Patch adds a device tree function to detect the nest pmu
support. Function will look for specific dt property "ibm,ima-chip"
as a detection mechanism for the nest pmu.
For Nest pmu, device tree will have two set of information.
1) Per-chip Homer address region for nest pmu counter collection area.
2) Supported Nest PMUs and events
Device tree layout for the Nest PMU as follows.
/ -- DT root folder
|
-nest-ima -- Nest PMU folder
|
-ima-chip@<chip-id> -- Per-chip folder for HOMER region information
|
-ibm,chip-id -- Chip id
-ibm,ima-chip
-reg -- HOMER PORE Nest Counter collection Address (RA)
-size -- size to map in kernel space
-Alink_BW -- Nest PMU folder
|
-Alink0 -- Nest PMU Alink Event file
-scale.Alink0.scale -- Event scale file
-unit.Alink0.unit -- Event unit file
-device_type -- "nest-ima-unit" marker
....
Patch save per-chip HOMER offset and maps the same to kernel structure.
Subsequent patch will parse the next part of the DT to find various
Nest PMUs and their events.
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khand...@linux.vnet.ibm.com>
Cc: Stephane Eranian <eran...@google.com>
Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com>
---
arch/powerpc/perf/nest-pmu.c | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c
index 345707c..c979e57 100644
--- a/arch/powerpc/perf/nest-pmu.c
+++ b/arch/powerpc/perf/nest-pmu.c
@@ -11,6 +11,7 @@
#include "nest-pmu.h"
+static struct perchip_nest_info p8_perchip_nest_info[P8_MAX_CHIP];
static cpumask_t cpu_mask_nest_pmu;
static ssize_t cpumask_nest_pmu_get_attr(struct device *dev,
@@ -242,6 +243,36 @@ static int update_pmu_ops(struct nest_pmu *pmu)
return 0;
}
+static int nest_ima_detect_parse(void)
+{
+ const __be32 *gcid;
+ const __be64 *chip_ima_reg;
+ const __be64 *chip_ima_size;
+ struct device_node *dev;
+ int rc = -EINVAL, idx;
+
+ for_each_node_with_property(dev, "ibm,ima-chip") {
+ gcid = of_get_property(dev, "ibm,chip-id", NULL);
+ chip_ima_reg = of_get_property(dev, "reg", NULL);
+ chip_ima_size = of_get_property(dev, "size", NULL);
+ if ((!gcid) || (!chip_ima_reg) || (!chip_ima_size)) {
+ pr_err("%s: device %s missing property \n",
+ __func__, dev->full_name);
+ return rc;
+ }
+
+ idx = (uint32_t)be32_to_cpup(gcid);
+ p8_perchip_nest_info[idx].pbase = be64_to_cpup(chip_ima_reg);
+ p8_perchip_nest_info[idx].size = be64_to_cpup(chip_ima_size);
+ p8_perchip_nest_info[idx].vbase = (uint64_t)
+ phys_to_virt(p8_perchip_nest_info[idx].pbase);
+
+ rc = 0;
+ }
+
+ return rc;
+}
+
static int __init nest_pmu_init(void)
{
int ret = 0;
@@ -256,6 +287,12 @@ static int __init nest_pmu_init(void)
cpumask_chip();
+ /*
+ * Detect the Nest PMU feature
+ */
+ if (nest_ima_detect_parse())
+ return 0;
+
return 0;
}
device_initcall(nest_pmu_init);
--
1.9.1
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