[PATCH 4.14 196/205] perf/x86/intel/uncore: Add Node ID mask

Greg Kroah-Hartman
2019-02-11T15:22:59Z

From: Kan Liang <kan.liang@linux.intel.com>

commit 9e63a7894fd302082cf3627fe90844421a6cbe7f upstream.

Some PCI uncore PMUs cannot be registered on an 8-socket system (HPE
Superdome Flex).

To understand which Socket the PCI uncore PMUs belongs to, perf retrieves
the local Node ID of the uncore device from CPUNODEID(0xC0) of the PCI
configuration space, and the mapping between Socket ID and Node ID from
GIDNIDMAP(0xD4). The Socket ID can be calculated accordingly.

The local Node ID is only available at bit 2:0, but current code doesn't
mask it. If a BIOS doesn't clear the rest of the bits, an incorrect Node ID
will be fetched.

Filter the Node ID by adding a mask.

Reported-by: Song Liu <songliubraving@fb.com>
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org> # v3.7+
Fixes: 7c94ee2e0917 ("perf/x86: Add Intel Nehalem and Sandy Bridge-EP uncore support")
Link: https://lkml.kernel.org/r/1548600794-33162-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/events/intel/uncore_snbep.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -1221,6 +1221,8 @@ static struct pci_driver snbep_uncore_pc
.id_table = snbep_uncore_pci_ids,
};

+#define NODE_ID_MASK 0x7
+
/*
* build pci bus to socket mapping
*/
@@ -1242,7 +1244,7 @@ static int snbep_pci2phy_map_init(int de
err = pci_read_config_dword(ubox_dev, nodeid_loc, &config);
if (err)
break;
- nodeid = config;
+ nodeid = config & NODE_ID_MASK;
/* get the Node ID mapping */
err = pci_read_config_dword(ubox_dev, idmap_loc, &config);
if (err)