1/*
  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, PAGE_SIZE);
 43		if (!(address & 0xffff)) {
 44			if (PAGE_SIZE < (4 * 1024 * 1024) &&
 45			    !(address & 0x3fffff) &&
 46			    !(offset & 0x3ffffe) &&
 47			    end >= address + 0x400000) {
 48				entry = mk_pte_io(offset, prot, space,
 49						  4 * 1024 * 1024);
 50				curend = address + 0x400000;
 51				offset += 0x400000;
 52			} else if (PAGE_SIZE < (512 * 1024) &&
 53				   !(address & 0x7ffff) &&
 54				   !(offset & 0x7fffe) &&
 55				   end >= address + 0x80000) {
 56				entry = mk_pte_io(offset, prot, space,
 57						  512 * 1024 * 1024);
 58				curend = address + 0x80000;
 59				offset += 0x80000;
 60			} else if (PAGE_SIZE < (64 * 1024) &&
 61				   !(offset & 0xfffe) &&
 62				   end >= address + 0x10000) {
 63				entry = mk_pte_io(offset, prot, space,
 64						  64 * 1024);
 65				curend = address + 0x10000;
 66				offset += 0x10000;
 67			} else
 68				offset += PAGE_SIZE;
 69		} else
 70			offset += PAGE_SIZE;
 71
 72		if (pte_write(entry))
 73			entry = pte_mkdirty(entry);
 74		do {
 75			BUG_ON(!pte_none(*pte));
 76			set_pte_at(mm, address, pte, entry);
 77			address += PAGE_SIZE;
 78			pte_val(entry) += PAGE_SIZE;
 79			pte++;
 80		} while (address < curend);
 81	} while (address < end);
 82}
 83
 84static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
 85	unsigned long offset, pgprot_t prot, int space)
 86{
 87	unsigned long end;
 88
 89	address &= ~PGDIR_MASK;
 90	end = address + size;
 91	if (end > PGDIR_SIZE)
 92		end = PGDIR_SIZE;
 93	offset -= address;
 94	do {
 95		pte_t *pte = pte_alloc_map(mm, NULL, pmd, address);
 96		if (!pte)
 97			return -ENOMEM;
 98		io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
 99		pte_unmap(pte);
100		address = (address + PMD_SIZE) & PMD_MASK;
101		pmd++;
102	} while (address < end);
103	return 0;
104}
105
106static inline int io_remap_pud_range(struct mm_struct *mm, pud_t * pud, unsigned long address, unsigned long size,
107	unsigned long offset, pgprot_t prot, int space)
108{
109	unsigned long end;
110
111	address &= ~PUD_MASK;
112	end = address + size;
113	if (end > PUD_SIZE)
114		end = PUD_SIZE;
115	offset -= address;
116	do {
117		pmd_t *pmd = pmd_alloc(mm, pud, address);
118		if (!pud)
119			return -ENOMEM;
120		io_remap_pmd_range(mm, pmd, address, end - address, address + offset, prot, space);
121		address = (address + PUD_SIZE) & PUD_MASK;
122		pud++;
123	} while (address < end);
124	return 0;
125}
126
127int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
128		unsigned long pfn, unsigned long size, pgprot_t prot)
129{
130	int error = 0;
131	pgd_t * dir;
132	unsigned long beg = from;
133	unsigned long end = from + size;
134	struct mm_struct *mm = vma->vm_mm;
135	int space = GET_IOSPACE(pfn);
136	unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
137	unsigned long phys_base;
138
139	phys_base = offset | (((unsigned long) space) << 32UL);
140
141	/* See comment in mm/memory.c remap_pfn_range */
142	vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
143	vma->vm_pgoff = phys_base >> PAGE_SHIFT;
144
145	offset -= from;
146	dir = pgd_offset(mm, from);
147	flush_cache_range(vma, beg, end);
148
149	while (from < end) {
150		pud_t *pud = pud_alloc(mm, dir, from);
151		error = -ENOMEM;
152		if (!pud)
153			break;
154		error = io_remap_pud_range(mm, pud, from, end - from, offset + from, prot, space);
155		if (error)
156			break;
157		from = (from + PGDIR_SIZE) & PGDIR_MASK;
158		dir++;
159	}
160
161	flush_tlb_range(vma, beg, end);
162	return error;
163}
164EXPORT_SYMBOL(io_remap_pfn_range);