Merge tag 'acpi-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI updates from Rafael Wysocki:
 "These update the ACPICA code in the kernel to the 20180508 upstream
  revision and make it support the RT patch, add CPPC v3 support to the
  ACPI CPPC library, add a WDAT-based watchdog quirk to prevent clashes
  with the RTC, add quirks to the ACPI AC and battery drivers, and
  update the ACPI SoC drivers.

  Specifics:

   - Update the ACPICA code in the kernel to the 20180508 upstream
     revision including:
       * iASL -tc option enhancement (Bob Moore).
       * Debugger improvements (Bob Moore).
       * Support for tables larger than 1 MB in acpidump/acpixtract (Bob
         Moore).
       * Minor fixes and cleanups (Colin Ian King, Toomas Soome).

   - Make the ACPICA code in the kernel support the RT patch (Sebastian
     Andrzej Siewior, Steven Rostedt).

   - Add a kmemleak annotation to the ACPICA code (Larry Finger).

   - Add CPPC v3 support to the ACPI CPPC library and fix two issues
     related to CPPC (Prashanth Prakash, Al Stone).

   - Add an ACPI WDAT-based watchdog quirk to prefer iTCO_wdt on systems
     where WDAT clashes with the RTC SRAM (Mika Westerberg).

   - Add some quirks to the ACPI AC and battery drivers (Carlo Caione,
     Hans de Goede).

   - Update the ACPI SoC drivers for Intel (LPSS) and AMD (APD)
     platforms (Akshu Agrawal, Hans de Goede).

   - Fix up some assorted minor issues (Al Stone, Laszlo Toth, Mathieu
     Malaterre)"

* tag 'acpi-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  ACPICA: Mark acpi_ut_create_internal_object_dbg() memory allocations as non-leaks
  ACPI / watchdog: Prefer iTCO_wdt always when WDAT table uses RTC SRAM
  mailbox: PCC: erroneous error message when parsing ACPI PCCT
  ACPICA: Update version to 20180508
  ACPICA: acpidump/acpixtract: Support for tables larger than 1MB
  ACPI: APD: Add AMD misc clock handler support
  clk: x86: Add ST oscout platform clock
  ACPICA: Update version to 20180427
  ACPICA: Debugger: Removed direct support for EC address space in "Test Objects"
  ACPICA: Debugger: Add Package support for "test objects" command
  ACPICA: Improve error messages for the namespace root node
  ACPICA: Fix potential infinite loop in acpi_rs_dump_byte_list
  ACPICA: vsnprintf: this statement may fall through
  ACPICA: Tables: Fix spelling mistake in comment
  ACPICA: iASL: Enhance the -tc option (create AML hex file in C)
  ACPI: Add missing prototype_for arch_post_acpi_subsys_init()
  ACPI / tables: improve comments regarding acpi_parse_entries_array()
  ACPICA: Convert acpi_gbl_hardware lock back to an acpi_raw_spinlock
  ACPICA: provide abstraction for raw_spinlock_t
  ACPI / CPPC: Fix invalid PCC channel status errors
  ...

1 files changed, 69 insertions, 0 deletions

diff --git a/Documentation/acpi/cppc_sysfs.txt b/Documentation/acpi/cppc_sysfs.txt
new file mode 100644
index 000000000000..f20fb445135d
--- /dev/null
+++ b/Documentation/acpi/cppc_sysfs.txt
@@ -0,0 +1,69 @@
+
+	Collaborative Processor Performance Control (CPPC)
+
+CPPC defined in the ACPI spec describes a mechanism for the OS to manage the
+performance of a logical processor on a contigious and abstract performance
+scale. CPPC exposes a set of registers to describe abstract performance scale,
+to request performance levels and to measure per-cpu delivered performance.
+
+For more details on CPPC please refer to the ACPI specification at:
+
+http://uefi.org/specifications
+
+Some of the CPPC registers are exposed via sysfs under:
+
+/sys/devices/system/cpu/cpuX/acpi_cppc/
+
+for each cpu X
+
+--------------------------------------------------------------------------------
+
+$ ls -lR  /sys/devices/system/cpu/cpu0/acpi_cppc/
+/sys/devices/system/cpu/cpu0/acpi_cppc/:
+total 0
+-r--r--r-- 1 root root 65536 Mar  5 19:38 feedback_ctrs
+-r--r--r-- 1 root root 65536 Mar  5 19:38 highest_perf
+-r--r--r-- 1 root root 65536 Mar  5 19:38 lowest_freq
+-r--r--r-- 1 root root 65536 Mar  5 19:38 lowest_nonlinear_perf
+-r--r--r-- 1 root root 65536 Mar  5 19:38 lowest_perf
+-r--r--r-- 1 root root 65536 Mar  5 19:38 nominal_freq
+-r--r--r-- 1 root root 65536 Mar  5 19:38 nominal_perf
+-r--r--r-- 1 root root 65536 Mar  5 19:38 reference_perf
+-r--r--r-- 1 root root 65536 Mar  5 19:38 wraparound_time
+
+--------------------------------------------------------------------------------
+
+* highest_perf : Highest performance of this processor (abstract scale).
+* nominal_perf : Highest sustained performance of this processor (abstract scale).
+* lowest_nonlinear_perf : Lowest performance of this processor with nonlinear
+  power savings (abstract scale).
+* lowest_perf : Lowest performance of this processor (abstract scale).
+
+* lowest_freq : CPU frequency corresponding to lowest_perf (in MHz).
+* nominal_freq : CPU frequency corresponding to nominal_perf (in MHz).
+  The above frequencies should only be used to report processor performance in
+  freqency instead of abstract scale. These values should not be used for any
+  functional decisions.
+
+* feedback_ctrs : Includes both Reference and delivered performance counter.
+  Reference counter ticks up proportional to processor's reference performance.
+  Delivered counter ticks up proportional to processor's delivered performance.
+* wraparound_time: Minimum time for the feedback counters to wraparound (seconds).
+* reference_perf : Performance level at which reference performance counter
+  accumulates (abstract scale).
+
+--------------------------------------------------------------------------------
+
+		Computing Average Delivered Performance
+
+Below describes the steps to compute the average performance delivered by taking
+two different snapshots of feedback counters at time T1 and T2.
+
+T1: Read feedback_ctrs as fbc_t1
+    Wait or run some workload
+T2: Read feedback_ctrs as fbc_t2
+
+delivered_counter_delta = fbc_t2[del] - fbc_t1[del]
+reference_counter_delta = fbc_t2[ref] - fbc_t1[ref]
+
+delivered_perf = (refernce_perf x delivered_counter_delta) / reference_counter_delta