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 --- arch/x86/lib/usercopy.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 arch/x86/lib/usercopy.c (limited to 'arch/x86/lib/usercopy.c') diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c new file mode 100644 index 000000000..24b48af27 --- /dev/null +++ b/arch/x86/lib/usercopy.c @@ -0,0 +1,55 @@ +/* + * User address space access functions. + * + * For licencing details see kernel-base/COPYING + */ + +#include +#include +#include + +#include + +/** + * copy_from_user_nmi - NMI safe copy from user + * @to: Pointer to the destination buffer + * @from: Pointer to a user space address of the current task + * @n: Number of bytes to copy + * + * Returns: The number of not copied bytes. 0 is success, i.e. all bytes copied + * + * Contrary to other copy_from_user() variants this function can be called + * from NMI context. Despite the name it is not restricted to be called + * from NMI context. It is safe to be called from any other context as + * well. It disables pagefaults across the copy which means a fault will + * abort the copy. + * + * For NMI context invocations this relies on the nested NMI work to allow + * atomic faults from the NMI path; the nested NMI paths are careful to + * preserve CR2. + */ +unsigned long +copy_from_user_nmi(void *to, const void __user *from, unsigned long n) +{ + unsigned long ret; + + if (!__access_ok(from, n)) + return n; + + if (!nmi_uaccess_okay()) + return n; + + /* + * Even though this function is typically called from NMI/IRQ context + * disable pagefaults so that its behaviour is consistent even when + * called from other contexts. + */ + pagefault_disable(); + instrument_copy_from_user_before(to, from, n); + ret = raw_copy_from_user(to, from, n); + instrument_copy_from_user_after(to, from, n, ret); + pagefault_enable(); + + return ret; +} +EXPORT_SYMBOL_GPL(copy_from_user_nmi); -- cgit v1.3.1