ACPI / PPTT: cacheinfo: Label caches based on fw_token

hulk inclusion
category: feature
feature: ARM MPAM support
bugzilla: 48265
CVE: NA

--------------------------------

According to James's implementation: http://www.linux-arm.org/git?p=linux-
jm.git;a=commit;h=413eb4281b072e1ee60f88b814f2a418358f2155, "ACPI / PPTT:
cacheinfo: Label caches based on fw_token".

For resctrl ABI, cache node labeled by min_physid of leaf cpu node can
not be good recognized, for this, we use to label each cache node by
numa node id, it can be acquired by leaf cpu node with min_physid.

But there also has some problems when doing this, with current MPAM ACPI
Description 1.0, we haven't enough information to label those cache node
when using partition mode, we hope fixing that when getting unified des-
cription.
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/include/asm/acpi.h

@@ -100,6 +100,11 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
 void __init acpi_init_cpus(void);
 int apei_claim_sea(struct pt_regs *regs);
+void acpi_pptt_find_min_physid_cpu_node(struct acpi_table_header *table_hdr,
+			struct acpi_pptt_processor *cpu_node,
+			phys_cpuid_t *min_physid,
+			struct acpi_pptt_processor **min_cpu_node);
+
 #else
 static inline void acpi_init_cpus(void) { }
 static inline int apei_claim_sea(struct pt_regs *regs) { return -ENOENT; }

drivers/acpi/pptt.c

@@ -430,6 +430,61 @@ static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *ta
 	return found;
 }
 
+/**
+ * acpi_pptt_min_physid_from_cpu_node() - Recursivly find @min_physid for all
+ * leaf CPUs below @cpu_node.
+ * @table_hdr:  Pointer to the head of the PPTT table
+ * @cpu_node:   The point in the toplogy to start the walk
+ * @min_physid: The min_physid to update with leaf CPUs.
+ * @min_cpu_node: The min_cpu_node to update with leaf CPUs.
+ */
+void acpi_pptt_find_min_physid_cpu_node(struct acpi_table_header *table_hdr,
+			struct acpi_pptt_processor *cpu_node,
+			phys_cpuid_t *min_physid,
+			struct acpi_pptt_processor **min_cpu_node)
+{
+	bool leaf = true;
+	u32 acpi_processor_id;
+	phys_cpuid_t cpu_node_phys_id;
+	struct acpi_subtable_header *iter;
+	struct acpi_pptt_processor *iter_node = NULL;
+	u32 target_node = ACPI_PTR_DIFF(cpu_node, table_hdr);
+	u32 proc_sz = sizeof(struct acpi_pptt_processor *);
+	unsigned long table_end = (unsigned long)table_hdr + table_hdr->length;
+
+	/*
+	 * Walk the PPTT, looking for nodes that reference cpu_node
+	 * as parent.
+	 */
+	iter = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
+				sizeof(struct acpi_table_pptt));
+
+	while ((unsigned long)iter + proc_sz < table_end) {
+		iter_node = (struct acpi_pptt_processor *)iter;
+
+		if (iter->type == ACPI_PPTT_TYPE_PROCESSOR &&
+			iter_node->parent == target_node) {
+			leaf = false;
+			acpi_pptt_find_min_physid_cpu_node(table_hdr, iter_node,
+						min_physid, min_cpu_node);
+		}
+
+		if (iter->length == 0)
+			return;
+		iter = ACPI_ADD_PTR(struct acpi_subtable_header, iter,
+					iter->length);
+	}
+
+	acpi_processor_id = cpu_node->acpi_processor_id;
+	cpu_node_phys_id = acpi_id_to_phys_cpuid(acpi_processor_id);
+	if (!invalid_phys_cpuid(cpu_node_phys_id) &&
+		*min_physid > cpu_node_phys_id &&
+		leaf == true) {
+		*min_physid = cpu_node_phys_id;
+		*min_cpu_node = cpu_node;
+	}
+}
+
 /**
  * update_cache_properties() - Update cacheinfo for the given processor
  * @this_leaf: Kernel cache info structure being updated