[PATCH AUTOSEL 5.8 04/72] perf/x86/intel/uncore: Fix oops when counting IMC uncore events on some TGL

Sasha Levin
2020-08-08T23:51:55Z

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

[ Upstream commit 2af834f1faab3f1e218fcbcab70a399121620d62 ]

When counting IMC uncore events on some TGL machines, an oops will be
triggered.
[ 393.101262] BUG: unable to handle page fault for address:
ffffb45200e15858
[ 393.101269] #PF: supervisor read access in kernel mode
[ 393.101271] #PF: error_code(0x0000) - not-present page

Current perf uncore driver still use the IMC MAP SIZE inherited from
SNB, which is 0x6000.
However, the offset of IMC uncore counters is larger than 0x6000,
e.g. 0xd8a0.

Enlarge the IMC MAP SIZE for TGL to 0xe000.

Fixes: fdb64822443e ("perf/x86: Add Intel Tiger Lake uncore support")
Reported-by: Ammy Yi <ammy.yi@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Ammy Yi <ammy.yi@intel.com>
Tested-by: Chao Qin <chao.qin@intel.com>
Link: https://lkml.kernel.org/r/1590679169-61823-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/events/intel/uncore_snb.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c
index 3de1065eefc44..1038e9f1e3542 100644
--- a/arch/x86/events/intel/uncore_snb.c
+++ b/arch/x86/events/intel/uncore_snb.c
@@ -1085,6 +1085,7 @@ static struct pci_dev *tgl_uncore_get_mc_dev(void)
}

#define TGL_UNCORE_MMIO_IMC_MEM_OFFSET 0x10000
+#define TGL_UNCORE_PCI_IMC_MAP_SIZE 0xe000

static void tgl_uncore_imc_freerunning_init_box(struct intel_uncore_box *box)
{
@@ -1112,7 +1113,7 @@ static void tgl_uncore_imc_freerunning_init_box(struct intel_uncore_box *box)
addr |= ((resource_size_t)mch_bar << 32);
#endif

- box->io_addr = ioremap(addr, SNB_UNCORE_PCI_IMC_MAP_SIZE);
+ box->io_addr = ioremap(addr, TGL_UNCORE_PCI_IMC_MAP_SIZE);
}

static struct intel_uncore_ops tgl_uncore_imc_freerunning_ops = {
--
2.25.1