1 files changed, 83 insertions, 0 deletions
diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
new file mode 100644
index 0000000..2d42745
--- /dev/null
+++ b/arch/powerpc/mm/8xx_mmu.c
@@ -0,0 +1,83 @@
+/*
+ * This file contains the routines for initializing the MMU
+ * on the 8xx series of chips.
+ *  -- christophe
+ *
+ *  Derived from arch/powerpc/mm/40x_mmu.c:
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/memblock.h>
+
+#include "mmu_decl.h"
+
+extern int __map_without_ltlbs;
+/*
+ * MMU_init_hw does the chip-specific initialization of the MMU hardware.
+ */
+void __init MMU_init_hw(void)
+{
+	/* Nothing to do for the time being but keep it similar to other PPC */
+}
+
+#define LARGE_PAGE_SIZE_4M	(1<<22)
+#define LARGE_PAGE_SIZE_8M	(1<<23)
+#define LARGE_PAGE_SIZE_64M	(1<<26)
+
+unsigned long __init mmu_mapin_ram(unsigned long top)
+{
+	unsigned long v, s, mapped;
+	phys_addr_t p;
+
+	v = KERNELBASE;
+	p = 0;
+	s = top;
+
+	if (__map_without_ltlbs)
+		return 0;
+
+#ifdef CONFIG_PPC_4K_PAGES
+	while (s >= LARGE_PAGE_SIZE_8M) {
+		pmd_t *pmdp;
+		unsigned long val = p | MD_PS8MEG;
+
+		pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
+		*pmdp++ = __pmd(val);
+		*pmdp++ = __pmd(val + LARGE_PAGE_SIZE_4M);
+
+		v += LARGE_PAGE_SIZE_8M;
+		p += LARGE_PAGE_SIZE_8M;
+		s -= LARGE_PAGE_SIZE_8M;
+	}
+#else /* CONFIG_PPC_16K_PAGES */
+	while (s >= LARGE_PAGE_SIZE_64M) {
+		pmd_t *pmdp;
+		unsigned long val = p | MD_PS8MEG;
+
+		pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
+		*pmdp++ = __pmd(val);
+
+		v += LARGE_PAGE_SIZE_64M;
+		p += LARGE_PAGE_SIZE_64M;
+		s -= LARGE_PAGE_SIZE_64M;
+	}
+#endif
+
+	mapped = top - s;
+
+	/* If the size of RAM is not an exact power of two, we may not
+	 * have covered RAM in its entirety with 8 MiB
+	 * pages. Consequently, restrict the top end of RAM currently
+	 * allocable so that calls to the MEMBLOCK to allocate PTEs for "tail"
+	 * coverage with normal-sized pages (or other reasons) do not
+	 * attempt to allocate outside the allowed range.
+	 */
+	memblock_set_current_limit(mapped);
+
+	return mapped;
+}