sh: Use the now generic SH-4 clear/copy page ops for all MMU platforms.

Now that the SH-4 page clear/copy ops are generic, they can be used for
all platforms with CONFIG_MMU=y. SH-5 remains the odd one out, but it too
will gradually be converted over to using this interface.

SH-3 platforms which do not contain aliases will see no impact from this
change, while aliasing SH-3 platforms will get the same interface as
SH-4.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 136 insertions, 0 deletions

diff --git a/arch/sh/mm/pg-mmu.c b/arch/sh/mm/pg-mmu.c
new file mode 100644
index 000000000000..356d2cdcb209
--- /dev/null
+++ b/arch/sh/mm/pg-mmu.c
@@ -0,0 +1,136 @@
+/*
+ * arch/sh/mm/pg-mmu.c
+ *
+ * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
+ * Copyright (C) 2002 - 2009  Paul Mundt
+ *
+ * Released under the terms of the GNU GPL v2.0.
+ */
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/fs.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <asm/mmu_context.h>
+#include <asm/cacheflush.h>
+
+#define kmap_get_fixmap_pte(vaddr)                                     \
+        pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
+
+static pte_t *kmap_coherent_pte;
+
+void __init kmap_coherent_init(void)
+{
+#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
+        unsigned long vaddr;
+
+        /* cache the first coherent kmap pte */
+        vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
+        kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
+#endif
+}
+
+static inline void *kmap_coherent(struct page *page, unsigned long addr)
+{
+        enum fixed_addresses idx;
+        unsigned long vaddr, flags;
+        pte_t pte;
+
+        inc_preempt_count();
+
+        idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
+        vaddr = __fix_to_virt(FIX_CMAP_END - idx);
+        pte = mk_pte(page, PAGE_KERNEL);
+
+        local_irq_save(flags);
+        flush_tlb_one(get_asid(), vaddr);
+        local_irq_restore(flags);
+
+        update_mmu_cache(NULL, vaddr, pte);
+
+        set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
+
+        return (void *)vaddr;
+}
+
+static inline void kunmap_coherent(struct page *page)
+{
+        dec_preempt_count();
+        preempt_check_resched();
+}
+
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+                       unsigned long vaddr, void *dst, const void *src,
+                       unsigned long len)
+{
+        if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
+            !test_bit(PG_dcache_dirty, &page->flags)) {
+                void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
+                memcpy(vto, src, len);
+                kunmap_coherent(vto);
+        } else {
+                memcpy(dst, src, len);
+                if (boot_cpu_data.dcache.n_aliases)
+                        set_bit(PG_dcache_dirty, &page->flags);
+        }
+
+        if (vma->vm_flags & VM_EXEC)
+                flush_cache_page(vma, vaddr, page_to_pfn(page));
+}
+
+void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
+                         unsigned long vaddr, void *dst, const void *src,
+                         unsigned long len)
+{
+        if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
+            !test_bit(PG_dcache_dirty, &page->flags)) {
+                void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
+                memcpy(dst, vfrom, len);
+                kunmap_coherent(vfrom);
+        } else {
+                memcpy(dst, src, len);
+                if (boot_cpu_data.dcache.n_aliases)
+                        set_bit(PG_dcache_dirty, &page->flags);
+        }
+}
+
+void copy_user_highpage(struct page *to, struct page *from,
+                        unsigned long vaddr, struct vm_area_struct *vma)
+{
+        void *vfrom, *vto;
+
+        vto = kmap_atomic(to, KM_USER1);
+
+        if (boot_cpu_data.dcache.n_aliases && page_mapped(from) &&
+            !test_bit(PG_dcache_dirty, &from->flags)) {
+                vfrom = kmap_coherent(from, vaddr);
+                copy_page(vto, vfrom);
+                kunmap_coherent(vfrom);
+        } else {
+                vfrom = kmap_atomic(from, KM_USER0);
+                copy_page(vto, vfrom);
+                kunmap_atomic(vfrom, KM_USER0);
+        }
+
+        if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
+                __flush_wback_region(vto, PAGE_SIZE);
+
+        kunmap_atomic(vto, KM_USER1);
+        /* Make sure this page is cleared on other CPU's too before using it */
+        smp_wmb();
+}
+EXPORT_SYMBOL(copy_user_highpage);
+
+void clear_user_highpage(struct page *page, unsigned long vaddr)
+{
+        void *kaddr = kmap_atomic(page, KM_USER0);
+
+        clear_page(kaddr);
+
+        if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK))
+                __flush_wback_region(kaddr, PAGE_SIZE);
+
+        kunmap_atomic(kaddr, KM_USER0);
+}
+EXPORT_SYMBOL(clear_user_highpage);