sh: Generalise the pte handling code for the fixmap path

Generalise the code for setting and clearing pte's and allow TLB entries
to be pinned and unpinned if the _PAGE_WIRED flag is present.

Signed-off-by: Matt Fleming <matt@console-pimps.org>

1 files changed, 40 insertions, 4 deletions

diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index d5fb014279ad..30a9b530d456 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -39,7 +39,7 @@ unsigned long cached_to_uncached = P2SEG - P1SEG;
 #endif
 
 #ifdef CONFIG_MMU
-static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
+static pte_t *__get_pte_phys(unsigned long addr)
 {
         pgd_t *pgd;
         pud_t *pud;
@@ -49,22 +49,30 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
         pgd = pgd_offset_k(addr);
         if (pgd_none(*pgd)) {
                 pgd_ERROR(*pgd);
-                return;
+                return NULL;
         }
 
         pud = pud_alloc(NULL, pgd, addr);
         if (unlikely(!pud)) {
                 pud_ERROR(*pud);
-                return;
+                return NULL;
         }
 
         pmd = pmd_alloc(NULL, pud, addr);
         if (unlikely(!pmd)) {
                 pmd_ERROR(*pmd);
-                return;
+                return NULL;
         }
 
         pte = pte_offset_kernel(pmd, addr);
+        return pte;
+}
+
+static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
+{
+        pte_t *pte;
+
+        pte = __get_pte_phys(addr);
         if (!pte_none(*pte)) {
                 pte_ERROR(*pte);
                 return;
@@ -72,6 +80,22 @@ static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
 
         set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
         local_flush_tlb_one(get_asid(), addr);
+
+        if (pgprot_val(prot) & _PAGE_WIRED)
+                tlb_wire_entry(NULL, addr, *pte);
+}
+
+static void clear_pte_phys(unsigned long addr, pgprot_t prot)
+{
+        pte_t *pte;
+
+        pte = __get_pte_phys(addr);
+
+        if (pgprot_val(prot) & _PAGE_WIRED)
+                tlb_unwire_entry();
+
+        set_pte(pte, pfn_pte(0, __pgprot(0)));
+        local_flush_tlb_one(get_asid(), addr);
 }
 
 /*
@@ -101,6 +125,18 @@ void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
         set_pte_phys(address, phys, prot);
 }
 
+void __clear_fixmap(enum fixed_addresses idx, pgprot_t prot)
+{
+        unsigned long address = __fix_to_virt(idx);
+
+        if (idx >= __end_of_fixed_addresses) {
+                BUG();
+                return;
+        }
+
+        clear_pte_phys(address, prot);
+}
+
 void __init page_table_range_init(unsigned long start, unsigned long end,
                                          pgd_t *pgd_base)
 {