From f146c7bc85a51f95c05e0f8173d484eb301ece78 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Thu, 13 Aug 2026 18:52:04 +0200 Subject: PCI: Add pci_irq_type() to query the allocated interrupt type Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX based on the interrupt type the PCI core selected after pci_alloc_irq_vectors(). Several drivers already open-code this check against pdev->msix_enabled and pdev->msi_enabled, or even open code this helper [1]. A common helper avoids the duplication and keeps drivers from accessing the bitfield directly (see also [2]). Acked-by: Bjorn Helgaas Tested-by: John Hubbard Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1] Inspired-by: John Hubbard Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2] Reviewed-by: Gary Guo Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org [ Add missing pci_irq_type() stub for CONFIG_PCI=n. ] Signed-off-by: Danilo Krummrich --- include/vdso/futex.h | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 include/vdso/futex.h (limited to 'include/vdso/futex.h') diff --git a/include/vdso/futex.h b/include/vdso/futex.h new file mode 100644 index 000000000..3cd175eef --- /dev/null +++ b/include/vdso/futex.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _VDSO_FUTEX_H +#define _VDSO_FUTEX_H + +#include + +/** + * __vdso_futex_robust_list64_try_unlock - Try to unlock an uncontended robust futex + * with a 64-bit pending op pointer + * @lock: Pointer to the futex lock object + * @tid: The TID of the calling task + * @pop: Pointer to the task's robust_list_head::list_pending_op + * + * Return: The content of *@lock. On success this is the same as @tid. + * + * The function implements: + * if (atomic_try_cmpxchg(lock, &tid, 0)) + * *op = NULL; + * return tid; + * + * There is a race between a successful unlock and clearing the pending op + * pointer in the robust list head. If the calling task is interrupted in the + * race window and has to handle a (fatal) signal on return to user space then + * the kernel handles the clearing of @pending_op before attempting to deliver + * the signal. That ensures that a task cannot exit with a potentially invalid + * pending op pointer. + * + * User space uses it in the following way: + * + * if (__vdso_futex_robust_list64_try_unlock(lock, tid, &pending_op) != tid) + * err = sys_futex($OP | FUTEX_ROBUST_UNLOCK,....); + * + * If the unlock attempt fails due to the FUTEX_WAITERS bit set in the lock, + * then the syscall does the unlock, clears the pending op pointer and wakes the + * requested number of waiters. + */ +__u32 __vdso_futex_robust_list64_try_unlock(__u32 *lock, __u32 tid, __u64 *pop); + +/** + * __vdso_futex_robust_list32_try_unlock - Try to unlock an uncontended robust futex + * with a 32-bit pending op pointer + * @lock: Pointer to the futex lock object + * @tid: The TID of the calling task + * @pop: Pointer to the task's robust_list_head::list_pending_op + * + * Return: The content of *@lock. On success this is the same as @tid. + * + * Same as __vdso_futex_robust_list64_try_unlock() just with a 32-bit @pop pointer. + */ +__u32 __vdso_futex_robust_list32_try_unlock(__u32 *lock, __u32 tid, __u32 *pop); + +#endif -- cgit v1.3.1