Merge tag 'acpi-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and PNP updates from Rafael Wysocki:
 "These include new code (for instance, support for the FFH address
  space type and support for new firmware data structures in ACPICA),
  some new quirks (mostly related to backlight handling and I2C
  enumeration), a number of fixes and a fair amount of cleanups all
  over.

  Specifics:

   - Update the ACPICA code in the kernel to the 20221020 upstream
     version and fix a couple of issues in it:
      - Make acpi_ex_load_op() match upstream implementation (Rafael
        Wysocki)
      - Add support for loong_arch-specific APICs in MADT (Huacai Chen)
      - Add support for fixed PCIe wake event (Huacai Chen)
      - Add EBDA pointer sanity checks (Vit Kabele)
      - Avoid accessing VGA memory when EBDA < 1KiB (Vit Kabele)
      - Add CCEL table support to both compiler/disassembler (Kuppuswamy
        Sathyanarayanan)
      - Add a couple of new UUIDs to the known UUID list (Bob Moore)
      - Add support for FFH Opregion special context data (Sudeep
        Holla)
      - Improve warning message for "invalid ACPI name" (Bob Moore)
      - Add support for CXL 3.0 structures (CXIMS & RDPAS) in the CEDT
        table (Alison Schofield)
      - Prepare IORT support for revision E.e (Robin Murphy)
      - Finish support for the CDAT table (Bob Moore)
      - Fix error code path in acpi_ds_call_control_method() (Rafael
        Wysocki)
      - Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage() (Li
        Zetao)
      - Update the version of the ACPICA code in the kernel (Bob Moore)

   - Use ZERO_PAGE(0) instead of empty_zero_page in the ACPI device
     enumeration code (Giulio Benetti)

   - Change the return type of the ACPI driver remove callback to void
     and update its users accordingly (Dawei Li)

   - Add general support for FFH address space type and implement the
     low- level part of it for ARM64 (Sudeep Holla)

   - Fix stale comments in the ACPI tables parsing code and make it
     print more messages related to MADT (Hanjun Guo, Huacai Chen)

   - Replace invocations of generic library functions with more kernel-
     specific counterparts in the ACPI sysfs interface (Christophe
     JAILLET, Xu Panda)

   - Print full name paths of ACPI power resource objects during
     enumeration (Kane Chen)

   - Eliminate a compiler warning regarding a missing function prototype
     in the ACPI power management code (Sudeep Holla)

   - Fix and clean up the ACPI processor driver (Rafael Wysocki, Li
     Zhong, Colin Ian King, Sudeep Holla)

   - Add quirk for the HP Pavilion Gaming 15-cx0041ur to the ACPI EC
     driver (Mia Kanashi)

   - Add some mew ACPI backlight handling quirks and update some
     existing ones (Hans de Goede)

   - Make the ACPI backlight driver prefer the native backlight control
     over vendor backlight control when possible (Hans de Goede)

   - Drop unsetting ACPI APEI driver data on remove (Uwe Kleine-König)

   - Use xchg_release() instead of cmpxchg() for updating new GHES cache
     slots (Ard Biesheuvel)

   - Clean up the ACPI APEI code (Sudeep Holla, Christophe JAILLET, Jay
     Lu)

   - Add new I2C device enumeration quirks for Medion Lifetab S10346 and
     Lenovo Yoga Tab 3 Pro (YT3-X90F) (Hans de Goede)

   - Make the ACPI battery driver notify user space about adding new
     battery hooks and removing the existing ones (Armin Wolf)

   - Modify the pfr_update and pfr_telemetry drivers to use ACPI_FREE()
     for freeing acpi_object structures to help diagnostics (Wang
     ShaoBo)

   - Make the ACPI fan driver use sysfs_emit_at() in its sysfs interface
     code (ye xingchen)

   - Fix the _FIF package extraction failure handling in the ACPI fan
     driver (Hanjun Guo)

   - Fix the PCC mailbox handling error code path (Huisong Li)

   - Avoid using PCC Opregions if there is no platform interrupt
     allocated for this purpose (Huisong Li)

   - Use sysfs_emit() instead of scnprintf() in the ACPI PAD driver and
     CPPC library (ye xingchen)

   - Fix some kernel-doc issues in the ACPI GSI processing code
     (Xiongfeng Wang)

   - Fix name memory leak in pnp_alloc_dev() (Yang Yingliang)

   - Do not disable PNP devices on suspend when they cannot be
     re-enabled on resume (Hans de Goede)

   - Clean up the ACPI thermal driver a bit (Rafael Wysocki)"

* tag 'acpi-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (67 commits)
  ACPI: x86: Add skip i2c clients quirk for Medion Lifetab S10346
  ACPI: APEI: EINJ: Refactor available_error_type_show()
  ACPI: APEI: EINJ: Fix formatting errors
  ACPI: processor: perflib: Adjust acpi_processor_notify_smm() return value
  ACPI: processor: perflib: Rearrange acpi_processor_notify_smm()
  ACPI: processor: perflib: Rearrange unregistration routine
  ACPI: processor: perflib: Drop redundant parentheses
  ACPI: processor: perflib: Adjust white space
  ACPI: processor: idle: Drop unnecessary statements and parens
  ACPI: thermal: Adjust critical.flags.valid check
  ACPI: fan: Convert to use sysfs_emit_at() API
  ACPICA: Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage()
  ACPI: battery: Call power_supply_changed() when adding hooks
  ACPI: use sysfs_emit() instead of scnprintf()
  ACPI: x86: Add skip i2c clients quirk for Lenovo Yoga Tab 3 Pro (YT3-X90F)
  ACPI: APEI: Remove a useless include
  PNP: Do not disable devices on suspend when they cannot be re-enabled on resume
  ACPI: processor: Silence missing prototype warnings
  ACPI: processor_idle: Silence missing prototype warnings
  ACPI: PM: Silence missing prototype warning
  ...

1 files changed, 33 insertions, 29 deletions

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index 9952f3a792ba..94c4872ae55f 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -138,7 +138,7 @@ struct ghes_vendor_record_entry {
 static struct gen_pool *ghes_estatus_pool;
 static unsigned long ghes_estatus_pool_size_request;
 
-static struct ghes_estatus_cache *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
+static struct ghes_estatus_cache __rcu *ghes_estatus_caches[GHES_ESTATUS_CACHES_SIZE];
 static atomic_t ghes_estatus_cache_alloced;
 
 static int ghes_panic_timeout __read_mostly = 30;
@@ -773,48 +773,42 @@ static struct ghes_estatus_cache *ghes_estatus_cache_alloc(
 	return cache;
 }
 
-static void ghes_estatus_cache_free(struct ghes_estatus_cache *cache)
+static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
 {
+	struct ghes_estatus_cache *cache;
 	u32 len;
 
+	cache = container_of(head, struct ghes_estatus_cache, rcu);
 	len = cper_estatus_len(GHES_ESTATUS_FROM_CACHE(cache));
 	len = GHES_ESTATUS_CACHE_LEN(len);
 	gen_pool_free(ghes_estatus_pool, (unsigned long)cache, len);
 	atomic_dec(&ghes_estatus_cache_alloced);
 }
 
-static void ghes_estatus_cache_rcu_free(struct rcu_head *head)
-{
-	struct ghes_estatus_cache *cache;
-
-	cache = container_of(head, struct ghes_estatus_cache, rcu);
-	ghes_estatus_cache_free(cache);
-}
-
-static void ghes_estatus_cache_add(
-	struct acpi_hest_generic *generic,
-	struct acpi_hest_generic_status *estatus)
+static void
+ghes_estatus_cache_add(struct acpi_hest_generic *generic,
+		       struct acpi_hest_generic_status *estatus)
 {
-	int i, slot = -1, count;
 	unsigned long long now, duration, period, max_period = 0;
-	struct ghes_estatus_cache *cache, *slot_cache = NULL, *new_cache;
+	struct ghes_estatus_cache *cache, *new_cache;
+	struct ghes_estatus_cache __rcu *victim;
+	int i, slot = -1, count;
 
 	new_cache = ghes_estatus_cache_alloc(generic, estatus);
-	if (new_cache == NULL)
+	if (!new_cache)
 		return;
+
 	rcu_read_lock();
 	now = sched_clock();
 	for (i = 0; i < GHES_ESTATUS_CACHES_SIZE; i++) {
 		cache = rcu_dereference(ghes_estatus_caches[i]);
 		if (cache == NULL) {
 			slot = i;
-			slot_cache = NULL;
 			break;
 		}
 		duration = now - cache->time_in;
 		if (duration >= GHES_ESTATUS_IN_CACHE_MAX_NSEC) {
 			slot = i;
-			slot_cache = cache;
 			break;
 		}
 		count = atomic_read(&cache->count);
@@ -823,18 +817,30 @@ static void ghes_estatus_cache_add(
 		if (period > max_period) {
 			max_period = period;
 			slot = i;
-			slot_cache = cache;
 		}
 	}
-	/* new_cache must be put into array after its contents are written */
-	smp_wmb();
-	if (slot != -1 && cmpxchg(ghes_estatus_caches + slot,
-				  slot_cache, new_cache) == slot_cache) {
-		if (slot_cache)
-			call_rcu(&slot_cache->rcu, ghes_estatus_cache_rcu_free);
-	} else
-		ghes_estatus_cache_free(new_cache);
 	rcu_read_unlock();
+
+	if (slot != -1) {
+		/*
+		 * Use release semantics to ensure that ghes_estatus_cached()
+		 * running on another CPU will see the updated cache fields if
+		 * it can see the new value of the pointer.
+		 */
+		victim = xchg_release(&ghes_estatus_caches[slot],
+				      RCU_INITIALIZER(new_cache));
+
+		/*
+		 * At this point, victim may point to a cached item different
+		 * from the one based on which we selected the slot. Instead of
+		 * going to the loop again to pick another slot, let's just
+		 * drop the other item anyway: this may cause a false cache
+		 * miss later on, but that won't cause any problems.
+		 */
+		if (victim)
+			call_rcu(&unrcu_pointer(victim)->rcu,
+				 ghes_estatus_cache_rcu_free);
+	}
 }
 
 static void __ghes_panic(struct ghes *ghes,
@@ -1444,8 +1450,6 @@ static int ghes_remove(struct platform_device *ghes_dev)
 
 	kfree(ghes);
 
-	platform_set_drvdata(ghes_dev, NULL);
-
 	return 0;
 }