[PATCH 08/10] armv8: Add sysinfo driver for cache information

Raymond Mao raymond.mao at linaro.org
Fri Aug 16 17:46:51 CEST 2024


Add cache information sysinfo driver containing necessary information
required by SMBIOS type 7 for all armv8 platforms.

Signed-off-by: Raymond Mao <raymond.mao at linaro.org>
---
 arch/arm/cpu/armv8/sysinfo.c | 188 +++++++++++++++++++++++++++++++++++
 1 file changed, 188 insertions(+)

diff --git a/arch/arm/cpu/armv8/sysinfo.c b/arch/arm/cpu/armv8/sysinfo.c
index a8e17d654be..73e071212ae 100644
--- a/arch/arm/cpu/armv8/sysinfo.c
+++ b/arch/arm/cpu/armv8/sysinfo.c
@@ -13,6 +13,30 @@
 #define ELEMENT_RECORD_DATA_LEN 8
 #define ELEMENT_RECORD_NUM 2
 
+union ccsidr_el1 {
+	struct {
+		u64 linesize:3;
+		u64 associativity:10;
+		u64 numsets:15;
+		u64 unknown:4;
+		u64 reserved:32;
+	} no_ccidx;
+	struct {
+		u64 linesize:3;
+		u64 associativity:21;
+		u64 reserved1:8;
+		u64 numsets:24;
+		u64 reserved2:8;
+	} ccidx_aarch64;
+	struct {
+		u64 linesize:3;
+		u64 associativity:21;
+		u64 reserved:8;
+		u64 unallocated:32;
+	} ccidx_aarch32;
+	u64 data;
+};
+
 union midr_el1 {
 	struct {
 		u64 revision:4;
@@ -25,6 +49,28 @@ union midr_el1 {
 	u64 data;
 };
 
+enum {
+	CACHE_NONE,
+	CACHE_INST_ONLY,
+	CACHE_DATA_ONLY,
+	CACHE_INST_WITH_DATA,
+	CACHE_UNIFIED,
+};
+
+enum {
+	CACHE_ASSOC_DIRECT_MAPPED = 1,
+	CACHE_ASSOC_2WAY = 2,
+	CACHE_ASSOC_4WAY = 4,
+	CACHE_ASSOC_8WAY = 8,
+	CACHE_ASSOC_16WAY = 16,
+	CACHE_ASSOC_12WAY = 12,
+	CACHE_ASSOC_24WAY = 24,
+	CACHE_ASSOC_32WAY = 32,
+	CACHE_ASSOC_48WAY = 48,
+	CACHE_ASSOC_64WAY = 64,
+	CACHE_ASSOC_20WAY = 20,
+};
+
 enum {
 	VENDOR_RESERVED = 0,
 	VENDOR_ARM = 0x41,
@@ -47,6 +93,7 @@ struct __packed enclosure_element_record {
 	u8 data[ELEMENT_RECORD_DATA_LEN];
 };
 
+struct cache_info cache_info_armv8[SYSINFO_CACHE_LVL_MAX];
 struct processor_info processor_info_armv8;
 
 /* Default data for the enclosure contained elements */
@@ -65,6 +112,144 @@ struct enclosure_element_record contained_elements[ELEMENT_RECORD_NUM] = {
 	},
 };
 
+/*
+ * TODO:
+ * To support ARMv8.3, we need to read "CCIDX, bits [23:20]" from
+ * ID_AA64MMFR2_EL1 to get the format of CCSIDR_EL1:
+ *
+ * 0b0000 - 32-bit format implemented for all levels of the CCSIDR_EL1.
+ * 0b0001 - 64-bit format implemented for all levels of the CCSIDR_EL1.
+ *
+ * Here we assume to use CCSIDR_EL1 in no CCIDX layout:
+ * NumSets, bits [27:13]: (Number of sets in cache) - 1
+ * Associativity, bits [12:3]: (Associativity of cache) - 1
+ * LineSize, bits [2:0]: (Log2(Number of bytes in cache line)) - 4
+ */
+int sysinfo_get_cache_info(u8 level, struct cache_info *cinfo)
+{
+	u64 clidr_el1;
+	u32 csselr_el1;
+	u32 num_sets;
+	union ccsidr_el1 creg;
+	int cache_type;
+
+	sysinfo_cache_info_default(cinfo);
+
+	/* Read CLIDR_EL1 */
+	asm volatile("mrs %0, clidr_el1" : "=r" (clidr_el1));
+	log_debug("CLIDR_EL1: 0x%llx\n", clidr_el1);
+
+	cache_type = (clidr_el1 >> (3 * level)) & 0x7;
+	log_debug("cache_type:%d\n", cache_type);
+
+	if (cache_type == CACHE_NONE) /* level does not exist */
+		return -1;
+
+	switch (cache_type) {
+	case CACHE_INST_ONLY:
+		cinfo->cache_type = SMBIOS_CACHE_SYSCACHE_TYPE_INSTRUCTION;
+		break;
+	case CACHE_DATA_ONLY:
+		cinfo->cache_type = SMBIOS_CACHE_SYSCACHE_TYPE_DATA;
+		break;
+	case CACHE_UNIFIED:
+		cinfo->cache_type = SMBIOS_CACHE_SYSCACHE_TYPE_UNIFIED;
+		break;
+	case CACHE_INST_WITH_DATA:
+		cinfo->cache_type = SMBIOS_CACHE_SYSCACHE_TYPE_OTHER;
+		break;
+	default:
+		cinfo->cache_type = SMBIOS_CACHE_SYSCACHE_TYPE_UNKNOWN;
+		break;
+	}
+
+	/* Select cache level */
+	csselr_el1 = (level << 1);
+	asm volatile("msr csselr_el1, %0" : : "r" (csselr_el1));
+
+	/* Read CCSIDR_EL1 */
+	asm volatile("mrs %0, ccsidr_el1" : "=r" (creg.data));
+	log_debug("CCSIDR_EL1 (Level %d): 0x%llx\n", level + 1, creg.data);
+
+	/* Extract cache size and associativity */
+	cinfo->line_size = 1 << (creg.no_ccidx.linesize + 4);
+
+	/* Map the associativity value */
+	switch (creg.no_ccidx.associativity + 1) {
+	case CACHE_ASSOC_DIRECT_MAPPED:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_DMAPPED;
+		break;
+	case CACHE_ASSOC_2WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_2WAY;
+		break;
+	case CACHE_ASSOC_4WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_4WAY;
+		break;
+	case CACHE_ASSOC_8WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_8WAY;
+		break;
+	case CACHE_ASSOC_16WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_16WAY;
+		break;
+	case CACHE_ASSOC_12WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_12WAY;
+		break;
+	case CACHE_ASSOC_24WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_24WAY;
+		break;
+	case CACHE_ASSOC_32WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_32WAY;
+		break;
+	case CACHE_ASSOC_48WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_48WAY;
+		break;
+	case CACHE_ASSOC_64WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_64WAY;
+		break;
+	case CACHE_ASSOC_20WAY:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_20WAY;
+		break;
+	default:
+		cinfo->associativity = SMBIOS_CACHE_ASSOC_UNKNOWN;
+		break;
+	}
+
+	num_sets = creg.no_ccidx.numsets + 1;
+	/* Size in KB */
+	cinfo->max_size = (cinfo->associativity * num_sets * cinfo->line_size) /
+			  1024;
+
+	log_debug("L%d Cache:\n", level + 1);
+	log_debug("Number of bytes in cache line:%u\n", cinfo->line_size);
+	log_debug("Associativity of cache:%u\n", cinfo->associativity);
+	log_debug("Number of sets in cache:%u\n", num_sets);
+	log_debug("Cache size in KB:%u\n", cinfo->max_size);
+
+	cinfo->inst_size = cinfo->max_size;
+
+	/*
+	 * Below fields are set with default values for Arm arch,
+	 * More information are hardware platform specific.
+	 */
+	cinfo->socket_design = "Not Specified";
+	cinfo->config.fields.level = level;
+	/* Generally, "Not-Socketed" is for integrated caches */
+	cinfo->config.fields.bsocketed = SMBIOS_CACHE_UNSOCKETED;
+	/* For modern SoCs, L1/L2 cache are usually internal */
+	cinfo->config.fields.locate = SMBIOS_CACHE_LOCATE_INTERNAL;
+	cinfo->config.fields.benabled = SMBIOS_CACHE_ENABLED;
+	/* Generally, L1 and L2 caches are write-back */
+	cinfo->config.fields.opmode = SMBIOS_CACHE_OP_WB;
+
+	/*
+	 * Other fields are typically specific to the implementation of the ARM
+	 * processor by the silicon vendor:
+	 * supp_sram_type, curr_sram_type, speed, err_corr_type
+	 */
+
+	return 0;
+}
+
 int sysinfo_get_processor_info(struct processor_info *pinfo)
 {
 	u64 mpidr, core_count;
@@ -195,6 +380,9 @@ struct sysinfo_plat sysinfo_smbios_armv8 = {
 
 	/* Processor Information */
 	.processor = &processor_info_armv8,
+
+	/* Cache Information */
+	.cache = &cache_info_armv8[0],
 };
 
 U_BOOT_DRVINFO(sysinfo_smbios_plat) = {
-- 
2.25.1



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