Messages in this thread | | | Date | Thu, 7 Aug 2014 18:38:32 +0100 | From | Leif Lindholm <> | Subject | Re: [PATCH 1/8] arm: use generic fixmap.h |
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On Thu, Aug 07, 2014 at 08:01:46AM -0700, Kees Cook wrote: > From: Mark Salter <msalter@redhat.com> > > ARM is different from other architectures in that fixmap pages are indexed > with a positive offset from FIXADDR_START. Other architectures index with > a negative offset from FIXADDR_TOP. In order to use the generic fixmap.h > definitions, this patch redefines FIXADDR_TOP to be inclusive of the > useable range. That is, FIXADDR_TOP is the virtual address of the topmost > fixed page. The newly defined FIXADDR_END is the first virtual address > past the fixed mappings. > > Signed-off-by: Mark Salter <msalter@redhat.com> > Reviewed-by: Doug Anderson <dianders@chromium.org> > [update for "ARM: 8031/2: change fixmap mapping region to support 32 CPUs"] > [flipped highmem order, thanks to Laura Abbott] > Signed-off-by: Kees Cook <keescook@chromium.org> > Cc: Laura Abbott <lauraa@codeaurora.org> > --- > arch/arm/include/asm/fixmap.h | 27 +++++++++------------------ > arch/arm/mm/highmem.c | 8 ++++++-- > arch/arm/mm/init.c | 2 +- > 3 files changed, 16 insertions(+), 21 deletions(-) > > diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h > index 74124b0d0d79..190142d174ee 100644 > --- a/arch/arm/include/asm/fixmap.h > +++ b/arch/arm/include/asm/fixmap.h > @@ -2,27 +2,18 @@ > #define _ASM_FIXMAP_H > > #define FIXADDR_START 0xffc00000UL > -#define FIXADDR_TOP 0xffe00000UL > -#define FIXADDR_SIZE (FIXADDR_TOP - FIXADDR_START) > +#define FIXADDR_END 0xffe00000UL > +#define FIXADDR_TOP (FIXADDR_END - PAGE_SIZE) > +#define FIXADDR_SIZE (FIXADDR_END - FIXADDR_START) > > #define FIX_KMAP_NR_PTES (FIXADDR_SIZE >> PAGE_SHIFT) > > -#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) > -#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) > +enum fixed_addresses { > + FIX_KMAP_BEGIN, > + FIX_KMAP_END = FIX_KMAP_NR_PTES - 1, > + __end_of_fixed_addresses > +}; > > -extern void __this_fixmap_does_not_exist(void); > - > -static inline unsigned long fix_to_virt(const unsigned int idx) > -{ > - if (idx >= FIX_KMAP_NR_PTES) > - __this_fixmap_does_not_exist(); > - return __fix_to_virt(idx); > -} > - > -static inline unsigned int virt_to_fix(const unsigned long vaddr) > -{ > - BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); > - return __virt_to_fix(vaddr); > -} > +#include <asm-generic/fixmap.h> > > #endif > diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c > index 45aeaaca9052..a1241ee8425e 100644 > --- a/arch/arm/mm/highmem.c > +++ b/arch/arm/mm/highmem.c > @@ -23,14 +23,18 @@ 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); > + pte_t *ppte = pte_offset_kernel(pmd_off_k(FIXADDR_START), vaddr); > + > + set_pte_ext(ppte, 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);
idx is now "unused variable".
> - return *(fixmap_page_table + idx); > + pte_t *ppte = pte_offset_kernel(pmd_off_k(FIXADDR_START), vaddr); > + > + return *ppte; > } > > void *kmap(struct page *page) > diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c > index 659c75d808dc..ad82c05bfc3a 100644 > --- a/arch/arm/mm/init.c > +++ b/arch/arm/mm/init.c > @@ -570,7 +570,7 @@ void __init mem_init(void) > MLK(DTCM_OFFSET, (unsigned long) dtcm_end), > MLK(ITCM_OFFSET, (unsigned long) itcm_end), > #endif > - MLK(FIXADDR_START, FIXADDR_TOP), > + MLK(FIXADDR_START, FIXADDR_END), > MLM(VMALLOC_START, VMALLOC_END), > MLM(PAGE_OFFSET, (unsigned long)high_memory), > #ifdef CONFIG_HIGHMEM > -- > 1.9.1
Apart from that, verified with early_ioremap/UEFI patches on TC2.
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
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