[RFC/PATCH 1/12] powerpc: Remove calculation of io hole

[Michael Ellerman]

In mm_init_ppc64() we calculate the location of the "IO hole", but then
no one ever looks at the value. So don't bother.

That's actually all mm_init_ppc64() does, so get rid of it too.

 arch/powerpc/kernel/setup_64.c |    2 -
 arch/powerpc/mm/init_64.c      |   48 -----------------------------------------
 include/asm-powerpc/mmu.h      |    1 
 3 files changed, 51 deletions(-)

Index: linux/arch/powerpc/kernel/setup_64.c
===================================================================
--- linux.orig/arch/powerpc/kernel/setup_64.c
+++ linux/arch/powerpc/kernel/setup_64.c
@@ -494,8 +494,6 @@ void __init setup_system(void)
 #endif
 	printk("-----------------------------------------------------\n");
 
-	mm_init_ppc64();
-
 	DBG(" <- setup_system()\n");
 }
 
Index: linux/arch/powerpc/mm/init_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/init_64.c
+++ linux/arch/powerpc/mm/init_64.c
@@ -84,54 +84,6 @@
 /* max amount of RAM to use */
 unsigned long __max_memory;
 
-/* info on what we think the IO hole is */
-unsigned long 	io_hole_start;
-unsigned long	io_hole_size;
-
-/*
- * Do very early mm setup.
- */
-void __init mm_init_ppc64(void)
-{
-#ifndef CONFIG_PPC_ISERIES
-	unsigned long i;
-#endif
-
-	ppc64_boot_msg(0x100, "MM Init");
-
-	/* This is the story of the IO hole... please, keep seated,
-	 * unfortunately, we are out of oxygen masks at the moment.
-	 * So we need some rough way to tell where your big IO hole
-	 * is. On pmac, it's between 2G and 4G, on POWER3, it's around
-	 * that area as well, on POWER4 we don't have one, etc...
-	 * We need that as a "hint" when sizing the TCE table on POWER3
-	 * So far, the simplest way that seem work well enough for us it
-	 * to just assume that the first discontinuity in our physical
-	 * RAM layout is the IO hole. That may not be correct in the future
-	 * (and isn't on iSeries but then we don't care ;)
-	 */
-
-#ifndef CONFIG_PPC_ISERIES
-	for (i = 1; i < lmb.memory.cnt; i++) {
-		unsigned long base, prevbase, prevsize;
-
-		prevbase = lmb.memory.region[i-1].base;
-		prevsize = lmb.memory.region[i-1].size;
-		base = lmb.memory.region[i].base;
-		if (base > (prevbase + prevsize)) {
-			io_hole_start = prevbase + prevsize;
-			io_hole_size = base  - (prevbase + prevsize);
-			break;
-		}
-	}
-#endif /* CONFIG_PPC_ISERIES */
-	if (io_hole_start)
-		printk("IO Hole assumed to be %lx -> %lx\n",
-		       io_hole_start, io_hole_start + io_hole_size - 1);
-
-	ppc64_boot_msg(0x100, "MM Init Done");
-}
-
 void free_initmem(void)
 {
 	unsigned long addr;
Index: linux/include/asm-powerpc/mmu.h
===================================================================
--- linux.orig/include/asm-powerpc/mmu.h
+++ linux/include/asm-powerpc/mmu.h
@@ -235,7 +235,6 @@ extern void htab_initialize_secondary(vo
 extern void hpte_init_native(void);
 extern void hpte_init_lpar(void);
 extern void hpte_init_iSeries(void);
-extern void mm_init_ppc64(void);
 
 extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
 				     unsigned long va, unsigned long prpn,