[v3,1/4] acpi: Move common tables helper functions to common lib

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index ccbeab9500ec..320d36b2ec78 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -12,6 +12,7 @@  menuconfig ACPI
 	select PNP
 	select NLS
 	select CRC32
+	select FIRMWARE_TABLE
 	default y if X86
 	help
 	  Advanced Configuration and Power Interface (ACPI) support for 
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 7b4680da57d7..cfc76efd8788 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -37,18 +37,6 @@  static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
 
 static int acpi_apic_instance __initdata_or_acpilib;
 
-enum acpi_subtable_type {
-	ACPI_SUBTABLE_COMMON,
-	ACPI_SUBTABLE_HMAT,
-	ACPI_SUBTABLE_PRMT,
-	ACPI_SUBTABLE_CEDT,
-};
-
-struct acpi_subtable_entry {
-	union acpi_subtable_headers *hdr;
-	enum acpi_subtable_type type;
-};
-
 /*
  * Disable table checksum verification for the early stage due to the size
  * limitation of the current x86 early mapping implementation.
@@ -227,167 +215,6 @@  void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
 	}
 }
 
-static unsigned long __init_or_acpilib
-acpi_get_entry_type(struct acpi_subtable_entry *entry)
-{
-	switch (entry->type) {
-	case ACPI_SUBTABLE_COMMON:
-		return entry->hdr->common.type;
-	case ACPI_SUBTABLE_HMAT:
-		return entry->hdr->hmat.type;
-	case ACPI_SUBTABLE_PRMT:
-		return 0;
-	case ACPI_SUBTABLE_CEDT:
-		return entry->hdr->cedt.type;
-	}
-	return 0;
-}
-
-static unsigned long __init_or_acpilib
-acpi_get_entry_length(struct acpi_subtable_entry *entry)
-{
-	switch (entry->type) {
-	case ACPI_SUBTABLE_COMMON:
-		return entry->hdr->common.length;
-	case ACPI_SUBTABLE_HMAT:
-		return entry->hdr->hmat.length;
-	case ACPI_SUBTABLE_PRMT:
-		return entry->hdr->prmt.length;
-	case ACPI_SUBTABLE_CEDT:
-		return entry->hdr->cedt.length;
-	}
-	return 0;
-}
-
-static unsigned long __init_or_acpilib
-acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
-{
-	switch (entry->type) {
-	case ACPI_SUBTABLE_COMMON:
-		return sizeof(entry->hdr->common);
-	case ACPI_SUBTABLE_HMAT:
-		return sizeof(entry->hdr->hmat);
-	case ACPI_SUBTABLE_PRMT:
-		return sizeof(entry->hdr->prmt);
-	case ACPI_SUBTABLE_CEDT:
-		return sizeof(entry->hdr->cedt);
-	}
-	return 0;
-}
-
-static enum acpi_subtable_type __init_or_acpilib
-acpi_get_subtable_type(char *id)
-{
-	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
-		return ACPI_SUBTABLE_HMAT;
-	if (strncmp(id, ACPI_SIG_PRMT, 4) == 0)
-		return ACPI_SUBTABLE_PRMT;
-	if (strncmp(id, ACPI_SIG_CEDT, 4) == 0)
-		return ACPI_SUBTABLE_CEDT;
-	return ACPI_SUBTABLE_COMMON;
-}
-
-static __init_or_acpilib bool has_handler(struct acpi_subtable_proc *proc)
-{
-	return proc->handler || proc->handler_arg;
-}
-
-static __init_or_acpilib int call_handler(struct acpi_subtable_proc *proc,
-					  union acpi_subtable_headers *hdr,
-					  unsigned long end)
-{
-	if (proc->handler)
-		return proc->handler(hdr, end);
-	if (proc->handler_arg)
-		return proc->handler_arg(hdr, proc->arg, end);
-	return -EINVAL;
-}
-
-/**
- * acpi_parse_entries_array - for each proc_num find a suitable subtable
- *
- * @id: table id (for debugging purposes)
- * @table_size: size of the root table
- * @table_header: where does the table start?
- * @proc: array of acpi_subtable_proc struct containing entry id
- *        and associated handler with it
- * @proc_num: how big proc is?
- * @max_entries: how many entries can we process?
- *
- * For each proc_num find a subtable with proc->id and run proc->handler
- * on it. Assumption is that there's only single handler for particular
- * entry id.
- *
- * The table_size is not the size of the complete ACPI table (the length
- * field in the header struct), but only the size of the root table; i.e.,
- * the offset from the very first byte of the complete ACPI table, to the
- * first byte of the very first subtable.
- *
- * On success returns sum of all matching entries for all proc handlers.
- * Otherwise, -ENODEV or -EINVAL is returned.
- */
-static int __init_or_acpilib acpi_parse_entries_array(
-	char *id, unsigned long table_size,
-	struct acpi_table_header *table_header, struct acpi_subtable_proc *proc,
-	int proc_num, unsigned int max_entries)
-{
-	struct acpi_subtable_entry entry;
-	unsigned long table_end, subtable_len, entry_len;
-	int count = 0;
-	int errs = 0;
-	int i;
-
-	table_end = (unsigned long)table_header + table_header->length;
-
-	/* Parse all entries looking for a match. */
-
-	entry.type = acpi_get_subtable_type(id);
-	entry.hdr = (union acpi_subtable_headers *)
-	    ((unsigned long)table_header + table_size);
-	subtable_len = acpi_get_subtable_header_length(&entry);
-
-	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
-		if (max_entries && count >= max_entries)
-			break;
-
-		for (i = 0; i < proc_num; i++) {
-			if (acpi_get_entry_type(&entry) != proc[i].id)
-				continue;
-			if (!has_handler(&proc[i]) ||
-			    (!errs &&
-			     call_handler(&proc[i], entry.hdr, table_end))) {
-				errs++;
-				continue;
-			}
-
-			proc[i].count++;
-			break;
-		}
-		if (i != proc_num)
-			count++;
-
-		/*
-		 * If entry->length is 0, break from this loop to avoid
-		 * infinite loop.
-		 */
-		entry_len = acpi_get_entry_length(&entry);
-		if (entry_len == 0) {
-			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
-			return -EINVAL;
-		}
-
-		entry.hdr = (union acpi_subtable_headers *)
-		    ((unsigned long)entry.hdr + entry_len);
-	}
-
-	if (max_entries && count > max_entries) {
-		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
-			id, proc->id, count);
-	}
-
-	return errs ? -EINVAL : count;
-}
-
 int __init_or_acpilib acpi_table_parse_entries_array(
 	char *id, unsigned long table_size, struct acpi_subtable_proc *proc,
 	int proc_num, unsigned int max_entries)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 7b71dd74baeb..57004cd0a7a3 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -15,6 +15,7 @@ 
 #include <linux/mod_devicetable.h>
 #include <linux/property.h>
 #include <linux/uuid.h>
+#include <linux/fw_table.h>
 
 struct irq_domain;
 struct irq_domain_ops;
@@ -132,21 +133,8 @@  enum acpi_address_range_id {
 
 
 /* Table Handlers */
-union acpi_subtable_headers {
-	struct acpi_subtable_header common;
-	struct acpi_hmat_structure hmat;
-	struct acpi_prmt_module_header prmt;
-	struct acpi_cedt_header cedt;
-};
-
 typedef int (*acpi_tbl_table_handler)(struct acpi_table_header *table);
 
-typedef int (*acpi_tbl_entry_handler)(union acpi_subtable_headers *header,
-				      const unsigned long end);
-
-typedef int (*acpi_tbl_entry_handler_arg)(union acpi_subtable_headers *header,
-					  void *arg, const unsigned long end);
-
 /* Debugger support */
 
 struct acpi_debugger_ops {
@@ -220,14 +208,6 @@  static inline int acpi_debugger_notify_command_complete(void)
 		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
 		((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
 
-struct acpi_subtable_proc {
-	int id;
-	acpi_tbl_entry_handler handler;
-	acpi_tbl_entry_handler_arg handler_arg;
-	void *arg;
-	int count;
-};
-
 void __iomem *__acpi_map_table(unsigned long phys, unsigned long size);
 void __acpi_unmap_table(void __iomem *map, unsigned long size);
 int early_acpi_boot_init(void);
diff --git a/include/linux/fw_table.h b/include/linux/fw_table.h
new file mode 100644
index 000000000000..ff8fa58d5818
--- /dev/null
+++ b/include/linux/fw_table.h
@@ -0,0 +1,43 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  fw_tables.h - Parsing support for ACPI and ACPI-like tables provided by
+ *                platform or device firmware
+ *
+ *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2023 Intel Corp.
+ */
+#ifndef _FW_TABLE_H_
+#define _FW_TABLE_H_
+
+union acpi_subtable_headers;
+
+typedef int (*acpi_tbl_entry_handler)(union acpi_subtable_headers *header,
+				      const unsigned long end);
+
+typedef int (*acpi_tbl_entry_handler_arg)(union acpi_subtable_headers *header,
+					  void *arg, const unsigned long end);
+
+struct acpi_subtable_proc {
+	int id;
+	acpi_tbl_entry_handler handler;
+	acpi_tbl_entry_handler_arg handler_arg;
+	void *arg;
+	int count;
+};
+
+#include <linux/acpi.h>
+#include <acpi/acpi.h>
+
+union acpi_subtable_headers {
+	struct acpi_subtable_header common;
+	struct acpi_hmat_structure hmat;
+	struct acpi_prmt_module_header prmt;
+	struct acpi_cedt_header cedt;
+};
+
+int acpi_parse_entries_array(char *id, unsigned long table_size,
+			     struct acpi_table_header *table_header,
+			     struct acpi_subtable_proc *proc,
+			     int proc_num, unsigned int max_entries);
+
+#endif
diff --git a/lib/Kconfig b/lib/Kconfig
index 5c2da561c516..b03714d45444 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -763,3 +763,6 @@  config ASN1_ENCODER
 
 config POLYNOMIAL
        tristate
+
+config FIRMWARE_TABLE
+	bool
diff --git a/lib/Makefile b/lib/Makefile
index 876fcdeae34e..16e238baef4b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -397,6 +397,8 @@  obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
 
 obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
 
+obj-$(CONFIG_FIRMWARE_TABLE) += fw_table.o
+
 # FORTIFY_SOURCE compile-time behavior tests
 TEST_FORTIFY_SRCS = $(wildcard $(srctree)/$(src)/test_fortify/*-*.c)
 TEST_FORTIFY_LOGS = $(patsubst $(srctree)/$(src)/%.c, %.log, $(TEST_FORTIFY_SRCS))
diff --git a/lib/fw_table.c b/lib/fw_table.c
new file mode 100644
index 000000000000..e84bd0866e10
--- /dev/null
+++ b/lib/fw_table.c
@@ -0,0 +1,189 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  fw_tables.c - Parsing support for ACPI and ACPI-like tables provided by
+ *                platform or device firmware
+ *
+ *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2023 Intel Corp.
+ */
+#include <linux/errno.h>
+#include <linux/fw_table.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+enum acpi_subtable_type {
+	ACPI_SUBTABLE_COMMON,
+	ACPI_SUBTABLE_HMAT,
+	ACPI_SUBTABLE_PRMT,
+	ACPI_SUBTABLE_CEDT,
+};
+
+struct acpi_subtable_entry {
+	union acpi_subtable_headers *hdr;
+	enum acpi_subtable_type type;
+};
+
+static unsigned long __init_or_acpilib
+acpi_get_entry_type(struct acpi_subtable_entry *entry)
+{
+	switch (entry->type) {
+	case ACPI_SUBTABLE_COMMON:
+		return entry->hdr->common.type;
+	case ACPI_SUBTABLE_HMAT:
+		return entry->hdr->hmat.type;
+	case ACPI_SUBTABLE_PRMT:
+		return 0;
+	case ACPI_SUBTABLE_CEDT:
+		return entry->hdr->cedt.type;
+	}
+	return 0;
+}
+
+static unsigned long __init_or_acpilib
+acpi_get_entry_length(struct acpi_subtable_entry *entry)
+{
+	switch (entry->type) {
+	case ACPI_SUBTABLE_COMMON:
+		return entry->hdr->common.length;
+	case ACPI_SUBTABLE_HMAT:
+		return entry->hdr->hmat.length;
+	case ACPI_SUBTABLE_PRMT:
+		return entry->hdr->prmt.length;
+	case ACPI_SUBTABLE_CEDT:
+		return entry->hdr->cedt.length;
+	}
+	return 0;
+}
+
+static unsigned long __init_or_acpilib
+acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
+{
+	switch (entry->type) {
+	case ACPI_SUBTABLE_COMMON:
+		return sizeof(entry->hdr->common);
+	case ACPI_SUBTABLE_HMAT:
+		return sizeof(entry->hdr->hmat);
+	case ACPI_SUBTABLE_PRMT:
+		return sizeof(entry->hdr->prmt);
+	case ACPI_SUBTABLE_CEDT:
+		return sizeof(entry->hdr->cedt);
+	}
+	return 0;
+}
+
+static enum acpi_subtable_type __init_or_acpilib
+acpi_get_subtable_type(char *id)
+{
+	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
+		return ACPI_SUBTABLE_HMAT;
+	if (strncmp(id, ACPI_SIG_PRMT, 4) == 0)
+		return ACPI_SUBTABLE_PRMT;
+	if (strncmp(id, ACPI_SIG_CEDT, 4) == 0)
+		return ACPI_SUBTABLE_CEDT;
+	return ACPI_SUBTABLE_COMMON;
+}
+
+static __init_or_acpilib bool has_handler(struct acpi_subtable_proc *proc)
+{
+	return proc->handler || proc->handler_arg;
+}
+
+static __init_or_acpilib int call_handler(struct acpi_subtable_proc *proc,
+					  union acpi_subtable_headers *hdr,
+					  unsigned long end)
+{
+	if (proc->handler)
+		return proc->handler(hdr, end);
+	if (proc->handler_arg)
+		return proc->handler_arg(hdr, proc->arg, end);
+	return -EINVAL;
+}
+
+/**
+ * acpi_parse_entries_array - for each proc_num find a suitable subtable
+ *
+ * @id: table id (for debugging purposes)
+ * @table_size: size of the root table
+ * @table_header: where does the table start?
+ * @proc: array of acpi_subtable_proc struct containing entry id
+ *        and associated handler with it
+ * @proc_num: how big proc is?
+ * @max_entries: how many entries can we process?
+ *
+ * For each proc_num find a subtable with proc->id and run proc->handler
+ * on it. Assumption is that there's only single handler for particular
+ * entry id.
+ *
+ * The table_size is not the size of the complete ACPI table (the length
+ * field in the header struct), but only the size of the root table; i.e.,
+ * the offset from the very first byte of the complete ACPI table, to the
+ * first byte of the very first subtable.
+ *
+ * On success returns sum of all matching entries for all proc handlers.
+ * Otherwise, -ENODEV or -EINVAL is returned.
+ */
+int __init_or_acpilib
+acpi_parse_entries_array(char *id, unsigned long table_size,
+			 struct acpi_table_header *table_header,
+			 struct acpi_subtable_proc *proc,
+			 int proc_num, unsigned int max_entries)
+{
+	unsigned long table_end, subtable_len, entry_len;
+	struct acpi_subtable_entry entry;
+	int count = 0;
+	int errs = 0;
+	int i;
+
+	table_end = (unsigned long)table_header + table_header->length;
+
+	/* Parse all entries looking for a match. */
+
+	entry.type = acpi_get_subtable_type(id);
+	entry.hdr = (union acpi_subtable_headers *)
+	    ((unsigned long)table_header + table_size);
+	subtable_len = acpi_get_subtable_header_length(&entry);
+
+	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
+		if (max_entries && count >= max_entries)
+			break;
+
+		for (i = 0; i < proc_num; i++) {
+			if (acpi_get_entry_type(&entry) != proc[i].id)
+				continue;
+			if (!has_handler(&proc[i]) ||
+			    (!errs &&
+			     call_handler(&proc[i], entry.hdr, table_end))) {
+				errs++;
+				continue;
+			}
+
+			proc[i].count++;
+			break;
+		}
+		if (i != proc_num)
+			count++;
+
+		/*
+		 * If entry->length is 0, break from this loop to avoid
+		 * infinite loop.
+		 */
+		entry_len = acpi_get_entry_length(&entry);
+		if (entry_len == 0) {
+			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
+			return -EINVAL;
+		}
+
+		entry.hdr = (union acpi_subtable_headers *)
+		    ((unsigned long)entry.hdr + entry_len);
+	}
+
+	if (max_entries && count > max_entries) {
+		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
+			id, proc->id, count);
+	}
+
+	return errs ? -EINVAL : count;
+}
+EXPORT_SYMBOL_GPL(acpi_parse_entries_array);