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awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/mips/loongson/common/mem.c
10818 views
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/*

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 * This program is free software; you can redistribute  it and/or modify it

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 * under  the terms of  the GNU General  Public License as published by the

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 * Free Software Foundation;  either version 2 of the  License, or (at your

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 * option) any later version.

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 */

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#include <linux/fs.h>

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#include <linux/fcntl.h>

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#include <linux/mm.h>

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#include <asm/bootinfo.h>

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#include <loongson.h>

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#include <mem.h>

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#include <pci.h>

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void __init prom_init_memory(void)

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{

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	add_memory_region(0x0, (memsize << 20), BOOT_MEM_RAM);

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	add_memory_region(memsize << 20, LOONGSON_PCI_MEM_START - (memsize <<

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				20), BOOT_MEM_RESERVED);

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#ifdef CONFIG_CPU_SUPPORTS_ADDRWINCFG

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	{

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		int bit;

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		bit = fls(memsize + highmemsize);

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		if (bit != ffs(memsize + highmemsize))

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			bit += 20;

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		else

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			bit = bit + 20 - 1;

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		/* set cpu window3 to map CPU to DDR: 2G -> 2G */

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		LOONGSON_ADDRWIN_CPUTODDR(ADDRWIN_WIN3, 0x80000000ul,

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					  0x80000000ul, (1 << bit));

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		mmiowb();

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	}

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#endif /* !CONFIG_CPU_SUPPORTS_ADDRWINCFG */

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#ifdef CONFIG_64BIT

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	if (highmemsize > 0)

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		add_memory_region(LOONGSON_HIGHMEM_START,

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				  highmemsize << 20, BOOT_MEM_RAM);

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	add_memory_region(LOONGSON_PCI_MEM_END + 1, LOONGSON_HIGHMEM_START -

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			  LOONGSON_PCI_MEM_END - 1, BOOT_MEM_RESERVED);

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#endif /* !CONFIG_64BIT */

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}

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/* override of arch/mips/mm/cache.c: __uncached_access */

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int __uncached_access(struct file *file, unsigned long addr)

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{

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	if (file->f_flags & O_DSYNC)

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		return 1;

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	return addr >= __pa(high_memory) ||

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		((addr >= LOONGSON_MMIO_MEM_START) &&

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		 (addr < LOONGSON_MMIO_MEM_END));

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}

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#ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED

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#include <linux/pci.h>

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#include <linux/sched.h>

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#include <asm/current.h>

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static unsigned long uca_start, uca_end;

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pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,

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			      unsigned long size, pgprot_t vma_prot)

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{

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	unsigned long offset = pfn << PAGE_SHIFT;

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	unsigned long end = offset + size;

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	if (__uncached_access(file, offset)) {

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		if (uca_start && (offset >= uca_start) &&

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		    (end <= uca_end))

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			return __pgprot((pgprot_val(vma_prot) &

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					 ~_CACHE_MASK) |

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					_CACHE_UNCACHED_ACCELERATED);

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		else

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			return pgprot_noncached(vma_prot);

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	}

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	return vma_prot;

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}

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static int __init find_vga_mem_init(void)

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{

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	struct pci_dev *dev = 0;

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	struct resource *r;

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	int idx;

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	if (uca_start)

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		return 0;

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	for_each_pci_dev(dev) {

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		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {

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			for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {

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				r = &dev->resource[idx];

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				if (!r->start && r->end)

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					continue;

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				if (r->flags & IORESOURCE_IO)

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					continue;

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				if (r->flags & IORESOURCE_MEM) {

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					uca_start = r->start;

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					uca_end = r->end;

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					return 0;

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				}

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			}

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		}

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	}

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	return 0;

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}

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late_initcall(find_vga_mem_init);

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#endif /* !CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED */

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