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

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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: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Liu Hua <sdu.liu@huawei.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Liu Hua 2014-04-18 09:43:32 +01:00 committed by Russell King
parent 4221e2e6b3
commit a05e54c103
5 changed files with 29 additions and 21 deletions
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2
Documentation/arm/memory.txt
View File

@ -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

16
arch/arm/include/asm/fixmap.h
View File

@ -1,20 +1,8 @@
#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)

1
arch/arm/include/asm/highmem.h
View File

@ -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);

27
arch/arm/mm/highmem.c
View File

@ -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));
}

4
arch/arm/mm/mmu.c
View File

@ -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
}