1 files changed, 378 insertions, 0 deletions
diff --git a/drivers/platform/x86/amd/hsmp/acpi.c b/drivers/platform/x86/amd/hsmp/acpi.c
new file mode 100644
index 000000000000..444b43be35a2
--- /dev/null
+++ b/drivers/platform/x86/amd/hsmp/acpi.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD HSMP Platform Driver
+ * Copyright (c) 2024, AMD.
+ * All Rights Reserved.
+ *
+ * This file provides an ACPI based driver implementation for HSMP interface.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <asm/amd_hsmp.h>
+#include <asm/amd_nb.h>
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/dev_printk.h>
+#include <linux/ioport.h>
+#include <linux/kstrtox.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+#include <linux/uuid.h>
+
+#include <uapi/asm-generic/errno-base.h>
+
+#include "hsmp.h"
+
+#define DRIVER_NAME		"amd_hsmp"
+#define DRIVER_VERSION		"2.3"
+#define ACPI_HSMP_DEVICE_HID	"AMDI0097"
+
+/* These are the strings specified in ACPI table */
+#define MSG_IDOFF_STR		"MsgIdOffset"
+#define MSG_ARGOFF_STR		"MsgArgOffset"
+#define MSG_RESPOFF_STR		"MsgRspOffset"
+
+static struct hsmp_plat_device *hsmp_pdev;
+
+static int amd_hsmp_acpi_rdwr(struct hsmp_socket *sock, u32 offset,
+			      u32 *value, bool write)
+{
+	if (write)
+		iowrite32(*value, sock->virt_base_addr + offset);
+	else
+		*value = ioread32(sock->virt_base_addr + offset);
+
+	return 0;
+}
+
+/* This is the UUID used for HSMP */
+static const guid_t acpi_hsmp_uuid = GUID_INIT(0xb74d619d, 0x5707, 0x48bd,
+						0xa6, 0x9f, 0x4e, 0xa2,
+						0x87, 0x1f, 0xc2, 0xf6);
+
+static inline bool is_acpi_hsmp_uuid(union acpi_object *obj)
+{
+	if (obj->type == ACPI_TYPE_BUFFER && obj->buffer.length == UUID_SIZE)
+		return guid_equal((guid_t *)obj->buffer.pointer, &acpi_hsmp_uuid);
+
+	return false;
+}
+
+static inline int hsmp_get_uid(struct device *dev, u16 *sock_ind)
+{
+	char *uid;
+
+	/*
+	 * UID (ID00, ID01..IDXX) is used for differentiating sockets,
+	 * read it and strip the "ID" part of it and convert the remaining
+	 * bytes to integer.
+	 */
+	uid = acpi_device_uid(ACPI_COMPANION(dev));
+
+	return kstrtou16(uid + 2, 10, sock_ind);
+}
+
+static acpi_status hsmp_resource(struct acpi_resource *res, void *data)
+{
+	struct hsmp_socket *sock = data;
+	struct resource r;
+
+	switch (res->type) {
+	case ACPI_RESOURCE_TYPE_FIXED_MEMORY32:
+		if (!acpi_dev_resource_memory(res, &r))
+			return AE_ERROR;
+		if (!r.start || r.end < r.start || !(r.flags & IORESOURCE_MEM_WRITEABLE))
+			return AE_ERROR;
+		sock->mbinfo.base_addr = r.start;
+		sock->mbinfo.size = resource_size(&r);
+		break;
+	case ACPI_RESOURCE_TYPE_END_TAG:
+		break;
+	default:
+		return AE_ERROR;
+	}
+
+	return AE_OK;
+}
+
+static int hsmp_read_acpi_dsd(struct hsmp_socket *sock)
+{
+	struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *guid, *mailbox_package;
+	union acpi_object *dsd;
+	acpi_status status;
+	int ret = 0;
+	int j;
+
+	status = acpi_evaluate_object_typed(ACPI_HANDLE(sock->dev), "_DSD", NULL,
+					    &buf, ACPI_TYPE_PACKAGE);
+	if (ACPI_FAILURE(status)) {
+		dev_err(sock->dev, "Failed to read mailbox reg offsets from DSD table, err: %s\n",
+			acpi_format_exception(status));
+		return -ENODEV;
+	}
+
+	dsd = buf.pointer;
+
+	/* HSMP _DSD property should contain 2 objects.
+	 * 1. guid which is an acpi object of type ACPI_TYPE_BUFFER
+	 * 2. mailbox which is an acpi object of type ACPI_TYPE_PACKAGE
+	 *    This mailbox object contains 3 more acpi objects of type
+	 *    ACPI_TYPE_PACKAGE for holding msgid, msgresp, msgarg offsets
+	 *    these packages inturn contain 2 acpi objects of type
+	 *    ACPI_TYPE_STRING and ACPI_TYPE_INTEGER
+	 */
+	if (!dsd || dsd->type != ACPI_TYPE_PACKAGE || dsd->package.count != 2) {
+		ret = -EINVAL;
+		goto free_buf;
+	}
+
+	guid = &dsd->package.elements[0];
+	mailbox_package = &dsd->package.elements[1];
+	if (!is_acpi_hsmp_uuid(guid) || mailbox_package->type != ACPI_TYPE_PACKAGE) {
+		dev_err(sock->dev, "Invalid hsmp _DSD table data\n");
+		ret = -EINVAL;
+		goto free_buf;
+	}
+
+	for (j = 0; j < mailbox_package->package.count; j++) {
+		union acpi_object *msgobj, *msgstr, *msgint;
+
+		msgobj	= &mailbox_package->package.elements[j];
+		msgstr	= &msgobj->package.elements[0];
+		msgint	= &msgobj->package.elements[1];
+
+		/* package should have 1 string and 1 integer object */
+		if (msgobj->type != ACPI_TYPE_PACKAGE ||
+		    msgstr->type != ACPI_TYPE_STRING ||
+		    msgint->type != ACPI_TYPE_INTEGER) {
+			ret = -EINVAL;
+			goto free_buf;
+		}
+
+		if (!strncmp(msgstr->string.pointer, MSG_IDOFF_STR,
+			     msgstr->string.length)) {
+			sock->mbinfo.msg_id_off = msgint->integer.value;
+		} else if (!strncmp(msgstr->string.pointer, MSG_RESPOFF_STR,
+				    msgstr->string.length)) {
+			sock->mbinfo.msg_resp_off =  msgint->integer.value;
+		} else if (!strncmp(msgstr->string.pointer, MSG_ARGOFF_STR,
+				    msgstr->string.length)) {
+			sock->mbinfo.msg_arg_off = msgint->integer.value;
+		} else {
+			ret = -ENOENT;
+			goto free_buf;
+		}
+	}
+
+	if (!sock->mbinfo.msg_id_off || !sock->mbinfo.msg_resp_off ||
+	    !sock->mbinfo.msg_arg_off)
+		ret = -EINVAL;
+
+free_buf:
+	ACPI_FREE(buf.pointer);
+	return ret;
+}
+
+static int hsmp_read_acpi_crs(struct hsmp_socket *sock)
+{
+	acpi_status status;
+
+	status = acpi_walk_resources(ACPI_HANDLE(sock->dev), METHOD_NAME__CRS,
+				     hsmp_resource, sock);
+	if (ACPI_FAILURE(status)) {
+		dev_err(sock->dev, "Failed to look up MP1 base address from CRS method, err: %s\n",
+			acpi_format_exception(status));
+		return -EINVAL;
+	}
+	if (!sock->mbinfo.base_addr || !sock->mbinfo.size)
+		return -EINVAL;
+
+	/* The mapped region should be un-cached */
+	sock->virt_base_addr = devm_ioremap_uc(sock->dev, sock->mbinfo.base_addr,
+					       sock->mbinfo.size);
+	if (!sock->virt_base_addr) {
+		dev_err(sock->dev, "Failed to ioremap MP1 base address\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/* Parse the ACPI table to read the data */
+static int hsmp_parse_acpi_table(struct device *dev, u16 sock_ind)
+{
+	struct hsmp_socket *sock = &hsmp_pdev->sock[sock_ind];
+	int ret;
+
+	sock->sock_ind		= sock_ind;
+	sock->dev		= dev;
+	sock->amd_hsmp_rdwr	= amd_hsmp_acpi_rdwr;
+
+	sema_init(&sock->hsmp_sem, 1);
+
+	dev_set_drvdata(dev, sock);
+
+	/* Read MP1 base address from CRS method */
+	ret = hsmp_read_acpi_crs(sock);
+	if (ret)
+		return ret;
+
+	/* Read mailbox offsets from DSD table */
+	return hsmp_read_acpi_dsd(sock);
+}
+
+static ssize_t hsmp_metric_tbl_acpi_read(struct file *filp, struct kobject *kobj,
+					 const struct bin_attribute *bin_attr, char *buf,
+					 loff_t off, size_t count)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct hsmp_socket *sock = dev_get_drvdata(dev);
+
+	return hsmp_metric_tbl_read(sock, buf, count);
+}
+
+static umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
+					 const struct bin_attribute *battr, int id)
+{
+	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6)
+		return battr->attr.mode;
+
+	return 0;
+}
+
+static int init_acpi(struct device *dev)
+{
+	u16 sock_ind;
+	int ret;
+
+	ret = hsmp_get_uid(dev, &sock_ind);
+	if (ret)
+		return ret;
+	if (sock_ind >= hsmp_pdev->num_sockets)
+		return -EINVAL;
+
+	ret = hsmp_parse_acpi_table(dev, sock_ind);
+	if (ret) {
+		dev_err(dev, "Failed to parse ACPI table\n");
+		return ret;
+	}
+
+	/* Test the hsmp interface */
+	ret = hsmp_test(sock_ind, 0xDEADBEEF);
+	if (ret) {
+		dev_err(dev, "HSMP test message failed on Fam:%x model:%x\n",
+			boot_cpu_data.x86, boot_cpu_data.x86_model);
+		dev_err(dev, "Is HSMP disabled in BIOS ?\n");
+		return ret;
+	}
+
+	ret = hsmp_cache_proto_ver(sock_ind);
+	if (ret) {
+		dev_err(dev, "Failed to read HSMP protocol version\n");
+		return ret;
+	}
+
+	if (hsmp_pdev->proto_ver == HSMP_PROTO_VER6) {
+		ret = hsmp_get_tbl_dram_base(sock_ind);
+		if (ret)
+			dev_err(dev, "Failed to init metric table\n");
+	}
+
+	return ret;
+}
+
+static const struct bin_attribute  hsmp_metric_tbl_attr = {
+	.attr = { .name = HSMP_METRICS_TABLE_NAME, .mode = 0444},
+	.read_new = hsmp_metric_tbl_acpi_read,
+	.size = sizeof(struct hsmp_metric_table),
+};
+
+static const struct bin_attribute *hsmp_attr_list[] = {
+	&hsmp_metric_tbl_attr,
+	NULL
+};
+
+static const struct attribute_group hsmp_attr_grp = {
+	.bin_attrs_new = hsmp_attr_list,
+	.is_bin_visible = hsmp_is_sock_attr_visible,
+};
+
+static const struct attribute_group *hsmp_groups[] = {
+	&hsmp_attr_grp,
+	NULL
+};
+
+static const struct acpi_device_id amd_hsmp_acpi_ids[] = {
+	{ACPI_HSMP_DEVICE_HID, 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, amd_hsmp_acpi_ids);
+
+static int hsmp_acpi_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	hsmp_pdev = get_hsmp_pdev();
+	if (!hsmp_pdev)
+		return -ENOMEM;
+
+	if (!hsmp_pdev->is_probed) {
+		hsmp_pdev->num_sockets = amd_nb_num();
+		if (hsmp_pdev->num_sockets == 0 || hsmp_pdev->num_sockets > MAX_AMD_SOCKETS)
+			return -ENODEV;
+
+		hsmp_pdev->sock = devm_kcalloc(&pdev->dev, hsmp_pdev->num_sockets,
+					       sizeof(*hsmp_pdev->sock),
+					       GFP_KERNEL);
+		if (!hsmp_pdev->sock)
+			return -ENOMEM;
+	}
+
+	ret = init_acpi(&pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize HSMP interface.\n");
+		return ret;
+	}
+
+	if (!hsmp_pdev->is_probed) {
+		ret = hsmp_misc_register(&pdev->dev);
+		if (ret)
+			return ret;
+		hsmp_pdev->is_probed = true;
+	}
+
+	return 0;
+}
+
+static void hsmp_acpi_remove(struct platform_device *pdev)
+{
+	/*
+	 * We register only one misc_device even on multi-socket system.
+	 * So, deregister should happen only once.
+	 */
+	if (hsmp_pdev->is_probed) {
+		hsmp_misc_deregister();
+		hsmp_pdev->is_probed = false;
+	}
+}
+
+static struct platform_driver amd_hsmp_driver = {
+	.probe		= hsmp_acpi_probe,
+	.remove		= hsmp_acpi_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.acpi_match_table = amd_hsmp_acpi_ids,
+		.dev_groups = hsmp_groups,
+	},
+};
+
+module_platform_driver(amd_hsmp_driver);
+
+MODULE_IMPORT_NS("AMD_HSMP");
+MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");