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 <zide.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://patch.msgid.link/20251231224233.113839-4-zide.chen@intel.com

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 78a03af87204f8f13d353f31257282c754da60ab..2387b1a80ca05ceb3e6a08abceb324a3ba9f8a8f 100644 (file)
--- 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 25b6a65c961482e18d3b1b6fa9142f64716a5a9c..aaa081011fd6a07cfb8973d293fdcc302e1c361d 100644 (file)
--- 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;