oprofile, x86: Add support for IBS periodic op counter extension
The count value for IBS op sampling has been extended by 7 bits. The
feature is reflected in bit 6 (OpCntExt) of the IBS capability
register (CPUID Fn8000_001B_EAX).
Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index 9de33fa..65f0a1e 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -83,6 +83,7 @@
#define IBS_CAPS_RDWROPCNT (1U<<3)
#define IBS_CAPS_OPCNT (1U<<4)
#define IBS_CAPS_BRNTRGT (1U<<5)
+#define IBS_CAPS_OPCNTEXT (1U<<6)
#define IBS_CAPS_DEFAULT (IBS_CAPS_AVAIL \
| IBS_CAPS_FETCHSAM \
@@ -246,8 +247,16 @@
memset(&ibs_state, 0, sizeof(ibs_state));
+ /*
+ * Note: Since the max count settings may out of range we
+ * write back the actual used values so that userland can read
+ * it.
+ */
+
if (ibs_config.fetch_enabled) {
- val = (ibs_config.max_cnt_fetch >> 4) & IBS_FETCH_MAX_CNT;
+ val = ibs_config.max_cnt_fetch >> 4;
+ val = min(val, IBS_FETCH_MAX_CNT);
+ ibs_config.max_cnt_fetch = val << 4;
val |= ibs_config.rand_en ? IBS_FETCH_RAND_EN : 0;
val |= IBS_FETCH_ENABLE;
wrmsrl(MSR_AMD64_IBSFETCHCTL, val);
@@ -261,6 +270,7 @@
* op_amd_randomize_ibs_op() for details.
*/
val = clamp(val, 0x0081ULL, 0xFF80ULL);
+ ibs_config.max_cnt_op = val << 4;
} else {
/*
* The start value is randomized with a
@@ -268,9 +278,15 @@
* with the half of the randomized range. Also
* avoid underflows.
*/
- val = min(val + IBS_RANDOM_MAXCNT_OFFSET,
- IBS_OP_MAX_CNT);
+ val += IBS_RANDOM_MAXCNT_OFFSET;
+ if (ibs_caps & IBS_CAPS_OPCNTEXT)
+ val = min(val, IBS_OP_MAX_CNT_EXT);
+ else
+ val = min(val, IBS_OP_MAX_CNT);
+ ibs_config.max_cnt_op =
+ (val - IBS_RANDOM_MAXCNT_OFFSET) << 4;
}
+ val = ((val & ~IBS_OP_MAX_CNT) << 4) | (val & IBS_OP_MAX_CNT);
val |= ibs_config.dispatched_ops ? IBS_OP_CNT_CTL : 0;
val |= IBS_OP_ENABLE;
ibs_state.ibs_op_ctl = val;