v4.19.13 snapshot.
diff --git a/arch/mips/loongson64/common/mem.c b/arch/mips/loongson64/common/mem.c
new file mode 100644
index 0000000..c549e52
--- /dev/null
+++ b/arch/mips/loongson64/common/mem.c
@@ -0,0 +1,161 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#include <linux/fs.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+
+#include <asm/bootinfo.h>
+
+#include <loongson.h>
+#include <boot_param.h>
+#include <mem.h>
+#include <pci.h>
+
+#ifndef CONFIG_LEFI_FIRMWARE_INTERFACE
+
+u32 memsize, highmemsize;
+
+void __init prom_init_memory(void)
+{
+ add_memory_region(0x0, (memsize << 20), BOOT_MEM_RAM);
+
+ add_memory_region(memsize << 20, LOONGSON_PCI_MEM_START - (memsize <<
+ 20), BOOT_MEM_RESERVED);
+
+#ifdef CONFIG_CPU_SUPPORTS_ADDRWINCFG
+ {
+ int bit;
+
+ bit = fls(memsize + highmemsize);
+ if (bit != ffs(memsize + highmemsize))
+ bit += 20;
+ else
+ bit = bit + 20 - 1;
+
+ /* set cpu window3 to map CPU to DDR: 2G -> 2G */
+ LOONGSON_ADDRWIN_CPUTODDR(ADDRWIN_WIN3, 0x80000000ul,
+ 0x80000000ul, (1 << bit));
+ mmiowb();
+ }
+#endif /* !CONFIG_CPU_SUPPORTS_ADDRWINCFG */
+
+#ifdef CONFIG_64BIT
+ if (highmemsize > 0)
+ add_memory_region(LOONGSON_HIGHMEM_START,
+ highmemsize << 20, BOOT_MEM_RAM);
+
+ add_memory_region(LOONGSON_PCI_MEM_END + 1, LOONGSON_HIGHMEM_START -
+ LOONGSON_PCI_MEM_END - 1, BOOT_MEM_RESERVED);
+
+#endif /* !CONFIG_64BIT */
+}
+
+#else /* CONFIG_LEFI_FIRMWARE_INTERFACE */
+
+void __init prom_init_memory(void)
+{
+ int i;
+ u32 node_id;
+ u32 mem_type;
+
+ /* parse memory information */
+ for (i = 0; i < loongson_memmap->nr_map; i++) {
+ node_id = loongson_memmap->map[i].node_id;
+ mem_type = loongson_memmap->map[i].mem_type;
+
+ if (node_id == 0) {
+ switch (mem_type) {
+ case SYSTEM_RAM_LOW:
+ add_memory_region(loongson_memmap->map[i].mem_start,
+ (u64)loongson_memmap->map[i].mem_size << 20,
+ BOOT_MEM_RAM);
+ break;
+ case SYSTEM_RAM_HIGH:
+ add_memory_region(loongson_memmap->map[i].mem_start,
+ (u64)loongson_memmap->map[i].mem_size << 20,
+ BOOT_MEM_RAM);
+ break;
+ case SYSTEM_RAM_RESERVED:
+ add_memory_region(loongson_memmap->map[i].mem_start,
+ (u64)loongson_memmap->map[i].mem_size << 20,
+ BOOT_MEM_RESERVED);
+ break;
+ }
+ }
+ }
+}
+
+#endif /* CONFIG_LEFI_FIRMWARE_INTERFACE */
+
+/* override of arch/mips/mm/cache.c: __uncached_access */
+int __uncached_access(struct file *file, unsigned long addr)
+{
+ if (file->f_flags & O_DSYNC)
+ return 1;
+
+ return addr >= __pa(high_memory) ||
+ ((addr >= LOONGSON_MMIO_MEM_START) &&
+ (addr < LOONGSON_MMIO_MEM_END));
+}
+
+#ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
+
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+
+static unsigned long uca_start, uca_end;
+
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot)
+{
+ unsigned long offset = pfn << PAGE_SHIFT;
+ unsigned long end = offset + size;
+
+ if (__uncached_access(file, offset)) {
+ if (uca_start && (offset >= uca_start) &&
+ (end <= uca_end))
+ return __pgprot((pgprot_val(vma_prot) &
+ ~_CACHE_MASK) |
+ _CACHE_UNCACHED_ACCELERATED);
+ else
+ return pgprot_noncached(vma_prot);
+ }
+ return vma_prot;
+}
+
+static int __init find_vga_mem_init(void)
+{
+ struct pci_dev *dev = 0;
+ struct resource *r;
+ int idx;
+
+ if (uca_start)
+ return 0;
+
+ for_each_pci_dev(dev) {
+ if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
+ for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {
+ r = &dev->resource[idx];
+ if (!r->start && r->end)
+ continue;
+ if (r->flags & IORESOURCE_IO)
+ continue;
+ if (r->flags & IORESOURCE_MEM) {
+ uca_start = r->start;
+ uca_end = r->end;
+ return 0;
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+late_initcall(find_vga_mem_init);
+#endif /* !CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED */