platform/x86/amd/pmf: Implement util layer ioctl handler

Implement the ioctl handler for the util layer character device. This
support adds the actual functionality to populate PMF metrics from the
TA shared memory buffer and return them to userspace.

The implementation includes:
- amd_pmf_populate_data() to extract metrics from TA shared memory
- amd_pmf_set_ioctl() to handle userspace ioctl requests
- Size negotiation for forward/backward compatibility
- Feature-based population of struct fields
- Export amd_pmf_get_ta_custom_bios_inputs()

Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://patch.msgid.link/20260609081044.2416731-6-Shyam-sundar.S-k@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

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

@@ -903,6 +903,7 @@ int amd_pmf_smartpc_apply_bios_output(struct amd_pmf_dev *dev, u32 val, u32 preq
 void amd_pmf_populate_ta_inputs(struct amd_pmf_dev *dev, struct ta_pmf_enact_table *in);
 void amd_pmf_dump_ta_inputs(struct amd_pmf_dev *dev, struct ta_pmf_enact_table *in);
 int amd_pmf_invoke_cmd_enact(struct amd_pmf_dev *dev);
+u32 amd_pmf_get_ta_custom_bios_inputs(struct ta_pmf_enact_table *in, int index);
 
 int amd_pmf_tee_init(struct amd_pmf_dev *dev, const uuid_t *uuid);
 void amd_pmf_tee_deinit(struct amd_pmf_dev *dev);

drivers/platform/x86/amd/pmf/spc.c

@@ -18,7 +18,7 @@
 #include "pmf.h"
 
 #ifdef CONFIG_AMD_PMF_DEBUG
-static u32 amd_pmf_get_ta_custom_bios_inputs(struct ta_pmf_enact_table *in, int index)
+u32 amd_pmf_get_ta_custom_bios_inputs(struct ta_pmf_enact_table *in, int index)
 {
 	switch (index) {
 	case 0 ... 1:
@@ -29,6 +29,7 @@ static u32 amd_pmf_get_ta_custom_bios_inputs(struct ta_pmf_enact_table *in, int
 		return 0;
 	}
 }
+EXPORT_SYMBOL(amd_pmf_get_ta_custom_bios_inputs);
 
 void amd_pmf_dump_ta_inputs(struct amd_pmf_dev *dev, struct ta_pmf_enact_table *in)
 {

drivers/platform/x86/amd/pmf/util.c

@@ -10,6 +10,7 @@
  */
 
 #include <linux/amd-pmf.h>
+#include <linux/minmax.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
 #include <linux/uaccess.h>
@@ -19,9 +20,93 @@
 static struct amd_pmf_dev *pmf_dev_handle;
 static DEFINE_MUTEX(pmf_util_lock);
 
+static int amd_pmf_populate_data(struct amd_pmf_dev *pdev, struct amd_pmf_info *info)
+{
+	struct ta_pmf_shared_memory *ta_sm = NULL;
+	struct ta_pmf_enact_table *in = NULL;
+	int idx;
+
+	if (!pdev || !info)
+		return -EINVAL;
+
+	if (!pdev->shbuf)
+		return -EINVAL;
+
+	ta_sm = pdev->shbuf;
+	in = &ta_sm->pmf_input.enact_table;
+
+	/* Set size */
+	info->size = sizeof(*info);
+
+	/* PMF Feature support flags */
+	if (is_apmf_func_supported(pdev, APMF_FUNC_AUTO_MODE))
+		info->features_supported |= AMD_PMF_FEAT_AUTO_MODE;
+	if (is_apmf_func_supported(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR))
+		info->features_supported |= AMD_PMF_FEAT_STATIC_POWER_SLIDER;
+	if (pdev->smart_pc_enabled)
+		info->features_supported |= AMD_PMF_FEAT_POLICY_BUILDER;
+	if (is_apmf_func_supported(pdev, APMF_FUNC_DYN_SLIDER_AC))
+		info->features_supported |= AMD_PMF_FEAT_DYNAMIC_POWER_SLIDER_AC;
+	if (is_apmf_func_supported(pdev, APMF_FUNC_DYN_SLIDER_DC))
+		info->features_supported |= AMD_PMF_FEAT_DYNAMIC_POWER_SLIDER_DC;
+
+	/* Device States */
+	info->platform_type = in->ev_info.platform_type;
+	info->laptop_placement = in->ev_info.device_state;
+	info->lid_state = in->ev_info.lid_state;
+	info->user_presence = in->ev_info.user_present;
+	info->slider_position = in->ev_info.power_slider;
+
+	/* Thermal and Power Metrics */
+	info->power_source = in->ev_info.power_source;
+	info->skin_temp = in->ev_info.skin_temperature;
+	info->gfx_busy = in->ev_info.gfx_busy;
+	info->ambient_light = in->ev_info.ambient_light;
+	info->avg_c0_residency = in->ev_info.avg_c0residency;
+	info->max_c0_residency = in->ev_info.max_c0residency;
+	info->socket_power = in->ev_info.socket_power;
+
+	/* Custom BIOS input parameters */
+	for (idx = 0; idx < AMD_PMF_BIOS_PARAMS_MAX; idx++)
+		info->bios_input[idx] = amd_pmf_get_ta_custom_bios_inputs(in, idx);
+
+	/* BIOS output parameters */
+	for (idx = 0; idx < AMD_PMF_BIOS_PARAMS_MAX; idx++)
+		info->bios_output[idx] = pdev->bios_output[idx];
+
+	return 0;
+}
+
 static long amd_pmf_set_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-	return -ENOTTY;
+	struct amd_pmf_dev *pdev = filp->private_data;
+	void __user *argp = (void __user *)arg;
+	struct amd_pmf_info info = {};
+	size_t copy_size;
+	__u64 user_size;
+	int ret;
+
+	if (cmd != IOCTL_AMD_PMF_POPULATE_DATA)
+		return -ENOTTY;
+
+	/* First read just the size field from userspace */
+	if (copy_from_user(&user_size, argp, sizeof(user_size)))
+		return -EFAULT;
+
+	guard(mutex)(&pmf_util_lock);
+	ret = amd_pmf_populate_data(pdev, &info);
+	if (ret)
+		return ret;
+
+	copy_size = min_t(size_t, user_size, sizeof(info));
+
+	/* Set actual size being copied */
+	info.size = copy_size;
+
+	if (copy_to_user(argp, &info, copy_size))
+		return -EFAULT;
+
+	return 0;
 }
 
 static int amd_pmf_open(struct inode *inode, struct file *filp)