Merge: Updates for perf threshold Value

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/5224

Description: Updates for perf threshold Value

JIRA: https://issues.redhat.com/browse/RHEL-50637

Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=64126547

Tested: Verified Brew build test kernel RPMs and confirmed issue is resovled

Signed-off-by: Mamatha Inamdar <minamdar@redhat.com>

commit 505d316
Author: Kajol Jain <kjain@linux.ibm.com>
Date:   Fri May 6 11:40:14 2022 +0530

    powerpc/perf: Fix the threshold compare group constraint for power10

    Thresh compare bits for a event is used to program thresh compare
    field in Monitor Mode Control Register A (MMCRA: 8-18 bits for power10).
    When scheduling events as a group, all events in that group should
    match value in threshold bits. Otherwise event open for the sibling
    events should fail. But in the current code, incase thresh compare bits are
    not valid, we are not failing in group_constraint function which can result
    in invalid group schduling.

    Fix the issue by returning -1 incase event is threshold and threshold
    compare value is not valid in group_constraint function.

    Patch also fixes the p10_thresh_cmp_val function to return -1,
    incase threshold bits are not valid and changes corresponding check in
    is_thresh_cmp_valid function to return false only when the thresh_cmp
    value is less then 0.

    Thresh control bits in the event code is used to program thresh_ctl
    field in Monitor Mode Control Register A (MMCRA: 48-55). In below example,
    the scheduling of group events PM_MRK_INST_CMPL (3534401e0) and
    PM_THRESH_MET (34340101ec) is expected to fail as both event
    request different thresh control bits.

    Result before the patch changes:

    [command]# perf stat -e "{r35340401e0,r34340101ec}" sleep 1

     Performance counter stats for 'sleep 1':

                 8,482      r35340401e0
                     0      r34340101ec

           1.001474838 seconds time elapsed

           0.001145000 seconds user
           0.000000000 seconds sys

    Result after the patch changes:

    [command]# perf stat -e "{r35340401e0,r34340101ec}" sleep 1

     Performance counter stats for 'sleep 1':

         <not counted>      r35340401e0
       <not supported>      r34340101ec

           1.001499607 seconds time elapsed

           0.000204000 seconds user
           0.000760000 seconds sys

    Fixes: 82d2c16 ("powerpc/perf: Adds support for programming of Thresholding in P10")
    Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
    Reviewed-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    Link: https://lore.kernel.org/r/20220506061015.43916-1-kjain@linux.ibm.com

Signed-off-by: Mamatha Inamdar <minamdar@redhat.com>

Approved-by: Steve Best <sbest@redhat.com>
Approved-by: Tony Camuso <tcamuso@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Rado Vrbovsky <rvrbovsk@redhat.com>

Author: emmil

arch/powerpc/perf/isa207-common.c

@@ -108,7 +108,7 @@ static void mmcra_sdar_mode(u64 event, unsigned long *mmcra)
 		*mmcra |= MMCRA_SDAR_MODE_TLB;
 }
 
-static u64 p10_thresh_cmp_val(u64 value)
+static int p10_thresh_cmp_val(u64 value)
 {
 	int exp = 0;
 	u64 result = value;
@@ -139,7 +139,7 @@ static u64 p10_thresh_cmp_val(u64 value)
 		 * exponent is also zero.
 		 */
 		if (!(value & 0xC0) && exp)
-			result = 0;
+			result = -1;
 		else
 			result = (exp << 8) | value;
 	}
@@ -187,7 +187,7 @@ static bool is_thresh_cmp_valid(u64 event)
 	unsigned int cmp, exp;
 
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
-		return p10_thresh_cmp_val(event) != 0;
+		return p10_thresh_cmp_val(event) >= 0;
 
 	/*
 	 * Check the mantissa upper two bits are not zero, unless the
@@ -502,7 +502,8 @@ int isa207_get_constraint(u64 event, unsigned long *maskp, unsigned long *valp,
 			value |= CNST_THRESH_CTL_SEL_VAL(event >> EVENT_THRESH_SHIFT);
 			mask  |= p10_CNST_THRESH_CMP_MASK;
 			value |= p10_CNST_THRESH_CMP_VAL(p10_thresh_cmp_val(event_config1));
-		}
+		} else if (event_is_threshold(event))
+			return -1;
 	} else if (cpu_has_feature(CPU_FTR_ARCH_300))  {
 		if (event_is_threshold(event) && is_thresh_cmp_valid(event)) {
 			mask  |= CNST_THRESH_MASK;