Merge branches 'acpi-scan', 'acpi-bus', 'acpi-tables' and 'acpi-sysfs'

Merge ACPI changes related to device enumeration, device object
managenet, operation region handling, table parsing and sysfs
interface:

 - 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).

* acpi-scan:
  ACPI: scan: substitute empty_zero_page with helper ZERO_PAGE(0)

* acpi-bus:
  ACPI: FFH: Silence missing prototype warnings
  ACPI: make remove callback of ACPI driver void
  ACPI: bus: Fix the _OSC capability check for FFH OpRegion
  arm64: Add architecture specific ACPI FFH Opregion callbacks
  ACPI: Implement a generic FFH Opregion handler

* acpi-tables:
  ACPI: tables: Fix the stale comments for acpi_locate_initial_tables()
  ACPI: tables: Print CORE_PIC information when MADT is parsed

* acpi-sysfs:
  ACPI: sysfs: use sysfs_emit() to instead of scnprintf()
  ACPI: sysfs: Use kstrtobool() instead of strtobool()

arch/arm64/kernel/acpi.c

@@ -13,6 +13,7 @@
 #define pr_fmt(fmt) "ACPI: " fmt
 
 #include <linux/acpi.h>
+#include <linux/arm-smccc.h>
 #include <linux/cpumask.h>
 #include <linux/efi.h>
 #include <linux/efi-bgrt.h>
@@ -411,3 +412,108 @@ void arch_reserve_mem_area(acpi_physical_address addr, size_t size)
 {
 	memblock_mark_nomap(addr, size);
 }
+
+#ifdef CONFIG_ACPI_FFH
+/*
+ * Implements ARM64 specific callbacks to support ACPI FFH Operation Region as
+ * specified in https://developer.arm.com/docs/den0048/latest
+ */
+struct acpi_ffh_data {
+	struct acpi_ffh_info info;
+	void (*invoke_ffh_fn)(unsigned long a0, unsigned long a1,
+			      unsigned long a2, unsigned long a3,
+			      unsigned long a4, unsigned long a5,
+			      unsigned long a6, unsigned long a7,
+			      struct arm_smccc_res *args,
+			      struct arm_smccc_quirk *res);
+	void (*invoke_ffh64_fn)(const struct arm_smccc_1_2_regs *args,
+				struct arm_smccc_1_2_regs *res);
+};
+
+int acpi_ffh_address_space_arch_setup(void *handler_ctxt, void **region_ctxt)
+{
+	enum arm_smccc_conduit conduit;
+	struct acpi_ffh_data *ffh_ctxt;
+
+	ffh_ctxt = kzalloc(sizeof(*ffh_ctxt), GFP_KERNEL);
+	if (!ffh_ctxt)
+		return -ENOMEM;
+
+	if (arm_smccc_get_version() < ARM_SMCCC_VERSION_1_2)
+		return -EOPNOTSUPP;
+
+	conduit = arm_smccc_1_1_get_conduit();
+	if (conduit == SMCCC_CONDUIT_NONE) {
+		pr_err("%s: invalid SMCCC conduit\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	if (conduit == SMCCC_CONDUIT_SMC) {
+		ffh_ctxt->invoke_ffh_fn = __arm_smccc_smc;
+		ffh_ctxt->invoke_ffh64_fn = arm_smccc_1_2_smc;
+	} else {
+		ffh_ctxt->invoke_ffh_fn = __arm_smccc_hvc;
+		ffh_ctxt->invoke_ffh64_fn = arm_smccc_1_2_hvc;
+	}
+
+	memcpy(ffh_ctxt, handler_ctxt, sizeof(ffh_ctxt->info));
+
+	*region_ctxt = ffh_ctxt;
+	return AE_OK;
+}
+
+static bool acpi_ffh_smccc_owner_allowed(u32 fid)
+{
+	int owner = ARM_SMCCC_OWNER_NUM(fid);
+
+	if (owner == ARM_SMCCC_OWNER_STANDARD ||
+	    owner == ARM_SMCCC_OWNER_SIP || owner == ARM_SMCCC_OWNER_OEM)
+		return true;
+
+	return false;
+}
+
+int acpi_ffh_address_space_arch_handler(acpi_integer *value, void *region_context)
+{
+	int ret = 0;
+	struct acpi_ffh_data *ffh_ctxt = region_context;
+
+	if (ffh_ctxt->info.offset == 0) {
+		/* SMC/HVC 32bit call */
+		struct arm_smccc_res res;
+		u32 a[8] = { 0 }, *ptr = (u32 *)value;
+
+		if (!ARM_SMCCC_IS_FAST_CALL(*ptr) || ARM_SMCCC_IS_64(*ptr) ||
+		    !acpi_ffh_smccc_owner_allowed(*ptr) ||
+		    ffh_ctxt->info.length > 32) {
+			ret = AE_ERROR;
+		} else {
+			int idx, len = ffh_ctxt->info.length >> 2;
+
+			for (idx = 0; idx < len; idx++)
+				a[idx] = *(ptr + idx);
+
+			ffh_ctxt->invoke_ffh_fn(a[0], a[1], a[2], a[3], a[4],
+						a[5], a[6], a[7], &res, NULL);
+			memcpy(value, &res, sizeof(res));
+		}
+
+	} else if (ffh_ctxt->info.offset == 1) {
+		/* SMC/HVC 64bit call */
+		struct arm_smccc_1_2_regs *r = (struct arm_smccc_1_2_regs *)value;
+
+		if (!ARM_SMCCC_IS_FAST_CALL(r->a0) || !ARM_SMCCC_IS_64(r->a0) ||
+		    !acpi_ffh_smccc_owner_allowed(r->a0) ||
+		    ffh_ctxt->info.length > sizeof(*r)) {
+			ret = AE_ERROR;
+		} else {
+			ffh_ctxt->invoke_ffh64_fn(r, r);
+			memcpy(value, r, ffh_ctxt->info.length);
+		}
+	} else {
+		ret = AE_ERROR;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_ACPI_FFH */

arch/ia64/hp/common/aml_nfw.c

@@ -187,9 +187,9 @@ static int aml_nfw_add(struct acpi_device *device)
 	return aml_nfw_add_global_handler();
 }
 
-static int aml_nfw_remove(struct acpi_device *device)
+static void aml_nfw_remove(struct acpi_device *device)
 {
-	return aml_nfw_remove_global_handler();
+	aml_nfw_remove_global_handler();
 }
 
 static const struct acpi_device_id aml_nfw_ids[] = {

arch/x86/platform/olpc/olpc-xo15-sci.c

@@ -183,13 +183,12 @@ static int xo15_sci_add(struct acpi_device *device)
 	return r;
 }
 
-static int xo15_sci_remove(struct acpi_device *device)
+static void xo15_sci_remove(struct acpi_device *device)
 {
 	acpi_disable_gpe(NULL, xo15_sci_gpe);
 	acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 	cancel_work_sync(&sci_work);
 	sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
-	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP

drivers/acpi/Kconfig

@@ -564,6 +564,16 @@ config ACPI_PCC
 	  Enable this feature if you want to set up and install the PCC Address
 	  Space handler to handle PCC OpRegion in the firmware.
 
+config ACPI_FFH
+	bool "ACPI FFH Address Space"
+	default n
+	help
+	  The FFH(Fixed Function Hardware) Address Space also referred as FFH
+	  Operation Region allows to define platform specific opregion.
+
+	  Enable this feature if you want to set up and install the FFH Address
+	  Space handler to handle FFH OpRegion in the firmware.
+
 source "drivers/acpi/pmic/Kconfig"
 
 config ACPI_VIOT

drivers/acpi/Makefile

@@ -68,6 +68,7 @@ acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
 acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
 acpi-$(CONFIG_ACPI_PRMT)	+= prmt.o
 acpi-$(CONFIG_ACPI_PCC)		+= acpi_pcc.o
+acpi-$(CONFIG_ACPI_FFH)		+= acpi_ffh.o
 
 # Address translation
 acpi-$(CONFIG_ACPI_ADXL)	+= acpi_adxl.o

drivers/acpi/ac.c

@@ -33,7 +33,7 @@ MODULE_DESCRIPTION("ACPI AC Adapter Driver");
 MODULE_LICENSE("GPL");
 
 static int acpi_ac_add(struct acpi_device *device);
-static int acpi_ac_remove(struct acpi_device *device);
+static void acpi_ac_remove(struct acpi_device *device);
 static void acpi_ac_notify(struct acpi_device *device, u32 event);
 
 static const struct acpi_device_id ac_device_ids[] = {
@@ -288,21 +288,19 @@ static int acpi_ac_resume(struct device *dev)
 #define acpi_ac_resume NULL
 #endif
 
-static int acpi_ac_remove(struct acpi_device *device)
+static void acpi_ac_remove(struct acpi_device *device)
 {
 	struct acpi_ac *ac = NULL;
 
 	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
+		return;
 
 	ac = acpi_driver_data(device);
 
 	power_supply_unregister(ac->charger);
 	unregister_acpi_notifier(&ac->battery_nb);
 
 	kfree(ac);
-
-	return 0;
 }
 
 static int __init acpi_ac_init(void)

drivers/acpi/acpi_ffh.c

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Author: Sudeep Holla <sudeep.holla@arm.com>
+ * Copyright 2022 Arm Limited
+ */
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/completion.h>
+#include <linux/idr.h>
+#include <linux/io.h>
+
+#include <linux/arm-smccc.h>
+
+static struct acpi_ffh_info ffh_ctx;
+
+int __weak acpi_ffh_address_space_arch_setup(void *handler_ctxt,
+					     void **region_ctxt)
+{
+	return -EOPNOTSUPP;
+}
+
+int __weak acpi_ffh_address_space_arch_handler(acpi_integer *value,
+					       void *region_context)
+{
+	return -EOPNOTSUPP;
+}
+
+static acpi_status
+acpi_ffh_address_space_setup(acpi_handle region_handle, u32 function,
+			     void *handler_context,  void **region_context)
+{
+	return acpi_ffh_address_space_arch_setup(handler_context,
+						 region_context);
+}
+
+static acpi_status
+acpi_ffh_address_space_handler(u32 function, acpi_physical_address addr,
+			       u32 bits, acpi_integer *value,
+			       void *handler_context, void *region_context)
+{
+	return acpi_ffh_address_space_arch_handler(value, region_context);
+}
+
+void __init acpi_init_ffh(void)
+{
+	acpi_status status;
+
+	status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
+						    ACPI_ADR_SPACE_FIXED_HARDWARE,
+						    &acpi_ffh_address_space_handler,
+						    &acpi_ffh_address_space_setup,
+						    &ffh_ctx);
+	if (ACPI_FAILURE(status))
+		pr_alert("OperationRegion handler could not be installed\n");
+}

drivers/acpi/acpi_pad.c

@@ -449,7 +449,7 @@ static int acpi_pad_add(struct acpi_device *device)
 	return 0;
 }
 
-static int acpi_pad_remove(struct acpi_device *device)
+static void acpi_pad_remove(struct acpi_device *device)
 {
 	mutex_lock(&isolated_cpus_lock);
 	acpi_pad_idle_cpus(0);
@@ -458,7 +458,6 @@ static int acpi_pad_remove(struct acpi_device *device)
 	acpi_remove_notify_handler(device->handle,
 		ACPI_DEVICE_NOTIFY, acpi_pad_notify);
 	acpi_pad_remove_sysfs(device);
-	return 0;
 }
 
 static const struct acpi_device_id pad_device_ids[] = {

drivers/acpi/acpi_video.c

@@ -86,7 +86,7 @@ static DEFINE_MUTEX(register_count_mutex);
 static DEFINE_MUTEX(video_list_lock);
 static LIST_HEAD(video_bus_head);
 static int acpi_video_bus_add(struct acpi_device *device);
-static int acpi_video_bus_remove(struct acpi_device *device);
+static void acpi_video_bus_remove(struct acpi_device *device);
 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
 static void acpi_video_bus_register_backlight_work(struct work_struct *ignored);
 static DECLARE_DELAYED_WORK(video_bus_register_backlight_work,
@@ -2067,13 +2067,13 @@ static int acpi_video_bus_add(struct acpi_device *device)
 	return error;
 }
 
-static int acpi_video_bus_remove(struct acpi_device *device)
+static void acpi_video_bus_remove(struct acpi_device *device)
 {
 	struct acpi_video_bus *video = NULL;
 
 
 	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
+		return;
 
 	video = acpi_driver_data(device);
 
@@ -2087,8 +2087,6 @@ static int acpi_video_bus_remove(struct acpi_device *device)
 
 	kfree(video->attached_array);
 	kfree(video);
-
-	return 0;
 }
 
 static void acpi_video_bus_register_backlight_work(struct work_struct *ignored)

drivers/acpi/battery.c

@@ -1208,20 +1208,19 @@ static int acpi_battery_add(struct acpi_device *device)
 	return result;
 }
 
-static int acpi_battery_remove(struct acpi_device *device)
+static void acpi_battery_remove(struct acpi_device *device)
 {
 	struct acpi_battery *battery = NULL;
 
 	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
+		return;
 	device_init_wakeup(&device->dev, 0);
 	battery = acpi_driver_data(device);
 	unregister_pm_notifier(&battery->pm_nb);
 	sysfs_remove_battery(battery);
 	mutex_destroy(&battery->lock);
 	mutex_destroy(&battery->sysfs_lock);
 	kfree(battery);
-	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP

drivers/acpi/bus.c

@@ -323,6 +323,8 @@ static void acpi_bus_osc_negotiate_platform_control(void)
 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;
 	if (IS_ENABLED(CONFIG_ACPI_PRMT))
 		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PRM_SUPPORT;
+	if (IS_ENABLED(CONFIG_ACPI_FFH))
+		capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_FFH_OPR_SUPPORT;
 
 #ifdef CONFIG_ARM64
 	capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_GENERIC_INITIATOR_SUPPORT;
@@ -1408,6 +1410,7 @@ static int __init acpi_init(void)
 		disable_acpi();
 		return result;
 	}
+	acpi_init_ffh();
 
 	pci_mmcfg_late_init();
 	acpi_iort_init();

drivers/acpi/button.c

@@ -125,7 +125,7 @@ static const struct dmi_system_id dmi_lid_quirks[] = {
 };
 
 static int acpi_button_add(struct acpi_device *device);
-static int acpi_button_remove(struct acpi_device *device);
+static void acpi_button_remove(struct acpi_device *device);
 static void acpi_button_notify(struct acpi_device *device, u32 event);
 
 #ifdef CONFIG_PM_SLEEP
@@ -580,14 +580,13 @@ static int acpi_button_add(struct acpi_device *device)
 	return error;
 }
 
-static int acpi_button_remove(struct acpi_device *device)
+static void acpi_button_remove(struct acpi_device *device)
 {
 	struct acpi_button *button = acpi_driver_data(device);
 
 	acpi_button_remove_fs(device);
 	input_unregister_device(button->input);
 	kfree(button);
-	return 0;
 }
 
 static int param_set_lid_init_state(const char *val,

drivers/acpi/ec.c

@@ -1663,12 +1663,12 @@ static int acpi_ec_add(struct acpi_device *device)
 	return ret;
 }
 
-static int acpi_ec_remove(struct acpi_device *device)
+static void acpi_ec_remove(struct acpi_device *device)
 {
 	struct acpi_ec *ec;
 
 	if (!device)
-		return -EINVAL;
+		return;
 
 	ec = acpi_driver_data(device);
 	release_region(ec->data_addr, 1);
@@ -1678,7 +1678,6 @@ static int acpi_ec_remove(struct acpi_device *device)
 		ec_remove_handlers(ec);
 		acpi_ec_free(ec);
 	}
-	return 0;
 }
 
 static acpi_status