[PATCH v2 2/2] ARM : change fixmap mapping region to support 32 CPUs
From: Liu Hua
Date: Fri Apr 11 2014 - 04:11:25 EST
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.
Signed-off-by: Liu Hua <sdu.liu@xxxxxxxxxx>
---
Documentation/arm/memory.txt | 2 +-
arch/arm/include/asm/fixmap.h | 4 ++--
arch/arm/include/asm/highmem.h | 1 +
arch/arm/mm/highmem.c | 10 +++++-----
arch/arm/mm/mm.h | 7 +++++++
arch/arm/mm/mmu.c | 4 ++++
mm/highmem.c | 1 +
7 files changed, 21 insertions(+), 8 deletions(-)
diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt
index 8a361c0..4bca737 100644
--- a/Documentation/arm/memory.txt
+++ b/Documentation/arm/memory.txt
@@ -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
+ffc00000 ffdfffff Fixmap mapping region. Addresses provided
by fix_to_virt() will be located here.
ff000000 ffbfffff Reserved for future expansion of DMA
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
index bbae919..014a70d 100644
--- a/arch/arm/include/asm/fixmap.h
+++ b/arch/arm/include/asm/fixmap.h
@@ -13,8 +13,8 @@
* 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_BEGIN 0
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 91b99ab..5355795 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -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);
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 21b9e1b..9bc8988 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -69,14 +69,14 @@ 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 +95,7 @@ void __kunmap_atomic(void *kvaddr)
__cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
- set_top_pte(vaddr, __pte(0));
+ set_fixmap_pte(idx, __pte(0));
#else
(void) idx; /* to kill a warning */
#endif
@@ -119,9 +119,9 @@ void *kmap_atomic_pfn(unsigned long pfn)
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + 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;
}
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 7ea641b..3460d73 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -1,6 +1,7 @@
#ifdef CONFIG_MMU
#include <linux/list.h>
#include <linux/vmalloc.h>
+#include <asm/fixmap.h>
/* the upper-most page table pointer */
extern pmd_t *top_pmd;
@@ -25,6 +26,12 @@ static inline void set_top_pte(unsigned long va, pte_t pte)
local_flush_tlb_kernel_page(va);
}
+static inline void set_fixmap_pte(int idx, pte_t pte)
+{
+ unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+ set_pte_ext(fixmap_page_table + idx, pte, 0);
+ local_flush_tlb_kernel_page(vaddr);
+}
static inline pte_t get_top_pte(unsigned long va)
{
pte_t *ptep = pte_offset_kernel(top_pmd, va);
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index b68c6b2..09c0a16 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -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
}
diff --git a/mm/highmem.c b/mm/highmem.c
index b32b70c..d0094ba 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -72,6 +72,7 @@ static unsigned int last_pkmap_nr;
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kmap_lock);
pte_t * pkmap_page_table;
+pte_t *fixmap_page_table;
static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait);
--
1.9.0
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