Merge tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "We have a few new features this time, including a new SFI-based
  cpufreq driver, a new devfreq driver for Tegra Activity Monitor, a new
  devfreq class for providing its governors with raw utilization data
  and a new ACPI driver for AMD SoCs.

  Still, the majority of changes here are reworks of existing code to
  make it more straightforward or to prepare it for implementing new
  features on top of it.  The primary example is the rework of ACPI
  resources handling from Jiang Liu, Thomas Gleixner and Lv Zheng with
  support for IOAPIC hotplug implemented on top of it, but there is
  quite a number of changes of this kind in the cpufreq core, ACPICA,
  ACPI EC driver, ACPI processor driver and the generic power domains
  core code too.

  The most active developer is Viresh Kumar with his cpufreq changes.

  Specifics:

   - Rework of the core ACPI resources parsing code to fix issues in it
     and make using resource offsets more convenient and consolidation
     of some resource-handing code in a couple of places that have grown
     analagous data structures and code to cover the the same gap in the
     core (Jiang Liu, Thomas Gleixner, Lv Zheng).

   - ACPI-based IOAPIC hotplug support on top of the resources handling
     rework (Jiang Liu, Yinghai Lu).

   - ACPICA update to upstream release 20150204 including an interrupt
     handling rework that allows drivers to install raw handlers for
     ACPI GPEs which then become entirely responsible for the given GPE
     and the ACPICA core code won't touch it (Lv Zheng, David E Box,
     Octavian Purdila).

   - ACPI EC driver rework to fix several concurrency issues and other
     problems related to events handling on top of the ACPICA's new
     support for raw GPE handlers (Lv Zheng).

   - New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
     Subsystem) driver for Intel chips (Ken Xue).

   - Two minor fixes of the ACPI LPSS driver (Heikki Krogerus, Jarkko
     Nikula).

   - Two new blacklist entries for machines (Samsung 730U3E/740U3E and
     510R) where the native backlight interface doesn't work correctly
     while the ACPI one does (Hans de Goede).

   - Rework of the ACPI processor driver's handling of idle states to
     make the code more straightforward and less bloated overall (Rafael
     J Wysocki).

   - Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
     Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki, Yaowei
     Bai).

   - PCI core power management modification to avoid resuming (some)
     runtime-suspended devices during system suspend if they are in the
     right states already (Rafael J Wysocki).

   - New SFI-based cpufreq driver for Intel platforms using SFI
     (Srinidhi Kasagar).

   - cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
     Doug Anderson, Wolfram Sang).

   - SkyLake CPU support and other updates for the intel_pstate driver
     (Kristen Carlson Accardi, Srinivas Pandruvada).

   - cpufreq-dt driver cleanup (Markus Elfring).

   - Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).

   - Generic power domains core code fixes and cleanups (Ulf Hansson).

   - Operating Performance Points (OPP) core code cleanups and kernel
     documentation update (Nishanth Menon).

   - New dabugfs interface to make the list of PM QoS constraints
     available to user space (Nishanth Menon).

   - New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).

   - New devfreq class (devfreq_event) to provide raw utilization data
     to devfreq governors (Chanwoo Choi).

   - Assorted minor fixes and cleanups related to power management
     (Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist, Pavel
     Machek, Todd E Brandt, Wonhong Kwon).

   - turbostat updates (Len Brown) and cpupower Makefile improvement
     (Sriram Raghunathan)"

* tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (151 commits)
  tools/power turbostat: relax dependency on APERF_MSR
  tools/power turbostat: relax dependency on invariant TSC
  Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources
  tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS
  tools/power turbostat: relax dependency on root permission
  ACPI / video: Add disable_native_backlight quirk for Samsung 510R
  ACPI / PM: Remove unneeded nested #ifdef
  USB / PM: Remove unneeded #ifdef and associated dead code
  intel_pstate: provide option to only use intel_pstate with HWP
  ACPI / EC: Add GPE reference counting debugging messages
  ACPI / EC: Add query flushing support
  ACPI / EC: Refine command storm prevention support
  ACPI / EC: Add command flushing support.
  ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag
  ACPI: add AMD ACPI2Platform device support for x86 system
  ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()
  ACPI / EC: Update revision due to raw handler mode.
  ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp.
  ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode.
  ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model
  ...

14 files changed, 321 insertions, 107 deletions

diff --git a/tools/power/acpi/common/cmfsize.c b/tools/power/acpi/common/cmfsize.c
index f4b953354ff7..eec688041500 100644
--- a/tools/power/acpi/common/cmfsize.c
+++ b/tools/power/acpi/common/cmfsize.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/common/getopt.c b/tools/power/acpi/common/getopt.c
index 2f0f34a36db4..5da129e10aa2 100644
--- a/tools/power/acpi/common/getopt.c
+++ b/tools/power/acpi/common/getopt.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/os_specific/service_layers/oslibcfs.c b/tools/power/acpi/os_specific/service_layers/oslibcfs.c
index c13ff9c51d74..b51e40a9a120 100644
--- a/tools/power/acpi/os_specific/service_layers/oslibcfs.c
+++ b/tools/power/acpi/os_specific/service_layers/oslibcfs.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/os_specific/service_layers/oslinuxtbl.c b/tools/power/acpi/os_specific/service_layers/oslinuxtbl.c
index 0dc2485dedf5..92f1fd700344 100644
--- a/tools/power/acpi/os_specific/service_layers/oslinuxtbl.c
+++ b/tools/power/acpi/os_specific/service_layers/oslinuxtbl.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/os_specific/service_layers/osunixdir.c b/tools/power/acpi/os_specific/service_layers/osunixdir.c
index 733f9e490fc4..e153fcb12b1a 100644
--- a/tools/power/acpi/os_specific/service_layers/osunixdir.c
+++ b/tools/power/acpi/os_specific/service_layers/osunixdir.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/os_specific/service_layers/osunixmap.c b/tools/power/acpi/os_specific/service_layers/osunixmap.c
index 99b47b6194a3..3853a7350440 100644
--- a/tools/power/acpi/os_specific/service_layers/osunixmap.c
+++ b/tools/power/acpi/os_specific/service_layers/osunixmap.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/os_specific/service_layers/osunixxf.c b/tools/power/acpi/os_specific/service_layers/osunixxf.c
index 7ccb073f8316..6858c0893c91 100644
--- a/tools/power/acpi/os_specific/service_layers/osunixxf.c
+++ b/tools/power/acpi/os_specific/service_layers/osunixxf.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/tools/acpidump/acpidump.h b/tools/power/acpi/tools/acpidump/acpidump.h
index a2d37d610639..84bdef0136cb 100644
--- a/tools/power/acpi/tools/acpidump/acpidump.h
+++ b/tools/power/acpi/tools/acpidump/acpidump.h
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/tools/acpidump/apdump.c b/tools/power/acpi/tools/acpidump/apdump.c
index 24d32968802d..c736adf5fb55 100644
--- a/tools/power/acpi/tools/acpidump/apdump.c
+++ b/tools/power/acpi/tools/acpidump/apdump.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/tools/acpidump/apfiles.c b/tools/power/acpi/tools/acpidump/apfiles.c
index d470046a6d81..8f2fe168228e 100644
--- a/tools/power/acpi/tools/acpidump/apfiles.c
+++ b/tools/power/acpi/tools/acpidump/apfiles.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/acpi/tools/acpidump/apmain.c b/tools/power/acpi/tools/acpidump/apmain.c
index 853b4da22c3e..d0ba6535f5af 100644
--- a/tools/power/acpi/tools/acpidump/apmain.c
+++ b/tools/power/acpi/tools/acpidump/apmain.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2014, Intel Corp.
+ * Copyright (C) 2000 - 2015, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/tools/power/cpupower/Makefile b/tools/power/cpupower/Makefile
index 2e2ba2efa0d9..3ed7c0476d48 100644
--- a/tools/power/cpupower/Makefile
+++ b/tools/power/cpupower/Makefile
@@ -209,7 +209,7 @@ $(OUTPUT)%.o: %.c
 
 $(OUTPUT)cpupower: $(UTIL_OBJS) $(OUTPUT)libcpupower.so.$(LIB_MAJ)
 	$(ECHO) "  CC      " $@
-	$(QUIET) $(CC) $(CFLAGS) $(LDFLAGS) $(UTIL_OBJS) -lcpupower -lrt -lpci -L$(OUTPUT) -o $@
+	$(QUIET) $(CC) $(CFLAGS) $(LDFLAGS) $(UTIL_OBJS) -lcpupower -Wl,-rpath=./ -lrt -lpci -L$(OUTPUT) -o $@
 	$(QUIET) $(STRIPCMD) $@
 
 $(OUTPUT)po/$(PACKAGE).pot: $(UTIL_SRC)
diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8
index 56bfb523c5bb..9b950699e63d 100644
--- a/tools/power/x86/turbostat/turbostat.8
+++ b/tools/power/x86/turbostat/turbostat.8
@@ -12,16 +12,16 @@ turbostat \- Report processor frequency and idle statistics
 .RB [ "\-i interval_sec" ]
 .SH DESCRIPTION
 \fBturbostat \fP reports processor topology, frequency,
-idle power-state statistics, temperature and power on modern X86 processors.
-Either \fBcommand\fP is forked and statistics are printed
-upon its completion, or statistics are printed periodically.
-
-\fBturbostat \fP
-must be run on root, and
-minimally requires that the processor
-supports an "invariant" TSC, plus the APERF and MPERF MSRs.
-Additional information is reported depending on hardware counter support.
-
+idle power-state statistics, temperature and power on X86 processors.
+There are two ways to invoke turbostat.
+The first method is to supply a
+\fBcommand\fP, which is forked and statistics are printed
+upon its completion.
+The second method is to omit the command,
+and turbodstat will print statistics every 5 seconds.
+The 5-second interval can changed using the -i option.
+
+Some information is not availalbe on older processors.
 .SS Options
 The \fB-p\fP option limits output to the 1st thread in 1st core of each package.
 .PP
@@ -130,12 +130,13 @@ cpu3: MSR_IA32_THERM_STATUS: 0x884e0000 (27 C +/- 1)
  ...
 .fi
 The \fBmax efficiency\fP frequency, a.k.a. Low Frequency Mode, is the frequency
-available at the minimum package voltage.  The \fBTSC frequency\fP is the nominal
-maximum frequency of the processor if turbo-mode were not available.  This frequency
+available at the minimum package voltage.  The \fBTSC frequency\fP is the base
+frequency of the processor -- this should match the brand string
+in /proc/cpuinfo.  This base frequency
 should be sustainable on all CPUs indefinitely, given nominal power and cooling.
 The remaining rows show what maximum turbo frequency is possible
-depending on the number of idle cores.  Note that this information is
-not available on all processors.
+depending on the number of idle cores.  Note that not all information is
+available on all processors.
 .SH FORK EXAMPLE
 If turbostat is invoked with a command, it will fork that command
 and output the statistics gathered when the command exits.
@@ -176,6 +177,11 @@ not including any non-busy idle time.
 
 .B "turbostat "
 must be run as root.
+Alternatively, non-root users can be enabled to run turbostat this way:
+
+# setcap cap_sys_rawio=ep ./turbostat
+
+# chmod +r /dev/cpu/*/msr
 
 .B "turbostat "
 reads hardware counters, but doesn't write them.
@@ -184,15 +190,33 @@ multiple invocations of itself.
 
 \fBturbostat \fP
 may work poorly on Linux-2.6.20 through 2.6.29,
-as \fBacpi-cpufreq \fPperiodically cleared the APERF and MPERF
+as \fBacpi-cpufreq \fPperiodically cleared the APERF and MPERF MSRs
 in those kernels.
 
-If the TSC column does not make sense, then
-the other numbers will also make no sense.
-Turbostat is lightweight, and its data collection is not atomic.
-These issues are usually caused by an extremely short measurement
-interval (much less than 1 second), or system activity that prevents
-turbostat from being able to run on all CPUS to quickly collect data.
+AVG_MHz = APERF_delta/measurement_interval.  This is the actual
+number of elapsed cycles divided by the entire sample interval --
+including idle time.  Note that this calculation is resiliant
+to systems lacking a non-stop TSC.
+
+TSC_MHz = TSC_delta/measurement_interval.
+On a system with an invariant TSC, this value will be constant
+and will closely match the base frequency value shown
+in the brand string in /proc/cpuinfo.  On a system where
+the TSC stops in idle, TSC_MHz will drop
+below the processor's base frequency.
+
+%Busy = MPERF_delta/TSC_delta
+
+Bzy_MHz = TSC_delta/APERF_delta/MPERF_delta/measurement_interval
+
+Note that these calculations depend on TSC_delta, so they
+are not reliable during intervals when TSC_MHz is not running at the base frequency.
+
+Turbostat data collection is not atomic.
+Extremely short measurement intervals (much less than 1 second),
+or system activity that prevents turbostat from being able
+to run on all CPUS to quickly collect data, will result in
+inconsistent results.
 
 The APERF, MPERF MSRs are defined to count non-halted cycles.
 Although it is not guaranteed by the architecture, turbostat assumes
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 5b1b807265a1..a02c02f25e88 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -38,6 +38,8 @@
 #include <ctype.h>
 #include <sched.h>
 #include <cpuid.h>
+#include <linux/capability.h>
+#include <errno.h>
 
 char *proc_stat = "/proc/stat";
 unsigned int interval_sec = 5;	/* set with -i interval_sec */
@@ -59,8 +61,8 @@ unsigned int has_epb;
 unsigned int units = 1000000;	/* MHz etc */
 unsigned int genuine_intel;
 unsigned int has_invariant_tsc;
-unsigned int do_nehalem_platform_info;
-unsigned int do_nehalem_turbo_ratio_limit;
+unsigned int do_nhm_platform_info;
+unsigned int do_nhm_turbo_ratio_limit;
 unsigned int do_ivt_turbo_ratio_limit;
 unsigned int extra_msr_offset32;
 unsigned int extra_msr_offset64;
@@ -81,6 +83,9 @@ unsigned int tcc_activation_temp;
 unsigned int tcc_activation_temp_override;
 double rapl_power_units, rapl_energy_units, rapl_time_units;
 double rapl_joule_counter_range;
+unsigned int do_core_perf_limit_reasons;
+unsigned int do_gfx_perf_limit_reasons;
+unsigned int do_ring_perf_limit_reasons;
 
 #define RAPL_PKG		(1 << 0)
 					/* 0x610 MSR_PKG_POWER_LIMIT */
@@ -251,15 +256,13 @@ int get_msr(int cpu, off_t offset, unsigned long long *msr)
 	sprintf(pathname, "/dev/cpu/%d/msr", cpu);
 	fd = open(pathname, O_RDONLY);
 	if (fd < 0)
-		return -1;
+		err(-1, "%s open failed, try chown or chmod +r /dev/cpu/*/msr, or run as root", pathname);
 
 	retval = pread(fd, msr, sizeof *msr, offset);
 	close(fd);
 
-	if (retval != sizeof *msr) {
-		fprintf(stderr, "%s offset 0x%llx read failed\n", pathname, (unsigned long long)offset);
-		return -1;
-	}
+	if (retval != sizeof *msr)
+		err(-1, "%s offset 0x%llx read failed", pathname, (unsigned long long)offset);
 
 	return 0;
 }
@@ -281,7 +284,7 @@ void print_header(void)
 		outp += sprintf(outp, "     CPU");
 	if (has_aperf)
 		outp += sprintf(outp, " Avg_MHz");
-	if (do_nhm_cstates)
+	if (has_aperf)
 		outp += sprintf(outp, "   %%Busy");
 	if (has_aperf)
 		outp += sprintf(outp, " Bzy_MHz");
@@ -337,7 +340,7 @@ void print_header(void)
 			outp += sprintf(outp, "   PKG_%%");
 		if (do_rapl & RAPL_DRAM_PERF_STATUS)
 			outp += sprintf(outp, "   RAM_%%");
-	} else {
+	} else if (do_rapl && rapl_joules) {
 		if (do_rapl & RAPL_PKG)
 			outp += sprintf(outp, "   Pkg_J");
 		if (do_rapl & RAPL_CORES)
@@ -457,25 +460,25 @@ int format_counters(struct thread_data *t, struct core_data *c,
 			outp += sprintf(outp, "%8d", t->cpu_id);
 	}
 
-	/* AvgMHz */
+	/* Avg_MHz */
 	if (has_aperf)
 		outp += sprintf(outp, "%8.0f",
 			1.0 / units * t->aperf / interval_float);
 
-	/* %c0 */
-	if (do_nhm_cstates) {
+	/* %Busy */
+	if (has_aperf) {
 		if (!skip_c0)
 			outp += sprintf(outp, "%8.2f", 100.0 * t->mperf/t->tsc);
 		else
 			outp += sprintf(outp, "********");
 	}
 
-	/* BzyMHz */
+	/* Bzy_MHz */
 	if (has_aperf)
 		outp += sprintf(outp, "%8.0f",
 			1.0 * t->tsc / units * t->aperf / t->mperf / interval_float);
 
-	/* TSC */
+	/* TSC_MHz */
 	outp += sprintf(outp, "%8.0f", 1.0 * t->tsc/units/interval_float);
 
 	/* SMI */
@@ -561,7 +564,7 @@ int format_counters(struct thread_data *t, struct core_data *c,
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_pkg_perf_status * rapl_time_units / interval_float);
 		if (do_rapl & RAPL_DRAM_PERF_STATUS)
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_dram_perf_status * rapl_time_units / interval_float);
-	} else {
+	} else if (do_rapl && rapl_joules) {
 		if (do_rapl & RAPL_PKG)
 			outp += sprintf(outp, fmt8,
 					p->energy_pkg * rapl_energy_units);
@@ -578,8 +581,8 @@ int format_counters(struct thread_data *t, struct core_data *c,
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_pkg_perf_status * rapl_time_units / interval_float);
 		if (do_rapl & RAPL_DRAM_PERF_STATUS)
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_dram_perf_status * rapl_time_units / interval_float);
-	outp += sprintf(outp, fmt8, interval_float);
 
+		outp += sprintf(outp, fmt8, interval_float);
 	}
 done:
 	outp += sprintf(outp, "\n");
@@ -670,24 +673,26 @@ delta_thread(struct thread_data *new, struct thread_data *old,
 
 	old->c1 = new->c1 - old->c1;
 
-	if ((new->aperf > old->aperf) && (new->mperf > old->mperf)) {
-		old->aperf = new->aperf - old->aperf;
-		old->mperf = new->mperf - old->mperf;
-	} else {
+	if (has_aperf) {
+		if ((new->aperf > old->aperf) && (new->mperf > old->mperf)) {
+			old->aperf = new->aperf - old->aperf;
+			old->mperf = new->mperf - old->mperf;
+		} else {
 
-		if (!aperf_mperf_unstable) {
-			fprintf(stderr, "%s: APERF or MPERF went backwards *\n", progname);
-			fprintf(stderr, "* Frequency results do not cover entire interval *\n");
-			fprintf(stderr, "* fix this by running Linux-2.6.30 or later *\n");
+			if (!aperf_mperf_unstable) {
+				fprintf(stderr, "%s: APERF or MPERF went backwards *\n", progname);
+				fprintf(stderr, "* Frequency results do not cover entire interval *\n");
+				fprintf(stderr, "* fix this by running Linux-2.6.30 or later *\n");
 
-			aperf_mperf_unstable = 1;
+				aperf_mperf_unstable = 1;
+			}
+			/*
+			 * mperf delta is likely a huge "positive" number
+			 * can not use it for calculating c0 time
+			 */
+			skip_c0 = 1;
+			skip_c1 = 1;
 		}
-		/*
-		 * mperf delta is likely a huge "positive" number
-		 * can not use it for calculating c0 time
-		 */
-		skip_c0 = 1;
-		skip_c1 = 1;
 	}
 
 
@@ -1019,7 +1024,7 @@ void print_verbose_header(void)
 	unsigned long long msr;
 	unsigned int ratio;
 
-	if (!do_nehalem_platform_info)
+	if (!do_nhm_platform_info)
 		return;
 
 	get_msr(0, MSR_NHM_PLATFORM_INFO, &msr);
@@ -1132,7 +1137,7 @@ print_nhm_turbo_ratio_limits:
 	}
 	fprintf(stderr, ")\n");
 
-	if (!do_nehalem_turbo_ratio_limit)
+	if (!do_nhm_turbo_ratio_limit)
 		return;
 
 	get_msr(0, MSR_NHM_TURBO_RATIO_LIMIT, &msr);
@@ -1178,6 +1183,7 @@ print_nhm_turbo_ratio_limits:
 	if (ratio)
 		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 1 active cores\n",
 			ratio, bclk, ratio * bclk);
+
 }
 
 void free_all_buffers(void)
@@ -1458,17 +1464,60 @@ void check_dev_msr()
 	struct stat sb;
 
 	if (stat("/dev/cpu/0/msr", &sb))
-		err(-5, "no /dev/cpu/0/msr\n"
-		    "Try \"# modprobe msr\"");
+		err(-5, "no /dev/cpu/0/msr, Try \"# modprobe msr\" ");
 }
 
-void check_super_user()
+void check_permissions()
 {
-	if (getuid() != 0)
-		errx(-6, "must be root");
+	struct __user_cap_header_struct cap_header_data;
+	cap_user_header_t cap_header = &cap_header_data;
+	struct __user_cap_data_struct cap_data_data;
+	cap_user_data_t cap_data = &cap_data_data;
+	extern int capget(cap_user_header_t hdrp, cap_user_data_t datap);
+	int do_exit = 0;
+
+	/* check for CAP_SYS_RAWIO */
+	cap_header->pid = getpid();
+	cap_header->version = _LINUX_CAPABILITY_VERSION;
+	if (capget(cap_header, cap_data) < 0)
+		err(-6, "capget(2) failed");
+
+	if ((cap_data->effective & (1 << CAP_SYS_RAWIO)) == 0) {
+		do_exit++;
+		warnx("capget(CAP_SYS_RAWIO) failed,"
+			" try \"# setcap cap_sys_rawio=ep %s\"", progname);
+	}
+
+	/* test file permissions */
+	if (euidaccess("/dev/cpu/0/msr", R_OK)) {
+		do_exit++;
+		warn("/dev/cpu/0/msr open failed, try chown or chmod +r /dev/cpu/*/msr");
+	}
+
+	/* if all else fails, thell them to be root */
+	if (do_exit)
+		if (getuid() != 0)
+			warnx("... or simply run as root");
+
+	if (do_exit)
+		exit(-6);
 }
 
-int has_nehalem_turbo_ratio_limit(unsigned int family, unsigned int model)
+/*
+ * NHM adds support for additional MSRs:
+ *
+ * MSR_SMI_COUNT                   0x00000034
+ *
+ * MSR_NHM_PLATFORM_INFO           0x000000ce
+ * MSR_NHM_SNB_PKG_CST_CFG_CTL     0x000000e2
+ *
+ * MSR_PKG_C3_RESIDENCY            0x000003f8
+ * MSR_PKG_C6_RESIDENCY            0x000003f9
+ * MSR_CORE_C3_RESIDENCY           0x000003fc
+ * MSR_CORE_C6_RESIDENCY           0x000003fd
+ *
+ */
+int has_nhm_msrs(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return 0;
@@ -1495,13 +1544,27 @@ int has_nehalem_turbo_ratio_limit(unsigned int family, unsigned int model)
 	case 0x3D:	/* BDW */
 	case 0x4F:	/* BDX */
 	case 0x56:	/* BDX-DE */
-		return 1;
 	case 0x2E:	/* Nehalem-EX Xeon - Beckton */
 	case 0x2F:	/* Westmere-EX Xeon - Eagleton */
+		return 1;
 	default:
 		return 0;
 	}
 }
+int has_nhm_turbo_ratio_limit(unsigned int family, unsigned int model)
+{
+	if (!has_nhm_msrs(family, model))
+		return 0;
+
+	switch (model) {
+	/* Nehalem compatible, but do not include turbo-ratio limit support */
+	case 0x2E:	/* Nehalem-EX Xeon - Beckton */
+	case 0x2F:	/* Westmere-EX Xeon - Eagleton */
+		return 0;
+	default:
+		return 1;
+	}
+}
 int has_ivt_turbo_ratio_limit(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
@@ -1564,6 +1627,103 @@ int print_epb(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 	return 0;
 }
 
+/*
+ * print_perf_limit()
+ */
+int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data *p)
+{
+	unsigned long long msr;
+	int cpu;
+
+	cpu = t->cpu_id;
+
+	/* per-package */
+	if (!(t->flags & CPU_IS_FIRST_THREAD_IN_CORE) || !(t->flags & CPU_IS_FIRST_CORE_IN_PACKAGE))
+		return 0;
+
+	if (cpu_migrate(cpu)) {
+		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		return -1;
+	}
+
+	if (do_core_perf_limit_reasons) {
+		get_msr(cpu, MSR_CORE_PERF_LIMIT_REASONS, &msr);
+		fprintf(stderr, "cpu%d: MSR_CORE_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
+		fprintf(stderr, " (Active: %s%s%s%s%s%s%s%s%s%s%s%s%s%s)",
+			(msr & 1 << 0) ? "PROCHOT, " : "",
+			(msr & 1 << 1) ? "ThermStatus, " : "",
+			(msr & 1 << 2) ? "bit2, " : "",
+			(msr & 1 << 4) ? "Graphics, " : "",
+			(msr & 1 << 5) ? "Auto-HWP, " : "",
+			(msr & 1 << 6) ? "VR-Therm, " : "",
+			(msr & 1 << 8) ? "Amps, " : "",
+			(msr & 1 << 9) ? "CorePwr, " : "",
+			(msr & 1 << 10) ? "PkgPwrL1, " : "",
+			(msr & 1 << 11) ? "PkgPwrL2, " : "",
+			(msr & 1 << 12) ? "MultiCoreTurbo, " : "",
+			(msr & 1 << 13) ? "Transitions, " : "",
+			(msr & 1 << 14) ? "bit14, " : "",
+			(msr & 1 << 15) ? "bit15, " : "");
+		fprintf(stderr, " (Logged: %s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
+			(msr & 1 << 16) ? "PROCHOT, " : "",
+			(msr & 1 << 17) ? "ThermStatus, " : "",
+			(msr & 1 << 18) ? "bit18, " : "",
+			(msr & 1 << 20) ? "Graphics, " : "",
+			(msr & 1 << 21) ? "Auto-HWP, " : "",
+			(msr & 1 << 22) ? "VR-Therm, " : "",
+			(msr & 1 << 24) ? "Amps, " : "",
+			(msr & 1 << 25) ? "CorePwr, " : "",
+			(msr & 1 << 26) ? "PkgPwrL1, " : "",
+			(msr & 1 << 27) ? "PkgPwrL2, " : "",
+			(msr & 1 << 28) ? "MultiCoreTurbo, " : "",
+			(msr & 1 << 29) ? "Transitions, " : "",
+			(msr & 1 << 30) ? "bit30, " : "",
+			(msr & 1 << 31) ? "bit31, " : "");
+
+	}
+	if (do_gfx_perf_limit_reasons) {
+		get_msr(cpu, MSR_GFX_PERF_LIMIT_REASONS, &msr);
+		fprintf(stderr, "cpu%d: MSR_GFX_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
+		fprintf(stderr, " (Active: %s%s%s%s%s%s%s%s)",
+			(msr & 1 << 0) ? "PROCHOT, " : "",
+			(msr & 1 << 1) ? "ThermStatus, " : "",
+			(msr & 1 << 4) ? "Graphics, " : "",
+			(msr & 1 << 6) ? "VR-Therm, " : "",
+			(msr & 1 << 8) ? "Amps, " : "",
+			(msr & 1 << 9) ? "GFXPwr, " : "",
+			(msr & 1 << 10) ? "PkgPwrL1, " : "",
+			(msr & 1 << 11) ? "PkgPwrL2, " : "");
+		fprintf(stderr, " (Logged: %s%s%s%s%s%s%s%s)\n",
+			(msr & 1 << 16) ? "PROCHOT, " : "",
+			(msr & 1 << 17) ? "ThermStatus, " : "",
+			(msr & 1 << 20) ? "Graphics, " : "",
+			(msr & 1 << 22) ? "VR-Therm, " : "",
+			(msr & 1 << 24) ? "Amps, " : "",
+			(msr & 1 << 25) ? "GFXPwr, " : "",
+			(msr & 1 << 26) ? "PkgPwrL1, " : "",
+			(msr & 1 << 27) ? "PkgPwrL2, " : "");
+	}
+	if (do_ring_perf_limit_reasons) {
+		get_msr(cpu, MSR_RING_PERF_LIMIT_REASONS, &msr);
+		fprintf(stderr, "cpu%d: MSR_RING_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
+		fprintf(stderr, " (Active: %s%s%s%s%s%s)",
+			(msr & 1 << 0) ? "PROCHOT, " : "",
+			(msr & 1 << 1) ? "ThermStatus, " : "",
+			(msr & 1 << 6) ? "VR-Therm, " : "",
+			(msr & 1 << 8) ? "Amps, " : "",
+			(msr & 1 << 10) ? "PkgPwrL1, " : "",
+			(msr & 1 << 11) ? "PkgPwrL2, " : "");
+		fprintf(stderr, " (Logged: %s%s%s%s%s%s)\n",
+			(msr & 1 << 16) ? "PROCHOT, " : "",
+			(msr & 1 << 17) ? "ThermStatus, " : "",
+			(msr & 1 << 22) ? "VR-Therm, " : "",
+			(msr & 1 << 24) ? "Amps, " : "",
+			(msr & 1 << 26) ? "PkgPwrL1, " : "",
+			(msr & 1 << 27) ? "PkgPwrL2, " : "");
+	}
+	return 0;
+}
+
 #define	RAPL_POWER_GRANULARITY	0x7FFF	/* 15 bit power granularity */
 #define	RAPL_TIME_GRANULARITY	0x3F /* 6 bit time granularity */
 
@@ -1653,6 +1813,27 @@ void rapl_probe(unsigned int family, unsigned int model)
 	return;
 }
 
+void perf_limit_reasons_probe(family, model)
+{
+	if (!genuine_intel)
+		return;
+
+	if (family != 6)
+		return;
+
+	switch (model) {
+	case 0x3C:	/* HSW */
+	case 0x45:	/* HSW */
+	case 0x46:	/* HSW */
+		do_gfx_perf_limit_reasons = 1;
+	case 0x3F:	/* HSX */
+		do_core_perf_limit_reasons = 1;
+		do_ring_perf_limit_reasons = 1;
+	default:
+		return;
+	}
+}
+
 int print_thermal(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 {
 	unsigned long long msr;
@@ -1842,8 +2023,15 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 	return 0;
 }
 
+/*
+ * SNB adds support for additional MSRs:
+ *
+ * MSR_PKG_C7_RESIDENCY            0x000003fa
+ * MSR_CORE_C7_RESIDENCY           0x000003fe
+ * MSR_PKG_C2_RESIDENCY            0x0000060d
+ */
 
-int is_snb(unsigned int family, unsigned int model)
+int has_snb_msrs(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return 0;
@@ -1865,7 +2053,14 @@ int is_snb(unsigned int family, unsigned int model)
 	return 0;
 }
 
-int has_c8_c9_c10(unsigned int family, unsigned int model)
+/*
+ * HSW adds support for additional MSRs:
+ *
+ * MSR_PKG_C8_RESIDENCY            0x00000630
+ * MSR_PKG_C9_RESIDENCY            0x00000631
+ * MSR_PKG_C10_RESIDENCY           0x00000632
+ */
+int has_hsw_msrs(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return 0;
@@ -1917,7 +2112,7 @@ double slm_bclk(void)
 
 double discover_bclk(unsigned int family, unsigned int model)
 {
-	if (is_snb(family, model))
+	if (has_snb_msrs(family, model))
 		return 100.00;
 	else if (is_slm(family, model))
 		return slm_bclk();
@@ -1965,7 +2160,7 @@ int set_temperature_target(struct thread_data *t, struct core_data *c, struct pk
 	}
 
 	/* Temperature Target MSR is Nehalem and newer only */
-	if (!do_nehalem_platform_info)
+	if (!do_nhm_platform_info)
 		goto guess;
 
 	if (get_msr(0, MSR_IA32_TEMPERATURE_TARGET, &msr))
@@ -2029,18 +2224,15 @@ void check_cpuid()
 	ebx = ecx = edx = 0;
 	__get_cpuid(0x80000000, &max_level, &ebx, &ecx, &edx);
 
-	if (max_level < 0x80000007)
-		errx(1, "CPUID: no invariant TSC (max_level 0x%x)", max_level);
+	if (max_level >= 0x80000007) {
 
-	/*
-	 * Non-Stop TSC is advertised by CPUID.EAX=0x80000007: EDX.bit8
-	 * this check is valid for both Intel and AMD
-	 */
-	__get_cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
-	has_invariant_tsc = edx & (1 << 8);
-
-	if (!has_invariant_tsc)
-		errx(1, "No invariant TSC");
+		/*
+		 * Non-Stop TSC is advertised by CPUID.EAX=0x80000007: EDX.bit8
+		 * this check is valid for both Intel and AMD
+		 */
+		__get_cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
+		has_invariant_tsc = edx & (1 << 8);
+	}
 
 	/*
 	 * APERF/MPERF is advertised by CPUID.EAX=0x6: ECX.bit0
@@ -2054,26 +2246,22 @@ void check_cpuid()
 	has_epb = ecx & (1 << 3);
 
 	if (verbose)
-		fprintf(stderr, "CPUID(6): %s%s%s%s\n",
-			has_aperf ? "APERF" : "No APERF!",
-			do_dts ? ", DTS" : "",
-			do_ptm ? ", PTM": "",
-			has_epb ? ", EPB": "");
-
-	if (!has_aperf)
-		errx(-1, "No APERF");
-
-	do_nehalem_platform_info = genuine_intel && has_invariant_tsc;
-	do_nhm_cstates = genuine_intel;	/* all Intel w/ non-stop TSC have NHM counters */
-	do_smi = do_nhm_cstates;
-	do_snb_cstates = is_snb(family, model);
-	do_c8_c9_c10 = has_c8_c9_c10(family, model);
+		fprintf(stderr, "CPUID(6): %sAPERF, %sDTS, %sPTM, %sEPB\n",
+			has_aperf ? "" : "No ",
+			do_dts ? "" : "No ",
+			do_ptm ? "" : "No ",
+			has_epb ? "" : "No ");
+
+	do_nhm_platform_info = do_nhm_cstates = do_smi = has_nhm_msrs(family, model);
+	do_snb_cstates = has_snb_msrs(family, model);
+	do_c8_c9_c10 = has_hsw_msrs(family, model);
 	do_slm_cstates = is_slm(family, model);
 	bclk = discover_bclk(family, model);
 
-	do_nehalem_turbo_ratio_limit = has_nehalem_turbo_ratio_limit(family, model);
+	do_nhm_turbo_ratio_limit = has_nhm_turbo_ratio_limit(family, model);
 	do_ivt_turbo_ratio_limit = has_ivt_turbo_ratio_limit(family, model);
 	rapl_probe(family, model);
+	perf_limit_reasons_probe(family, model);
 
 	return;
 }
@@ -2299,10 +2487,9 @@ void setup_all_buffers(void)
 
 void turbostat_init()
 {
-	check_cpuid();
-
 	check_dev_msr();
-	check_super_user();
+	check_permissions();
+	check_cpuid();
 
 	setup_all_buffers();
 
@@ -2313,6 +2500,9 @@ void turbostat_init()
 		for_all_cpus(print_epb, ODD_COUNTERS);
 
 	if (verbose)
+		for_all_cpus(print_perf_limit, ODD_COUNTERS);
+
+	if (verbose)
 		for_all_cpus(print_rapl, ODD_COUNTERS);
 
 	for_all_cpus(set_temperature_target, ODD_COUNTERS);
@@ -2441,7 +2631,7 @@ int main(int argc, char **argv)
 	cmdline(argc, argv);
 
 	if (verbose)
-		fprintf(stderr, "turbostat v3.7 Feb 6, 2014"
+		fprintf(stderr, "turbostat v3.9 23-Jan, 2015"
 			" - Len Brown <lenb@kernel.org>\n");
 
 	turbostat_init();