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x86: mm: Re-use the early_ioremap fixed area 

The temp fixed area is only used during boot for early_ioremap(), and
it is unused when ioremap() is functional. vmalloc/pkmap area become
available after early boot so the temp fixed area is available for
re-use.

The virtual address is more precious on i386, especially turning on
high memory. So we can re-use the virtual address space.

Remove the now unused defines FIXADDR_BOOT_START and FIXADDR_BOOT_SIZE.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Cc: pbonzini@redhat.com
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1414582717-32729-1-git-send-email-mnfhuang@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Minfei Huang 2014-10-29 19:38:37 +08:00 committed by Thomas Gleixner
parent 96e70f8328
commit 63e7b6d90c
3 changed files with 16 additions and 15 deletions
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2
arch/x86/include/asm/fixmap.h
View File

@ -136,9 +136,7 @@ enum fixed_addresses {
extern void reserve_top_address(unsigned long reserve);
#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
#define FIXADDR_BOOT_START (FIXADDR_TOP - FIXADDR_BOOT_SIZE)
extern int fixmaps_set;

25
arch/x86/include/asm/highmem.h
View File

@ -38,17 +38,20 @@ extern unsigned long highstart_pfn, highend_pfn;
/*
* Ordering is:
*
* FIXADDR_TOP
* fixed_addresses
* FIXADDR_START
* temp fixed addresses
* FIXADDR_BOOT_START
* Persistent kmap area
* PKMAP_BASE
* VMALLOC_END
* Vmalloc area
* VMALLOC_START
* high_memory
* high memory on: high_memory off:
* FIXADDR_TOP FIXADDR_TOP
* fixed addresses fixed addresses
* FIXADDR_START FIXADDR_START
* temp fixed addresses/persistent kmap area VMALLOC_END
* PKMAP_BASE temp fixed addresses/vmalloc area
* VMALLOC_END VMALLOC_START
* vmalloc area high_memory
* VMALLOC_START
* high_memory
*
* The temp fixed area is only used during boot for early_ioremap(), and
* it is unused when the ioremap() is functional. vmalloc/pkmap area become
* available after early boot so the temp fixed area is available for re-use.
*/
#define LAST_PKMAP_MASK (LAST_PKMAP-1)
#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)

4
arch/x86/include/asm/pgtable_32_types.h
View File

@ -37,13 +37,13 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */
#define LAST_PKMAP 1024
#endif
#define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \
& PMD_MASK)
#ifdef CONFIG_HIGHMEM
# define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE)
#else
# define VMALLOC_END (FIXADDR_BOOT_START - 2 * PAGE_SIZE)
# define VMALLOC_END (FIXADDR_START - 2 * PAGE_SIZE)
#endif
#define MODULES_VADDR VMALLOC_START