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Commit a05e54c1 authored by Liu Hua's avatar Liu Hua Committed by Russell King
Browse files

ARM: 8031/2: change fixmap mapping region to support 32 CPUs 



In 32-bit ARM systems, the fixmap mapping region can support no more
than 14 CPUs(total: 896k; one CPU: 64K). And we can configure NR_CPUS
up to 32. So there is a mismatch.

This patch moves fixmapping region downwards to region 0xffc00000-
0xffe00000. Then the fixmap mapping region can support up to 32 CPUs.

Reviewed-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarLiu Hua <sdu.liu@huawei.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 4221e2e6

Documentation/arm/memory.txt

+1 −1
Original line number Diff line number Diff line
@@ -41,7 +41,7 @@ fffe8000 fffeffff DTCM mapping area for platforms with 
fffe0000	fffe7fff	ITCM mapping area for platforms with

				ITCM mounted inside the CPU.



fff00000	fffdffff	Fixmap mapping region.  Addresses provided

fffc0000	ffdfffff	Fixmap mapping region.  Addresses provided

				by fix_to_virt() will be located here.



fee00000	feffffff	Mapping of PCI I/O space. This is a static

arch/arm/include/asm/fixmap.h

+2 −14
Original line number Diff line number Diff line 
#ifndef _ASM_FIXMAP_H

#define _ASM_FIXMAP_H



/*

 * Nothing too fancy for now.

 *

 * On ARM we already have well known fixed virtual addresses imposed by

 * the architecture such as the vector page which is located at 0xffff0000,

 * therefore a second level page table is already allocated covering

 * 0xfff00000 upwards.

 *

 * The cache flushing code in proc-xscale.S uses the virtual area between

 * 0xfffe0000 and 0xfffeffff.

 */



#define FIXADDR_START		0xfff00000UL

#define FIXADDR_TOP		0xfffe0000UL

#define FIXADDR_START		0xffc00000UL

#define FIXADDR_TOP		0xffe00000UL

#define FIXADDR_SIZE		(FIXADDR_TOP - FIXADDR_START)



#define FIX_KMAP_NR_PTES	(FIXADDR_SIZE >> PAGE_SHIFT)

arch/arm/include/asm/highmem.h

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
	} while (0)



extern pte_t *pkmap_page_table;

extern pte_t *fixmap_page_table;



extern void *kmap_high(struct page *page);

extern void kunmap_high(struct page *page);

arch/arm/mm/highmem.c

+21 −6
Original line number Diff line number Diff line
@@ -18,6 +18,21 @@ 
#include <asm/tlbflush.h>

#include "mm.h"



pte_t *fixmap_page_table;



static inline void set_fixmap_pte(int idx, pte_t pte)

{

	unsigned long vaddr = __fix_to_virt(idx);

	set_pte_ext(fixmap_page_table + idx, pte, 0);

	local_flush_tlb_kernel_page(vaddr);

}



static inline pte_t get_fixmap_pte(unsigned long vaddr)

{

	unsigned long idx = __virt_to_fix(vaddr);

	return *(fixmap_page_table + idx);

}



void *kmap(struct page *page)

{

	might_sleep();
@@ -69,14 +84,14 @@ void *kmap_atomic(struct page *page) 
	 * With debugging enabled, kunmap_atomic forces that entry to 0.

	 * Make sure it was indeed properly unmapped.

	 */

	BUG_ON(!pte_none(get_top_pte(vaddr)));

	BUG_ON(!pte_none(*(fixmap_page_table + idx)));

#endif

	/*

	 * When debugging is off, kunmap_atomic leaves the previous mapping

	 * in place, so the contained TLB flush ensures the TLB is updated

	 * with the new mapping.

	 */

	set_top_pte(vaddr, mk_pte(page, kmap_prot));

	set_fixmap_pte(idx, mk_pte(page, kmap_prot));



	return (void *)vaddr;

}
@@ -95,7 +110,7 @@ void __kunmap_atomic(void *kvaddr) 
			__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);

#ifdef CONFIG_DEBUG_HIGHMEM

		BUG_ON(vaddr != __fix_to_virt(idx));

		set_top_pte(vaddr, __pte(0));

		set_fixmap_pte(idx, __pte(0));

#else

		(void) idx;  /* to kill a warning */

#endif
@@ -119,9 +134,9 @@ void *kmap_atomic_pfn(unsigned long pfn) 
	idx = type + KM_TYPE_NR * smp_processor_id();

	vaddr = __fix_to_virt(idx);

#ifdef CONFIG_DEBUG_HIGHMEM

	BUG_ON(!pte_none(get_top_pte(vaddr)));

	BUG_ON(!pte_none(*(fixmap_page_table + idx)));

#endif

	set_top_pte(vaddr, pfn_pte(pfn, kmap_prot));

	set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));



	return (void *)vaddr;

}
@@ -133,5 +148,5 @@ struct page *kmap_atomic_to_page(const void *ptr) 
	if (vaddr < FIXADDR_START)

		return virt_to_page(ptr);



	return pte_page(get_top_pte(vaddr));

	return pte_page(get_fixmap_pte(vaddr));

}

arch/arm/mm/mmu.c

+4 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <asm/mach/arch.h>

#include <asm/mach/map.h>

#include <asm/mach/pci.h>

#include <asm/fixmap.h>



#include "mm.h"

#include "tcm.h"
@@ -1359,6 +1360,9 @@ static void __init kmap_init(void) 
#ifdef CONFIG_HIGHMEM

	pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),

		PKMAP_BASE, _PAGE_KERNEL_TABLE);



	fixmap_page_table = early_pte_alloc(pmd_off_k(FIXADDR_START),

		FIXADDR_START, _PAGE_KERNEL_TABLE);

#endif

}