linux-kernel - [PATCH 3/5] perf/x86/uncore: Ignore broken units in discovery table

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Date:   Tue, 29 Nov 2022 11:10:21 -0800
From:   kan.liang@...ux.intel.com
To:     peterz@...radead.org, mingo@...hat.com,
        linux-kernel@...r.kernel.org
Cc:     steve.wahl@....com, alexander.antonov@...ux.intel.com,
        ak@...ux.intel.com, eranian@...gle.com, namhyung@...nel.org,
        Kan Liang <kan.liang@...ux.intel.com>
Subject: [PATCH 3/5] perf/x86/uncore: Ignore broken units in discovery table

From: Kan Liang <kan.liang@...ux.intel.com>

Some units in a discovery table may be broken, e.g., UPI of SPR MCC.
A generic method is required to ignore the broken units.

Add uncore_units_ignore in the struct intel_uncore_init_fun, which
indicates the type ID of broken units. It will be assigned by the
platform-specific code later when the platform has a broken discovery
table.

Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
---
 arch/x86/events/intel/uncore.c           |  8 ++++++--
 arch/x86/events/intel/uncore.h           |  2 ++
 arch/x86/events/intel/uncore_discovery.c | 26 +++++++++++++++++++++---
 arch/x86/events/intel/uncore_discovery.h |  2 +-
 4 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index d63be6d1224e..751df6460bff 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1695,7 +1695,10 @@ struct intel_uncore_init_fun {
 	void	(*cpu_init)(void);
 	int	(*pci_init)(void);
 	void	(*mmio_init)(void);
+	/* Discovery table is required */
 	bool	use_discovery;
+	/* The units in the discovery table should be ignored. */
+	int	*uncore_units_ignore;
 };
 
 static const struct intel_uncore_init_fun nhm_uncore_init __initconst = {
@@ -1873,7 +1876,7 @@ static int __init intel_uncore_init(void)
 
 	id = x86_match_cpu(intel_uncore_match);
 	if (!id) {
-		if (!uncore_no_discover && intel_uncore_has_discovery_tables())
+		if (!uncore_no_discover && intel_uncore_has_discovery_tables(NULL))
 			uncore_init = (struct intel_uncore_init_fun *)&generic_uncore_init;
 		else
 			return -ENODEV;
@@ -1881,7 +1884,8 @@ static int __init intel_uncore_init(void)
 		uncore_init = (struct intel_uncore_init_fun *)id->driver_data;
 		if (uncore_no_discover && uncore_init->use_discovery)
 			return -ENODEV;
-		if (uncore_init->use_discovery && !intel_uncore_has_discovery_tables())
+		if (uncore_init->use_discovery &&
+		    !intel_uncore_has_discovery_tables(uncore_init->uncore_units_ignore))
 			return -ENODEV;
 	}
 
diff --git a/arch/x86/events/intel/uncore.h b/arch/x86/events/intel/uncore.h
index 8d493bea9eb6..bbaa57cd868d 100644
--- a/arch/x86/events/intel/uncore.h
+++ b/arch/x86/events/intel/uncore.h
@@ -34,6 +34,8 @@
 
 #define UNCORE_EVENT_CONSTRAINT(c, n) EVENT_CONSTRAINT(c, n, 0xff)
 
+#define UNCORE_IGNORE_END		-1
+
 struct pci_extra_dev {
 	struct pci_dev *dev[UNCORE_EXTRA_PCI_DEV_MAX];
 };
diff --git a/arch/x86/events/intel/uncore_discovery.c b/arch/x86/events/intel/uncore_discovery.c
index 08af92af2be2..abb51191f5af 100644
--- a/arch/x86/events/intel/uncore_discovery.c
+++ b/arch/x86/events/intel/uncore_discovery.c
@@ -190,8 +190,25 @@ uncore_insert_box_info(struct uncore_unit_discovery *unit,
 
 }
 
+static bool
+uncore_ignore_unit(struct uncore_unit_discovery *unit, int *ignore)
+{
+	int i;
+
+	if (!ignore)
+		return false;
+
+	for (i = 0; ignore[i] != UNCORE_IGNORE_END ; i++) {
+		if (unit->box_type == ignore[i])
+			return true;
+	}
+
+	return false;
+}
+
 static int parse_discovery_table(struct pci_dev *dev, int die,
-				 u32 bar_offset, bool *parsed)
+				 u32 bar_offset, bool *parsed,
+				 int *ignore)
 {
 	struct uncore_global_discovery global;
 	struct uncore_unit_discovery unit;
@@ -246,6 +263,9 @@ static int parse_discovery_table(struct pci_dev *dev, int die,
 		if (unit.access_type >= UNCORE_ACCESS_MAX)
 			continue;
 
+		if (uncore_ignore_unit(&unit, ignore))
+			continue;
+
 		uncore_insert_box_info(&unit, die, *parsed);
 	}
 
@@ -254,7 +274,7 @@ static int parse_discovery_table(struct pci_dev *dev, int die,
 	return 0;
 }
 
-bool intel_uncore_has_discovery_tables(void)
+bool intel_uncore_has_discovery_tables(int *ignore)
 {
 	u32 device, val, entry_id, bar_offset;
 	int die, dvsec = 0, ret = true;
@@ -290,7 +310,7 @@ bool intel_uncore_has_discovery_tables(void)
 			if (die < 0)
 				continue;
 
-			parse_discovery_table(dev, die, bar_offset, &parsed);
+			parse_discovery_table(dev, die, bar_offset, &parsed, ignore);
 		}
 	}
 
diff --git a/arch/x86/events/intel/uncore_discovery.h b/arch/x86/events/intel/uncore_discovery.h
index f4439357779a..41637022b5d1 100644
--- a/arch/x86/events/intel/uncore_discovery.h
+++ b/arch/x86/events/intel/uncore_discovery.h
@@ -122,7 +122,7 @@ struct intel_uncore_discovery_type {
 	unsigned int	*box_offset;	/* Box offset */
 };
 
-bool intel_uncore_has_discovery_tables(void);
+bool intel_uncore_has_discovery_tables(int *ignore);
 void intel_uncore_clear_discovery_tables(void);
 void intel_uncore_generic_uncore_cpu_init(void);
 int intel_uncore_generic_uncore_pci_init(void);
-- 
2.35.1