arch/powerpc/kernel/msi.c
Source file repositories/reference/linux-study-clean/arch/powerpc/kernel/msi.c
File Facts
- System
- Linux kernel
- Corpus path
arch/powerpc/kernel/msi.c- Extension
.c- Size
- 989 bytes
- Lines
- 40
- Domain
- Architecture Layer
- Bucket
- arch/powerpc
- Inferred role
- Architecture Layer: implementation source
- Status
- source implementation candidate
Why This File Exists
CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/kernel.hlinux/msi.hlinux/pci.hasm/machdep.h
Detected Declarations
function arch_setup_msi_irqsfunction arch_teardown_msi_irqs
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2006-2007, Michael Ellerman, IBM Corporation.
*/
#include <linux/kernel.h>
#include <linux/msi.h>
#include <linux/pci.h>
#include <asm/machdep.h>
int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
struct pci_controller *phb = pci_bus_to_host(dev->bus);
if (!phb->controller_ops.setup_msi_irqs ||
!phb->controller_ops.teardown_msi_irqs) {
pr_debug("msi: Platform doesn't provide MSI callbacks.\n");
return -ENOSYS;
}
/* PowerPC doesn't support multiple MSI yet */
if (type == PCI_CAP_ID_MSI && nvec > 1)
return 1;
return phb->controller_ops.setup_msi_irqs(dev, nvec, type);
}
void arch_teardown_msi_irqs(struct pci_dev *dev)
{
struct pci_controller *phb = pci_bus_to_host(dev->bus);
/*
* We can be called even when arch_setup_msi_irqs() returns -ENOSYS,
* so check the pointer again.
*/
if (phb->controller_ops.teardown_msi_irqs)
phb->controller_ops.teardown_msi_irqs(dev);
}
Annotation
- Immediate include surface: `linux/kernel.h`, `linux/msi.h`, `linux/pci.h`, `asm/machdep.h`.
- Detected declarations: `function arch_setup_msi_irqs`, `function arch_teardown_msi_irqs`.
- Atlas domain: Architecture Layer / arch/powerpc.
- Implementation status: source implementation candidate.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.