From 1897336728b4ab0229fb73bb6f1e94cfe914afa9 Mon Sep 17 00:00:00 2001 From: Zide Chen Date: Wed, 31 Dec 2025 14:42:20 -0800 Subject: [PATCH] perf/x86/intel/uncore: Remove has_generic_discovery_table() In the !x86_match_cpu() fallback path, has_generic_discovery_table() is removed because it does not handle multiple PCI devices. Instead, use PCI_ANY_ID in generic_uncore_init[] to probe all PCI devices. For MSR portals, only probe MSR 0x201e to keep the fallback simple, as this path is best-effort only. Signed-off-by: Zide Chen Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Dapeng Mi Link: https://patch.msgid.link/20251231224233.113839-4-zide.chen@intel.com --- arch/x86/events/intel/uncore.c | 3 ++ arch/x86/events/intel/uncore_discovery.c | 42 +++++------------------- 2 files changed, 12 insertions(+), 33 deletions(-) diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c index 78a03af87204f..2387b1a80ca05 100644 --- a/arch/x86/events/intel/uncore.c +++ b/arch/x86/events/intel/uncore.c @@ -1835,6 +1835,9 @@ static const struct uncore_plat_init generic_uncore_init __initconst = { .cpu_init = intel_uncore_generic_uncore_cpu_init, .pci_init = intel_uncore_generic_uncore_pci_init, .mmio_init = intel_uncore_generic_uncore_mmio_init, + .domain[0].base_is_pci = true, + .domain[0].discovery_base = PCI_ANY_ID, + .domain[1].discovery_base = UNCORE_DISCOVERY_MSR, }; static const struct x86_cpu_id intel_uncore_match[] __initconst = { diff --git a/arch/x86/events/intel/uncore_discovery.c b/arch/x86/events/intel/uncore_discovery.c index 25b6a65c96148..aaa081011fd6a 100644 --- a/arch/x86/events/intel/uncore_discovery.c +++ b/arch/x86/events/intel/uncore_discovery.c @@ -12,24 +12,6 @@ static struct rb_root discovery_tables = RB_ROOT; static int num_discovered_types[UNCORE_ACCESS_MAX]; -static bool has_generic_discovery_table(void) -{ - struct pci_dev *dev; - int dvsec; - - dev = pci_get_device(PCI_VENDOR_ID_INTEL, UNCORE_DISCOVERY_TABLE_DEVICE, NULL); - if (!dev) - return false; - - /* A discovery table device has the unique capability ID. */ - dvsec = pci_find_next_ext_capability(dev, 0, UNCORE_EXT_CAP_ID_DISCOVERY); - pci_dev_put(dev); - if (dvsec) - return true; - - return false; -} - static int logical_die_id; static int get_device_die_id(struct pci_dev *dev) @@ -358,12 +340,7 @@ static bool uncore_discovery_pci(struct uncore_discovery_domain *domain) struct pci_dev *dev = NULL; bool parsed = false; - if (domain->discovery_base) - device = domain->discovery_base; - else if (has_generic_discovery_table()) - device = UNCORE_DISCOVERY_TABLE_DEVICE; - else - device = PCI_ANY_ID; + device = domain->discovery_base; /* * Start a new search and iterates through the list of @@ -406,7 +383,7 @@ static bool uncore_discovery_msr(struct uncore_discovery_domain *domain) { unsigned long *die_mask; bool parsed = false; - int cpu, die, msr; + int cpu, die; u64 base; die_mask = kcalloc(BITS_TO_LONGS(uncore_max_dies()), @@ -414,16 +391,13 @@ static bool uncore_discovery_msr(struct uncore_discovery_domain *domain) if (!die_mask) return false; - msr = domain->discovery_base ? - domain->discovery_base : UNCORE_DISCOVERY_MSR; - cpus_read_lock(); for_each_online_cpu(cpu) { die = topology_logical_die_id(cpu); if (__test_and_set_bit(die, die_mask)) continue; - if (rdmsrq_safe_on_cpu(cpu, msr, &base)) + if (rdmsrq_safe_on_cpu(cpu, domain->discovery_base, &base)) continue; if (!base) @@ -446,10 +420,12 @@ bool uncore_discovery(struct uncore_plat_init *init) for (i = 0; i < UNCORE_DISCOVERY_DOMAINS; i++) { domain = &init->domain[i]; - if (!domain->base_is_pci) - ret |= uncore_discovery_msr(domain); - else - ret |= uncore_discovery_pci(domain); + if (domain->discovery_base) { + if (!domain->base_is_pci) + ret |= uncore_discovery_msr(domain); + else + ret |= uncore_discovery_pci(domain); + } } return ret; -- 2.47.3