perf/x86/intel/uncore: Support MSR portal for discovery tables

JIRA: https://issues.redhat.com/browse/RHEL-47456

JIRA: https://issues.redhat.com/browse/RHEL-47442

upstream
========
commit cf002da
Author: Kan Liang <kan.liang@linux.intel.com>
Date: Mon Jul 7 13:17:47 2025 -0700

description
===========
Starting from the Panther Lake, the discovery table mechanism is also
supported in client platforms. The difference is that the portal of the
global discovery table is retrieved from an MSR.

The layout of discovery tables are the same as the server platforms.
Factor out __parse_discovery_table() to parse discover tables.

The uncore PMON is Die scope. Need to parse the discovery tables for
each die.

    Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
    Link: https://lore.kernel.org/r/20250707201750.616527-2-kan.liang@linux.intel.com

Conflicts:
==========
In RHEL-9, we haven't adopted the s/rdmsrl/rdmsrq/ rename: c435e60
("x86/msr: Rename 'rdmsrl()' to 'rdmsrq()'"), thus we need to fall back
to rdmsrl_safe_on_cpu().

Signed-off-by: Michael Petlan <mpetlan@redhat.com>

Author: rfmvh

arch/x86/events/intel/uncore_discovery.c

@@ -273,32 +273,15 @@ uncore_ignore_unit(struct uncore_unit_discovery *unit, int *ignore)
 	return false;
 }
 
-static int parse_discovery_table(struct pci_dev *dev, int die,
-				 u32 bar_offset, bool *parsed,
-				 int *ignore)
+static int __parse_discovery_table(resource_size_t addr, int die,
+				   bool *parsed, int *ignore)
 {
 	struct uncore_global_discovery global;
 	struct uncore_unit_discovery unit;
 	void __iomem *io_addr;
-	resource_size_t addr;
 	unsigned long size;
-	u32 val;
 	int i;
 
-	pci_read_config_dword(dev, bar_offset, &val);
-
-	if (val & ~PCI_BASE_ADDRESS_MEM_MASK & ~PCI_BASE_ADDRESS_MEM_TYPE_64)
-		return -EINVAL;
-
-	addr = (resource_size_t)(val & PCI_BASE_ADDRESS_MEM_MASK);
-#ifdef CONFIG_PHYS_ADDR_T_64BIT
-	if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
-		u32 val2;
-
-		pci_read_config_dword(dev, bar_offset + 4, &val2);
-		addr |= ((resource_size_t)val2) << 32;
-	}
-#endif
 	size = UNCORE_DISCOVERY_GLOBAL_MAP_SIZE;
 	io_addr = ioremap(addr, size);
 	if (!io_addr)
@@ -341,7 +324,32 @@ static int parse_discovery_table(struct pci_dev *dev, int die,
 	return 0;
 }
 
-bool intel_uncore_has_discovery_tables(int *ignore)
+static int parse_discovery_table(struct pci_dev *dev, int die,
+				 u32 bar_offset, bool *parsed,
+				 int *ignore)
+{
+	resource_size_t addr;
+	u32 val;
+
+	pci_read_config_dword(dev, bar_offset, &val);
+
+	if (val & ~PCI_BASE_ADDRESS_MEM_MASK & ~PCI_BASE_ADDRESS_MEM_TYPE_64)
+		return -EINVAL;
+
+	addr = (resource_size_t)(val & PCI_BASE_ADDRESS_MEM_MASK);
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
+	if ((val & PCI_BASE_ADDRESS_MEM_TYPE_MASK) == PCI_BASE_ADDRESS_MEM_TYPE_64) {
+		u32 val2;
+
+		pci_read_config_dword(dev, bar_offset + 4, &val2);
+		addr |= ((resource_size_t)val2) << 32;
+	}
+#endif
+
+	return __parse_discovery_table(addr, die, parsed, ignore);
+}
+
+static bool intel_uncore_has_discovery_tables_pci(int *ignore)
 {
 	u32 device, val, entry_id, bar_offset;
 	int die, dvsec = 0, ret = true;
@@ -390,6 +398,45 @@ bool intel_uncore_has_discovery_tables(int *ignore)
 	return ret;
 }
 
+static bool intel_uncore_has_discovery_tables_msr(int *ignore)
+{
+	unsigned long *die_mask;
+	bool parsed = false;
+	int cpu, die;
+	u64 base;
+
+	die_mask = kcalloc(BITS_TO_LONGS(uncore_max_dies()),
+			   sizeof(unsigned long), GFP_KERNEL);
+	if (!die_mask)
+		return false;
+
+	cpus_read_lock();
+	for_each_online_cpu(cpu) {
+		die = topology_logical_die_id(cpu);
+		if (__test_and_set_bit(die, die_mask))
+			continue;
+
+		if (rdmsrl_safe_on_cpu(cpu, UNCORE_DISCOVERY_MSR, &base))
+			continue;
+
+		if (!base)
+			continue;
+
+		__parse_discovery_table(base, die, &parsed, ignore);
+	}
+
+	cpus_read_unlock();
+
+	kfree(die_mask);
+	return parsed;
+}
+
+bool intel_uncore_has_discovery_tables(int *ignore)
+{
+	return intel_uncore_has_discovery_tables_msr(ignore) ||
+	       intel_uncore_has_discovery_tables_pci(ignore);
+}
+
 void intel_uncore_clear_discovery_tables(void)
 {
 	struct intel_uncore_discovery_type *type, *next;

arch/x86/events/intel/uncore_discovery.h

@@ -1,5 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+/* Store the full address of the global discovery table */
+#define UNCORE_DISCOVERY_MSR			0x201e
+
 /* Generic device ID of a discovery table device */
 #define UNCORE_DISCOVERY_TABLE_DEVICE		0x09a7
 /* Capability ID for a discovery table device */