[PATCH v7 3/7] powerpc/powernv: Nest PMU detection and device tree parser
From: Madhavan Srinivasan <hidden>
Date: 2015-08-03 07:36:30
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Create a file "nest-pmu.c" to contain nest pmu related functions. Code
to detect nest pmu support and parser to collect per-chip reserved memory
region information from device tree (DT).
Detection mechanism is to look for specific property "ibm,ima-chip" in DT.
For Nest pmu, device tree will have two set of information.
1) Per-chip reserved memory 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 reserved 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
....
Subsequent patch will parse the next part of the DT to find various
Nest PMUs and their events.
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <redacted>
Cc: Anton Blanchard <redacted>
Cc: Sukadev Bhattiprolu <redacted>
Cc: Daniel Axtens <redacted>
Cc: Stephane Eranian <redacted>
Signed-off-by: Madhavan Srinivasan <redacted>
---
arch/powerpc/perf/Makefile | 2 +-
arch/powerpc/perf/nest-pmu.c | 72 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 73 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/perf/nest-pmu.c
diff --git a/arch/powerpc/perf/Makefile b/arch/powerpc/perf/Makefile
index f9c083a5652a..6da656b50e3c 100644
--- a/arch/powerpc/perf/Makefile
+++ b/arch/powerpc/perf/Makefile@@ -5,7 +5,7 @@ obj-$(CONFIG_PERF_EVENTS) += callchain.o obj-$(CONFIG_PPC_PERF_CTRS) += core-book3s.o bhrb.o obj64-$(CONFIG_PPC_PERF_CTRS) += power4-pmu.o ppc970-pmu.o power5-pmu.o \ power5+-pmu.o power6-pmu.o power7-pmu.o \ - power8-pmu.o + power8-pmu.o nest-pmu.o obj32-$(CONFIG_PPC_PERF_CTRS) += mpc7450-pmu.o obj-$(CONFIG_FSL_EMB_PERF_EVENT) += core-fsl-emb.o
diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c
new file mode 100644
index 000000000000..48738f9f6426
--- /dev/null
+++ b/arch/powerpc/perf/nest-pmu.c@@ -0,0 +1,72 @@ +/* + * Nest Performance Monitor counter support for POWER8 processors. + * + * Copyright (C) 2015 Madhavan Srinivasan, IBM Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include "nest-pmu.h" + +static struct perchip_nest_info p8_nest_perchip_info[P8_NEST_MAX_CHIPS]; + +static int nest_ima_dt_parser(void) +{ + struct device_node *dev; + struct perchip_nest_info *p8ni; + u32 idx; + + /* + * "nest-ima" folder contains two things, + * a) per-chip reserved memory region for Nest PMU Counter data + * b) Support Nest PMU units and their event files + */ + for_each_node_with_property(dev, "ibm,ima-chip") { + if (of_property_read_u32(dev, "ibm,chip-id", &idx)) { + pr_err("Nest_PMU: device %s missing property\n", + dev->full_name); + return -ENODEV; + } + p8ni = &p8_nest_perchip_info[idx]; + + if (of_property_read_u64(dev, "reg", &p8ni->pbase)) { + pr_err("Nest_PMU: device %s missing property\n", + dev->full_name); + return -ENODEV; + } + p8ni->vbase = (u64)phys_to_virt(p8ni->pbase); + } + + return 0; +} + +static int __init nest_pmu_init(void) +{ + int ret = -ENODEV; + + /* + * Lets do this only if we are hypervisor + */ + if (!cpu_has_feature(CPU_FTR_HVMODE)) + return ret; + + /* + * Nest PMU information is grouped under "nest-ima" node + * of the top-level device-tree directory. Detect Nest PMU + * by the "ibm,ima-chip" property. + */ + if (!of_find_node_with_property(NULL, "ibm,ima-chip")) + return ret; + + /* + * Parse device-tree for Nest PMU information + */ + ret = nest_ima_dt_parser(); + if (ret) + return ret; + + return 0; +} +device_initcall(nest_pmu_init);
--
1.9.1