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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
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070051void iomap_free(resource_size_t base, unsigned long size)
Venkatesh Pallipadi9e36fda2009-07-10 09:57:35 -070052{
53 io_free_memtype(base, base + size);
54}
55EXPORT_SYMBOL_GPL(iomap_free);
Venkatesh Pallipadi4ab0d472009-02-24 17:35:12 -080056
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070057void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
Keith Packardfd940932008-10-30 19:37:09 -070058{
Keith Packardfd940932008-10-30 19:37:09 -070059 unsigned long vaddr;
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070060 int idx, type;
Keith Packardfd940932008-10-30 19:37:09 -070061
62 pagefault_disable();
63
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070064 type = kmap_atomic_idx_push();
Ingo Molnardd63fdc2009-03-13 03:20:49 +010065 idx = type + KM_TYPE_NR * smp_processor_id();
66 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
67 set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
68 arch_flush_lazy_mmu_mode();
69
70 return (void *)vaddr;
71}
72
73/*
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070074 * Map 'pfn' using protections 'prot'
Keith Packardfd940932008-10-30 19:37:09 -070075 */
Francisco Jerezcc1a8e52010-09-04 22:56:43 +020076void __iomem *
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070077iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
Keith Packardfd940932008-10-30 19:37:09 -070078{
Eric Anholtef5fa0a2009-01-23 14:14:21 -080079 /*
80 * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
81 * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
82 * MTRR is UC or WC. UC_MINUS gets the real intention, of the
83 * user, which is "WC if the MTRR is WC, UC if you can't do that."
84 */
85 if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC))
86 prot = PAGE_KERNEL_UC_MINUS;
87
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070088 return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
Keith Packardfd940932008-10-30 19:37:09 -070089}
90EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
91
92void
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070093iounmap_atomic(void __iomem *kvaddr)
Keith Packardfd940932008-10-30 19:37:09 -070094{
95 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
Keith Packardfd940932008-10-30 19:37:09 -070096
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070097 if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
98 vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
99 int idx, type;
100
Peter Zijlstra20273942010-10-27 15:32:58 -0700101 type = kmap_atomic_idx();
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -0700102 idx = type + KM_TYPE_NR * smp_processor_id();
103
104#ifdef CONFIG_DEBUG_HIGHMEM
105 WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
106#endif
107 /*
108 * Force other mappings to Oops if they'll try to access this
109 * pte without first remap it. Keeping stale mappings around
110 * is a bad idea also, in case the page changes cacheability
111 * attributes or becomes a protected page in a hypervisor.
112 */
Keith Packardfd940932008-10-30 19:37:09 -0700113 kpte_clear_flush(kmap_pte-idx, vaddr);
Peter Zijlstra20273942010-10-27 15:32:58 -0700114 kmap_atomic_idx_pop();
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -0700115 }
Keith Packardfd940932008-10-30 19:37:09 -0700116
Keith Packardfd940932008-10-30 19:37:09 -0700117 pagefault_enable();
118}
119EXPORT_SYMBOL_GPL(iounmap_atomic);