From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/acpi/proc.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 drivers/acpi/proc.c (limited to 'drivers/acpi/proc.c') diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c new file mode 100644 index 000000000..c08ead072 --- /dev/null +++ b/drivers/acpi/proc.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include + +#include "sleep.h" +#include "internal.h" + +/* + * this file provides support for: + * /proc/acpi/wakeup + */ + +static int +acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset) +{ + struct acpi_device *dev, *tmp; + + seq_printf(seq, "Device\tS-state\t Status Sysfs node\n"); + + mutex_lock(&acpi_device_lock); + list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list, + wakeup_list) { + struct acpi_device_physical_node *entry; + + if (!dev->wakeup.flags.valid) + continue; + + seq_printf(seq, "%s\t S%llu\t", + dev->pnp.bus_id, + dev->wakeup.sleep_state); + + mutex_lock(&dev->physical_node_lock); + + if (!dev->physical_node_count) { + seq_printf(seq, "%c%-8s\n", + dev->wakeup.flags.valid ? '*' : ' ', + str_enabled_disabled(device_may_wakeup(&dev->dev))); + } else { + struct device *ldev; + list_for_each_entry(entry, &dev->physical_node_list, + node) { + ldev = get_device(entry->dev); + if (!ldev) + continue; + + if (&entry->node != + dev->physical_node_list.next) + seq_printf(seq, "\t\t"); + + seq_printf(seq, "%c%-8s %s:%s\n", + dev->wakeup.flags.valid ? '*' : ' ', + str_enabled_disabled(device_may_wakeup(ldev) || + device_may_wakeup(&dev->dev)), + ldev->bus ? ldev->bus->name : + "no-bus", dev_name(ldev)); + put_device(ldev); + } + } + + mutex_unlock(&dev->physical_node_lock); + } + mutex_unlock(&acpi_device_lock); + return 0; +} + +static void physical_device_enable_wakeup(struct acpi_device *adev) +{ + struct acpi_device_physical_node *entry; + + mutex_lock(&adev->physical_node_lock); + + list_for_each_entry(entry, + &adev->physical_node_list, node) + if (entry->dev && device_can_wakeup(entry->dev)) { + bool enable = !device_may_wakeup(entry->dev); + device_set_wakeup_enable(entry->dev, enable); + } + + mutex_unlock(&adev->physical_node_lock); +} + +static ssize_t +acpi_system_write_wakeup_device(struct file *file, + const char __user * buffer, + size_t count, loff_t * ppos) +{ + struct acpi_device *dev, *tmp; + char strbuf[5]; + char str[5] = ""; + + if (count > 4) + count = 4; + + if (copy_from_user(strbuf, buffer, count)) + return -EFAULT; + strbuf[count] = '\0'; + sscanf(strbuf, "%s", str); + + mutex_lock(&acpi_device_lock); + list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list, + wakeup_list) { + if (!dev->wakeup.flags.valid) + continue; + + if (!strncmp(dev->pnp.bus_id, str, 4)) { + if (device_can_wakeup(&dev->dev)) { + bool enable = !device_may_wakeup(&dev->dev); + device_set_wakeup_enable(&dev->dev, enable); + } else { + physical_device_enable_wakeup(dev); + } + break; + } + } + mutex_unlock(&acpi_device_lock); + return count; +} + +static int +acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file) +{ + return single_open(file, acpi_system_wakeup_device_seq_show, + pde_data(inode)); +} + +static const struct proc_ops acpi_system_wakeup_device_proc_ops = { + .proc_open = acpi_system_wakeup_device_open_fs, + .proc_read = seq_read, + .proc_write = acpi_system_write_wakeup_device, + .proc_lseek = seq_lseek, + .proc_release = single_release, +}; + +void __init acpi_sleep_proc_init(void) +{ + /* 'wakeup device' [R/W] */ + proc_create("wakeup", 0644, acpi_root_dir, &acpi_system_wakeup_device_proc_ops); +} -- cgit v1.3.1