Merge tag 'acpi-5.8-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 upstream revision
  20200430, fix several reference counting errors related to ACPI
  tables, add _Exx / _Lxx support to the GED driver, add a new
  acpi_evaluate_reg() helper, add new DPTF battery participant driver
  and extend the DPFT power participant driver, improve the handling of
  memory failures in the APEI code, add a blacklist entry to the
  backlight driver, update the PMIC driver and the processor idle
  driver, fix two kobject reference count leaks, and make a few janitory
  changes.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20200430:

      - Move acpi_gbl_next_cmd_num definition (Erik Kaneda).

      - Ignore AE_ALREADY_EXISTS status in the disassembler when parsing
        create operators (Erik Kaneda).

      - Add status checks to the dispatcher (Erik Kaneda).

      - Fix required parameters for _NIG and _NIH (Erik Kaneda).

      - Make acpi_protocol_lengths static (Yue Haibing).

   - Fix ACPI table reference counting errors in several places, mostly
     in error code paths (Hanjun Guo).

   - Extend the Generic Event Device (GED) driver to support _Exx and
     _Lxx handler methods (Ard Biesheuvel).

   - Add new acpi_evaluate_reg() helper and modify the ACPI PCI hotplug
     code to use it (Hans de Goede).

   - Add new DPTF battery participant driver and make the DPFT power
     participant driver create more sysfs device attributes (Srinivas
     Pandruvada).

   - Improve the handling of memory failures in APEI (James Morse).

   - Add new blacklist entry for Acer TravelMate 5735Z to the backlight
     driver (Paul Menzel).

   - Add i2c address for thermal control to the PMIC driver (Mauro
     Carvalho Chehab).

   - Allow the ACPI processor idle driver to work on platforms with only
     one ACPI C-state present (Zhang Rui).

   - Fix kobject reference count leaks in error code paths in two places
     (Qiushi Wu).

   - Delete unused proc filename macros and make some symbols static
     (Pascal Terjan, Zheng Zengkai, Zou Wei)"

* tag 'acpi-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
  ACPI: CPPC: Fix reference count leak in acpi_cppc_processor_probe()
  ACPI: sysfs: Fix reference count leak in acpi_sysfs_add_hotplug_profile()
  ACPI: GED: use correct trigger type field in _Exx / _Lxx handling
  ACPI: DPTF: Add battery participant driver
  ACPI: DPTF: Additional sysfs attributes for power participant driver
  ACPI: video: Use native backlight on Acer TravelMate 5735Z
  arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work
  ACPI: APEI: Kick the memory_failure() queue for synchronous errors
  mm/memory-failure: Add memory_failure_queue_kick()
  ACPI / PMIC: Add i2c address for thermal control
  ACPI: GED: add support for _Exx / _Lxx handler methods
  ACPI: Delete unused proc filename macros
  ACPI: hotplug: PCI: Use the new acpi_evaluate_reg() helper
  ACPI: utils: Add acpi_evaluate_reg() helper
  ACPI: debug: Make two functions static
  ACPI: sleep: Put the FACS table after using it
  ACPI: scan: Put SPCR and STAO table after using it
  ACPI: EC: Put the ACPI table after using it
  ACPI: APEI: Put the HEST table for error path
  ACPI: APEI: Put the error record serialization table for error path
  ...

1 files changed, 56 insertions, 11 deletions

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index aabe9c5ee515..81bf71b10d44 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -40,6 +40,7 @@
 #include <linux/sched/clock.h>
 #include <linux/uuid.h>
 #include <linux/ras.h>
+#include <linux/task_work.h>
 
 #include <acpi/actbl1.h>
 #include <acpi/ghes.h>
@@ -408,23 +409,46 @@ static void ghes_clear_estatus(struct ghes *ghes,
 		ghes_ack_error(ghes->generic_v2);
 }
 
-static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int sev)
+/*
+ * Called as task_work before returning to user-space.
+ * Ensure any queued work has been done before we return to the context that
+ * triggered the notification.
+ */
+static void ghes_kick_task_work(struct callback_head *head)
+{
+	struct acpi_hest_generic_status *estatus;
+	struct ghes_estatus_node *estatus_node;
+	u32 node_len;
+
+	estatus_node = container_of(head, struct ghes_estatus_node, task_work);
+	if (IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
+		memory_failure_queue_kick(estatus_node->task_work_cpu);
+
+	estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
+	node_len = GHES_ESTATUS_NODE_LEN(cper_estatus_len(estatus));
+	gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, node_len);
+}
+
+static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata,
+				       int sev)
 {
-#ifdef CONFIG_ACPI_APEI_MEMORY_FAILURE
 	unsigned long pfn;
 	int flags = -1;
 	int sec_sev = ghes_severity(gdata->error_severity);
 	struct cper_sec_mem_err *mem_err = acpi_hest_get_payload(gdata);
 
+	if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE))
+		return false;
+
 	if (!(mem_err->validation_bits & CPER_MEM_VALID_PA))
-		return;
+		return false;
 
 	pfn = mem_err->physical_addr >> PAGE_SHIFT;
 	if (!pfn_valid(pfn)) {
 		pr_warn_ratelimited(FW_WARN GHES_PFX
 		"Invalid address in generic error data: %#llx\n",
 		mem_err->physical_addr);
-		return;
+		return false;
 	}
 
 	/* iff following two events can be handled properly by now */
@@ -434,9 +458,12 @@ static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int
 	if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE)
 		flags = 0;
 
-	if (flags != -1)
+	if (flags != -1) {
 		memory_failure_queue(pfn, flags);
-#endif
+		return true;
+	}
+
+	return false;
 }
 
 /*
@@ -484,7 +511,7 @@ static void ghes_handle_aer(struct acpi_hest_generic_data *gdata)
 #endif
 }
 
-static void ghes_do_proc(struct ghes *ghes,
+static bool ghes_do_proc(struct ghes *ghes,
 			 const struct acpi_hest_generic_status *estatus)
 {
 	int sev, sec_sev;
@@ -492,6 +519,7 @@ static void ghes_do_proc(struct ghes *ghes,
 	guid_t *sec_type;
 	const guid_t *fru_id = &guid_null;
 	char *fru_text = "";
+	bool queued = false;
 
 	sev = ghes_severity(estatus->error_severity);
 	apei_estatus_for_each_section(estatus, gdata) {
@@ -509,7 +537,7 @@ static void ghes_do_proc(struct ghes *ghes,
 			ghes_edac_report_mem_error(sev, mem_err);
 
 			arch_apei_report_mem_error(sev, mem_err);
-			ghes_handle_memory_failure(gdata, sev);
+			queued = ghes_handle_memory_failure(gdata, sev);
 		}
 		else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
 			ghes_handle_aer(gdata);
@@ -526,6 +554,8 @@ static void ghes_do_proc(struct ghes *ghes,
 					       gdata->error_data_length);
 		}
 	}
+
+	return queued;
 }
 
 static void __ghes_print_estatus(const char *pfx,
@@ -821,7 +851,9 @@ static void ghes_proc_in_irq(struct irq_work *irq_work)
 	struct ghes_estatus_node *estatus_node;
 	struct acpi_hest_generic *generic;
 	struct acpi_hest_generic_status *estatus;
+	bool task_work_pending;
 	u32 len, node_len;
+	int ret;
 
 	llnode = llist_del_all(&ghes_estatus_llist);
 	/*
@@ -836,14 +868,26 @@ static void ghes_proc_in_irq(struct irq_work *irq_work)
 		estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 		len = cper_estatus_len(estatus);
 		node_len = GHES_ESTATUS_NODE_LEN(len);
-		ghes_do_proc(estatus_node->ghes, estatus);
+		task_work_pending = ghes_do_proc(estatus_node->ghes, estatus);
 		if (!ghes_estatus_cached(estatus)) {
 			generic = estatus_node->generic;
 			if (ghes_print_estatus(NULL, generic, estatus))
 				ghes_estatus_cache_add(generic, estatus);
 		}
-		gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node,
-			      node_len);
+
+		if (task_work_pending && current->mm != &init_mm) {
+			estatus_node->task_work.func = ghes_kick_task_work;
+			estatus_node->task_work_cpu = smp_processor_id();
+			ret = task_work_add(current, &estatus_node->task_work,
+					    true);
+			if (ret)
+				estatus_node->task_work.func = NULL;
+		}
+
+		if (!estatus_node->task_work.func)
+			gen_pool_free(ghes_estatus_pool,
+				      (unsigned long)estatus_node, node_len);
+
 		llnode = next;
 	}
 }
@@ -903,6 +947,7 @@ static int ghes_in_nmi_queue_one_entry(struct ghes *ghes,
 
 	estatus_node->ghes = ghes;
 	estatus_node->generic = ghes->generic;
+	estatus_node->task_work.func = NULL;
 	estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
 
 	if (__ghes_read_estatus(estatus, buf_paddr, fixmap_idx, len)) {