Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index da031b1..f31544d 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -164,7 +164,7 @@
 }
 
 /**
- * acpi_count_levels() - Given a PPTT table, and a cpu node, count the caches
+ * acpi_count_levels() - Given a PPTT table, and a CPU node, count the caches
  * @table_hdr: Pointer to the head of the PPTT table
  * @cpu_node: processor node we wish to count caches for
  *
@@ -209,6 +209,9 @@
 	struct acpi_pptt_processor *cpu_node;
 	u32 proc_sz;
 
+	if (table_hdr->revision > 1)
+		return (node->flags & ACPI_PPTT_ACPI_LEAF_NODE);
+
 	table_end = (unsigned long)table_hdr + table_hdr->length;
 	node_entry = ACPI_PTR_DIFF(node, table_hdr);
 	entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
@@ -232,7 +235,7 @@
 /**
  * acpi_find_processor_node() - Given a PPTT table find the requested processor
  * @table_hdr:  Pointer to the head of the PPTT table
- * @acpi_cpu_id: cpu we are searching for
+ * @acpi_cpu_id: CPU we are searching for
  *
  * Find the subtable entry describing the provided processor.
  * This is done by iterating the PPTT table looking for processor nodes
@@ -429,17 +432,40 @@
 	}
 }
 
+static bool flag_identical(struct acpi_table_header *table_hdr,
+			   struct acpi_pptt_processor *cpu)
+{
+	struct acpi_pptt_processor *next;
+
+	/* heterogeneous machines must use PPTT revision > 1 */
+	if (table_hdr->revision < 2)
+		return false;
+
+	/* Locate the last node in the tree with IDENTICAL set */
+	if (cpu->flags & ACPI_PPTT_ACPI_IDENTICAL) {
+		next = fetch_pptt_node(table_hdr, cpu->parent);
+		if (!(next && next->flags & ACPI_PPTT_ACPI_IDENTICAL))
+			return true;
+	}
+
+	return false;
+}
+
 /* Passing level values greater than this will result in search termination */
 #define PPTT_ABORT_PACKAGE 0xFF
 
-static struct acpi_pptt_processor *acpi_find_processor_package_id(struct acpi_table_header *table_hdr,
-								  struct acpi_pptt_processor *cpu,
-								  int level, int flag)
+static struct acpi_pptt_processor *acpi_find_processor_tag(struct acpi_table_header *table_hdr,
+							   struct acpi_pptt_processor *cpu,
+							   int level, int flag)
 {
 	struct acpi_pptt_processor *prev_node;
 
 	while (cpu && level) {
-		if (cpu->flags & flag)
+		/* special case the identical flag to find last identical */
+		if (flag == ACPI_PPTT_ACPI_IDENTICAL) {
+			if (flag_identical(table_hdr, cpu))
+				break;
+		} else if (cpu->flags & flag)
 			break;
 		pr_debug("level %d\n", level);
 		prev_node = fetch_pptt_node(table_hdr, cpu->parent);
@@ -451,18 +477,23 @@
 	return cpu;
 }
 
+static void acpi_pptt_warn_missing(void)
+{
+	pr_warn_once("No PPTT table found, CPU and cache topology may be inaccurate\n");
+}
+
 /**
  * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature
  * @table: Pointer to the head of the PPTT table
- * @cpu: Kernel logical cpu number
+ * @cpu: Kernel logical CPU number
  * @level: A level that terminates the search
  * @flag: A flag which terminates the search
  *
- * Get a unique value given a cpu, and a topology level, that can be
+ * Get a unique value given a CPU, and a topology level, that can be
  * matched to determine which cpus share common topological features
  * at that level.
  *
- * Return: Unique value, or -ENOENT if unable to locate cpu
+ * Return: Unique value, or -ENOENT if unable to locate CPU
  */
 static int topology_get_acpi_cpu_tag(struct acpi_table_header *table,
 				     unsigned int cpu, int level, int flag)
@@ -472,8 +503,8 @@
 
 	cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
 	if (cpu_node) {
-		cpu_node = acpi_find_processor_package_id(table, cpu_node,
-							  level, flag);
+		cpu_node = acpi_find_processor_tag(table, cpu_node,
+						   level, flag);
 		/*
 		 * As per specification if the processor structure represents
 		 * an actual processor, then ACPI processor ID must be valid.
@@ -498,11 +529,11 @@
 
 	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
 	if (ACPI_FAILURE(status)) {
-		pr_warn_once("No PPTT table found, cpu topology may be inaccurate\n");
+		acpi_pptt_warn_missing();
 		return -ENOENT;
 	}
 	retval = topology_get_acpi_cpu_tag(table, cpu, level, flag);
-	pr_debug("Topology Setup ACPI cpu %d, level %d ret = %d\n",
+	pr_debug("Topology Setup ACPI CPU %d, level %d ret = %d\n",
 		 cpu, level, retval);
 	acpi_put_table(table);
 
@@ -510,10 +541,48 @@
 }
 
 /**
- * acpi_find_last_cache_level() - Determines the number of cache levels for a PE
- * @cpu: Kernel logical cpu number
+ * check_acpi_cpu_flag() - Determine if CPU node has a flag set
+ * @cpu: Kernel logical CPU number
+ * @rev: The minimum PPTT revision defining the flag
+ * @flag: The flag itself
  *
- * Given a logical cpu number, returns the number of levels of cache represented
+ * Check the node representing a CPU for a given flag.
+ *
+ * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or
+ *	   the table revision isn't new enough.
+ *	   1, any passed flag set
+ *	   0, flag unset
+ */
+static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
+{
+	struct acpi_table_header *table;
+	acpi_status status;
+	u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+	struct acpi_pptt_processor *cpu_node = NULL;
+	int ret = -ENOENT;
+
+	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
+	if (ACPI_FAILURE(status)) {
+		acpi_pptt_warn_missing();
+		return ret;
+	}
+
+	if (table->revision >= rev)
+		cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
+
+	if (cpu_node)
+		ret = (cpu_node->flags & flag) != 0;
+
+	acpi_put_table(table);
+
+	return ret;
+}
+
+/**
+ * acpi_find_last_cache_level() - Determines the number of cache levels for a PE
+ * @cpu: Kernel logical CPU number
+ *
+ * Given a logical CPU number, returns the number of levels of cache represented
  * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0
  * indicating we didn't find any cache levels.
  *
@@ -526,12 +595,12 @@
 	int number_of_levels = 0;
 	acpi_status status;
 
-	pr_debug("Cache Setup find last level cpu=%d\n", cpu);
+	pr_debug("Cache Setup find last level CPU=%d\n", cpu);
 
 	acpi_cpu_id = get_acpi_id_for_cpu(cpu);
 	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
 	if (ACPI_FAILURE(status)) {
-		pr_warn_once("No PPTT table found, cache topology may be inaccurate\n");
+		acpi_pptt_warn_missing();
 	} else {
 		number_of_levels = acpi_find_cache_levels(table, acpi_cpu_id);
 		acpi_put_table(table);
@@ -543,14 +612,14 @@
 
 /**
  * cache_setup_acpi() - Override CPU cache topology with data from the PPTT
- * @cpu: Kernel logical cpu number
+ * @cpu: Kernel logical CPU number
  *
  * Updates the global cache info provided by cpu_get_cacheinfo()
  * when there are valid properties in the acpi_pptt_cache nodes. A
  * successful parse may not result in any updates if none of the
- * cache levels have any valid flags set.  Futher, a unique value is
+ * cache levels have any valid flags set.  Further, a unique value is
  * associated with each known CPU cache entry. This unique value
- * can be used to determine whether caches are shared between cpus.
+ * can be used to determine whether caches are shared between CPUs.
  *
  * Return: -ENOENT on failure to find table, or 0 on success
  */
@@ -559,11 +628,11 @@
 	struct acpi_table_header *table;
 	acpi_status status;
 
-	pr_debug("Cache Setup ACPI cpu %d\n", cpu);
+	pr_debug("Cache Setup ACPI CPU %d\n", cpu);
 
 	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
 	if (ACPI_FAILURE(status)) {
-		pr_warn_once("No PPTT table found, cache topology may be inaccurate\n");
+		acpi_pptt_warn_missing();
 		return -ENOENT;
 	}
 
@@ -574,8 +643,22 @@
 }
 
 /**
- * find_acpi_cpu_topology() - Determine a unique topology value for a given cpu
- * @cpu: Kernel logical cpu number
+ * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread
+ * @cpu: Kernel logical CPU number
+ *
+ * Return: 1, a thread
+ *         0, not a thread
+ *         -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or
+ *         the table revision isn't new enough.
+ */
+int acpi_pptt_cpu_is_thread(unsigned int cpu)
+{
+	return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD);
+}
+
+/**
+ * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU
+ * @cpu: Kernel logical CPU number
  * @level: The topological level for which we would like a unique ID
  *
  * Determine a topology unique ID for each thread/core/cluster/mc_grouping
@@ -588,7 +671,7 @@
  * other levels beyond this use a generated value to uniquely identify
  * a topological feature.
  *
- * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found.
+ * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
  * Otherwise returns a value which represents a unique topological feature.
  */
 int find_acpi_cpu_topology(unsigned int cpu, int level)
@@ -598,12 +681,12 @@
 
 /**
  * find_acpi_cpu_cache_topology() - Determine a unique cache topology value
- * @cpu: Kernel logical cpu number
+ * @cpu: Kernel logical CPU number
  * @level: The cache level for which we would like a unique ID
  *
  * Determine a unique ID for each unified cache in the system
  *
- * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found.
+ * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
  * Otherwise returns a value which represents a unique topological feature.
  */
 int find_acpi_cpu_cache_topology(unsigned int cpu, int level)
@@ -617,7 +700,7 @@
 
 	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
 	if (ACPI_FAILURE(status)) {
-		pr_warn_once("No PPTT table found, topology may be inaccurate\n");
+		acpi_pptt_warn_missing();
 		return -ENOENT;
 	}
 
@@ -633,22 +716,47 @@
 	return ret;
 }
 
-
 /**
- * find_acpi_cpu_topology_package() - Determine a unique cpu package value
- * @cpu: Kernel logical cpu number
+ * find_acpi_cpu_topology_package() - Determine a unique CPU package value
+ * @cpu: Kernel logical CPU number
  *
- * Determine a topology unique package ID for the given cpu.
+ * Determine a topology unique package ID for the given CPU.
  * This ID can then be used to group peers, which will have matching ids.
  *
  * The search terminates when either a level is found with the PHYSICAL_PACKAGE
  * flag set or we reach a root node.
  *
- * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found.
- * Otherwise returns a value which represents the package for this cpu.
+ * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
+ * Otherwise returns a value which represents the package for this CPU.
  */
 int find_acpi_cpu_topology_package(unsigned int cpu)
 {
 	return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
 					  ACPI_PPTT_PHYSICAL_PACKAGE);
 }
+
+/**
+ * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag
+ * @cpu: Kernel logical CPU number
+ *
+ * Determine a unique heterogeneous tag for the given CPU. CPUs with the same
+ * implementation should have matching tags.
+ *
+ * The returned tag can be used to group peers with identical implementation.
+ *
+ * The search terminates when a level is found with the identical implementation
+ * flag set or we reach a root node.
+ *
+ * Due to limitations in the PPTT data structure, there may be rare situations
+ * where two cores in a heterogeneous machine may be identical, but won't have
+ * the same tag.
+ *
+ * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
+ * Otherwise returns a value which represents a group of identical cores
+ * similar to this CPU.
+ */
+int find_acpi_cpu_topology_hetero_id(unsigned int cpu)
+{
+	return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
+					  ACPI_PPTT_ACPI_IDENTICAL);
+}