Merge tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "The big ticket items here are the rework of suspend-to-idle in order
  to add proper support for power button wakeup from it on recent Dell
  laptops and the rework of interfaces exporting the current CPU
  frequency on x86.

  In addition to that, support for a few new pieces of hardware is
  added, the PCI/ACPI device wakeup infrastructure is simplified
  significantly and the wakeup IRQ framework is fixed to unbreak the IRQ
  bus locking infrastructure.

  Also, there are some functional improvements for intel_pstate, tools
  updates and small fixes and cleanups all over.

  Specifics:

   - Rework suspend-to-idle to allow it to take wakeup events signaled
     by the EC into account on ACPI-based platforms in order to properly
     support power button wakeup from suspend-to-idle on recent Dell
     laptops (Rafael Wysocki).

     That includes the core suspend-to-idle code rework, support for the
     Low Power S0 _DSM interface, and support for the ACPI INT0002
     Virtual GPIO device from Hans de Goede (required for USB keyboard
     wakeup from suspend-to-idle to work on some machines).

   - Stop trying to export the current CPU frequency via /proc/cpuinfo
     on x86 as that is inaccurate and confusing (Len Brown).

   - Rework the way in which the current CPU frequency is exported by
     the kernel (over the cpufreq sysfs interface) on x86 systems with
     the APERF and MPERF registers by always using values read from
     these registers, when available, to compute the current frequency
     regardless of which cpufreq driver is in use (Len Brown).

   - Rework the PCI/ACPI device wakeup infrastructure to remove the
     questionable and artificial distinction between "devices that can
     wake up the system from sleep states" and "devices that can
     generate wakeup signals in the working state" from it, which allows
     the code to be simplified quite a bit (Rafael Wysocki).

   - Fix the wakeup IRQ framework by making it use SRCU instead of RCU
     which doesn't allow sleeping in the read-side critical sections,
     but which in turn is expected to be allowed by the IRQ bus locking
     infrastructure (Thomas Gleixner).

   - Modify some computations in the intel_pstate driver to avoid
     rounding errors resulting from them (Srinivas Pandruvada).

   - Reduce the overhead of the intel_pstate driver in the HWP
     (hardware-managed P-states) mode and when the "performance" P-state
     selection algorithm is in use by making it avoid registering
     scheduler callbacks in those cases (Len Brown).

   - Rework the energy_performance_preference sysfs knob in intel_pstate
     by changing the values that correspond to different symbolic hint
     names used by it (Len Brown).

   - Make it possible to use more than one cpuidle driver at the same
     time on ARM (Daniel Lezcano).

   - Make it possible to prevent the cpuidle menu governor from using
     the 0 state by disabling it via sysfs (Nicholas Piggin).

   - Add support for FFH (Fixed Functional Hardware) MWAIT in ACPI C1 on
     AMD systems (Yazen Ghannam).

   - Make the CPPC cpufreq driver take the lowest nonlinear performance
     information into account (Prashanth Prakash).

   - Add support for hi3660 to the cpufreq-dt driver, fix the imx6q
     driver and clean up the sfi, exynos5440 and intel_pstate drivers
     (Colin Ian King, Krzysztof Kozlowski, Octavian Purdila, Rafael
     Wysocki, Tao Wang).

   - Fix a few minor issues in the generic power domains (genpd)
     framework and clean it up somewhat (Krzysztof Kozlowski, Mikko
     Perttunen, Viresh Kumar).

   - Fix a couple of minor issues in the operating performance points
     (OPP) framework and clean it up somewhat (Viresh Kumar).

   - Fix a CONFIG dependency in the hibernation core and clean it up
     slightly (Balbir Singh, Arvind Yadav, BaoJun Luo).

   - Add rk3228 support to the rockchip-io adaptive voltage scaling
     (AVS) driver (David Wu).

   - Fix an incorrect bit shift operation in the RAPL power capping
     driver (Adam Lessnau).

   - Add support for the EPP field in the HWP (hardware managed
     P-states) control register, HWP.EPP, to the x86_energy_perf_policy
     tool and update msr-index.h with HWP.EPP values (Len Brown).

   - Fix some minor issues in the turbostat tool (Len Brown).

   - Add support for AMD family 0x17 CPUs to the cpupower tool and fix a
     minor issue in it (Sherry Hurwitz).

   - Assorted cleanups, mostly related to the constification of some
     data structures (Arvind Yadav, Joe Perches, Kees Cook, Krzysztof
     Kozlowski)"

* tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (69 commits)
  cpufreq: Update scaling_cur_freq documentation
  cpufreq: intel_pstate: Clean up after performance governor changes
  PM: hibernate: constify attribute_group structures.
  cpuidle: menu: allow state 0 to be disabled
  intel_idle: Use more common logging style
  PM / Domains: Fix missing default_power_down_ok comment
  PM / Domains: Fix unsafe iteration over modified list of domains
  PM / Domains: Fix unsafe iteration over modified list of domain providers
  PM / Domains: Fix unsafe iteration over modified list of device links
  PM / Domains: Handle safely genpd_syscore_switch() call on non-genpd device
  PM / Domains: Call driver's noirq callbacks
  PM / core: Drop run_wake flag from struct dev_pm_info
  PCI / PM: Simplify device wakeup settings code
  PCI / PM: Drop pme_interrupt flag from struct pci_dev
  ACPI / PM: Consolidate device wakeup settings code
  ACPI / PM: Drop run_wake from struct acpi_device_wakeup_flags
  PM / QoS: constify *_attribute_group.
  PM / AVS: rockchip-io: add io selectors and supplies for rk3228
  powercap/RAPL: prevent overridding bits outside of the mask
  PM / sysfs: Constify attribute groups
  ...

1 files changed, 147 insertions, 5 deletions

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 097d630ab886..be17664736b2 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -650,38 +650,165 @@ static const struct platform_suspend_ops acpi_suspend_ops_old = {
         .recover = acpi_pm_finish,
 };
 
+static bool s2idle_in_progress;
+static bool s2idle_wakeup;
+
+/*
+ * On platforms supporting the Low Power S0 Idle interface there is an ACPI
+ * device object with the PNP0D80 compatible device ID (System Power Management
+ * Controller) and a specific _DSM method under it.  That method, if present,
+ * can be used to indicate to the platform that the OS is transitioning into a
+ * low-power state in which certain types of activity are not desirable or that
+ * it is leaving such a state, which allows the platform to adjust its operation
+ * mode accordingly.
+ */
+static const struct acpi_device_id lps0_device_ids[] = {
+        {"PNP0D80", },
+        {"", },
+};
+
+#define ACPI_LPS0_DSM_UUID      "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
+
+#define ACPI_LPS0_SCREEN_OFF    3
+#define ACPI_LPS0_SCREEN_ON     4
+#define ACPI_LPS0_ENTRY         5
+#define ACPI_LPS0_EXIT          6
+
+#define ACPI_S2IDLE_FUNC_MASK   ((1 << ACPI_LPS0_ENTRY) | (1 << ACPI_LPS0_EXIT))
+
+static acpi_handle lps0_device_handle;
+static guid_t lps0_dsm_guid;
+static char lps0_dsm_func_mask;
+
+static void acpi_sleep_run_lps0_dsm(unsigned int func)
+{
+        union acpi_object *out_obj;
+
+        if (!(lps0_dsm_func_mask & (1 << func)))
+                return;
+
+        out_obj = acpi_evaluate_dsm(lps0_device_handle, &lps0_dsm_guid, 1, func, NULL);
+        ACPI_FREE(out_obj);
+
+        acpi_handle_debug(lps0_device_handle, "_DSM function %u evaluation %s\n",
+                          func, out_obj ? "successful" : "failed");
+}
+
+static int lps0_device_attach(struct acpi_device *adev,
+                              const struct acpi_device_id *not_used)
+{
+        union acpi_object *out_obj;
+
+        if (lps0_device_handle)
+                return 0;
+
+        if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
+                return 0;
+
+        guid_parse(ACPI_LPS0_DSM_UUID, &lps0_dsm_guid);
+        /* Check if the _DSM is present and as expected. */
+        out_obj = acpi_evaluate_dsm(adev->handle, &lps0_dsm_guid, 1, 0, NULL);
+        if (out_obj && out_obj->type == ACPI_TYPE_BUFFER) {
+                char bitmask = *(char *)out_obj->buffer.pointer;
+
+                if ((bitmask & ACPI_S2IDLE_FUNC_MASK) == ACPI_S2IDLE_FUNC_MASK) {
+                        lps0_dsm_func_mask = bitmask;
+                        lps0_device_handle = adev->handle;
+                }
+
+                acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
+                                  bitmask);
+        } else {
+                acpi_handle_debug(adev->handle,
+                                  "_DSM function 0 evaluation failed\n");
+        }
+        ACPI_FREE(out_obj);
+        return 0;
+}
+
+static struct acpi_scan_handler lps0_handler = {
+        .ids = lps0_device_ids,
+        .attach = lps0_device_attach,
+};
+
 static int acpi_freeze_begin(void)
 {
         acpi_scan_lock_acquire();
+        s2idle_in_progress = true;
         return 0;
 }
 
 static int acpi_freeze_prepare(void)
 {
-        acpi_enable_wakeup_devices(ACPI_STATE_S0);
-        acpi_enable_all_wakeup_gpes();
-        acpi_os_wait_events_complete();
+        if (lps0_device_handle) {
+                acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
+                acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
+        } else {
+                /*
+                 * The configuration of GPEs is changed here to avoid spurious
+                 * wakeups, but that should not be necessary if this is a
+                 * "low-power S0" platform and the low-power S0 _DSM is present.
+                 */
+                acpi_enable_all_wakeup_gpes();
+                acpi_os_wait_events_complete();
+        }
         if (acpi_sci_irq_valid())
                 enable_irq_wake(acpi_sci_irq);
+
         return 0;
 }
 
+static void acpi_freeze_wake(void)
+{
+        /*
+         * If IRQD_WAKEUP_ARMED is not set for the SCI at this point, it means
+         * that the SCI has triggered while suspended, so cancel the wakeup in
+         * case it has not been a wakeup event (the GPEs will be checked later).
+         */
+        if (acpi_sci_irq_valid() &&
+            !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) {
+                pm_system_cancel_wakeup();
+                s2idle_wakeup = true;
+        }
+}
+
+static void acpi_freeze_sync(void)
+{
+        /*
+         * Process all pending events in case there are any wakeup ones.
+         *
+         * The EC driver uses the system workqueue, so that one needs to be
+         * flushed too.
+         */
+        acpi_os_wait_events_complete();
+        flush_scheduled_work();
+        s2idle_wakeup = false;
+}
+
 static void acpi_freeze_restore(void)
 {
-        acpi_disable_wakeup_devices(ACPI_STATE_S0);
         if (acpi_sci_irq_valid())
                 disable_irq_wake(acpi_sci_irq);
-        acpi_enable_all_runtime_gpes();
+
+        if (lps0_device_handle) {
+                acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
+                acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
+        } else {
+                acpi_enable_all_runtime_gpes();
+        }
 }
 
 static void acpi_freeze_end(void)
 {
+        s2idle_in_progress = false;
         acpi_scan_lock_release();
 }
 
 static const struct platform_freeze_ops acpi_freeze_ops = {
         .begin = acpi_freeze_begin,
         .prepare = acpi_freeze_prepare,
+        .wake = acpi_freeze_wake,
+        .sync = acpi_freeze_sync,
         .restore = acpi_freeze_restore,
         .end = acpi_freeze_end,
 };
@@ -696,13 +823,28 @@ static void acpi_sleep_suspend_setup(void)
 
         suspend_set_ops(old_suspend_ordering ?
                 &acpi_suspend_ops_old : &acpi_suspend_ops);
+
+        acpi_scan_add_handler(&lps0_handler);
         freeze_set_ops(&acpi_freeze_ops);
 }
 
 #else /* !CONFIG_SUSPEND */
+#define s2idle_in_progress      (false)
+#define s2idle_wakeup           (false)
+#define lps0_device_handle      (NULL)
 static inline void acpi_sleep_suspend_setup(void) {}
 #endif /* !CONFIG_SUSPEND */
 
+bool acpi_s2idle_wakeup(void)
+{
+        return s2idle_wakeup;
+}
+
+bool acpi_sleep_no_ec_events(void)
+{
+        return !s2idle_in_progress || !lps0_device_handle;
+}
+
 #ifdef CONFIG_PM_SLEEP
 static u32 saved_bm_rld;