Anshuman Khandual <khand...@linux.vnet.ibm.com> wrote:
> Fixing some conditions during BHRB entry processing.
I think we can simplify this a lot more... something like the below.
Also, this marks the "to" address as all 1s, which is better poison
value since it's possible to branch to/from 0x0.
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index c627843..d410d65 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1463,65 +1463,45 @@ void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
{
u64 val;
u64 addr;
- int r_index, u_index, target, pred;
+ int r_index, u_index, pred;
r_index = 0;
u_index = 0;
while (r_index < ppmu->bhrb_nr) {
/* Assembly read function */
- val = read_bhrb(r_index);
+ val = read_bhrb(r_index++);
/* Terminal marker: End of valid BHRB entries */
- if (val == 0) {
+ if (!val) {
break;
} else {
/* BHRB field break up */
addr = val & BHRB_EA;
pred = val & BHRB_PREDICTION;
- target = val & BHRB_TARGET;
- /* Probable Missed entry: Not applicable for POWER8 */
- if ((addr == 0) && (target == 0) && (pred == 1)) {
- r_index++;
+ if (!addr)
+ /* invalid entry */
continue;
- }
-
- /* Real Missed entry: Power8 based missed entry */
- if ((addr == 0) && (target == 1) && (pred == 1)) {
- r_index++;
- continue;
- }
- /* Reserved condition: Not a valid entry */
- if ((addr == 0) && (target == 1) && (pred == 0)) {
- r_index++;
- continue;
- }
-
- /* Is a target address */
if (val & BHRB_TARGET) {
/* First address cannot be a target address */
- if (r_index == 0) {
- r_index++;
+ if (r_index == 0)
continue;
- }
/* Update target address for the previous entry
*/
cpuhw->bhrb_entries[u_index - 1].to = addr;
cpuhw->bhrb_entries[u_index - 1].mispred = pred;
cpuhw->bhrb_entries[u_index - 1].predicted =
~pred;
-
- /* Dont increment u_index */
- r_index++;
} else {
/* Update address, flags for current entry */
cpuhw->bhrb_entries[u_index].from = addr;
+ cpuhw->bhrb_entries[u_index].to =
+ 0xffffffffffffffff;
cpuhw->bhrb_entries[u_index].mispred = pred;
cpuhw->bhrb_entries[u_index].predicted = ~pred;
/* Successfully popullated one entry */
u_index++;
- r_index++;
}
}
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
