[POWERPC] Cleanup and fix breakage in tlbflush.h

BenH's commit a741e67969 in powerpc.git,
although (AFAICT) only intended to affect ppc64, also has side-effects
which break 44x.  I think 40x, 8xx and Freescale Book E are also
affected, though I haven't tested them.

The problem lies in unconditionally removing flush_tlb_pending() from
the versions of flush_tlb_mm(), flush_tlb_range() and
flush_tlb_kernel_range() used on ppc64 - which are also used the
embedded platforms mentioned above.

The patch below cleans up the convoluted #ifdef logic in tlbflush.h,
in the process restoring the necessary flushes for the software TLB
platforms.  There are three sets of definitions for the flushing
hooks: the software TLB versions (revised to avoid using names which
appear to related to TLB batching), the 32-bit hash based versions
(external functions) amd the 64-bit hash based versions (which
implement batching).

It also moves the declaration of update_mmu_cache() to always be in
tlbflush.h (previously it was in tlbflush.h except for PPC64, where it
was in pgtable.h).

Booted on Ebony (440GP) and compiled for 64-bit and 32-bit
multiplatform.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/mm/mmu_decl.h

@@ -19,6 +19,7 @@
  *  2 of the License, or (at your option) any later version.
  *
  */
+#include <linux/mm.h>
 #include <asm/tlbflush.h>
 #include <asm/mmu.h>
 

include/asm-powerpc/pgtable.h

@@ -448,16 +448,6 @@ extern pgd_t swapper_pg_dir[];
 
 extern void paging_init(void);
 
-/*
- * This gets called at the end of handling a page fault, when
- * the kernel has put a new PTE into the page table for the process.
- * We use it to put a corresponding HPTE into the hash table
- * ahead of time, instead of waiting for the inevitable extra
- * hash-table miss exception.
- */
-struct vm_area_struct;
-extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t);
-
 /* Encode and de-code a swap entry */
 #define __swp_type(entry)	(((entry).val >> 1) & 0x3f)
 #define __swp_offset(entry)	((entry).val >> 8)

include/asm-powerpc/tlbflush.h

@@ -17,10 +17,73 @@
  */
 #ifdef __KERNEL__
 
-
 struct mm_struct;
+struct vm_area_struct;
 
-#ifdef CONFIG_PPC64
+#if defined(CONFIG_4xx) || defined(CONFIG_8xx) || defined(CONFIG_FSL_BOOKE)
+/*
+ * TLB flushing for software loaded TLB chips
+ *
+ * TODO: (CONFIG_FSL_BOOKE) determine if flush_tlb_range &
+ * flush_tlb_kernel_range are best implemented as tlbia vs
+ * specific tlbie's
+ */
+
+extern void _tlbie(unsigned long address);
+
+#if defined(CONFIG_40x) || defined(CONFIG_8xx)
+#define _tlbia()	asm volatile ("tlbia; sync" : : : "memory")
+#else /* CONFIG_44x || CONFIG_FSL_BOOKE */
+extern void _tlbia(void);
+#endif
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+	_tlbia();
+}
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+				  unsigned long vmaddr)
+{
+	_tlbie(vmaddr);
+}
+
+static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
+					 unsigned long vmaddr)
+{
+	_tlbie(vmaddr);
+}
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end)
+{
+	_tlbia();
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+					  unsigned long end)
+{
+	_tlbia();
+}
+
+#elif defined(CONFIG_PPC32)
+/*
+ * TLB flushing for "classic" hash-MMMU 32-bit CPUs, 6xx, 7xx, 7xxx
+ */
+extern void _tlbie(unsigned long address);
+extern void _tlbia(void);
+
+extern void flush_tlb_mm(struct mm_struct *mm);
+extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
+extern void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr);
+extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+			    unsigned long end);
+extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
+
+#else
+/*
+ * TLB flushing for 64-bit has-MMU CPUs
+ */
 
 #include <linux/percpu.h>
 #include <asm/page.h>
@@ -67,23 +130,31 @@ extern void flush_hash_page(unsigned long va, real_pte_t pte, int psize,
 			    int local);
 extern void flush_hash_range(unsigned long number, int local);
 
-#else /* CONFIG_PPC64 */
 
-#include <linux/mm.h>
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+}
 
-extern void _tlbie(unsigned long address);
+static inline void flush_tlb_page(struct vm_area_struct *vma,
-extern void _tlbia(void);
+				  unsigned long vmaddr)
+{
+}
 
-/*
+static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
- * TODO: (CONFIG_FSL_BOOKE) determine if flush_tlb_range &
+					 unsigned long vmaddr)
- * flush_tlb_kernel_range are best implemented as tlbia vs
+{
- * specific tlbie's
+}
- */
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end)
+{
+}
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+					  unsigned long end)
+{
+}
 
-#if (defined(CONFIG_4xx) && !defined(CONFIG_44x)) || defined(CONFIG_8xx)
-#define flush_tlb_pending()	asm volatile ("tlbia; sync" : : : "memory")
-#elif defined(CONFIG_4xx) || defined(CONFIG_FSL_BOOKE)
-#define flush_tlb_pending()	_tlbia()
 #endif
 
 /*
@@ -97,59 +168,13 @@ extern void _tlbia(void);
  */
 extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t);
 
-#endif /* CONFIG_PPC64 */
-
-#if defined(CONFIG_PPC64) || defined(CONFIG_4xx) || \
-	defined(CONFIG_FSL_BOOKE) || defined(CONFIG_8xx)
-
-static inline void flush_tlb_mm(struct mm_struct *mm)
-{
-}
-
-static inline void flush_tlb_page(struct vm_area_struct *vma,
-				unsigned long vmaddr)
-{
-#ifndef CONFIG_PPC64
-	_tlbie(vmaddr);
-#endif
-}
-
-static inline void flush_tlb_page_nohash(struct vm_area_struct *vma,
-					 unsigned long vmaddr)
-{
-#ifndef CONFIG_PPC64
-	_tlbie(vmaddr);
-#endif
-}
-
-static inline void flush_tlb_range(struct vm_area_struct *vma,
-		unsigned long start, unsigned long end)
-{
-}
-
-static inline void flush_tlb_kernel_range(unsigned long start,
-		unsigned long end)
-{
-}
-
-#else	/* 6xx, 7xx, 7xxx cpus */
-
-extern void flush_tlb_mm(struct mm_struct *mm);
-extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
-extern void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr);
-extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
-			    unsigned long end);
-extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
-
-#endif
-
 /*
  * This is called in munmap when we have freed up some page-table
  * pages.  We don't need to do anything here, there's nothing special
  * about our page-table pages.  -- paulus
  */
 static inline void flush_tlb_pgtables(struct mm_struct *mm,
-		unsigned long start, unsigned long end)
+				      unsigned long start, unsigned long end)
 {
 }