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authorLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
commit3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch)
treeb767d7f6e26bc64334d3f14f8422d187239dc45d /drivers/acpi/reboot.c
downloadlinux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz
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Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe: - Fix a task_work add use-after-free with SQPOLL. The sqpoll thread could pop and complete the last request while io_req_normal_work_add() was still looking at them after the mpscq push. Use the same approach as DEFER_TASKRUN to protect from that, holding an RCU read lock across the add, and have exit wait for an RCU grace period for SQPOLL rings as well. - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED rings - Mark the source filter table as COW when cloning bpf filters, so registering another filter on the source doesn't modify the shared table in place - Initialize the task context before running the BPF loop - Requeue zcrx multishot receives stopped by a local resource - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit) * tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring: fix task_work add use-after-free with SQPOLL io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full io_uring/zcrx: requeue multishot receives stopped by a local resource io_uring: initialize task context before running the BPF loop io_uring: zero big_cqe for aux CQEs on CQE32 rings io_uring: fix free entry check for 32b CQEs on CQE32 rings io_uring: only post the dummy skip CQE on CQE_MIXED rings io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'drivers/acpi/reboot.c')
-rw-r--r--drivers/acpi/reboot.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/acpi/reboot.c b/drivers/acpi/reboot.c
new file mode 100644
index 000000000..b79b7c99c
--- /dev/null
+++ b/drivers/acpi/reboot.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define pr_fmt(fmt) "ACPI: " fmt
+
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <acpi/reboot.h>
+#include <linux/delay.h>
+
+#ifdef CONFIG_PCI
+static void acpi_pci_reboot(struct acpi_generic_address *rr, u8 reset_value)
+{
+ unsigned int devfn;
+ struct pci_bus *bus0;
+
+ /* The reset register can only live on bus 0. */
+ bus0 = pci_find_bus(0, 0);
+ if (!bus0)
+ return;
+ /* Form PCI device/function pair. */
+ devfn = PCI_DEVFN((rr->address >> 32) & 0xffff,
+ (rr->address >> 16) & 0xffff);
+ pr_debug("Resetting with ACPI PCI RESET_REG.\n");
+ /* Write the value that resets us. */
+ pci_bus_write_config_byte(bus0, devfn,
+ (rr->address & 0xffff), reset_value);
+}
+#else
+static inline void acpi_pci_reboot(struct acpi_generic_address *rr,
+ u8 reset_value)
+{
+ pr_warn_once("PCI configuration space access is not supported\n");
+}
+#endif
+
+void acpi_reboot(void)
+{
+ struct acpi_generic_address *rr;
+ u8 reset_value;
+
+ if (acpi_disabled)
+ return;
+
+ rr = &acpi_gbl_FADT.reset_register;
+
+ /* ACPI reset register was only introduced with v2 of the FADT */
+
+ if (acpi_gbl_FADT.header.revision < 2)
+ return;
+
+ /* Is the reset register supported? The spec says we should be
+ * checking the bit width and bit offset, but Windows ignores
+ * these fields */
+ if (!(acpi_gbl_FADT.flags & ACPI_FADT_RESET_REGISTER))
+ return;
+
+ reset_value = acpi_gbl_FADT.reset_value;
+
+ /* The reset register can only exist in I/O, Memory or PCI config space
+ * on a device on bus 0. */
+ switch (rr->space_id) {
+ case ACPI_ADR_SPACE_PCI_CONFIG:
+ acpi_pci_reboot(rr, reset_value);
+ break;
+
+ case ACPI_ADR_SPACE_SYSTEM_MEMORY:
+ case ACPI_ADR_SPACE_SYSTEM_IO:
+ pr_debug("ACPI MEMORY or I/O RESET_REG.\n");
+ acpi_reset();
+ break;
+ }
+
+ /*
+ * Some platforms do not shut down immediately after writing to the
+ * ACPI reset register, and this results in racing with the
+ * subsequent reboot mechanism.
+ *
+ * The 15ms delay has been found to be long enough for the system
+ * to reboot on the affected platforms.
+ */
+ mdelay(15);
+}