[tip:perf/core] perf/x86/intel/uncore: Add Node ID mask

[tip-bot for Kan Liang <tipbot@zytor.com>]

Commit-ID:  9e63a7894fd302082cf3627fe90844421a6cbe7f
Gitweb:     https://git.kernel.org/tip/9e63a7894fd302082cf3627fe90844421a6cbe7f
Author:     Kan Liang <kan.liang@linux.intel.com>
AuthorDate: Sun, 27 Jan 2019 06:53:14 -0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Mon, 4 Feb 2019 08:44:43 +0100

perf/x86/intel/uncore: Add Node ID mask

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

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index c07bee31abe8..b10e04387f38 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -1222,6 +1222,8 @@ static struct pci_driver snbep_uncore_pci_driver = {
 	.id_table	= snbep_uncore_pci_ids,
 };
 
+#define NODE_ID_MASK	0x7
+
 /*
  * build pci bus to socket mapping
  */
@@ -1243,7 +1245,7 @@ static int snbep_pci2phy_map_init(int devid, int nodeid_loc, int idmap_loc, bool
 		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)