From: Kan Liang kan.liang@linux.intel.com
[ Upstream commit 9d480158ee86ad606d3a8baaf81e6b71acbfd7d5 ]
There may be a kernel panic on the Haswell server and the Broadwell server, if the snbep_pci2phy_map_init() return error.
The uncore_extra_pci_dev[HSWEP_PCI_PCU_3] is used in the cpu_init() to detect the existence of the SBOX, which is a MSR type of PMON unit. The uncore_extra_pci_dev is allocated in the uncore_pci_init(). If the snbep_pci2phy_map_init() returns error, perf doesn't initialize the PCI type of the PMON units, so the uncore_extra_pci_dev will not be allocated. But perf may continue initializing the MSR type of PMON units. A null dereference kernel panic will be triggered.
The sockets in a Haswell server or a Broadwell server are identical. Only need to detect the existence of the SBOX once. Current perf probes all available PCU devices and stores them into the uncore_extra_pci_dev. It's unnecessary. Use the pci_get_device() to replace the uncore_extra_pci_dev. Only detect the existence of the SBOX on the first available PCU device once.
Factor out hswep_has_limit_sbox(), since the Haswell server and the Broadwell server uses the same way to detect the existence of the SBOX.
Add some macros to replace the magic number.
Fixes: 5306c31c5733 ("perf/x86/uncore/hsw-ep: Handle systems with only two SBOXes") Reported-by: Steve Wahl steve.wahl@hpe.com Signed-off-by: Kan Liang kan.liang@linux.intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Tested-by: Steve Wahl steve.wahl@hpe.com Link: https://lkml.kernel.org/r/1618521764-100923-1-git-send-email-kan.liang@linux... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/intel/uncore_snbep.c | 61 ++++++++++++---------------- 1 file changed, 26 insertions(+), 35 deletions(-)
diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c index ad20220af303..40751af62dd3 100644 --- a/arch/x86/events/intel/uncore_snbep.c +++ b/arch/x86/events/intel/uncore_snbep.c @@ -1093,7 +1093,6 @@ enum { SNBEP_PCI_QPI_PORT0_FILTER, SNBEP_PCI_QPI_PORT1_FILTER, BDX_PCI_QPI_PORT2_FILTER, - HSWEP_PCI_PCU_3, };
static int snbep_qpi_hw_config(struct intel_uncore_box *box, struct perf_event *event) @@ -2750,22 +2749,33 @@ static struct intel_uncore_type *hswep_msr_uncores[] = { NULL, };
-void hswep_uncore_cpu_init(void) +#define HSWEP_PCU_DID 0x2fc0 +#define HSWEP_PCU_CAPID4_OFFET 0x94 +#define hswep_get_chop(_cap) (((_cap) >> 6) & 0x3) + +static bool hswep_has_limit_sbox(unsigned int device) { - int pkg = boot_cpu_data.logical_proc_id; + struct pci_dev *dev = pci_get_device(PCI_VENDOR_ID_INTEL, device, NULL); + u32 capid4; + + if (!dev) + return false; + + pci_read_config_dword(dev, HSWEP_PCU_CAPID4_OFFET, &capid4); + if (!hswep_get_chop(capid4)) + return true;
+ return false; +} + +void hswep_uncore_cpu_init(void) +{ if (hswep_uncore_cbox.num_boxes > boot_cpu_data.x86_max_cores) hswep_uncore_cbox.num_boxes = boot_cpu_data.x86_max_cores;
/* Detect 6-8 core systems with only two SBOXes */ - if (uncore_extra_pci_dev[pkg].dev[HSWEP_PCI_PCU_3]) { - u32 capid4; - - pci_read_config_dword(uncore_extra_pci_dev[pkg].dev[HSWEP_PCI_PCU_3], - 0x94, &capid4); - if (((capid4 >> 6) & 0x3) == 0) - hswep_uncore_sbox.num_boxes = 2; - } + if (hswep_has_limit_sbox(HSWEP_PCU_DID)) + hswep_uncore_sbox.num_boxes = 2;
uncore_msr_uncores = hswep_msr_uncores; } @@ -3028,11 +3038,6 @@ static const struct pci_device_id hswep_uncore_pci_ids[] = { .driver_data = UNCORE_PCI_DEV_DATA(UNCORE_EXTRA_PCI_DEV, SNBEP_PCI_QPI_PORT1_FILTER), }, - { /* PCU.3 (for Capability registers) */ - PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x2fc0), - .driver_data = UNCORE_PCI_DEV_DATA(UNCORE_EXTRA_PCI_DEV, - HSWEP_PCI_PCU_3), - }, { /* end: all zeroes */ } };
@@ -3124,27 +3129,18 @@ static struct event_constraint bdx_uncore_pcu_constraints[] = { EVENT_CONSTRAINT_END };
+#define BDX_PCU_DID 0x6fc0 + void bdx_uncore_cpu_init(void) { - int pkg = topology_phys_to_logical_pkg(boot_cpu_data.phys_proc_id); - if (bdx_uncore_cbox.num_boxes > boot_cpu_data.x86_max_cores) bdx_uncore_cbox.num_boxes = boot_cpu_data.x86_max_cores; uncore_msr_uncores = bdx_msr_uncores;
- /* BDX-DE doesn't have SBOX */ - if (boot_cpu_data.x86_model == 86) { - uncore_msr_uncores[BDX_MSR_UNCORE_SBOX] = NULL; /* Detect systems with no SBOXes */ - } else if (uncore_extra_pci_dev[pkg].dev[HSWEP_PCI_PCU_3]) { - struct pci_dev *pdev; - u32 capid4; - - pdev = uncore_extra_pci_dev[pkg].dev[HSWEP_PCI_PCU_3]; - pci_read_config_dword(pdev, 0x94, &capid4); - if (((capid4 >> 6) & 0x3) == 0) - bdx_msr_uncores[BDX_MSR_UNCORE_SBOX] = NULL; - } + if ((boot_cpu_data.x86_model == 86) || hswep_has_limit_sbox(BDX_PCU_DID)) + uncore_msr_uncores[BDX_MSR_UNCORE_SBOX] = NULL; + hswep_uncore_pcu.constraints = bdx_uncore_pcu_constraints; }
@@ -3365,11 +3361,6 @@ static const struct pci_device_id bdx_uncore_pci_ids[] = { .driver_data = UNCORE_PCI_DEV_DATA(UNCORE_EXTRA_PCI_DEV, BDX_PCI_QPI_PORT2_FILTER), }, - { /* PCU.3 (for Capability registers) */ - PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x6fc0), - .driver_data = UNCORE_PCI_DEV_DATA(UNCORE_EXTRA_PCI_DEV, - HSWEP_PCI_PCU_3), - }, { /* end: all zeroes */ } };