platform/x86/amd/pmf: Add support for PMF-TA interaction

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>

drivers/platform/x86/amd/pmf/pmf.h

@@ -59,6 +59,9 @@
 #define ARG_NONE 0
 #define AVG_SAMPLE_SIZE 3
 
+/* TA macros */
+#define PMF_TA_IF_VERSION_MAJOR				1
+
 /* AMD PMF BIOS interfaces */
 struct apmf_verify_interface {
 	u16 size;
@@ -184,6 +187,7 @@ struct amd_pmf_dev {
 	struct tee_shm *fw_shm_pool;
 	u32 session_id;
 	void *shbuf;
+	struct delayed_work pb_work;
 	bool smart_pc_enabled;
 };
 
@@ -395,6 +399,12 @@ struct apmf_dyn_slider_output {
 	struct apmf_cnqf_power_set ps[APMF_CNQF_MAX];
 } __packed;
 
+/* Command ids for TA communication */
+enum ta_pmf_command {
+	TA_PMF_COMMAND_POLICY_BUILDER_INITIALIZE,
+	TA_PMF_COMMAND_POLICY_BUILDER_ENACT_POLICIES,
+};
+
 struct ta_pmf_shared_memory {
 	int command_id;
 	int resp_id;

drivers/platform/x86/amd/pmf/tee-if.c

@@ -13,9 +13,96 @@
 #include "pmf.h"
 
 #define MAX_TEE_PARAM	4
+
+/* Policy binary actions sampling frequency (in ms) */
+static int pb_actions_ms = MSEC_PER_SEC;
+#ifdef CONFIG_AMD_PMF_DEBUG
+module_param(pb_actions_ms, int, 0644);
+MODULE_PARM_DESC(pb_actions_ms, "Policy binary actions sampling frequency (default = 1000ms)");
+#endif
+
 static const uuid_t amd_pmf_ta_uuid = UUID_INIT(0x6fd93b77, 0x3fb8, 0x524d,
 						0xb1, 0x2d, 0xc5, 0x29, 0xb1, 0x3d, 0x85, 0x43);
 
+static void amd_pmf_prepare_args(struct amd_pmf_dev *dev, int cmd,
+				 struct tee_ioctl_invoke_arg *arg,
+				 struct tee_param *param)
+{
+	memset(arg, 0, sizeof(*arg));
+	memset(param, 0, MAX_TEE_PARAM * sizeof(*param));
+
+	arg->func = cmd;
+	arg->session = dev->session_id;
+	arg->num_params = MAX_TEE_PARAM;
+
+	/* Fill invoke cmd params */
+	param[0].u.memref.size = sizeof(struct ta_pmf_shared_memory);
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT;
+	param[0].u.memref.shm = dev->fw_shm_pool;
+	param[0].u.memref.shm_offs = 0;
+}
+
+static int amd_pmf_invoke_cmd_enact(struct amd_pmf_dev *dev)
+{
+	struct ta_pmf_shared_memory *ta_sm = NULL;
+	struct tee_param param[MAX_TEE_PARAM];
+	struct tee_ioctl_invoke_arg arg;
+	int ret = 0;
+
+	if (!dev->tee_ctx)
+		return -ENODEV;
+
+	ta_sm = dev->shbuf;
+	memset(ta_sm, 0, sizeof(*ta_sm));
+	ta_sm->command_id = TA_PMF_COMMAND_POLICY_BUILDER_ENACT_POLICIES;
+	ta_sm->if_version = PMF_TA_IF_VERSION_MAJOR;
+
+	amd_pmf_prepare_args(dev, TA_PMF_COMMAND_POLICY_BUILDER_ENACT_POLICIES, &arg, param);
+
+	ret = tee_client_invoke_func(dev->tee_ctx, &arg, param);
+	if (ret < 0 || arg.ret != 0) {
+		dev_err(dev->dev, "TEE enact cmd failed. err: %x, ret:%d\n", arg.ret, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+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 tee_ioctl_invoke_arg arg;
+	int ret = 0;
+
+	if (!dev->tee_ctx) {
+		dev_err(dev->dev, "Failed to get TEE context\n");
+		return -ENODEV;
+	}
+
+	ta_sm = dev->shbuf;
+	ta_sm->command_id = TA_PMF_COMMAND_POLICY_BUILDER_INITIALIZE;
+	ta_sm->if_version = PMF_TA_IF_VERSION_MAJOR;
+
+	amd_pmf_prepare_args(dev, TA_PMF_COMMAND_POLICY_BUILDER_INITIALIZE, &arg, param);
+
+	ret = tee_client_invoke_func(dev->tee_ctx, &arg, param);
+	if (ret < 0 || arg.ret != 0) {
+		dev_err(dev->dev, "Failed to invoke TEE init cmd. err: %x, ret:%d\n", arg.ret, ret);
+		return ret;
+	}
+
+	return ta_sm->pmf_result;
+}
+
+static void amd_pmf_invoke_cmd(struct work_struct *work)
+{
+	struct amd_pmf_dev *dev = container_of(work, struct amd_pmf_dev, pb_work.work);
+
+	amd_pmf_invoke_cmd_enact(dev);
+	schedule_delayed_work(&dev->pb_work, msecs_to_jiffies(pb_actions_ms));
+}
+
 static int amd_pmf_amdtee_ta_match(struct tee_ioctl_version_data *ver, const void *data)
 {
 	return ver->impl_id == TEE_IMPL_ID_AMDTEE;
@@ -96,10 +183,18 @@ static void amd_pmf_tee_deinit(struct amd_pmf_dev *dev)
 
 int amd_pmf_init_smart_pc(struct amd_pmf_dev *dev)
 {
-	return amd_pmf_tee_init(dev);
+	int ret;
+
+	ret = amd_pmf_tee_init(dev);
+	if (ret)
+		return ret;
+
+	INIT_DELAYED_WORK(&dev->pb_work, amd_pmf_invoke_cmd);
+	return 0;
 }
 
 void amd_pmf_deinit_smart_pc(struct amd_pmf_dev *dev)
 {
+	cancel_delayed_work_sync(&dev->pb_work);
 	amd_pmf_tee_deinit(dev);
 }