1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_GART_H
3#define _ASM_X86_GART_H
4
5#include <asm/e820/api.h>
6
7extern void set_up_gart_resume(u32, u32);
8
9extern int fallback_aper_order;
10extern int fallback_aper_force;
11extern int fix_aperture;
12
13/* PTE bits. */
14#define GPTE_VALID 1
15#define GPTE_COHERENT 2
16
17/* Aperture control register bits. */
18#define GARTEN (1<<0)
19#define DISGARTCPU (1<<4)
20#define DISGARTIO (1<<5)
21#define DISTLBWALKPRB (1<<6)
22
23/* GART cache control register bits. */
24#define INVGART (1<<0)
25#define GARTPTEERR (1<<1)
26
27/* K8 On-cpu GART registers */
28#define AMD64_GARTAPERTURECTL 0x90
29#define AMD64_GARTAPERTUREBASE 0x94
30#define AMD64_GARTTABLEBASE 0x98
31#define AMD64_GARTCACHECTL 0x9c
32
33#ifdef CONFIG_GART_IOMMU
34extern int gart_iommu_aperture;
35extern int gart_iommu_aperture_allowed;
36extern int gart_iommu_aperture_disabled;
37
38extern void early_gart_iommu_check(void);
39extern int gart_iommu_init(void);
40extern void __init gart_parse_options(char *);
41void gart_iommu_hole_init(void);
42
43#else
44#define gart_iommu_aperture 0
45#define gart_iommu_aperture_allowed 0
46#define gart_iommu_aperture_disabled 1
47
48static inline void early_gart_iommu_check(void)
49{
50}
51static inline void gart_parse_options(char *options)
52{
53}
54static inline void gart_iommu_hole_init(void)
55{
56}
57#endif
58
59extern int agp_amd64_init(void);
60
61static inline void gart_set_size_and_enable(struct pci_dev *dev, u32 order)
62{
63 u32 ctl;
64
65 /*
66 * Don't enable translation but enable GART IO and CPU accesses.
67 * Also, set DISTLBWALKPRB since GART tables memory is UC.
68 */
69 ctl = order << 1;
70
71 pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, val: ctl);
72}
73
74static inline void enable_gart_translation(struct pci_dev *dev, u64 addr)
75{
76 u32 tmp, ctl;
77
78 /* address of the mappings table */
79 addr >>= 12;
80 tmp = (u32) addr<<4;
81 tmp &= ~0xf;
82 pci_write_config_dword(dev, AMD64_GARTTABLEBASE, val: tmp);
83
84 /* Enable GART translation for this hammer. */
85 pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, val: &ctl);
86 ctl |= GARTEN | DISTLBWALKPRB;
87 ctl &= ~(DISGARTCPU | DISGARTIO);
88 pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, val: ctl);
89}
90
91static inline int aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
92{
93 if (!aper_base)
94 return 0;
95
96 if (aper_base + aper_size > 0x100000000ULL) {
97 printk(KERN_INFO "Aperture beyond 4GB. Ignoring.\n");
98 return 0;
99 }
100 if (e820__mapped_any(start: aper_base, end: aper_base + aper_size, type: E820_TYPE_RAM)) {
101 printk(KERN_INFO "Aperture pointing to e820 RAM. Ignoring.\n");
102 return 0;
103 }
104 if (aper_size < min_size) {
105 printk(KERN_INFO "Aperture too small (%d MB) than (%d MB)\n",
106 aper_size>>20, min_size>>20);
107 return 0;
108 }
109
110 return 1;
111}
112
113#endif /* _ASM_X86_GART_H */
114

source code of linux/arch/x86/include/asm/gart.h