diff options
Diffstat (limited to 'arch/x86/kernel/ds.c')
| -rw-r--r-- | arch/x86/kernel/ds.c | 142 |
1 files changed, 80 insertions, 62 deletions
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c index d9cab716805..7363e01ba08 100644 --- a/arch/x86/kernel/ds.c +++ b/arch/x86/kernel/ds.c @@ -19,43 +19,52 @@ * Markus Metzger <markus.t.metzger@intel.com>, 2007-2009 */ - -#include <asm/ds.h> - -#include <linux/errno.h> +#include <linux/kernel.h> #include <linux/string.h> -#include <linux/slab.h> +#include <linux/errno.h> #include <linux/sched.h> +#include <linux/slab.h> #include <linux/mm.h> -#include <linux/kernel.h> + +#include <asm/ds.h> #include "ds_selftest.h" /* - * The configuration for a particular DS hardware implementation. + * The configuration for a particular DS hardware implementation: */ struct ds_configuration { - /* The name of the configuration. */ - const char *name; - /* The size of pointer-typed fields in DS, BTS, and PEBS. */ - unsigned char sizeof_ptr_field; - /* The size of a BTS/PEBS record in bytes. */ - unsigned char sizeof_rec[2]; - /* Control bit-masks indexed by enum ds_feature. */ - unsigned long ctl[dsf_ctl_max]; + /* The name of the configuration: */ + const char *name; + + /* The size of pointer-typed fields in DS, BTS, and PEBS: */ + unsigned char sizeof_ptr_field; + + /* The size of a BTS/PEBS record in bytes: */ + unsigned char sizeof_rec[2]; + + /* Control bit-masks indexed by enum ds_feature: */ + unsigned long ctl[dsf_ctl_max]; }; static DEFINE_PER_CPU(struct ds_configuration, ds_cfg_array); #define ds_cfg per_cpu(ds_cfg_array, smp_processor_id()) -#define MAX_SIZEOF_DS (12 * 8) /* Maximal size of a DS configuration. */ -#define MAX_SIZEOF_BTS (3 * 8) /* Maximal size of a BTS record. */ -#define DS_ALIGNMENT (1 << 3) /* BTS and PEBS buffer alignment. */ +/* Maximal size of a DS configuration: */ +#define MAX_SIZEOF_DS (12 * 8) -#define BTS_CONTROL \ - (ds_cfg.ctl[dsf_bts] | ds_cfg.ctl[dsf_bts_kernel] | ds_cfg.ctl[dsf_bts_user] |\ - ds_cfg.ctl[dsf_bts_overflow]) +/* Maximal size of a BTS record: */ +#define MAX_SIZEOF_BTS (3 * 8) +/* BTS and PEBS buffer alignment: */ +#define DS_ALIGNMENT (1 << 3) + +/* Mask of control bits in the DS MSR register: */ +#define BTS_CONTROL \ + ( ds_cfg.ctl[dsf_bts] | \ + ds_cfg.ctl[dsf_bts_kernel] | \ + ds_cfg.ctl[dsf_bts_user] | \ + ds_cfg.ctl[dsf_bts_overflow] ) /* * A BTS or PEBS tracer. @@ -65,28 +74,32 @@ static DEFINE_PER_CPU(struct ds_configuration, ds_cfg_array); */ struct ds_tracer { /* The DS context (partially) owned by this tracer. */ - struct ds_context *context; + struct ds_context *context; /* The buffer provided on ds_request() and its size in bytes. */ - void *buffer; - size_t size; + void *buffer; + size_t size; }; struct bts_tracer { - /* The common DS part. */ - struct ds_tracer ds; - /* The trace including the DS configuration. */ - struct bts_trace trace; - /* Buffer overflow notification function. */ - bts_ovfl_callback_t ovfl; + /* The common DS part: */ + struct ds_tracer ds; + + /* The trace including the DS configuration: */ + struct bts_trace trace; + + /* Buffer overflow notification function: */ + bts_ovfl_callback_t ovfl; }; struct pebs_tracer { - /* The common DS part. */ - struct ds_tracer ds; - /* The trace including the DS configuration. */ - struct pebs_trace trace; - /* Buffer overflow notification function. */ - pebs_ovfl_callback_t ovfl; + /* The common DS part: */ + struct ds_tracer ds; + + /* The trace including the DS configuration: */ + struct pebs_trace trace; + + /* Buffer overflow notification function: */ + pebs_ovfl_callback_t ovfl; }; /* @@ -95,6 +108,7 @@ struct pebs_tracer { * * The DS configuration consists of the following fields; different * architetures vary in the size of those fields. + * * - double-word aligned base linear address of the BTS buffer * - write pointer into the BTS buffer * - end linear address of the BTS buffer (one byte beyond the end of @@ -133,19 +147,20 @@ enum ds_field { }; enum ds_qualifier { - ds_bts = 0, + ds_bts = 0, ds_pebs }; -static inline unsigned long ds_get(const unsigned char *base, - enum ds_qualifier qual, enum ds_field field) +static inline unsigned long +ds_get(const unsigned char *base, enum ds_qualifier qual, enum ds_field field) { base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual))); return *(unsigned long *)base; } -static inline void ds_set(unsigned char *base, enum ds_qualifier qual, - enum ds_field field, unsigned long value) +static inline void +ds_set(unsigned char *base, enum ds_qualifier qual, enum ds_field field, + unsigned long value) { base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual))); (*(unsigned long *)base) = value; @@ -157,7 +172,6 @@ static inline void ds_set(unsigned char *base, enum ds_qualifier qual, */ static DEFINE_SPINLOCK(ds_lock); - /* * We either support (system-wide) per-cpu or per-thread allocation. * We distinguish the two based on the task_struct pointer, where a @@ -211,17 +225,21 @@ static inline int check_tracer(struct task_struct *task) * deallocated when the last user puts the context. */ struct ds_context { - /* The DS configuration; goes into MSR_IA32_DS_AREA. */ - unsigned char ds[MAX_SIZEOF_DS]; - /* The owner of the BTS and PEBS configuration, respectively. */ - struct bts_tracer *bts_master; - struct pebs_tracer *pebs_master; - /* Use count. */ + /* The DS configuration; goes into MSR_IA32_DS_AREA: */ + unsigned char ds[MAX_SIZEOF_DS]; + + /* The owner of the BTS and PEBS configuration, respectively: */ + struct bts_tracer *bts_master; + struct pebs_tracer *pebs_master; + + /* Use count: */ unsigned long count; - /* Pointer to the context pointer field. */ - struct ds_context **this; - /* The traced task; NULL for current cpu. */ - struct task_struct *task; + + /* Pointer to the context pointer field: */ + struct ds_context **this; + + /* The traced task; NULL for current cpu: */ + struct task_struct *task; }; static DEFINE_PER_CPU(struct ds_context *, system_context_array); @@ -328,9 +346,9 @@ static void ds_overflow(struct ds_context *context, enum ds_qualifier qual) * The remainder of any partially written record is zeroed out. * * context: the DS context - * qual: the buffer type - * record: the data to write - * size: the size of the data + * qual: the buffer type + * record: the data to write + * size: the size of the data */ static int ds_write(struct ds_context *context, enum ds_qualifier qual, const void *record, size_t size) @@ -429,12 +447,12 @@ enum bts_field { bts_to, bts_flags, - bts_qual = bts_from, - bts_jiffies = bts_to, - bts_pid = bts_flags, + bts_qual = bts_from, + bts_jiffies = bts_to, + bts_pid = bts_flags, - bts_qual_mask = (bts_qual_max - 1), - bts_escape = ((unsigned long)-1 & ~bts_qual_mask) + bts_qual_mask = (bts_qual_max - 1), + bts_escape = ((unsigned long)-1 & ~bts_qual_mask) }; static inline unsigned long bts_get(const char *base, enum bts_field field) @@ -461,8 +479,8 @@ static inline void bts_set(char *base, enum bts_field field, unsigned long val) * * return: bytes read/written on success; -Eerrno, otherwise */ -static int bts_read(struct bts_tracer *tracer, const void *at, - struct bts_struct *out) +static int +bts_read(struct bts_tracer *tracer, const void *at, struct bts_struct *out) { if (!tracer) return -EINVAL; |