This is a note to let you know that I've just added the patch titled perf/x86/intel/uncore: Remove uncore extra PCI dev HSWEP_PCI_PCU_3 to the 5.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-x86-intel-uncore-remove-uncore-extra-pci-dev-hs.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f92221deb55d9ef8626baecd6541b020397c1b02 Author: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Date: Thu Apr 15 14:22:43 2021 -0700 perf/x86/intel/uncore: Remove uncore extra PCI dev HSWEP_PCI_PCU_3 [ 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@xxxxxxx> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Tested-by: Steve Wahl <steve.wahl@xxxxxxx> Link: https://lkml.kernel.org/r/1618521764-100923-1-git-send-email-kan.liang@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c index 7bdb1821215d..3112186a4f4b 100644 --- a/arch/x86/events/intel/uncore_snbep.c +++ b/arch/x86/events/intel/uncore_snbep.c @@ -1159,7 +1159,6 @@ 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) @@ -2816,22 +2815,33 @@ 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; } @@ -3094,11 +3104,6 @@ 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 */ } }; @@ -3190,27 +3195,18 @@ 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; } @@ -3431,11 +3427,6 @@ 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 */ } };