Commit-ID: bc44fb5f7d3e764ed7698c835a1a0f35aba2eb3d
Gitweb: http://git.kernel.org/tip/bc44fb5f7d3e764ed7698c835a1a0f35aba2eb3d
Author: Markus Metzger <markus.t.metzger@xxxxxxxxx>
AuthorDate: Fri, 13 Mar 2009 10:42:18 +0100
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Fri, 13 Mar 2009 11:57:19 +0100
x86, bts: detect size of DS fields
Impact: more robust DS feature enumeration
Detect the size of the pointer-type fields in the DS area
configuration via the DTES64 features rather than based on
the cpuid.
Rename a variable to denote that size to reflect that it only
covers the pointer-type fields.
Add more boot-time diagnostics giving the detected size and
the sizes of BTS and PEBS records.
Use the size of the BTS/PEBS record to indicate that the
respective feature is not available (if the record size is zero).
Signed-off-by: Markus Metzger <markus.t.metzger@xxxxxxxxx>
LKML-Reference: <20090313104218.A30096@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/ds.c | 84 ++++++++++++++++++++++++++------------------------
1 files changed, 44 insertions(+), 40 deletions(-)
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 87b67e3..6e5ec67 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -39,7 +39,7 @@ struct ds_configuration {
/* the size of one pointer-typed field in the DS structure and
in the BTS and PEBS buffers in bytes;
this covers the first 8 DS fields related to buffer management. */
- unsigned char sizeof_field;
+ unsigned char sizeof_ptr_field;
/* the size of a BTS/PEBS record in bytes */
unsigned char sizeof_rec[2];
/* a series of bit-masks to control various features indexed
@@ -142,14 +142,14 @@ enum ds_qualifier {
static inline unsigned long ds_get(const unsigned char *base,
enum ds_qualifier qual, enum ds_field field)
{
- base += (ds_cfg.sizeof_field * (field + (4 * qual)));
+ 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)
{
- base += (ds_cfg.sizeof_field * (field + (4 * qual)));
+ base += (ds_cfg.sizeof_ptr_field * (field + (4 * qual)));
(*(unsigned long *)base) = value;
}
@@ -410,7 +410,7 @@ static int ds_write(struct ds_context *context, enum ds_qualifier qual,
* Later architectures use 64bit pointers throughout, whereas earlier
* architectures use 32bit pointers in 32bit mode.
*
- * We compute the base address for the first 8 fields based on:
+ * We compute the base address for the fields based on:
* - the field size stored in the DS configuration
* - the relative field position
*
@@ -441,13 +441,13 @@ enum bts_field {
static inline unsigned long bts_get(const char *base, enum bts_field field)
{
- base += (ds_cfg.sizeof_field * field);
+ base += (ds_cfg.sizeof_ptr_field * field);
return *(unsigned long *)base;
}
static inline void bts_set(char *base, enum bts_field field, unsigned long val)
{
- base += (ds_cfg.sizeof_field * field);;
+ base += (ds_cfg.sizeof_ptr_field * field);;
(*(unsigned long *)base) = val;
}
@@ -593,6 +593,10 @@ static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
struct ds_context *context;
int error;
+ error = -EOPNOTSUPP;
+ if (!ds_cfg.sizeof_rec[qual])
+ goto out;
+
error = -EINVAL;
if (!base)
goto out;
@@ -635,10 +639,6 @@ struct bts_tracer *ds_request_bts(struct task_struct *task,
unsigned long irq;
int error;
- error = -EOPNOTSUPP;
- if (!ds_cfg.ctl[dsf_bts])
- goto out;
-
/* buffer overflow notification is not yet implemented */
error = -EOPNOTSUPP;
if (ovfl)
@@ -848,7 +848,8 @@ const struct pebs_trace *ds_read_pebs(struct pebs_tracer *tracer)
ds_read_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
tracer->trace.reset_value =
- *(u64 *)(tracer->ds.context->ds + (ds_cfg.sizeof_field * 8));
+ *(u64 *)(tracer->ds.context->ds +
+ (ds_cfg.sizeof_ptr_field * 8));
return &tracer->trace;
}
@@ -884,7 +885,8 @@ int ds_set_pebs_reset(struct pebs_tracer *tracer, u64 value)
if (!tracer)
return -EINVAL;
- *(u64 *)(tracer->ds.context->ds + (ds_cfg.sizeof_field * 8)) = value;
+ *(u64 *)(tracer->ds.context->ds +
+ (ds_cfg.sizeof_ptr_field * 8)) = value;
return 0;
}
@@ -894,52 +896,54 @@ 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),
-
- .sizeof_field = sizeof(long),
- .sizeof_rec[ds_bts] = sizeof(long) * 3,
-#ifdef __i386__
- .sizeof_rec[ds_pebs] = sizeof(long) * 10,
-#else
- .sizeof_rec[ds_pebs] = sizeof(long) * 18,
-#endif
};
static const struct ds_configuration ds_cfg_pentium_m = {
.name = "Pentium M",
.ctl[dsf_bts] = (1 << 6) | (1 << 7),
-
- .sizeof_field = sizeof(long),
- .sizeof_rec[ds_bts] = sizeof(long) * 3,
-#ifdef __i386__
- .sizeof_rec[ds_pebs] = sizeof(long) * 10,
-#else
- .sizeof_rec[ds_pebs] = sizeof(long) * 18,
-#endif
};
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),
-
- .sizeof_field = 8,
- .sizeof_rec[ds_bts] = 8 * 3,
- .sizeof_rec[ds_pebs] = 8 * 18,
};
static void
-ds_configure(const struct ds_configuration *cfg)
+ds_configure(const struct ds_configuration *cfg,
+ struct cpuinfo_x86 *cpu)
{
+ unsigned long nr_pebs_fields = 0;
+
+ printk(KERN_INFO "[ds] using %s configuration\n", cfg->name);
+
+#ifdef __i386__
+ nr_pebs_fields = 10;
+#else
+ nr_pebs_fields = 18;
+#endif
+
memset(&ds_cfg, 0, sizeof(ds_cfg));
ds_cfg = *cfg;
- printk(KERN_INFO "[ds] using %s configuration\n", ds_cfg.name);
+ ds_cfg.sizeof_ptr_field =
+ (cpu_has(cpu, X86_FEATURE_DTES64) ? 8 : 4);
- if (!cpu_has_bts) {
- ds_cfg.ctl[dsf_bts] = 0;
+ ds_cfg.sizeof_rec[ds_bts] = ds_cfg.sizeof_ptr_field * 3;
+ ds_cfg.sizeof_rec[ds_pebs] = ds_cfg.sizeof_ptr_field * nr_pebs_fields;
+
+ if (!cpu_has(cpu, X86_FEATURE_BTS)) {
+ ds_cfg.sizeof_rec[ds_bts] = 0;
printk(KERN_INFO "[ds] bts not available\n");
}
- if (!cpu_has_pebs)
+ if (!cpu_has(cpu, X86_FEATURE_PEBS)) {
+ ds_cfg.sizeof_rec[ds_pebs] = 0;
printk(KERN_INFO "[ds] pebs not available\n");
+ }
+
+ printk(KERN_INFO "[ds] sizes: address: %u bit, ",
+ 8 * ds_cfg.sizeof_ptr_field);
+ 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_field));
}
@@ -951,12 +955,12 @@ void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
switch (c->x86_model) {
case 0x9:
case 0xd: /* Pentium M */
- ds_configure(&ds_cfg_pentium_m);
+ ds_configure(&ds_cfg_pentium_m, c);
break;
case 0xf:
case 0x17: /* Core2 */
case 0x1c: /* Atom */
- ds_configure(&ds_cfg_core2_atom);
+ ds_configure(&ds_cfg_core2_atom, c);
break;
case 0x1a: /* i7 */
default:
@@ -969,7 +973,7 @@ void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
case 0x0:
case 0x1:
case 0x2: /* Netburst */
- ds_configure(&ds_cfg_netburst);
+ ds_configure(&ds_cfg_netburst, c);
break;
default:
/* sorry, don't know about them */
--
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