2 * Copyright © 2008 Ingo Molnar
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.
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.
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.
19 #include <asm/iomap.h>
21 #include <linux/module.h>
23 /* Map 'pfn' using fixed map 'type' and protections 'prot'
26 iomap_atomic_prot_pfn(unsigned long pfn
, enum km_type type
, pgprot_t prot
)
28 enum fixed_addresses idx
;
34 * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS.
35 * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the
36 * MTRR is UC or WC. UC_MINUS gets the real intention, of the
37 * user, which is "WC if the MTRR is WC, UC if you can't do that."
39 if (!pat_enabled
&& pgprot_val(prot
) == pgprot_val(PAGE_KERNEL_WC
))
40 prot
= PAGE_KERNEL_UC_MINUS
;
42 idx
= type
+ KM_TYPE_NR
*smp_processor_id();
43 vaddr
= __fix_to_virt(FIX_KMAP_BEGIN
+ idx
);
44 set_pte(kmap_pte
-idx
, pfn_pte(pfn
, prot
));
45 arch_flush_lazy_mmu_mode();
49 EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn
);
52 iounmap_atomic(void *kvaddr
, enum km_type type
)
54 unsigned long vaddr
= (unsigned long) kvaddr
& PAGE_MASK
;
55 enum fixed_addresses idx
= type
+ KM_TYPE_NR
*smp_processor_id();
58 * Force other mappings to Oops if they'll try to access this pte
59 * without first remap it. Keeping stale mappings around is a bad idea
60 * also, in case the page changes cacheability attributes or becomes
61 * a protected page in a hypervisor.
63 if (vaddr
== __fix_to_virt(FIX_KMAP_BEGIN
+idx
))
64 kpte_clear_flush(kmap_pte
-idx
, vaddr
);
66 arch_flush_lazy_mmu_mode();
69 EXPORT_SYMBOL_GPL(iounmap_atomic
);
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