dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

x86: add iomap_atomic*()/iounmap_atomic() on 32-bit using fixmaps 

Impact: introduce new APIs, separate kmap code from CONFIG_HIGHMEM

This takes the code used for CONFIG_HIGHMEM memory mappings except that
it's designed for dynamic IO resource mapping.

These fixmaps are available even with CONFIG_HIGHMEM turned off.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Keith Packard 2008-10-30 19:37:09 -07:00 committed by Ingo Molnar
parent 721d5dfe7e
commit fd94093435
7 changed files with 96 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/x86/include/asm/fixmap.h
View File

@ -9,6 +9,10 @@
extern int fixmaps_set;
extern pte_t *kmap_pte;
extern pgprot_t kmap_prot;
extern pte_t *pkmap_page_table;
void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
void native_set_fixmap(enum fixed_addresses idx,
unsigned long phys, pgprot_t flags);

4
arch/x86/include/asm/fixmap_32.h
View File

@ -28,10 +28,8 @@ extern unsigned long __FIXADDR_TOP;
#include <asm/acpi.h>
#include <asm/apicdef.h>
#include <asm/page.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#endif
/*
* Here we define all the compile-time 'special' virtual
@ -75,10 +73,8 @@ enum fixed_addresses {
#ifdef CONFIG_X86_CYCLONE_TIMER
FIX_CYCLONE_TIMER, /*cyclone timer register*/
#endif
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
#endif
#ifdef CONFIG_PCI_MMCONFIG
FIX_PCIE_MCFG,
#endif

5
arch/x86/include/asm/highmem.h
View File

@ -25,14 +25,11 @@
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
#include <asm/paravirt.h>
#include <asm/fixmap.h>
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
extern pte_t *kmap_pte;
extern pgprot_t kmap_prot;
extern pte_t *pkmap_page_table;
/*
* Right now we initialize only a single pte table. It can be extended
* easily, subsequent pte tables have to be allocated in one physical

2
arch/x86/mm/Makefile
View File

@ -1,7 +1,7 @@
obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
pat.o pgtable.o gup.o
obj-$(CONFIG_X86_32) += pgtable_32.o
obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_X86_PTDUMP) += dump_pagetables.o

3
arch/x86/mm/init_32.c
View File

@ -334,7 +334,6 @@ int devmem_is_allowed(unsigned long pagenr)
return 0;
}
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
@ -357,6 +356,7 @@ static void __init kmap_init(void)
kmap_prot = PAGE_KERNEL;
}
#ifdef CONFIG_HIGHMEM
static void __init permanent_kmaps_init(pgd_t *pgd_base)
{
unsigned long vaddr;
@ -436,7 +436,6 @@ static void __init set_highmem_pages_init(void)
#endif /* !CONFIG_NUMA */
#else
# define kmap_init() do { } while (0)
# define permanent_kmaps_init(pgd_base) do { } while (0)
# define set_highmem_pages_init() do { } while (0)
#endif /* CONFIG_HIGHMEM */

59
arch/x86/mm/iomap_32.c Normal file
View File

@ -0,0 +1,59 @@
/*
* Copyright © 2008 Ingo Molnar
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <asm/iomap.h>
#include <linux/module.h>
/* Map 'pfn' using fixed map 'type' and protections 'prot'
*/
void *
iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
{
enum fixed_addresses idx;
unsigned long vaddr;
pagefault_disable();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte-idx, pfn_pte(pfn, prot));
arch_flush_lazy_mmu_mode();
return (void*) vaddr;
}
EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
void
iounmap_atomic(void *kvaddr, enum km_type type)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
/*
* Force other mappings to Oops if they'll try to access this pte
* without first remap it. Keeping stale mappings around is a bad idea
* also, in case the page changes cacheability attributes or becomes
* a protected page in a hypervisor.
*/
if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
kpte_clear_flush(kmap_pte-idx, vaddr);
arch_flush_lazy_mmu_mode();
pagefault_enable();
}
EXPORT_SYMBOL_GPL(iounmap_atomic);

30
include/asm-x86/iomap.h Normal file
View File

@ -0,0 +1,30 @@
/*
* Copyright © 2008 Ingo Molnar
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
void *
iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
void
iounmap_atomic(void *kvaddr, enum km_type type);