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/asm-generic/cmpxchg.h | 115 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 include/asm-generic/cmpxchg.h (limited to 'include/asm-generic/cmpxchg.h') diff --git a/include/asm-generic/cmpxchg.h b/include/asm-generic/cmpxchg.h new file mode 100644 index 000000000..848de25fc --- /dev/null +++ b/include/asm-generic/cmpxchg.h @@ -0,0 +1,115 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Generic UP xchg and cmpxchg using interrupt disablement. Does not + * support SMP. + */ + +#ifndef __ASM_GENERIC_CMPXCHG_H +#define __ASM_GENERIC_CMPXCHG_H + +#ifdef CONFIG_SMP +#error "Cannot use generic cmpxchg on SMP" +#endif + +#include +#include + +/* + * This function doesn't exist, so you'll get a linker error if + * something tries to do an invalidly-sized xchg(). + */ +extern void __generic_xchg_called_with_bad_pointer(void); + +static inline +unsigned long __generic_xchg(unsigned long x, volatile void *ptr, int size) +{ + unsigned long ret, flags; + + switch (size) { + case 1: +#ifdef __xchg_u8 + return __xchg_u8(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u8 *)ptr; + *(volatile u8 *)ptr = (x & 0xffu); + local_irq_restore(flags); + return ret; +#endif /* __xchg_u8 */ + + case 2: +#ifdef __xchg_u16 + return __xchg_u16(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u16 *)ptr; + *(volatile u16 *)ptr = (x & 0xffffu); + local_irq_restore(flags); + return ret; +#endif /* __xchg_u16 */ + + case 4: +#ifdef __xchg_u32 + return __xchg_u32(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u32 *)ptr; + *(volatile u32 *)ptr = (x & 0xffffffffu); + local_irq_restore(flags); + return ret; +#endif /* __xchg_u32 */ + +#ifdef CONFIG_64BIT + case 8: +#ifdef __xchg_u64 + return __xchg_u64(x, ptr); +#else + local_irq_save(flags); + ret = *(volatile u64 *)ptr; + *(volatile u64 *)ptr = x; + local_irq_restore(flags); + return ret; +#endif /* __xchg_u64 */ +#endif /* CONFIG_64BIT */ + + default: + __generic_xchg_called_with_bad_pointer(); + return x; + } +} + +#define generic_xchg(ptr, x) ({ \ + ((__typeof__(*(ptr))) \ + __generic_xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \ +}) + +/* + * Atomic compare and exchange. + */ +#include + +#define generic_cmpxchg_local(ptr, o, n) ({ \ + ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))); \ +}) + +#define generic_cmpxchg64_local(ptr, o, n) \ + __generic_cmpxchg64_local((ptr), (o), (n)) + + +#ifndef arch_xchg +#define arch_xchg generic_xchg +#endif + +#ifndef arch_cmpxchg_local +#define arch_cmpxchg_local generic_cmpxchg_local +#endif + +#ifndef arch_cmpxchg64_local +#define arch_cmpxchg64_local generic_cmpxchg64_local +#endif + +#define arch_cmpxchg arch_cmpxchg_local +#define arch_cmpxchg64 arch_cmpxchg64_local + +#endif /* __ASM_GENERIC_CMPXCHG_H */ -- cgit v1.3.1