arch/s390/kernel/cache.c

Source file repositories/reference/linux-study-clean/arch/s390/kernel/cache.c

File Facts

System
Linux kernel
Corpus path
arch/s390/kernel/cache.c
Extension
.c
Size
4383 bytes
Lines
172
Domain
Architecture Layer
Bucket
arch/s390
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct cache_info {
	unsigned char	    : 4;
	unsigned char scope : 2;
	unsigned char type  : 2;
};

#define CACHE_MAX_LEVEL 8
union cache_topology {
	struct cache_info ci[CACHE_MAX_LEVEL];
	unsigned long raw;
};

static const char * const cache_type_string[] = {
	"",
	"Instruction",
	"Data",
	"",
	"Unified",
};

static const enum cache_type cache_type_map[] = {
	[CTYPE_SEPARATE] = CACHE_TYPE_SEPARATE,
	[CTYPE_DATA] = CACHE_TYPE_DATA,
	[CTYPE_INSTRUCTION] = CACHE_TYPE_INST,
	[CTYPE_UNIFIED] = CACHE_TYPE_UNIFIED,
};

void show_cacheinfo(struct seq_file *m)
{
	struct cpu_cacheinfo *this_cpu_ci;
	struct cacheinfo *cache;
	int idx;

	this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask));
	for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
		cache = this_cpu_ci->info_list + idx;
		seq_printf(m, "cache%-11d: ", idx);
		seq_printf(m, "level=%d ", cache->level);
		seq_printf(m, "type=%s ", cache_type_string[cache->type]);
		seq_printf(m, "scope=%s ",
			   cache->disable_sysfs ? "Shared" : "Private");
		seq_printf(m, "size=%dK ", cache->size >> 10);
		seq_printf(m, "line_size=%u ", cache->coherency_line_size);
		seq_printf(m, "associativity=%d", cache->ways_of_associativity);
		seq_puts(m, "\n");
	}
}

static inline enum cache_type get_cache_type(struct cache_info *ci, int level)
{
	if (level >= CACHE_MAX_LEVEL)
		return CACHE_TYPE_NOCACHE;
	ci += level;
	if (ci->scope != CACHE_SCOPE_SHARED && ci->scope != CACHE_SCOPE_PRIVATE)
		return CACHE_TYPE_NOCACHE;
	return cache_type_map[ci->type];
}

static inline unsigned long ecag(int ai, int li, int ti)
{
	return __ecag(ECAG_CACHE_ATTRIBUTE, ai << 4 | li << 1 | ti);
}

static void ci_leaf_init(struct cacheinfo *this_leaf, int private,
			 enum cache_type type, unsigned int level, int cpu)
{
	int ti, num_sets;

	if (type == CACHE_TYPE_INST)
		ti = CACHE_TI_INSTRUCTION;
	else
		ti = CACHE_TI_UNIFIED;
	this_leaf->level = level + 1;
	this_leaf->type = type;
	this_leaf->coherency_line_size = ecag(EXTRACT_LINE_SIZE, level, ti);
	this_leaf->ways_of_associativity = ecag(EXTRACT_ASSOCIATIVITY, level, ti);
	this_leaf->size = ecag(EXTRACT_SIZE, level, ti);
	num_sets = this_leaf->size / this_leaf->coherency_line_size;
	num_sets /= this_leaf->ways_of_associativity;
	this_leaf->number_of_sets = num_sets;
	cpumask_set_cpu(cpu, &this_leaf->shared_cpu_map);
	if (!private)
		this_leaf->disable_sysfs = true;
}

int init_cache_level(unsigned int cpu)
{
	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
	unsigned int level = 0, leaves = 0;
	union cache_topology ct;

Annotation

Implementation Notes