Commit 63e7b6d9 authored by Minfei Huang's avatar Minfei Huang Committed by Thomas Gleixner
Browse files

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: default avatarMinfei 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: default avatarThomas Gleixner <tglx@linutronix.de>
parent 96e70f83

arch/x86/include/asm/fixmap.h

+0 −2
Original line number Diff line number Diff line
@@ -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;

arch/x86/include/asm/highmem.h

+14 −11
Original line number Diff line number Diff line
@@ -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

 * 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)

arch/x86/include/asm/pgtable_32_types.h

+2 −2
Original line number Diff line number Diff line
@@ -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

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