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x86, ds: support Core i7
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Add debug store support for Core i7.

Core i7 adds a reset value for each performance counter and a new
PEBS record format.

Signed-off-by: Markus Metzger <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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markus-metzger authored and Ingo Molnar committed Apr 7, 2009
1 parent 150f516 commit 017bc61
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Showing 2 changed files with 71 additions and 10 deletions.
12 changes: 9 additions & 3 deletions arch/x86/include/asm/ds.h
Original file line number Diff line number Diff line change
Expand Up @@ -234,8 +234,12 @@ struct bts_trace {
struct pebs_trace {
struct ds_trace ds;

/* the PEBS reset value */
unsigned long long reset_value;
/* the number of valid counters in the below array */
unsigned int counters;

#define MAX_PEBS_COUNTERS 4
/* the counter reset value */
unsigned long long counter_reset[MAX_PEBS_COUNTERS];
};


Expand Down Expand Up @@ -270,9 +274,11 @@ extern int ds_reset_pebs(struct pebs_tracer *tracer);
* Returns 0 on success; -Eerrno on error
*
* tracer: the tracer handle returned from ds_request_pebs()
* counter: the index of the counter
* value: the new counter reset value
*/
extern int ds_set_pebs_reset(struct pebs_tracer *tracer, u64 value);
extern int ds_set_pebs_reset(struct pebs_tracer *tracer,
unsigned int counter, u64 value);

/*
* Initialization
Expand Down
69 changes: 62 additions & 7 deletions arch/x86/kernel/ds.c
Original file line number Diff line number Diff line change
Expand Up @@ -44,21 +44,30 @@ struct ds_configuration {
/* The size of a BTS/PEBS record in bytes: */
unsigned char sizeof_rec[2];

/* The number of pebs counter reset values in the DS structure. */
unsigned char nr_counter_reset;

/* Control bit-masks indexed by enum ds_feature: */
unsigned long ctl[dsf_ctl_max];
};
static struct ds_configuration ds_cfg __read_mostly;


/* Maximal size of a DS configuration: */
#define MAX_SIZEOF_DS (12 * 8)
#define MAX_SIZEOF_DS 0x80

/* Maximal size of a BTS record: */
#define MAX_SIZEOF_BTS (3 * 8)

/* BTS and PEBS buffer alignment: */
#define DS_ALIGNMENT (1 << 3)

/* Number of buffer pointers in DS: */
#define NUM_DS_PTR_FIELDS 8

/* Size of a pebs reset value in DS: */
#define PEBS_RESET_FIELD_SIZE 8

/* Mask of control bits in the DS MSR register: */
#define BTS_CONTROL \
( ds_cfg.ctl[dsf_bts] | \
Expand Down Expand Up @@ -1164,9 +1173,12 @@ const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer)
return NULL;

ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
tracer->trace.reset_value =
*(u64 *)(tracer->ds.context->ds +
(ds_cfg.sizeof_ptr_field * 8));

tracer->trace.counters = ds_cfg.nr_counter_reset;
memcpy(tracer->trace.counter_reset,
tracer->ds.context->ds +
(NUM_DS_PTR_FIELDS * ds_cfg.sizeof_ptr_field),
ds_cfg.nr_counter_reset * PEBS_RESET_FIELD_SIZE);

return &tracer->trace;
}
Expand Down Expand Up @@ -1197,13 +1209,18 @@ int ds_reset_pebs(struct pebs_tracer *tracer)
return 0;
}

int ds_set_pebs_reset(struct pebs_tracer *tracer, u64 value)
int ds_set_pebs_reset(struct pebs_tracer *tracer,
unsigned int counter, u64 value)
{
if (!tracer)
return -EINVAL;

if (ds_cfg.nr_counter_reset < counter)
return -EINVAL;

*(u64 *)(tracer->ds.context->ds +
(ds_cfg.sizeof_ptr_field * 8)) = value;
(NUM_DS_PTR_FIELDS * ds_cfg.sizeof_ptr_field) +
(counter * PEBS_RESET_FIELD_SIZE)) = value;

return 0;
}
Expand All @@ -1213,16 +1230,26 @@ static const struct ds_configuration ds_cfg_netburst = {
.ctl[dsf_bts] = (1 << 2) | (1 << 3),
.ctl[dsf_bts_kernel] = (1 << 5),
.ctl[dsf_bts_user] = (1 << 6),
.nr_counter_reset = 1,
};
static const struct ds_configuration ds_cfg_pentium_m = {
.name = "Pentium M",
.ctl[dsf_bts] = (1 << 6) | (1 << 7),
.nr_counter_reset = 1,
};
static const struct ds_configuration ds_cfg_core2_atom = {
.name = "Core 2/Atom",
.ctl[dsf_bts] = (1 << 6) | (1 << 7),
.ctl[dsf_bts_kernel] = (1 << 9),
.ctl[dsf_bts_user] = (1 << 10),
.nr_counter_reset = 1,
};
static const struct ds_configuration ds_cfg_core_i7 = {
.name = "Core i7",
.ctl[dsf_bts] = (1 << 6) | (1 << 7),
.ctl[dsf_bts_kernel] = (1 << 9),
.ctl[dsf_bts_user] = (1 << 10),
.nr_counter_reset = 4,
};

static void
Expand All @@ -1239,6 +1266,32 @@ ds_configure(const struct ds_configuration *cfg,
nr_pebs_fields = 18;
#endif

/*
* Starting with version 2, architectural performance
* monitoring supports a format specifier.
*/
if ((cpuid_eax(0xa) & 0xff) > 1) {
unsigned long perf_capabilities, format;

rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_capabilities);

format = (perf_capabilities >> 8) & 0xf;

switch (format) {
case 0:
nr_pebs_fields = 18;
break;
case 1:
nr_pebs_fields = 22;
break;
default:
printk(KERN_INFO
"[ds] unknown PEBS format: %lu\n", format);
nr_pebs_fields = 0;
break;
}
}

memset(&ds_cfg, 0, sizeof(ds_cfg));
ds_cfg = *cfg;

Expand All @@ -1262,7 +1315,7 @@ ds_configure(const struct ds_configuration *cfg,
printk("bts/pebs record: %u/%u bytes\n",
ds_cfg.sizeof_rec[ds_bts], ds_cfg.sizeof_rec[ds_pebs]);

WARN_ON_ONCE(MAX_SIZEOF_DS < (12 * ds_cfg.sizeof_ptr_field));
WARN_ON_ONCE(MAX_PEBS_COUNTERS < ds_cfg.nr_counter_reset);
}

void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
Expand All @@ -1284,6 +1337,8 @@ void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
ds_configure(&ds_cfg_core2_atom, c);
break;
case 0x1a: /* Core i7 */
ds_configure(&ds_cfg_core_i7, c);
break;
default:
/* Sorry, don't know about them. */
break;
Expand Down

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