ACPI fixes for 5.17-rc4

- Revert a recent change that attempted to avoid issues with
    conflicting address ranges during PCI initialization, because it
    turned out to introduce a regression (Hans de Goede).
 
  - Revert a change that limited EC GPE wakeups from suspend-to-idle
    to systems based on Intel hardware, because it turned out that
    systems based on hardware from other vendors depended on that
    functionality too (Mario Limonciello).
 
  - Fix two issues related to the handling of wakeup interrupts and
    wakeup events signaled through the EC GPE during suspend-to-idle
    on x86 (Rafael Wysocki).
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Merge tag 'acpi-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI fixes from Rafael Wysocki:
 "These revert two commits that turned out to be problematic and fix two
  issues related to wakeup from suspend-to-idle on x86.

  Specifics:

   - Revert a recent change that attempted to avoid issues with
     conflicting address ranges during PCI initialization, because it
     turned out to introduce a regression (Hans de Goede).

   - Revert a change that limited EC GPE wakeups from suspend-to-idle to
     systems based on Intel hardware, because it turned out that systems
     based on hardware from other vendors depended on that functionality
     too (Mario Limonciello).

   - Fix two issues related to the handling of wakeup interrupts and
     wakeup events signaled through the EC GPE during suspend-to-idle on
     x86 (Rafael Wysocki)"

* tag 'acpi-5.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  x86/PCI: revert "Ignore E820 reservations for bridge windows on newer systems"
  PM: s2idle: ACPI: Fix wakeup interrupts handling
  ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE
  ACPI: PM: Revert "Only mark EC GPE for wakeup on Intel systems"

arch/x86/kernel/resource.c

@@ -1,5 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/dmi.h>
 #include <linux/ioport.h>
 #include <asm/e820/api.h>
 
@@ -24,31 +23,11 @@ static void resource_clip(struct resource *res, resource_size_t start,
 		res->start = end + 1;
 }
 
-/*
- * Some BIOS-es contain a bug where they add addresses which map to
- * system RAM in the PCI host bridge window returned by the ACPI _CRS
- * method, see commit 4dc2287c1805 ("x86: avoid E820 regions when
- * allocating address space"). To avoid this Linux by default excludes
- * E820 reservations when allocating addresses since 2010.
- * In 2019 some systems have shown-up with E820 reservations which cover
- * the entire _CRS returned PCI host bridge window, causing all attempts
- * to assign memory to PCI BARs to fail if Linux uses E820 reservations.
- *
- * Ideally Linux would fully stop using E820 reservations, but then
- * the old systems this was added for will regress.
- * Instead keep the old behavior for old systems, while ignoring the
- * E820 reservations for any systems from now on.
- */
 static void remove_e820_regions(struct resource *avail)
 {
-	int i, year = dmi_get_bios_year();
+	int i;
 	struct e820_entry *entry;
 
-	if (year >= 2018)
-		return;
-
-	pr_info_once("PCI: Removing E820 reservations from host bridge windows\n");
-
 	for (i = 0; i < e820_table->nr_entries; i++) {
 		entry = &e820_table->entries[i];
 

drivers/acpi/ec.c

@@ -2065,6 +2065,16 @@ bool acpi_ec_dispatch_gpe(void)
 	if (acpi_any_gpe_status_set(first_ec->gpe))
 		return true;
 
+	/*
+	 * Cancel the SCI wakeup and process all pending events in case there
+	 * are any wakeup ones in there.
+	 *
+	 * Note that if any non-EC GPEs are active at this point, the SCI will
+	 * retrigger after the rearming in acpi_s2idle_wake(), so no events
+	 * should be missed by canceling the wakeup here.
+	 */
+	pm_system_cancel_wakeup();
+
 	/*
 	 * Dispatch the EC GPE in-band, but do not report wakeup in any case
 	 * to allow the caller to process events properly after that.

drivers/acpi/sleep.c

@@ -736,21 +736,15 @@ bool acpi_s2idle_wake(void)
 			return true;
 		}
 
-		/* Check non-EC GPE wakeups and dispatch the EC GPE. */
+		/*
+		 * Check non-EC GPE wakeups and if there are none, cancel the
+		 * SCI-related wakeup and dispatch the EC GPE.
+		 */
 		if (acpi_ec_dispatch_gpe()) {
 			pm_pr_dbg("ACPI non-EC GPE wakeup\n");
 			return true;
 		}
 
-		/*
-		 * Cancel the SCI wakeup and process all pending events in case
-		 * there are any wakeup ones in there.
-		 *
-		 * Note that if any non-EC GPEs are active at this point, the
-		 * SCI will retrigger after the rearming below, so no events
-		 * should be missed by canceling the wakeup here.
-		 */
-		pm_system_cancel_wakeup();
 		acpi_os_wait_events_complete();
 
 		/*
@@ -764,6 +758,7 @@ bool acpi_s2idle_wake(void)
 			return true;
 		}
 
+		pm_wakeup_clear(acpi_sci_irq);
 		rearm_wake_irq(acpi_sci_irq);
 	}
 

drivers/acpi/x86/s2idle.c

@@ -424,15 +424,11 @@ static int lps0_device_attach(struct acpi_device *adev,
 		mem_sleep_current = PM_SUSPEND_TO_IDLE;
 
 	/*
-	 * Some Intel based LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U don't
-	 * use intel-hid or intel-vbtn but require the EC GPE to be enabled while
-	 * suspended for certain wakeup devices to work, so mark it as wakeup-capable.
-	 *
-	 * Only enable on !AMD as enabling this universally causes problems for a number
-	 * of AMD based systems.
+	 * Some LPS0 systems, like ASUS Zenbook UX430UNR/i7-8550U, require the
+	 * EC GPE to be enabled while suspended for certain wakeup devices to
+	 * work, so mark it as wakeup-capable.
 	 */
-	if (!acpi_s2idle_vendor_amd())
-		acpi_ec_mark_gpe_for_wake();
+	acpi_ec_mark_gpe_for_wake();
 
 	return 0;
 }

drivers/base/power/wakeup.c

@@ -34,7 +34,8 @@ suspend_state_t pm_suspend_target_state;
 bool events_check_enabled __read_mostly;
 
 /* First wakeup IRQ seen by the kernel in the last cycle. */
-unsigned int pm_wakeup_irq __read_mostly;
+static unsigned int wakeup_irq[2] __read_mostly;
+static DEFINE_RAW_SPINLOCK(wakeup_irq_lock);
 
 /* If greater than 0 and the system is suspending, terminate the suspend. */
 static atomic_t pm_abort_suspend __read_mostly;
@@ -942,19 +943,45 @@ void pm_system_cancel_wakeup(void)
 	atomic_dec_if_positive(&pm_abort_suspend);
 }
 
-void pm_wakeup_clear(bool reset)
+void pm_wakeup_clear(unsigned int irq_number)
 {
-	pm_wakeup_irq = 0;
-	if (reset)
+	raw_spin_lock_irq(&wakeup_irq_lock);
+
+	if (irq_number && wakeup_irq[0] == irq_number)
+		wakeup_irq[0] = wakeup_irq[1];
+	else
+		wakeup_irq[0] = 0;
+
+	wakeup_irq[1] = 0;
+
+	raw_spin_unlock_irq(&wakeup_irq_lock);
+
+	if (!irq_number)
 		atomic_set(&pm_abort_suspend, 0);
 }
 
 void pm_system_irq_wakeup(unsigned int irq_number)
 {
-	if (pm_wakeup_irq == 0) {
-		pm_wakeup_irq = irq_number;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&wakeup_irq_lock, flags);
+
+	if (wakeup_irq[0] == 0)
+		wakeup_irq[0] = irq_number;
+	else if (wakeup_irq[1] == 0)
+		wakeup_irq[1] = irq_number;
+	else
+		irq_number = 0;
+
+	raw_spin_unlock_irqrestore(&wakeup_irq_lock, flags);
+
+	if (irq_number)
 		pm_system_wakeup();
-	}
+}
+
+unsigned int pm_wakeup_irq(void)
+{
+	return wakeup_irq[0];
 }
 
 /**

include/linux/suspend.h

@@ -497,14 +497,14 @@ extern void ksys_sync_helper(void);
 
 /* drivers/base/power/wakeup.c */
 extern bool events_check_enabled;
-extern unsigned int pm_wakeup_irq;
 extern suspend_state_t pm_suspend_target_state;
 
 extern bool pm_wakeup_pending(void);
 extern void pm_system_wakeup(void);
 extern void pm_system_cancel_wakeup(void);
-extern void pm_wakeup_clear(bool reset);
+extern void pm_wakeup_clear(unsigned int irq_number);
 extern void pm_system_irq_wakeup(unsigned int irq_number);
+extern unsigned int pm_wakeup_irq(void);
 extern bool pm_get_wakeup_count(unsigned int *count, bool block);
 extern bool pm_save_wakeup_count(unsigned int count);
 extern void pm_wakep_autosleep_enabled(bool set);

kernel/power/main.c

@@ -504,7 +504,10 @@ static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
 					struct kobj_attribute *attr,
 					char *buf)
 {
-	return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
+	if (!pm_wakeup_irq())
+		return -ENODATA;
+
+	return sprintf(buf, "%u\n", pm_wakeup_irq());
 }
 
 power_attr_ro(pm_wakeup_irq);

kernel/power/process.c

@@ -134,7 +134,7 @@ int freeze_processes(void)
 	if (!pm_freezing)
 		atomic_inc(&system_freezing_cnt);
 
-	pm_wakeup_clear(true);
+	pm_wakeup_clear(0);
 	pr_info("Freezing user space processes ... ");
 	pm_freezing = true;
 	error = try_to_freeze_tasks(true);

kernel/power/suspend.c

@@ -136,8 +136,6 @@ static void s2idle_loop(void)
 			break;
 		}
 
-		pm_wakeup_clear(false);
-
 		s2idle_enter();
 	}