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perf/x86/uncore: Don't WARN_ON_ONCE() for a broken discovery table
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commit 5d515ee upstream.

The kernel warning message is triggered, when SPR MCC is used.

[   17.945331] ------------[ cut here ]------------
[   17.946305] WARNING: CPU: 65 PID: 1 at
arch/x86/events/intel/uncore_discovery.c:184
intel_uncore_has_discovery_tables+0x4c0/0x65c
[   17.946305] Modules linked in:
[   17.946305] CPU: 65 PID: 1 Comm: swapper/0 Not tainted
5.4.17-2136.313.1-X10-2c+ #4

It's caused by the broken discovery table of UPI.

The discovery tables are from hardware. Except for dropping the broken
information, there is nothing Linux can do. Using WARN_ON_ONCE() is
overkilled.

Use the pr_info() to replace WARN_ON_ONCE(), and specify what uncore unit
is dropped and the reason.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/20230112200105.733466-6-kan.liang@linux.intel.com
Cc: Mahmoud Adam <mngyadam@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Kan Liang authored and gregkh committed Dec 20, 2023
1 parent d0fc081 commit f5494d9
Showing 1 changed file with 15 additions and 3 deletions.
18 changes: 15 additions & 3 deletions arch/x86/events/intel/uncore_discovery.c
Original file line number Diff line number Diff line change
Expand Up @@ -140,13 +140,21 @@ uncore_insert_box_info(struct uncore_unit_discovery *unit,
unsigned int *box_offset, *ids;
int i;

if (WARN_ON_ONCE(!unit->ctl || !unit->ctl_offset || !unit->ctr_offset))
if (!unit->ctl || !unit->ctl_offset || !unit->ctr_offset) {
pr_info("Invalid address is detected for uncore type %d box %d, "
"Disable the uncore unit.\n",
unit->box_type, unit->box_id);
return;
}

if (parsed) {
type = search_uncore_discovery_type(unit->box_type);
if (WARN_ON_ONCE(!type))
if (!type) {
pr_info("A spurious uncore type %d is detected, "
"Disable the uncore type.\n",
unit->box_type);
return;
}
/* Store the first box of each die */
if (!type->box_ctrl_die[die])
type->box_ctrl_die[die] = unit->ctl;
Expand Down Expand Up @@ -181,8 +189,12 @@ uncore_insert_box_info(struct uncore_unit_discovery *unit,
ids[i] = type->ids[i];
box_offset[i] = type->box_offset[i];

if (WARN_ON_ONCE(unit->box_id == ids[i]))
if (unit->box_id == ids[i]) {
pr_info("Duplicate uncore type %d box ID %d is detected, "
"Drop the duplicate uncore unit.\n",
unit->box_type, unit->box_id);
goto free_ids;
}
}
ids[i] = unit->box_id;
box_offset[i] = unit->ctl - type->box_ctrl;
Expand Down

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