[PATCH v3] powerpc/kernel/sysfs: Export ldbar spr to sysfs

From: Anju T Sudhakar
Date: Thu Nov 09 2017 - 07:13:37 EST


Add ldbar spr to sysfs. The spr holds thread level In-Memory Collection (IMC)
counter configuration data. Exposing this will help to understand the current
configuration of thread-level counters in the system.
Primarily, Bit 0 of ldbar says whether the counters are enabled or not.
And bit 1 indicates the mode (if 0-Accumulation Mode/if 1-Trace Mode).

Signed-off-by: Anju T Sudhakar <anju@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/sysfs.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 4437c70..f8caee0 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -485,6 +485,7 @@ SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
SYSFS_SPRSETUP(purr, SPRN_PURR);
SYSFS_SPRSETUP(spurr, SPRN_SPURR);
SYSFS_SPRSETUP(pir, SPRN_PIR);
+SYSFS_SPRSETUP(ldbar, SPRN_LDBAR);

/*
Lets only enable read for phyp resources and
@@ -492,6 +493,7 @@ SYSFS_SPRSETUP(pir, SPRN_PIR);
Lets be conservative and default to pseries.
*/
static DEVICE_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
+static DEVICE_ATTR(ldbar, 0400, show_ldbar, store_ldbar);
static DEVICE_ATTR(spurr, 0400, show_spurr, NULL);
static DEVICE_ATTR(purr, 0400, show_purr, store_purr);
static DEVICE_ATTR(pir, 0400, show_pir, NULL);
@@ -757,6 +759,9 @@ static int register_cpu_online(unsigned int cpu)
device_create_file(s, &pmc_attrs[i]);

#ifdef CONFIG_PPC64
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ device_create_file(s, &dev_attr_ldbar);
+
if (cpu_has_feature(CPU_FTR_MMCRA))
device_create_file(s, &dev_attr_mmcra);

@@ -842,6 +847,9 @@ static int unregister_cpu_online(unsigned int cpu)
device_remove_file(s, &pmc_attrs[i]);

#ifdef CONFIG_PPC64
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ device_remove_file(s, &dev_attr_ldbar);
+
if (cpu_has_feature(CPU_FTR_MMCRA))
device_remove_file(s, &dev_attr_mmcra);

--
2.7.4