1/* $Id: generic.c,v 1.1.1.1 2007/08/03 18:52:18 Exp $
2 * generic.c: Generic Sparc mm routines that are not dependent upon
3 *            MMU type but are Sparc specific.
4 *
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 */
7
8#include <linux/kernel.h>
9#include <linux/mm.h>
10#include <linux/swap.h>
11#include <linux/pagemap.h>
12
13#include <asm/pgalloc.h>
14#include <asm/pgtable.h>
15#include <asm/page.h>
16#include <asm/cacheflush.h>
17#include <asm/tlbflush.h>
18
19/* Remap IO memory, the same way as remap_pfn_range(), but use
20 * the obio memory space.
21 *
22 * They use a pgprot that sets PAGE_IO and does not check the
23 * mem_map table as this is independent of normal memory.
24 */
25static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte, unsigned long address, unsigned long size,
26	unsigned long offset, pgprot_t prot, int space)
27{
28	unsigned long end;
29
30	address &= ~PMD_MASK;
31	end = address + size;
32	if (end > PMD_SIZE)
33		end = PMD_SIZE;
34	do {
35		set_pte_at(mm, address, pte, mk_pte_io(offset, prot, space));
36		address += PAGE_SIZE;
37		offset += PAGE_SIZE;
38		pte++;
39	} while (address < end);
40}
41
42static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
43	unsigned long offset, pgprot_t prot, int space)
44{
45	unsigned long end;
46
47	address &= ~PGDIR_MASK;
48	end = address + size;
49	if (end > PGDIR_SIZE)
50		end = PGDIR_SIZE;
51	offset -= address;
52	do {
53		pte_t * pte = pte_alloc_map(mm, pmd, address);
54		if (!pte)
55			return -ENOMEM;
56		io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
57		address = (address + PMD_SIZE) & PMD_MASK;
58		pmd++;
59	} while (address < end);
60	return 0;
61}
62
63int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
64		       unsigned long pfn, unsigned long size, pgprot_t prot)
65{
66	int error = 0;
67	pgd_t * dir;
68	unsigned long beg = from;
69	unsigned long end = from + size;
70	struct mm_struct *mm = vma->vm_mm;
71	int space = GET_IOSPACE(pfn);
72	unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
73
74	/* See comment in mm/memory.c remap_pfn_range */
75	vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
76	vma->vm_pgoff = (offset >> PAGE_SHIFT) |
77		((unsigned long)space << 28UL);
78
79	offset -= from;
80	dir = pgd_offset(mm, from);
81	flush_cache_range(vma, beg, end);
82
83	while (from < end) {
84		pmd_t *pmd = pmd_alloc(mm, dir, from);
85		error = -ENOMEM;
86		if (!pmd)
87			break;
88		error = io_remap_pmd_range(mm, pmd, from, end - from, offset + from, prot, space);
89		if (error)
90			break;
91		from = (from + PGDIR_SIZE) & PGDIR_MASK;
92		dir++;
93	}
94
95	flush_tlb_range(vma, beg, end);
96	return error;
97}
98