Messages in this thread | | | Date | Tue, 15 Apr 2014 11:06:30 -0400 (EDT) | From | Nicolas Pitre <> | Subject | Re: [PATCH v3 2/2] ARM : change fixmap mapping region to support 32 CPUs |
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On Tue, 15 Apr 2014, Liu Hua wrote:
> 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@huawei.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
> --- > Documentation/arm/memory.txt | 2 +- > arch/arm/include/asm/fixmap.h | 16 ++-------------- > arch/arm/include/asm/highmem.h | 1 + > arch/arm/mm/highmem.c | 27 +++++++++++++++++++++------ > arch/arm/mm/mmu.c | 4 ++++ > 5 files changed, 29 insertions(+), 21 deletions(-) > > diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt > index 4bfb9ff..a9fc59b 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 > +fffc0000 ffdfffff Fixmap mapping region. Addresses provided > by fix_to_virt() will be located here. > > ffc00000 ffefffff DMA memory mapping region. Memory returned > diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h > index be55ebc..74124b0 100644 > --- a/arch/arm/include/asm/fixmap.h > +++ b/arch/arm/include/asm/fixmap.h > @@ -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) > 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 e05e8ad..45aeaac 100644 > --- a/arch/arm/mm/highmem.c > +++ b/arch/arm/mm/highmem.c > @@ -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)); > } > 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 > } > > -- > 1.9.0 >
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