blob: 84e236ce76ba9a8afd624cfc4c506ebaa654b926 [file] [log] [blame]
Keith Packardfd940932008-10-30 19:37:09 -07001/*
2 * Copyright © 2008 Ingo Molnar
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
17 */
18
19#include <asm/iomap.h>
Eric Anholtef5fa0a2009-01-23 14:14:21 -080020#include <asm/pat.h>
Keith Packardfd940932008-10-30 19:37:09 -070021#include <linux/module.h>
Akinobu Mita7ca43e72009-03-31 15:23:25 -070022#include <linux/highmem.h>
Keith Packardfd940932008-10-30 19:37:09 -070023
Venkatesh Pallipadi9e36fda2009-07-10 09:57:35 -070024static int is_io_mapping_possible(resource_size_t base, unsigned long size)
Venkatesh Pallipadi4ab0d472009-02-24 17:35:12 -080025{
Andrew Morton6a491e22009-04-02 16:44:38 -070026#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
Venkatesh Pallipadi4ab0d472009-02-24 17:35:12 -080027 /* There is no way to map greater than 1 << 32 address without PAE */
28 if (base + size > 0x100000000ULL)
29 return 0;
Ingo Molnar92b9af92009-02-28 14:09:27 +010030#endif
Venkatesh Pallipadi4ab0d472009-02-24 17:35:12 -080031 return 1;
32}
Venkatesh Pallipadi9e36fda2009-07-10 09:57:35 -070033
34int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
35{
36 unsigned long flag = _PAGE_CACHE_WC;
37 int ret;
38
39 if (!is_io_mapping_possible(base, size))
40 return -EINVAL;
41
42 ret = io_reserve_memtype(base, base + size, &flag);
43 if (ret)
44 return ret;
45
46 *prot = __pgprot(__PAGE_KERNEL | flag);
47 return 0;
48}
49EXPORT_SYMBOL_GPL(iomap_create_wc);
50
51void
52iomap_free(resource_size_t base, unsigned long size)
53{
54 io_free_memtype(base, base + size);
55}
56EXPORT_SYMBOL_GPL(iomap_free);
Venkatesh Pallipadi4ab0d472009-02-24 17:35:12 -080057
Ingo Molnardd63fdc2009-03-13 03:20:49 +010058void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
Keith Packardfd940932008-10-30 19:37:09 -070059{
60 enum fixed_addresses idx;
61 unsigned long vaddr;
62
63 pagefault_disable();
64
Akinobu Mitaa7f8c502009-04-02 16:01:26 +090065 debug_kmap_atomic(type);
Ingo Molnardd63fdc2009-03-13 03:20:49 +010066 idx = type + KM_TYPE_NR * smp_processor_id();
67 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
68 set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
69 arch_flush_lazy_mmu_mode();
70
71 return (void *)vaddr;
72}
73
74/*
75 * Map 'pfn' using fixed map 'type' and protections 'prot'
Keith Packardfd940932008-10-30 19:37:09 -070076 */
77void *
78iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
79{
Eric Anholtef5fa0a2009-01-23 14:14:21 -080080 /*
81 * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
82 * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
83 * MTRR is UC or WC. UC_MINUS gets the real intention, of the
84 * user, which is "WC if the MTRR is WC, UC if you can't do that."
85 */
86 if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC))
87 prot = PAGE_KERNEL_UC_MINUS;
88
Akinobu Mitabb6d59c2009-03-11 23:33:18 +090089 return kmap_atomic_prot_pfn(pfn, type, prot);
Keith Packardfd940932008-10-30 19:37:09 -070090}
91EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
92
93void
94iounmap_atomic(void *kvaddr, enum km_type type)
95{
96 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
97 enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
98
99 /*
100 * Force other mappings to Oops if they'll try to access this pte
101 * without first remap it. Keeping stale mappings around is a bad idea
102 * also, in case the page changes cacheability attributes or becomes
103 * a protected page in a hypervisor.
104 */
105 if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
106 kpte_clear_flush(kmap_pte-idx, vaddr);
107
Keith Packardfd940932008-10-30 19:37:09 -0700108 pagefault_enable();
109}
110EXPORT_SYMBOL_GPL(iounmap_atomic);