oprofile, x86: Introduce struct ibs_state

This patch introduces struct ibs_state that will extended by additinal
members in follow-on patches.

Signed-off-by: Robert Richter <robert.richter@amd.com>

arch/x86/oprofile/op_model_amd.c

@@ -48,7 +48,7 @@ static unsigned long reset_value[NUM_VIRT_COUNTERS];
 
 static u32 ibs_caps;
 
-struct op_ibs_config {
+struct ibs_config {
 	unsigned long op_enabled;
 	unsigned long fetch_enabled;
 	unsigned long max_cnt_fetch;
@@ -57,8 +57,12 @@ struct op_ibs_config {
 	unsigned long dispatched_ops;
 };
 
-static struct op_ibs_config ibs_config;
-static u64 ibs_op_ctl;
+struct ibs_state {
+	u64	ibs_op_ctl;
+};
+
+static struct ibs_config ibs_config;
+static struct ibs_state ibs_state;
 
 /*
  * IBS cpuid feature detection
@@ -219,7 +223,7 @@ op_amd_handle_ibs(struct pt_regs * const regs,
 			oprofile_write_commit(&entry);
 
 			/* reenable the IRQ */
-			ctl = op_amd_randomize_ibs_op(ibs_op_ctl);
+			ctl = op_amd_randomize_ibs_op(ibs_state.ibs_op_ctl);
 			wrmsrl(MSR_AMD64_IBSOPCTL, ctl);
 		}
 	}
@@ -232,6 +236,8 @@ static inline void op_amd_start_ibs(void)
 	if (!ibs_caps)
 		return;
 
+	memset(&ibs_state, 0, sizeof(ibs_state));
+
 	if (ibs_config.fetch_enabled) {
 		val = (ibs_config.max_cnt_fetch >> 4) & IBS_FETCH_MAX_CNT;
 		val |= ibs_config.rand_en ? IBS_FETCH_RAND_EN : 0;
@@ -240,26 +246,27 @@ static inline void op_amd_start_ibs(void)
 	}
 
 	if (ibs_config.op_enabled) {
-		ibs_op_ctl = ibs_config.max_cnt_op >> 4;
+		val = 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);
+			val = clamp(val, 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,
-					 IBS_OP_MAX_CNT);
+			val = min(val + IBS_RANDOM_MAXCNT_OFFSET,
+				  IBS_OP_MAX_CNT);
 		}
-		ibs_op_ctl |= ibs_config.dispatched_ops ? IBS_OP_CNT_CTL : 0;
-		ibs_op_ctl |= IBS_OP_ENABLE;
-		val = op_amd_randomize_ibs_op(ibs_op_ctl);
+		val |= ibs_config.dispatched_ops ? IBS_OP_CNT_CTL : 0;
+		val |= IBS_OP_ENABLE;
+		ibs_state.ibs_op_ctl = val;
+		val = op_amd_randomize_ibs_op(ibs_state.ibs_op_ctl);
 		wrmsrl(MSR_AMD64_IBSOPCTL, val);
 	}
 }