From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Lynch <nathanl@linux.ibm.com>,
Gautham R Shenoy <ego@linux.vnet.ibm.com>,
Michael Neuling <mikey@neuling.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Peter Zijlstra <peterz@infradead.org>,
Jordan Niethe <jniethe5@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Nicholas Piggin <npiggin@gmail.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Oliver O'Halloran <oohall@gmail.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
Ingo Molnar <mingo@kernel.org>
Subject: [PATCH v4 10/10] powerpc/smp: Implement cpu_to_coregroup_id
Date: Mon, 27 Jul 2020 11:02:30 +0530 [thread overview]
Message-ID: <20200727053230.19753-11-srikar@linux.vnet.ibm.com> (raw)
In-Reply-To: <20200727053230.19753-1-srikar@linux.vnet.ibm.com>
Lookup the coregroup id from the associativity array.
If unable to detect the coregroup id, fallback on the core id.
This way, ensure sched_domain degenerates and an extra sched domain is
not created.
Ideally this function should have been implemented in
arch/powerpc/kernel/smp.c. However if its implemented in mm/numa.c, we
don't need to find the primary domain again.
If the device-tree mentions more than one coregroup, then kernel
implements only the last or the smallest coregroup, which currently
corresponds to the penultimate domain in the device-tree.
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by : Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
---
Changelog v1 -> v2:
Move coregroup_enabled before getting associativity (Gautham)
arch/powerpc/mm/numa.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 0d57779e7942..8b3b3ec7fcc4 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1218,6 +1218,26 @@ int find_and_online_cpu_nid(int cpu)
int cpu_to_coregroup_id(int cpu)
{
+ __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0};
+ int index;
+
+ if (cpu < 0 || cpu > nr_cpu_ids)
+ return -1;
+
+ if (!coregroup_enabled)
+ goto out;
+
+ if (!firmware_has_feature(FW_FEATURE_VPHN))
+ goto out;
+
+ if (vphn_get_associativity(cpu, associativity))
+ goto out;
+
+ index = of_read_number(associativity, 1);
+ if (index > min_common_depth + 1)
+ return of_read_number(&associativity[index - 1], 1);
+
+out:
return cpu_to_core_id(cpu);
}
--
2.17.1
next prev parent reply other threads:[~2020-07-27 6:01 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 5:32 [PATCH v4 00/10] Coregroup support on Powerpc Srikar Dronamraju
2020-07-27 5:32 ` [PATCH v4 01/10] powerpc/smp: Fix a warning under !NEED_MULTIPLE_NODES Srikar Dronamraju
2020-07-27 5:32 ` [PATCH v4 02/10] powerpc/smp: Merge Power9 topology with Power topology Srikar Dronamraju
2020-07-27 5:32 ` [PATCH v4 03/10] powerpc/smp: Move powerpc_topology above Srikar Dronamraju
2020-07-27 5:32 ` [PATCH v4 04/10] powerpc/smp: Move topology fixups into a new function Srikar Dronamraju
2020-07-27 5:32 ` [PATCH v4 05/10] powerpc/smp: Dont assume l2-cache to be superset of sibling Srikar Dronamraju
2020-07-27 5:32 ` [PATCH v4 06/10] powerpc/smp: Generalize 2nd sched domain Srikar Dronamraju
2020-07-30 5:55 ` Gautham R Shenoy
2020-07-31 7:45 ` Michael Ellerman
2020-07-31 9:29 ` Srikar Dronamraju
2020-07-31 12:22 ` Michael Ellerman
2020-07-27 5:32 ` [PATCH v4 07/10] Powerpc/numa: Detect support for coregroup Srikar Dronamraju
2020-07-31 7:49 ` Michael Ellerman
2020-07-31 9:18 ` Srikar Dronamraju
2020-07-31 11:31 ` Michael Ellerman
2020-07-27 5:32 ` [PATCH v4 08/10] powerpc/smp: Allocate cpumask only after searching thread group Srikar Dronamraju
2020-07-31 7:52 ` Michael Ellerman
2020-07-31 9:49 ` Srikar Dronamraju
2020-07-31 12:14 ` Michael Ellerman
2020-07-27 5:32 ` [PATCH v4 09/10] Powerpc/smp: Create coregroup domain Srikar Dronamraju
2020-07-27 18:52 ` Gautham R Shenoy
2020-07-28 15:03 ` Valentin Schneider
2020-07-29 6:13 ` Srikar Dronamraju
2020-07-31 1:05 ` Valentin Schneider
2020-08-03 6:01 ` Srikar Dronamraju
2020-07-31 7:36 ` Gautham R Shenoy
2020-07-27 5:32 ` Srikar Dronamraju [this message]
2020-07-31 8:02 ` [PATCH v4 10/10] powerpc/smp: Implement cpu_to_coregroup_id Michael Ellerman
2020-07-31 9:58 ` Srikar Dronamraju
2020-07-31 11:29 ` Michael Ellerman
2020-07-30 17:22 ` [PATCH v4 00/10] Coregroup support on Powerpc Srikar Dronamraju
-- strict thread matches above, loose matches on Subject: below --
2020-07-27 5:17 Srikar Dronamraju
2020-07-27 5:18 ` [PATCH v4 10/10] powerpc/smp: Implement cpu_to_coregroup_id Srikar Dronamraju
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