arch/x86/include/asm/gart.h
Source file repositories/reference/linux-study-clean/arch/x86/include/asm/gart.h
File Facts
- System
- Linux kernel
- Corpus path
arch/x86/include/asm/gart.h- Extension
.h- Size
- 2682 bytes
- Lines
- 114
- Domain
- Architecture Layer
- Bucket
- arch/x86
- 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.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
asm/e820/api.h
Detected Declarations
function early_gart_iommu_checkfunction gart_set_size_and_enablefunction enable_gart_translationfunction aperture_valid
Annotated Snippet
#ifndef _ASM_X86_GART_H
#define _ASM_X86_GART_H
#include <asm/e820/api.h>
extern void set_up_gart_resume(u32, u32);
extern int fallback_aper_order;
extern int fallback_aper_force;
extern int fix_aperture;
/* PTE bits. */
#define GPTE_VALID 1
#define GPTE_COHERENT 2
/* Aperture control register bits. */
#define GARTEN (1<<0)
#define DISGARTCPU (1<<4)
#define DISGARTIO (1<<5)
#define DISTLBWALKPRB (1<<6)
/* GART cache control register bits. */
#define INVGART (1<<0)
#define GARTPTEERR (1<<1)
/* K8 On-cpu GART registers */
#define AMD64_GARTAPERTURECTL 0x90
#define AMD64_GARTAPERTUREBASE 0x94
#define AMD64_GARTTABLEBASE 0x98
#define AMD64_GARTCACHECTL 0x9c
#ifdef CONFIG_GART_IOMMU
extern int gart_iommu_aperture;
extern int gart_iommu_aperture_allowed;
extern int gart_iommu_aperture_disabled;
extern void early_gart_iommu_check(void);
extern int gart_iommu_init(void);
extern void __init gart_parse_options(char *);
void gart_iommu_hole_init(void);
#else
#define gart_iommu_aperture 0
#define gart_iommu_aperture_allowed 0
#define gart_iommu_aperture_disabled 1
static inline void early_gart_iommu_check(void)
{
}
static inline void gart_parse_options(char *options)
{
}
static inline void gart_iommu_hole_init(void)
{
}
#endif
extern int agp_amd64_init(void);
static inline void gart_set_size_and_enable(struct pci_dev *dev, u32 order)
{
u32 ctl;
/*
* Don't enable translation but enable GART IO and CPU accesses.
* Also, set DISTLBWALKPRB since GART tables memory is UC.
*/
ctl = order << 1;
pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
}
static inline void enable_gart_translation(struct pci_dev *dev, u64 addr)
{
u32 tmp, ctl;
/* address of the mappings table */
addr >>= 12;
tmp = (u32) addr<<4;
tmp &= ~0xf;
pci_write_config_dword(dev, AMD64_GARTTABLEBASE, tmp);
/* Enable GART translation for this hammer. */
pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &ctl);
ctl |= GARTEN | DISTLBWALKPRB;
ctl &= ~(DISGARTCPU | DISGARTIO);
pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
}
static inline int aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
Annotation
- Immediate include surface: `asm/e820/api.h`.
- Detected declarations: `function early_gart_iommu_check`, `function gart_set_size_and_enable`, `function enable_gart_translation`, `function aperture_valid`.
- Atlas domain: Architecture Layer / arch/x86.
- Implementation status: source implementation candidate.
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.