perf/x86/intel/uncore: Enable IIO stacks to PMON mapping for multi-segment SKX

IIO stacks to PMON mapping on Skylake servers is exposed through introduced
early attributes /sys/devices/uncore_iio_<pmu_idx>/dieX, where dieX is a
file which holds "Segment:Root Bus" for PCIe root port which can
be monitored by that IIO PMON block. These sysfs attributes are disabled
for multiple segment topologies except VMD domains which start at 0x10000.
This patch removes the limitation and enables IIO stacks to PMON mapping
for multi-segment Skylake servers by introducing segment-aware
intel_uncore_topology structure and attributing the topology configuration
to the segment in skx_iio_get_topology() function.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexander Antonov <alexander.antonov@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Kyle Meyer <kyle.meyer@hpe.com>
Link: https://lkml.kernel.org/r/20210323150507.2013-1-alexander.antonov@linux.intel.com

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 35b347027f93..a2b68bb7a30a 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -53,6 +53,18 @@ int uncore_pcibus_to_dieid(struct pci_bus *bus)
 	return die_id;
 }
 
+int uncore_die_to_segment(int die)
+{
+	struct pci_bus *bus = NULL;
+
+	/* Find first pci bus which attributes to specified die. */
+	while ((bus = pci_find_next_bus(bus)) &&
+	       (die != uncore_pcibus_to_dieid(bus)))
+		;
+
+	return bus ? pci_domain_nr(bus) : -EINVAL;
+}
+
 static void uncore_free_pcibus_map(void)
 {
 	struct pci2phy_map *map, *tmp;