platform/x86/amd/hsmp: Move ACPI code to acpi.c

An upcoming change splits HSMP driver into ACPI and platform device
variants. Prepare for the split by moving ACPI related code
to acpi.c from hsmp.c. Common code is kept in hsmp.c.

No logical/functional change.
We still have one driver at this point,
the driver probe will be split in the next patch.

Signed-off-by: Suma Hegde <suma.hegde@amd.com>
Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20241021111428.2676884-6-suma.hegde@amd.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

1 files changed, 272 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..61c072216fb7
--- /dev/null
+++ b/drivers/platform/x86/amd/hsmp/acpi.c
@@ -0,0 +1,272 @@
+// 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 <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/dev_printk.h>
+#include <linux/ioport.h>
+#include <linux/kstrtox.h>
+#include <linux/sysfs.h>
+#include <linux/uuid.h>
+
+#include <uapi/asm-generic/errno-base.h>
+
+#include "hsmp.h"
+
+/* These are the strings specified in ACPI table */
+#define MSG_IDOFF_STR		"MsgIdOffset"
+#define MSG_ARGOFF_STR		"MsgArgOffset"
+#define MSG_RESPOFF_STR		"MsgRspOffset"
+
+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 = &plat_dev.sock[sock_ind];
+	int ret;
+
+	sock->sock_ind		= sock_ind;
+	sock->dev		= dev;
+	sock->amd_hsmp_rdwr	= amd_hsmp_acpi_rdwr;
+	plat_dev.is_acpi_device	= true;
+
+	sema_init(&sock->hsmp_sem, 1);
+
+	/* 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);
+}
+
+int hsmp_create_acpi_sysfs_if(struct device *dev)
+{
+	struct attribute_group *attr_grp;
+	u16 sock_ind;
+	int ret;
+
+	attr_grp = devm_kzalloc(dev, sizeof(struct attribute_group), GFP_KERNEL);
+	if (!attr_grp)
+		return -ENOMEM;
+
+	attr_grp->is_bin_visible = hsmp_is_sock_attr_visible;
+
+	ret = hsmp_get_uid(dev, &sock_ind);
+	if (ret)
+		return ret;
+
+	ret = hsmp_create_attr_list(attr_grp, dev, sock_ind);
+	if (ret)
+		return ret;
+
+	return devm_device_add_group(dev, attr_grp);
+}
+
+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 >= plat_dev.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;
+	}
+
+	return ret;
+}