/arch/sparc64/mm/generic.c

  1/* $Id: generic.c,v 1.18 2001/12/21 04:56:15 davem 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/tlbflush.h>
 17
 18/* Remap IO memory, the same way as remap_pfn_range(), but use
 19 * the obio memory space.
 20 *
 21 * They use a pgprot that sets PAGE_IO and does not check the
 22 * mem_map table as this is independent of normal memory.
 23 */
 24static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte,
 25				      unsigned long address,
 26				      unsigned long size,
 27				      unsigned long offset, pgprot_t prot,
 28				      int space)
 29{
 30	unsigned long end;
 31
 32	/* clear hack bit that was used as a write_combine side-effect flag */
 33	offset &= ~0x1UL;
 34	address &= ~PMD_MASK;
 35	end = address + size;
 36	if (end > PMD_SIZE)
 37		end = PMD_SIZE;
 38	do {
 39		pte_t entry;
 40		unsigned long curend = address + PAGE_SIZE;
 41		
 42		entry = mk_pte_io(offset, prot, space);
 43		if (!(address & 0xffff)) {
 44			if (!(address & 0x3fffff) && !(offset & 0x3ffffe) && end >= address + 0x400000) {
 45				entry = mk_pte_io(offset,
 46						  __pgprot(pgprot_val (prot) | _PAGE_SZ4MB),
 47						  space);
 48				curend = address + 0x400000;
 49				offset += 0x400000;
 50			} else if (!(address & 0x7ffff) && !(offset & 0x7fffe) && end >= address + 0x80000) {
 51				entry = mk_pte_io(offset,
 52						  __pgprot(pgprot_val (prot) | _PAGE_SZ512K),
 53						  space);
 54				curend = address + 0x80000;
 55				offset += 0x80000;
 56			} else if (!(offset & 0xfffe) && end >= address + 0x10000) {
 57				entry = mk_pte_io(offset,
 58						  __pgprot(pgprot_val (prot) | _PAGE_SZ64K),
 59						  space);
 60				curend = address + 0x10000;
 61				offset += 0x10000;
 62			} else
 63				offset += PAGE_SIZE;
 64		} else
 65			offset += PAGE_SIZE;
 66
 67		do {
 68			BUG_ON(!pte_none(*pte));
 69			set_pte_at(mm, address, pte, entry);
 70			address += PAGE_SIZE;
 71			pte++;
 72		} while (address < curend);
 73	} while (address < end);
 74}
 75
 76static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
 77	unsigned long offset, pgprot_t prot, int space)
 78{
 79	unsigned long end;
 80
 81	address &= ~PGDIR_MASK;
 82	end = address + size;
 83	if (end > PGDIR_SIZE)
 84		end = PGDIR_SIZE;
 85	offset -= address;
 86	do {
 87		pte_t * pte = pte_alloc_map(mm, pmd, address);
 88		if (!pte)
 89			return -ENOMEM;
 90		io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
 91		pte_unmap(pte);
 92		address = (address + PMD_SIZE) & PMD_MASK;
 93		pmd++;
 94	} while (address < end);
 95	return 0;
 96}
 97
 98static inline int io_remap_pud_range(struct mm_struct *mm, pud_t * pud, unsigned long address, unsigned long size,
 99	unsigned long offset, pgprot_t prot, int space)
100{
101	unsigned long end;
102
103	address &= ~PUD_MASK;
104	end = address + size;
105	if (end > PUD_SIZE)
106		end = PUD_SIZE;
107	offset -= address;
108	do {
109		pmd_t *pmd = pmd_alloc(mm, pud, address);
110		if (!pud)
111			return -ENOMEM;
112		io_remap_pmd_range(mm, pmd, address, end - address, address + offset, prot, space);
113		address = (address + PUD_SIZE) & PUD_MASK;
114		pud++;
115	} while (address < end);
116	return 0;
117}
118
119int io_remap_page_range(struct vm_area_struct *vma, unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot, int space)
120{
121	int error = 0;
122	pgd_t * dir;
123	unsigned long beg = from;
124	unsigned long end = from + size;
125	struct mm_struct *mm = vma->vm_mm;
126
127	prot = __pgprot(pg_iobits);
128	offset -= from;
129	dir = pgd_offset(mm, from);
130	flush_cache_range(vma, beg, end);
131
132	spin_lock(&mm->page_table_lock);
133	while (from < end) {
134		pud_t *pud = pud_alloc(mm, dir, from);
135		error = -ENOMEM;
136		if (!pud)
137			break;
138		error = io_remap_pud_range(mm, pud, from, end - from, offset + from, prot, space);
139		if (error)
140			break;
141		from = (from + PGDIR_SIZE) & PGDIR_MASK;
142		dir++;
143	}
144	flush_tlb_range(vma, beg, end);
145	spin_unlock(&mm->page_table_lock);
146
147	return error;
148}
149
150int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
151		unsigned long pfn, unsigned long size, pgprot_t prot)
152{
153	int error = 0;
154	pgd_t * dir;
155	unsigned long beg = from;
156	unsigned long end = from + size;
157	struct mm_struct *mm = vma->vm_mm;
158	int space = GET_IOSPACE(pfn);
159	unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
160
161	prot = __pgprot(pg_iobits);
162	offset -= from;
163	dir = pgd_offset(mm, from);
164	flush_cache_range(vma, beg, end);
165
166	spin_lock(&mm->page_table_lock);
167	while (from < end) {
168		pud_t *pud = pud_alloc(current->mm, dir, from);
169		error = -ENOMEM;
170		if (!pud)
171			break;
172		error = io_remap_pud_range(mm, pud, from, end - from, offset + from, prot, space);
173		if (error)
174			break;
175		from = (from + PGDIR_SIZE) & PGDIR_MASK;
176		dir++;
177	}
178	flush_tlb_range(vma, beg, end);
179	spin_unlock(&mm->page_table_lock);
180
181	return error;
182}