drivers/acpi/pci_link.c
Source file repositories/reference/linux-study-clean/drivers/acpi/pci_link.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/acpi/pci_link.c- Extension
.c- Size
- 23599 bytes
- Lines
- 921
- Domain
- Driver Families
- Bucket
- drivers/acpi
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/syscore_ops.hlinux/kernel.hlinux/module.hlinux/init.hlinux/types.hlinux/spinlock.hlinux/pm.hlinux/pci.hlinux/mutex.hlinux/slab.hlinux/acpi.hlinux/irq.hinternal.h
Detected Declarations
struct acpi_pci_link_irqstruct acpi_pci_linkfunction contextfunction acpi_pci_link_get_possiblefunction acpi_pci_link_check_currentfunction acpi_pci_link_get_currentfunction acpi_pci_link_setfunction acpi_irq_pci_sharing_penaltyfunction list_for_each_entryfunction acpi_irq_get_penaltyfunction acpi_irq_penalty_initfunction acpi_pci_link_allocatefunction acpi_pci_link_allocate_irqfunction acpi_pci_link_free_irqfunction acpi_pci_link_addfunction acpi_pci_link_resumefunction irqrouter_resumefunction list_for_each_entryfunction acpi_pci_link_removefunction acpi_irq_penalty_updatefunction thefunction acpi_isa_irq_availablefunction acpi_penalize_sci_irqfunction acpi_irq_isafunction acpi_irq_pcifunction acpi_irq_nobalance_setfunction acpi_irq_balance_setfunction acpi_pci_link_init
Annotated Snippet
struct acpi_pci_link_irq {
u32 active; /* Current IRQ */
u8 triggering; /* All IRQs */
u8 polarity; /* All IRQs */
u8 resource_type;
u8 possible_count;
u32 possible[ACPI_PCI_LINK_MAX_POSSIBLE];
u8 initialized:1;
u8 reserved:7;
};
struct acpi_pci_link {
struct list_head list;
struct acpi_device *device;
struct acpi_pci_link_irq irq;
int refcnt;
};
static LIST_HEAD(acpi_link_list);
static DEFINE_MUTEX(acpi_link_lock);
static int sci_irq = -1, sci_penalty;
/* --------------------------------------------------------------------------
PCI Link Device Management
-------------------------------------------------------------------------- */
/*
* set context (link) possible list from resource list
*/
static acpi_status acpi_pci_link_check_possible(struct acpi_resource *resource,
void *context)
{
struct acpi_pci_link *link = context;
acpi_handle handle = link->device->handle;
u32 i;
switch (resource->type) {
case ACPI_RESOURCE_TYPE_START_DEPENDENT:
case ACPI_RESOURCE_TYPE_END_TAG:
return AE_OK;
case ACPI_RESOURCE_TYPE_IRQ:
{
struct acpi_resource_irq *p = &resource->data.irq;
if (!p->interrupt_count) {
acpi_handle_debug(handle,
"Blank _PRS IRQ resource\n");
return AE_OK;
}
for (i = 0;
(i < p->interrupt_count
&& i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
if (!p->interrupts[i]) {
acpi_handle_debug(handle,
"Invalid _PRS IRQ %d\n",
p->interrupts[i]);
continue;
}
link->irq.possible[i] = p->interrupts[i];
link->irq.possible_count++;
}
link->irq.triggering = p->triggering;
link->irq.polarity = p->polarity;
link->irq.resource_type = ACPI_RESOURCE_TYPE_IRQ;
break;
}
case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
{
struct acpi_resource_extended_irq *p =
&resource->data.extended_irq;
if (!p->interrupt_count) {
acpi_handle_debug(handle,
"Blank _PRS EXT IRQ resource\n");
return AE_OK;
}
for (i = 0;
(i < p->interrupt_count
&& i < ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
if (!p->interrupts[i]) {
acpi_handle_debug(handle,
"Invalid _PRS IRQ %d\n",
p->interrupts[i]);
continue;
}
link->irq.possible[i] = p->interrupts[i];
link->irq.possible_count++;
}
link->irq.triggering = p->triggering;
link->irq.polarity = p->polarity;
link->irq.resource_type = ACPI_RESOURCE_TYPE_EXTENDED_IRQ;
break;
Annotation
- Immediate include surface: `linux/syscore_ops.h`, `linux/kernel.h`, `linux/module.h`, `linux/init.h`, `linux/types.h`, `linux/spinlock.h`, `linux/pm.h`, `linux/pci.h`.
- Detected declarations: `struct acpi_pci_link_irq`, `struct acpi_pci_link`, `function context`, `function acpi_pci_link_get_possible`, `function acpi_pci_link_check_current`, `function acpi_pci_link_get_current`, `function acpi_pci_link_set`, `function acpi_irq_pci_sharing_penalty`, `function list_for_each_entry`, `function acpi_irq_get_penalty`.
- Atlas domain: Driver Families / drivers/acpi.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
- 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.