPE_SUCCESS) {
> + /* now its safe to announce that smart pc is enabled */
> + dev->smart_pc_enabled = 1;
> + schedule_delayed_work(&dev->pb_work, msecs_to_jiffies(pb_actions_ms * 3));
Why * 3? Explain in comment if you feel it's necessary as it's not
obvious.
--
i.
