v4.19.13 snapshot.
diff --git a/arch/x86/include/asm/gart.h b/arch/x86/include/asm/gart.h
new file mode 100644
index 0000000..3185565
--- /dev/null
+++ b/arch/x86/include/asm/gart.h
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 *);
+extern int 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 int gart_iommu_hole_init(void)
+{
+ return -ENODEV;
+}
+#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)
+{
+ if (!aper_base)
+ return 0;
+
+ if (aper_base + aper_size > 0x100000000ULL) {
+ printk(KERN_INFO "Aperture beyond 4GB. Ignoring.\n");
+ return 0;
+ }
+ if (e820__mapped_any(aper_base, aper_base + aper_size, E820_TYPE_RAM)) {
+ printk(KERN_INFO "Aperture pointing to e820 RAM. Ignoring.\n");
+ return 0;
+ }
+ if (aper_size < min_size) {
+ printk(KERN_INFO "Aperture too small (%d MB) than (%d MB)\n",
+ aper_size>>20, min_size>>20);
+ return 0;
+ }
+
+ return 1;
+}
+
+#endif /* _ASM_X86_GART_H */