MIPS: Fix highmem.

Commit 351336929ccf222ae38ff0cb7a8dd5fd5c6236a0 (kernel.org) rsp.
b3594a089f1c17ff919f8f78505c3f20e1f6f8ce (linux-mips.org):

> From: Chris Dearman <chris@mips.com>
> Date: Wed, 19 Sep 2007 00:58:24 +0100
> Subject: [PATCH] [MIPS] Allow setting of the cache attribute at run time.
>
> Slightly tacky, but there is a precedent in the sparc archirecture code.

introduces the variable _page_cachable_default, which defaults to zero and.
is used to create the prototype PTE for __kmap_atomic in
arch/mips/mm/init.c:kmap_init before initialization in
arch/mips/mm/c-r4k.c:coherency_setup, so the default value of 0 will be
used as the CCA of kmap atomic pages which on many processors is not a
defined CCA value and may result in writes to kmap_atomic pages getting
corrupted.  Debugged by Jon Fraser (jfraser@broadcom.com).

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 0 insertions, 26 deletions

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index d9348946a19e..c5511294a9ee 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)
 {