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From: Anshuman Khandual <khandual@linux.vnet.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH V11_RESEND 04/10] powerpc/perf: Re organize BHRB processing
Date: Tue, 16 Feb 2016 12:07:04 +0530	[thread overview]
Message-ID: <1455604630-16214-5-git-send-email-khandual@linux.vnet.ibm.com> (raw)
In-Reply-To: <1455604630-16214-1-git-send-email-khandual@linux.vnet.ibm.com>

This patch cleans up some existing indentation problem in code and
re organizes the BHRB processing code with an helper function named
'update_branch_entry' making it more readable. This patch does not
change any functionality.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
---
 arch/powerpc/perf/core-book3s.c | 105 ++++++++++++++++++++--------------------
 1 file changed, 52 insertions(+), 53 deletions(-)

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 0930a07..02b724b 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -421,11 +421,19 @@ static __u64 power_pmu_bhrb_to(u64 addr)
 	return target - (unsigned long)&instr + addr;
 }
 
+static inline void insert_branch(struct cpu_hw_events *cpuhw,
+			int index, u64 from, u64 to, bool mispred)
+{
+	cpuhw->bhrb_entries[index].from = from;
+	cpuhw->bhrb_entries[index].to = to;
+	cpuhw->bhrb_entries[index].mispred = mispred;
+	cpuhw->bhrb_entries[index].predicted = !mispred;
+}
+
 /* Processing BHRB entries */
 static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
 {
-	u64 val;
-	u64 addr;
+	u64 val, addr, to_addr;
 	int r_index, u_index;
 	bool mispred;
 
@@ -437,64 +445,55 @@ static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
 		if (!val)
 			/* Terminal marker: End of valid BHRB entries */
 			break;
-		else {
-			addr = val & BHRB_EA;
-			mispred = val & BHRB_PREDICTION;
 
-			if (!addr)
-				/* invalid entry */
-				continue;
+		addr = val & BHRB_EA;
+		mispred = val & BHRB_PREDICTION;
 
-			/* Branches are read most recent first (ie. mfbhrb 0 is
-			 * the most recent branch).
-			 * There are two types of valid entries:
-			 * 1) a target entry which is the to address of a
-			 *    computed goto like a blr,bctr,btar.  The next
-			 *    entry read from the bhrb will be branch
-			 *    corresponding to this target (ie. the actual
-			 *    blr/bctr/btar instruction).
-			 * 2) a from address which is an actual branch.  If a
-			 *    target entry proceeds this, then this is the
-			 *    matching branch for that target.  If this is not
-			 *    following a target entry, then this is a branch
-			 *    where the target is given as an immediate field
-			 *    in the instruction (ie. an i or b form branch).
-			 *    In this case we need to read the instruction from
-			 *    memory to determine the target/to address.
+		if (!addr)
+			/* invalid entry */
+			continue;
+
+		/* Branches are read most recent first (ie. mfbhrb 0 is
+		 * the most recent branch).
+		 * There are two types of valid entries:
+		 * 1) a target entry which is the to address of a
+		 *    computed goto like a blr,bctr,btar.  The next
+		 *    entry read from the bhrb will be branch
+		 *    corresponding to this target (ie. the actual
+		 *    blr/bctr/btar instruction).
+		 * 2) a from address which is an actual branch.  If a
+		 *    target entry proceeds this, then this is the
+		 *    matching branch for that target.  If this is not
+		 *    following a target entry, then this is a branch
+		 *    where the target is given as an immediate field
+		 *    in the instruction (ie. an i or b form branch).
+		 *    In this case we need to read the instruction from
+		 *    memory to determine the target/to address.
+		 */
+
+		if (val & BHRB_TARGET) {
+			/* Target branches use two entries
+			 * (ie. computed gotos/XL form)
 			 */
+			to_addr = addr;
 
+			/* Get from address in next entry */
+			val = read_bhrb(r_index++);
+			addr = val & BHRB_EA;
 			if (val & BHRB_TARGET) {
-				/* Target branches use two entries
-				 * (ie. computed gotos/XL form)
-				 */
-				cpuhw->bhrb_entries[u_index].to = addr;
-				cpuhw->bhrb_entries[u_index].mispred = mispred;
-				cpuhw->bhrb_entries[u_index].predicted =
-								~mispred;
-
-				/* Get from address in next entry */
-				val = read_bhrb(r_index++);
-				addr = val & BHRB_EA;
-				if (val & BHRB_TARGET) {
-					/* Shouldn't have two targets in a
-					   row.. Reset index and try again */
-					r_index--;
-					addr = 0;
-				}
-				cpuhw->bhrb_entries[u_index].from = addr;
-			} else {
-				/* Branches to immediate field 
-				   (ie I or B form) */
-				cpuhw->bhrb_entries[u_index].from = addr;
-				cpuhw->bhrb_entries[u_index].to =
-					power_pmu_bhrb_to(addr);
-				cpuhw->bhrb_entries[u_index].mispred = mispred;
-				cpuhw->bhrb_entries[u_index].predicted =
-								~mispred;
+				/* Shouldn't have two targets in a
+				   row.. Reset index and try again */
+				r_index--;
+				addr = 0;
 			}
-			u_index++;
-
+			insert_branch(cpuhw, u_index, addr, to_addr, mispred);
+		} else {
+			/* Branches to immediate field
+			   (ie I or B form) */
+			to_addr = power_pmu_bhrb_to(addr);
+			insert_branch(cpuhw, u_index, addr, to_addr, mispred);
 		}
+		u_index++;
 	}
 	cpuhw->bhrb_stack.nr = u_index;
 	return;
-- 
2.1.0

  parent reply	other threads:[~2016-02-16  6:38 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-16  6:37 [PATCH V11_RESEND 00/10] powerpc/perf: Enable SW branch filters Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 01/10] powerpc/perf: Change name & type of 'pred' in power_pmu_bhrb_read Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 02/10] powerpc/perf: Re organize PMU branch filter processing on POWER8 Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 03/10] powerpc/perf: Restore privilege level filter support for BHRB Anshuman Khandual
2016-02-16  6:37 ` Anshuman Khandual [this message]
2016-02-16  6:37 ` [PATCH V11_RESEND 05/10] powerpc/perf: Change the name of HW PMU branch filter tracking variable Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 06/10] powerpc/lib: Add new branch analysis support functions Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 07/10] powerpc/perf: Enable SW filtering in branch stack sampling framework Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 08/10] powerpc/perf: Change POWER8 PMU configuration to work with SW filters Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 09/10] powerpc/perf: Enable privilege mode SW branch filters Anshuman Khandual
2016-02-16  6:37 ` [PATCH V11_RESEND 10/10] selftests/powerpc: Add test for BHRB branch filters (HW & SW) Anshuman Khandual
2016-02-16 13:08 ` [PATCH V11_RESEND 00/10] powerpc/perf: Enable SW branch filters Christophe Leroy
2016-02-17  3:49   ` Anshuman Khandual
2016-02-17  4:23   ` Michael Ellerman

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