Hi Ralf,
Just wanted to acknowledge your email. I've been playing catch
up for the last week after spending a large amount of unscheduled time
finding the root cause of this bug. I should be able to get to applying
this patch this week. Were these against HOT or 2.6.29?
Jon
On Sat, 2009-04-25 at 02:24 -0700, Ralf Baechle wrote:
> On Fri, Apr 24, 2009 at 12:13:52PM -0400, Jon Fraser wrote:
>
> > That's why I haven't proposed a fix yet. But there are other people
> > dealing with the same HIGHMEM issues and I wanted them to know about the
> > problem.
>
> Can you test below fix? Thanks,
>
> Ralf
>
> Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
>
> arch/mips/include/asm/fixmap.h | 3 +++
> arch/mips/include/asm/highmem.h | 6 ++++--
> arch/mips/mm/highmem.c | 25 +++++++++++++++++++------
> arch/mips/mm/init.c | 26 --------------------------
> 4 files changed, 26 insertions(+), 34 deletions(-)
>
> diff --git a/arch/mips/include/asm/fixmap.h b/arch/mips/include/asm/fixmap.h
> index 9cc8522..0f5caa1 100644
> --- a/arch/mips/include/asm/fixmap.h
> +++ b/arch/mips/include/asm/fixmap.h
> @@ -108,6 +108,9 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr)
> return __virt_to_fix(vaddr);
> }
>
> +#define kmap_get_fixmap_pte(vaddr) \
> + pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
> +
> /*
> * Called from pgtable_init()
> */
> diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h
> index 4374ab2..25adfb0 100644
> --- a/arch/mips/include/asm/highmem.h
> +++ b/arch/mips/include/asm/highmem.h
> @@ -30,8 +30,6 @@
> /* declarations for highmem.c */
> extern unsigned long highstart_pfn, highend_pfn;
>
> -extern pte_t *kmap_pte;
> -extern pgprot_t kmap_prot;
> extern pte_t *pkmap_page_table;
>
> /*
> @@ -62,6 +60,10 @@ extern struct page *__kmap_atomic_to_page(void *ptr);
>
> #define flush_cache_kmaps() flush_cache_all()
>
> +extern void kmap_init(void);
> +
> +#define kmap_prot PAGE_KERNEL
> +
> #endif /* __KERNEL__ */
>
> #endif /* _ASM_HIGHMEM_H */
> diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
> index 4481656..2b1309b 100644
> --- a/arch/mips/mm/highmem.c
> +++ b/arch/mips/mm/highmem.c
> @@ -1,7 +1,12 @@
> #include <linux/module.h>
> #include <linux/highmem.h>
> +#include <asm/fixmap.h>
> #include <asm/tlbflush.h>
>
> +static pte_t *kmap_pte;
> +
> +unsigned long highstart_pfn, highend_pfn;
> +
> void *__kmap(struct page *page)
> {
> void *addr;
> @@ -14,6 +19,7 @@ void *__kmap(struct page *page)
>
> return addr;
> }
> +EXPORT_SYMBOL(__kmap);
>
> void __kunmap(struct page *page)
> {
> @@ -22,6 +28,7 @@ void __kunmap(struct page *page)
> return;
> kunmap_high(page);
> }
> +EXPORT_SYMBOL(__kunmap);
>
> /*
> * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
> @@ -48,11 +55,12 @@ void *__kmap_atomic(struct page *page, enum km_type type)
> #ifdef CONFIG_DEBUG_HIGHMEM
> BUG_ON(!pte_none(*(kmap_pte - idx)));
> #endif
> - set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
> + set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
> local_flush_tlb_one((unsigned long)vaddr);
>
> return (void*) vaddr;
> }
> +EXPORT_SYMBOL(__kmap_atomic);
>
> void __kunmap_atomic(void *kvaddr, enum km_type type)
> {
> @@ -77,6 +85,7 @@ void __kunmap_atomic(void *kvaddr, enum km_type type)
>
> pagefault_enable();
> }
> +EXPORT_SYMBOL(__kunmap_atomic);
>
> /*
> * This is the same as kmap_atomic() but can map memory that doesn't
> @@ -92,7 +101,7 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
> debug_kmap_atomic(type);
> idx = type + KM_TYPE_NR*smp_processor_id();
> vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
> - set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot));
> + set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
> flush_tlb_one(vaddr);
>
> return (void*) vaddr;
> @@ -111,7 +120,11 @@ struct page *__kmap_atomic_to_page(void *ptr)
> return pte_page(*pte);
> }
>
> -EXPORT_SYMBOL(__kmap);
> -EXPORT_SYMBOL(__kunmap);
> -EXPORT_SYMBOL(__kmap_atomic);
> -EXPORT_SYMBOL(__kunmap_atomic);
> +void __init kmap_init(void)
> +{
> + unsigned long kmap_vstart;
> +
> + /* cache the first kmap pte */
> + kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
> + kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
> +}
> diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
> index d934894..c551129 100644
> --- a/arch/mips/mm/init.c
> +++ b/arch/mips/mm/init.c
> @@ -104,14 +104,6 @@ unsigned long setup_zero_pages(void)
> return 1UL << order;
> }
>
> -/*
> - * These are almost like kmap_atomic / kunmap_atmic except they take an
> - * additional address argument as the hint.
> - */
> -
> -#define kmap_get_fixmap_pte(vaddr) \
> - pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
> -
> #ifdef CONFIG_MIPS_MT_SMTC
> static pte_t *kmap_coherent_pte;
> static void __init kmap_coherent_init(void)
> @@ -264,24 +256,6 @@ void copy_from_user_page(struct vm_area_struct *vma,
> }
> }
>
> -#ifdef CONFIG_HIGHMEM
> -unsigned long highstart_pfn, highend_pfn;
> -
> -pte_t *kmap_pte;
> -pgprot_t kmap_prot;
> -
> -static void __init kmap_init(void)
> -{
> - unsigned long kmap_vstart;
> -
> - /* cache the first kmap pte */
> - kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
> - kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
> -
> - kmap_prot = PAGE_KERNEL;
> -}
> -#endif /* CONFIG_HIGHMEM */
> -
> void __init fixrange_init(unsigned long start, unsigned long end,
> pgd_t *pgd_base)
> {
>
