[PATCH v5 3/5] cxl/pci: Find and register CXL PMU devices

From: Jonathan Cameron
Date: Tue Apr 11 2023 - 14:56:30 EST


CXL PMU devices can be found from entries in the Register
Locator DVSEC.

Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
v5:
- Switch to cxl_find_regblock_instance() as replacement for
indexed version of cxl_find_reblock()
- Dropped stale patch description.
- Rename all structure, functions etc from cpmu to pmu / cxl_pmu as
appropriate.
- Register definitions pushed down into drivers/perf/pmu.c as not
needed from drivers/cxl/
- Allow richer device naming based on which CXL memdev the CPMU is
associated with. /sys/bus/cxl/devices/pmu_memX.Y for instance Y
on device /sys/bus/cxl/devices/memX
- Tidy up definitions by adding include to linux/device.h for
struct device and a forwards reference for struct cxl_pmu_regs.
---
drivers/cxl/core/Makefile | 1 +
drivers/cxl/core/core.h | 1 +
drivers/cxl/core/pmu.c | 69 +++++++++++++++++++++++++++++++++++++++
drivers/cxl/core/port.c | 2 ++
drivers/cxl/core/regs.c | 16 +++++++++
drivers/cxl/cxl.h | 13 ++++++++
drivers/cxl/cxlpci.h | 1 +
drivers/cxl/pci.c | 26 ++++++++++++++-
drivers/cxl/pmu.h | 28 ++++++++++++++++
9 files changed, 156 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/core/Makefile b/drivers/cxl/core/Makefile
index ca4ae31d8f57..1f66b5d4d935 100644
--- a/drivers/cxl/core/Makefile
+++ b/drivers/cxl/core/Makefile
@@ -12,5 +12,6 @@ cxl_core-y += memdev.o
cxl_core-y += mbox.o
cxl_core-y += pci.o
cxl_core-y += hdm.o
+cxl_core-y += pmu.o
cxl_core-$(CONFIG_TRACING) += trace.o
cxl_core-$(CONFIG_CXL_REGION) += region.o
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index cde475e13216..c9504dfddfed 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -6,6 +6,7 @@

extern const struct device_type cxl_nvdimm_bridge_type;
extern const struct device_type cxl_nvdimm_type;
+extern const struct device_type cxl_pmu_type;

extern struct attribute_group cxl_base_attribute_group;

diff --git a/drivers/cxl/core/pmu.c b/drivers/cxl/core/pmu.c
new file mode 100644
index 000000000000..b55eb962235f
--- /dev/null
+++ b/drivers/cxl/core/pmu.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2023 Huawei. All rights reserved. */
+
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <cxlmem.h>
+#include <pmu.h>
+#include <cxl.h>
+#include "core.h"
+
+static void cxl_pmu_release(struct device *dev)
+{
+ struct cxl_pmu *pmu = to_cxl_pmu(dev);
+
+ kfree(pmu);
+}
+
+const struct device_type cxl_pmu_type = {
+ .name = "cxl_pmu",
+ .release = cxl_pmu_release,
+};
+
+static void remove_dev(void *dev)
+{
+ device_del(dev);
+}
+
+int devm_cxl_pmu_add(struct device *parent, struct cxl_pmu_regs *regs,
+ int assoc_id, int index, enum cxl_pmu_type type)
+{
+ struct cxl_pmu *pmu;
+ struct device *dev;
+ int rc;
+
+ pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
+ if (!pmu)
+ return -ENOMEM;
+
+ pmu->assoc_id = assoc_id;
+ pmu->index = index;
+ pmu->type = type;
+ pmu->base = regs->pmu;
+ dev = &pmu->dev;
+ device_initialize(dev);
+ device_set_pm_not_required(dev);
+ dev->parent = parent;
+ dev->bus = &cxl_bus_type;
+ dev->type = &cxl_pmu_type;
+ switch (pmu->type) {
+ case CXL_PMU_MEMDEV:
+ rc = dev_set_name(dev, "pmu_mem%d.%d", assoc_id, index);
+ break;
+ }
+ if (rc)
+ goto err;
+
+ rc = device_add(dev);
+ if (rc)
+ goto err;
+
+ return devm_add_action_or_reset(parent, remove_dev, dev);
+
+err:
+ put_device(&pmu->dev);
+ return rc;
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_pmu_add, CXL);
+
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 4d1f9c5b5029..9a71e249f458 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -57,6 +57,8 @@ static int cxl_device_id(const struct device *dev)
return CXL_DEVICE_MEMORY_EXPANDER;
if (dev->type == CXL_REGION_TYPE())
return CXL_DEVICE_REGION;
+ if (dev->type == &cxl_pmu_type)
+ return CXL_DEVICE_PMU;
return 0;
}

diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index 4b9672db867d..518bc2ad2c1e 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -6,6 +6,7 @@
#include <linux/pci.h>
#include <cxlmem.h>
#include <cxlpci.h>
+#include <pmu.h>

#include "core.h"

@@ -379,6 +380,21 @@ int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type)
}
EXPORT_SYMBOL_NS_GPL(cxl_count_regblock, CXL);

+int cxl_map_pmu_regs(struct pci_dev *pdev, struct cxl_pmu_regs *regs,
+ struct cxl_register_map *map)
+{
+ struct device *dev = &pdev->dev;
+ resource_size_t phys_addr;
+
+ phys_addr = map->resource;
+ regs->pmu = devm_cxl_iomap_block(dev, phys_addr, CXL_PMU_REGMAP_SIZE);
+ if (!regs->pmu)
+ return -ENOMEM;
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_map_pmu_regs, CXL);
+
resource_size_t cxl_rcrb_to_component(struct device *dev,
resource_size_t rcrb,
enum cxl_rcrb which)
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index f6e2a9ea5f41..610aa430276b 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -209,6 +209,10 @@ struct cxl_regs {
struct_group_tagged(cxl_device_regs, device_regs,
void __iomem *status, *mbox, *memdev;
);
+
+ struct_group_tagged(cxl_pmu_regs, pmu_regs,
+ void __iomem *pmu;
+ );
};

struct cxl_reg_map {
@@ -229,6 +233,10 @@ struct cxl_device_reg_map {
struct cxl_reg_map memdev;
};

+struct cxl_pmu_reg_map {
+ struct cxl_reg_map pmu;
+};
+
/**
* struct cxl_register_map - DVSEC harvested register block mapping parameters
* @base: virtual base of the register-block-BAR + @block_offset
@@ -237,6 +245,7 @@ struct cxl_device_reg_map {
* @reg_type: see enum cxl_regloc_type
* @component_map: cxl_reg_map for component registers
* @device_map: cxl_reg_maps for device registers
+ * @pmu_map: cxl_reg_maps for CXL Performance Monitoring Units
*/
struct cxl_register_map {
void __iomem *base;
@@ -246,6 +255,7 @@ struct cxl_register_map {
union {
struct cxl_component_reg_map component_map;
struct cxl_device_reg_map device_map;
+ struct cxl_pmu_reg_map pmu_map;
};
};

@@ -258,6 +268,8 @@ int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
unsigned long map_mask);
int cxl_map_device_regs(struct device *dev, struct cxl_device_regs *regs,
struct cxl_register_map *map);
+int cxl_map_pmu_regs(struct pci_dev *pdev, struct cxl_pmu_regs *regs,
+ struct cxl_register_map *map);

enum cxl_regloc_type;
int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type);
@@ -752,6 +764,7 @@ void cxl_driver_unregister(struct cxl_driver *cxl_drv);
#define CXL_DEVICE_REGION 6
#define CXL_DEVICE_PMEM_REGION 7
#define CXL_DEVICE_DAX_REGION 8
+#define CXL_DEVICE_PMU 9

#define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
#define CXL_MODALIAS_FMT "cxl:t%d"
diff --git a/drivers/cxl/cxlpci.h b/drivers/cxl/cxlpci.h
index 0465ef963cd6..b1bbf69b62c5 100644
--- a/drivers/cxl/cxlpci.h
+++ b/drivers/cxl/cxlpci.h
@@ -65,6 +65,7 @@ enum cxl_regloc_type {
CXL_REGLOC_RBI_COMPONENT,
CXL_REGLOC_RBI_VIRT,
CXL_REGLOC_RBI_MEMDEV,
+ CXL_REGLOC_RBI_PMU,
CXL_REGLOC_RBI_TYPES
};

diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 60b23624d167..8a39e9ef081f 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -14,6 +14,7 @@
#include "cxlmem.h"
#include "cxlpci.h"
#include "cxl.h"
+#include "pmu.h"

/**
* DOC: cxl pci
@@ -704,7 +705,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
struct cxl_register_map map;
struct cxl_memdev *cxlmd;
struct cxl_dev_state *cxlds;
- int rc;
+ int i, rc, pmu_count;

/*
* Double check the anonymous union trickery in struct cxl_regs
@@ -785,6 +786,29 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
if (IS_ERR(cxlmd))
return PTR_ERR(cxlmd);

+ pmu_count = cxl_count_regblock(pdev, CXL_REGLOC_RBI_PMU);
+ for (i = 0; i < pmu_count; i++) {
+ struct cxl_pmu_regs pmu_regs;
+
+ rc = cxl_find_regblock_instance(pdev, CXL_REGLOC_RBI_PMU, &map, i);
+ if (rc) {
+ dev_dbg(&pdev->dev, "Could not find PMU regblock\n");
+ break;
+ }
+
+ rc = cxl_map_pmu_regs(pdev, &pmu_regs, &map);
+ if (rc) {
+ dev_dbg(&pdev->dev, "Could not map PMU regs\n");
+ break;
+ }
+
+ rc = devm_cxl_pmu_add(cxlds->dev, &pmu_regs, cxlmd->id, i, CXL_PMU_MEMDEV);
+ if (rc) {
+ dev_dbg(&pdev->dev, "Could not add PMU instance\n");
+ break;
+ }
+ }
+
rc = cxl_event_config(host_bridge, cxlds);
if (rc)
return rc;
diff --git a/drivers/cxl/pmu.h b/drivers/cxl/pmu.h
new file mode 100644
index 000000000000..b1e9bcd9f28c
--- /dev/null
+++ b/drivers/cxl/pmu.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright(c) 2023 Huawei
+ * CXL Specification rev 3.0 Setion 8.2.7 (CPMU Register Interface)
+ */
+#ifndef CXL_PMU_H
+#define CXL_PMU_H
+#include <linux/device.h>
+
+enum cxl_pmu_type {
+ CXL_PMU_MEMDEV,
+};
+
+#define CXL_PMU_REGMAP_SIZE 0xe00 /* Table 8-32 CXL 3.0 specification */
+struct cxl_pmu {
+ struct device dev;
+ void __iomem *base;
+ int assoc_id;
+ int index;
+ enum cxl_pmu_type type;
+};
+
+#define to_cxl_pmu(dev) container_of(dev, struct cxl_pmu, dev)
+struct cxl_pmu_regs;
+int devm_cxl_pmu_add(struct device *parent, struct cxl_pmu_regs *regs,
+ int assoc_id, int idx, enum cxl_pmu_type type);
+
+#endif
--
2.37.2