#define IBS_FETCH_ENABLE (1ULL<<48)
#define IBS_FETCH_CNT_MASK 0xFFFF0000ULL
-/*IbsOpCtl bits */
+/* IbsOpCtl bits */
#define IBS_OP_CNT_CTL (1ULL<<19)
#define IBS_OP_VAL (1ULL<<18)
#define IBS_OP_ENABLE (1ULL<<17)
};
static struct op_ibs_config ibs_config;
+static u64 ibs_op_ctl;
/*
* IBS cpuid feature detection
* bit 0 is used to indicate the existence of IBS.
*/
#define IBS_CAPS_AVAIL (1LL<<0)
+#define IBS_CAPS_RDWROPCNT (1LL<<3)
#define IBS_CAPS_OPCNT (1LL<<4)
+/*
+ * IBS randomization macros
+ */
+#define IBS_RANDOM_BITS 12
+#define IBS_RANDOM_MASK ((1ULL << IBS_RANDOM_BITS) - 1)
+#define IBS_RANDOM_MAXCNT_OFFSET (1ULL << (IBS_RANDOM_BITS - 5))
+
static u32 get_ibs_caps(void)
{
u32 ibs_caps;
#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
-static void op_mux_fill_in_addresses(struct op_msrs * const msrs)
-{
- int i;
-
- for (i = 0; i < NUM_VIRT_COUNTERS; i++) {
- int hw_counter = op_x86_virt_to_phys(i);
- if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
- msrs->multiplex[i].addr = MSR_K7_PERFCTR0 + hw_counter;
- else
- msrs->multiplex[i].addr = 0;
- }
-}
-
static void op_mux_switch_ctrl(struct op_x86_model_spec const *model,
struct op_msrs const * const msrs)
{
/* enable active counters */
for (i = 0; i < NUM_COUNTERS; ++i) {
int virt = op_x86_phys_to_virt(i);
- if (!counter_config[virt].enabled)
+ if (!reset_value[virt])
continue;
rdmsrl(msrs->controls[i].addr, val);
val &= model->reserved;
}
}
-#else
-
-static inline void op_mux_fill_in_addresses(struct op_msrs * const msrs) { }
-
#endif
/* functions for op_amd_spec */
for (i = 0; i < NUM_COUNTERS; i++) {
if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
msrs->counters[i].addr = MSR_K7_PERFCTR0 + i;
- else
- msrs->counters[i].addr = 0;
}
for (i = 0; i < NUM_CONTROLS; i++) {
if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i))
msrs->controls[i].addr = MSR_K7_EVNTSEL0 + i;
- else
- msrs->controls[i].addr = 0;
}
-
- op_mux_fill_in_addresses(msrs);
}
static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
/* setup reset_value */
for (i = 0; i < NUM_VIRT_COUNTERS; ++i) {
- if (counter_config[i].enabled)
+ if (counter_config[i].enabled
+ && msrs->counters[op_x86_virt_to_phys(i)].addr)
reset_value[i] = counter_config[i].count;
else
reset_value[i] = 0;
/* clear all counters */
for (i = 0; i < NUM_CONTROLS; ++i) {
- if (unlikely(!msrs->controls[i].addr))
+ if (unlikely(!msrs->controls[i].addr)) {
+ if (counter_config[i].enabled && !smp_processor_id())
+ /*
+ * counter is reserved, this is on all
+ * cpus, so report only for cpu #0
+ */
+ op_x86_warn_reserved(i);
continue;
+ }
rdmsrl(msrs->controls[i].addr, val);
+ if (val & ARCH_PERFMON_EVENTSEL0_ENABLE)
+ op_x86_warn_in_use(i);
val &= model->reserved;
wrmsrl(msrs->controls[i].addr, val);
}
/* enable active counters */
for (i = 0; i < NUM_COUNTERS; ++i) {
int virt = op_x86_phys_to_virt(i);
- if (!counter_config[virt].enabled)
- continue;
- if (!msrs->counters[i].addr)
+ if (!reset_value[virt])
continue;
/* setup counter registers */
return lfsr_value;
}
+/*
+ * IBS software randomization
+ *
+ * The IBS periodic op counter is randomized in software. The lower 12
+ * bits of the 20 bit counter are randomized. IbsOpCurCnt is
+ * initialized with a 12 bit random value.
+ */
+static inline u64 op_amd_randomize_ibs_op(u64 val)
+{
+ unsigned int random = lfsr_random();
+
+ if (!(ibs_caps & IBS_CAPS_RDWROPCNT))
+ /*
+ * Work around if the hw can not write to IbsOpCurCnt
+ *
+ * Randomize the lower 8 bits of the 16 bit
+ * IbsOpMaxCnt [15:0] value in the range of -128 to
+ * +127 by adding/subtracting an offset to the
+ * maximum count (IbsOpMaxCnt).
+ *
+ * To avoid over or underflows and protect upper bits
+ * starting at bit 16, the initial value for
+ * IbsOpMaxCnt must fit in the range from 0x0081 to
+ * 0xff80.
+ */
+ val += (s8)(random >> 4);
+ else
+ val |= (u64)(random & IBS_RANDOM_MASK) << 32;
+
+ return val;
+}
+
static inline void
op_amd_handle_ibs(struct pt_regs * const regs,
struct op_msrs const * const msrs)
oprofile_write_commit(&entry);
/* reenable the IRQ */
- ctl &= ~IBS_OP_VAL & 0xFFFFFFFF;
- ctl |= IBS_OP_ENABLE;
+ ctl = op_amd_randomize_ibs_op(ibs_op_ctl);
wrmsrl(MSR_AMD64_IBSOPCTL, ctl);
}
}
}
if (ibs_config.op_enabled) {
- val = (ibs_config.max_cnt_op >> 4) & 0xFFFF;
+ ibs_op_ctl = ibs_config.max_cnt_op >> 4;
+ if (!(ibs_caps & IBS_CAPS_RDWROPCNT)) {
+ /*
+ * IbsOpCurCnt not supported. See
+ * op_amd_randomize_ibs_op() for details.
+ */
+ ibs_op_ctl = clamp(ibs_op_ctl, 0x0081ULL, 0xFF80ULL);
+ } else {
+ /*
+ * The start value is randomized with a
+ * positive offset, we need to compensate it
+ * with the half of the randomized range. Also
+ * avoid underflows.
+ */
+ ibs_op_ctl = min(ibs_op_ctl + IBS_RANDOM_MAXCNT_OFFSET,
+ 0xFFFFULL);
+ }
if (ibs_caps & IBS_CAPS_OPCNT && ibs_config.dispatched_ops)
- val |= IBS_OP_CNT_CTL;
- val |= IBS_OP_ENABLE;
+ ibs_op_ctl |= IBS_OP_CNT_CTL;
+ ibs_op_ctl |= IBS_OP_ENABLE;
+ val = op_amd_randomize_ibs_op(ibs_op_ctl);
wrmsrl(MSR_AMD64_IBSOPCTL, val);
}
}