include/linux/cacheinfo.h

   1 #ifndef _LINUX_CACHEINFO_H
   2 #define _LINUX_CACHEINFO_H
   3
   4 #include <linux/bitops.h>
   5 #include <linux/cpumask.h>
   6 #include <linux/smp.h>
   7
   8 struct device_node;
   9 struct attribute;
  10
  11 enum cache_type {
  12         CACHE_TYPE_NOCACHE = 0,
  13         CACHE_TYPE_INST = BIT(0),
  14         CACHE_TYPE_DATA = BIT(1),
  15         CACHE_TYPE_SEPARATE = CACHE_TYPE_INST | CACHE_TYPE_DATA,
  16         CACHE_TYPE_UNIFIED = BIT(2),
  17 };
  18
  19 /**
  20  * struct cacheinfo - represent a cache leaf node
  21  * @type: type of the cache - data, inst or unified
  22  * @level: represents the hierarchy in the multi-level cache
  23  * @coherency_line_size: size of each cache line usually representing
  24  *      the minimum amount of data that gets transferred from memory
  25  * @number_of_sets: total number of sets, a set is a collection of cache
  26  *      lines sharing the same index
  27  * @ways_of_associativity: number of ways in which a particular memory
  28  *      block can be placed in the cache
  29  * @physical_line_partition: number of physical cache lines sharing the
  30  *      same cachetag
  31  * @size: Total size of the cache
  32  * @shared_cpu_map: logical cpumask representing all the cpus sharing
  33  *      this cache node
  34  * @attributes: bitfield representing various cache attributes
  35  * @of_node: if devicetree is used, this represents either the cpu node in
  36  *      case there's no explicit cache node or the cache node itself in the
  37  *      device tree
  38  * @disable_sysfs: indicates whether this node is visible to the user via
  39  *      sysfs or not
  40  * @priv: pointer to any private data structure specific to particular
  41  *      cache design
  42  *
  43  * While @of_node, @disable_sysfs and @priv are used for internal book
  44  * keeping, the remaining members form the core properties of the cache
  45  */
  46 struct cacheinfo {
  47         enum cache_type type;
  48         unsigned int level;
  49         unsigned int coherency_line_size;
  50         unsigned int number_of_sets;
  51         unsigned int ways_of_associativity;
  52         unsigned int physical_line_partition;
  53         unsigned int size;
  54         cpumask_t shared_cpu_map;
  55         unsigned int attributes;
  56 #define CACHE_WRITE_THROUGH     BIT(0)
  57 #define CACHE_WRITE_BACK        BIT(1)
  58 #define CACHE_WRITE_POLICY_MASK         \
  59         (CACHE_WRITE_THROUGH | CACHE_WRITE_BACK)
  60 #define CACHE_READ_ALLOCATE     BIT(2)
  61 #define CACHE_WRITE_ALLOCATE    BIT(3)
  62 #define CACHE_ALLOCATE_POLICY_MASK      \
  63         (CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE)
  64
  65         struct device_node *of_node;
  66         bool disable_sysfs;
  67         void *priv;
  68 };
  69
  70 struct cpu_cacheinfo {
  71         struct cacheinfo *info_list;
  72         unsigned int num_levels;
  73         unsigned int num_leaves;
  74 };
  75
  76 /*
  77  * Helpers to make sure "func" is executed on the cpu whose cache
  78  * attributes are being detected
  79  */
  80 #define DEFINE_SMP_CALL_CACHE_FUNCTION(func)                    \
  81 static inline void _##func(void *ret)                           \
  82 {                                                               \
  83         int cpu = smp_processor_id();                           \
  84         *(int *)ret = __##func(cpu);                            \
  85 }                                                               \
  86                                                                 \
  87 int func(unsigned int cpu)                                      \
  88 {                                                               \
  89         int ret;                                                \
  90         smp_call_function_single(cpu, _##func, &ret, true);     \
  91         return ret;                                             \
  92 }
  93
  94 struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
  95 int init_cache_level(unsigned int cpu);
  96 int populate_cache_leaves(unsigned int cpu);
  97
  98 const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
  99
 100 #endif /* _LINUX_CACHEINFO_H */