4 files changed, 176 insertions, 1 deletions

diff --git a/drivers/platform/x86/amd/pmf/Makefile b/drivers/platform/x86/amd/pmf/Makefile
index 459005f659e5..2617eba773ce 100644
--- a/drivers/platform/x86/amd/pmf/Makefile
+++ b/drivers/platform/x86/amd/pmf/Makefile
@@ -5,4 +5,4 @@
 #
 
 obj-$(CONFIG_AMD_PMF) += amd-pmf.o
-amd-pmf-objs := core.o
+amd-pmf-objs := core.o acpi.o
diff --git a/drivers/platform/x86/amd/pmf/acpi.c b/drivers/platform/x86/amd/pmf/acpi.c
new file mode 100644
index 000000000000..b378f9e31194
--- /dev/null
+++ b/drivers/platform/x86/amd/pmf/acpi.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Platform Management Framework Driver
+ *
+ * Copyright (c) 2022, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ */
+
+#include <linux/acpi.h>
+#include "pmf.h"
+
+static union acpi_object *apmf_if_call(struct amd_pmf_dev *pdev, int fn, struct acpi_buffer *param)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	acpi_handle ahandle = ACPI_HANDLE(pdev->dev);
+	struct acpi_object_list apmf_if_arg_list;
+	union acpi_object apmf_if_args[2];
+	acpi_status status;
+
+	apmf_if_arg_list.count = 2;
+	apmf_if_arg_list.pointer = &apmf_if_args[0];
+
+	apmf_if_args[0].type = ACPI_TYPE_INTEGER;
+	apmf_if_args[0].integer.value = fn;
+
+	if (param) {
+		apmf_if_args[1].type = ACPI_TYPE_BUFFER;
+		apmf_if_args[1].buffer.length = param->length;
+		apmf_if_args[1].buffer.pointer = param->pointer;
+	} else {
+		apmf_if_args[1].type = ACPI_TYPE_INTEGER;
+		apmf_if_args[1].integer.value = 0;
+	}
+
+	status = acpi_evaluate_object(ahandle, "APMF", &apmf_if_arg_list, &buffer);
+	if (ACPI_FAILURE(status)) {
+		dev_err(pdev->dev, "APMF method:%d call failed\n", fn);
+		kfree(buffer.pointer);
+		return NULL;
+	}
+
+	return buffer.pointer;
+}
+
+static int apmf_if_call_store_buffer(struct amd_pmf_dev *pdev, int fn, void *dest, size_t out_sz)
+{
+	union acpi_object *info;
+	size_t size;
+	int err = 0;
+
+	info = apmf_if_call(pdev, fn, NULL);
+	if (!info)
+		return -EIO;
+
+	if (info->type != ACPI_TYPE_BUFFER) {
+		dev_err(pdev->dev, "object is not a buffer\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (info->buffer.length < 2) {
+		dev_err(pdev->dev, "buffer too small\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	size = *(u16 *)info->buffer.pointer;
+	if (info->buffer.length < size) {
+		dev_err(pdev->dev, "buffer smaller then headersize %u < %zu\n",
+			info->buffer.length, size);
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (size < out_sz) {
+		dev_err(pdev->dev, "buffer too small %zu\n", size);
+		err = -EINVAL;
+		goto out;
+	}
+
+	memcpy(dest, info->buffer.pointer, out_sz);
+
+out:
+	kfree(info);
+	return err;
+}
+
+int is_apmf_func_supported(struct amd_pmf_dev *pdev, unsigned long index)
+{
+	/* If bit-n is set, that indicates function n+1 is supported */
+	return !!(pdev->supported_func & BIT(index - 1));
+}
+
+static int apmf_if_verify_interface(struct amd_pmf_dev *pdev)
+{
+	struct apmf_verify_interface output;
+	int err;
+
+	err = apmf_if_call_store_buffer(pdev, APMF_FUNC_VERIFY_INTERFACE, &output, sizeof(output));
+	if (err)
+		return err;
+
+	pdev->supported_func = output.supported_functions;
+	dev_dbg(pdev->dev, "supported functions:0x%x notifications:0x%x\n",
+		output.supported_functions, output.notification_mask);
+
+	return 0;
+}
+
+static int apmf_get_system_params(struct amd_pmf_dev *dev)
+{
+	struct apmf_system_params params;
+	int err;
+
+	if (!is_apmf_func_supported(dev, APMF_FUNC_GET_SYS_PARAMS))
+		return -EINVAL;
+
+	err = apmf_if_call_store_buffer(dev, APMF_FUNC_GET_SYS_PARAMS, &params, sizeof(params));
+	if (err)
+		return err;
+
+	dev_dbg(dev->dev, "system params mask:0x%x flags:0x%x cmd_code:0x%x\n",
+		params.valid_mask,
+		params.flags,
+		params.command_code);
+	params.flags = params.flags & params.valid_mask;
+
+	return 0;
+}
+
+int apmf_acpi_init(struct amd_pmf_dev *pmf_dev)
+{
+	int ret;
+
+	ret = apmf_if_verify_interface(pmf_dev);
+	if (ret) {
+		dev_err(pmf_dev->dev, "APMF verify interface failed :%d\n", ret);
+		goto out;
+	}
+
+	ret = apmf_get_system_params(pmf_dev);
+	if (ret) {
+		dev_err(pmf_dev->dev, "APMF apmf_get_system_params failed :%d\n", ret);
+		goto out;
+	}
+
+out:
+	return ret;
+}
diff --git a/drivers/platform/x86/amd/pmf/core.c b/drivers/platform/x86/amd/pmf/core.c
index aef97965c181..c5002b7bb904 100644
--- a/drivers/platform/x86/amd/pmf/core.c
+++ b/drivers/platform/x86/amd/pmf/core.c
@@ -204,6 +204,7 @@ static int amd_pmf_probe(struct platform_device *pdev)
 	if (!dev->regbase)
 		return -ENOMEM;
 
+	apmf_acpi_init(dev);
 	platform_set_drvdata(pdev, dev);
 
 	mutex_init(&dev->lock);
diff --git a/drivers/platform/x86/amd/pmf/pmf.h b/drivers/platform/x86/amd/pmf/pmf.h
index 1c2e942e5096..bdadbff168ee 100644
--- a/drivers/platform/x86/amd/pmf/pmf.h
+++ b/drivers/platform/x86/amd/pmf/pmf.h
@@ -11,6 +11,12 @@
 #ifndef PMF_H
 #define PMF_H
 
+#include <linux/acpi.h>
+
+/* APMF Functions */
+#define APMF_FUNC_VERIFY_INTERFACE			0
+#define APMF_FUNC_GET_SYS_PARAMS			1
+
 /* Message Definitions */
 #define SET_SPL				0x03 /* SPL: Sustained Power Limit */
 #define SET_SPPT			0x05 /* SPPT: Slow Package Power Tracking */
@@ -30,6 +36,21 @@
 #define GET_STT_LIMIT_APU	0x20
 #define GET_STT_LIMIT_HS2	0x21
 
+/* AMD PMF BIOS interfaces */
+struct apmf_verify_interface {
+	u16 size;
+	u16 version;
+	u32 notification_mask;
+	u32 supported_functions;
+} __packed;
+
+struct apmf_system_params {
+	u16 size;
+	u32 valid_mask;
+	u32 flags;
+	u8 command_code;
+} __packed;
+
 struct amd_pmf_dev {
 	void __iomem *regbase;
 	void __iomem *smu_virt_addr;
@@ -38,9 +59,11 @@ struct amd_pmf_dev {
 	u32 cpu_id;
 	struct device *dev;
 	struct mutex lock; /* protects the PMF interface */
+	u32 supported_func;
 };
 
 /* Core Layer */
+int apmf_acpi_init(struct amd_pmf_dev *pmf_dev);
 int amd_pmf_send_cmd(struct amd_pmf_dev *dev, u8 message, bool get, u32 arg, u32 *data);
 
 #endif /* PMF_H */