[PATCH] ppc64: Abolish ioremap_mm

Currently ppc64 has two mm_structs for the kernel, init_mm and also
ioremap_mm.  The latter really isn't necessary: this patch abolishes it,
instead restricting vmallocs to the lower 1TB of the init_mm's range and
placing io mappings in the upper 1TB.  This simplifies the code in a number
of places and eliminates an unecessary set of pagetables.  It also tweaks
the unmap/free path a little, allowing us to remove the unmap_im_area() set
of page table walkers, replacing them with unmap_vm_area().

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 1 insertions, 13 deletions

diff --git a/arch/ppc64/kernel/eeh.c b/arch/ppc64/kernel/eeh.c
index d63d41f3eecf..af5272fedadf 100644
--- a/arch/ppc64/kernel/eeh.c
+++ b/arch/ppc64/kernel/eeh.c
@@ -505,7 +505,7 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
         pte_t *ptep;
         unsigned long pa;
 
-        ptep = find_linux_pte(ioremap_mm.pgd, token);
+        ptep = find_linux_pte(init_mm.pgd, token);
         if (!ptep)
                 return token;
         pa = pte_pfn(*ptep) << PAGE_SHIFT;
diff --git a/arch/ppc64/kernel/head.S b/arch/ppc64/kernel/head.S
index 346dbf606b5d..02c8f4e3e4bc 100644
--- a/arch/ppc64/kernel/head.S
+++ b/arch/ppc64/kernel/head.S
@@ -2121,10 +2121,6 @@ empty_zero_page:
 swapper_pg_dir:
         .space  4096
 
-        .globl  ioremap_dir
-ioremap_dir:
-        .space  4096
-
 #ifdef CONFIG_SMP
 /* 1 page segment table per cpu (max 48, cpu0 allocated at STAB0_PHYS_ADDR) */
         .globl  stab_array
diff --git a/arch/ppc64/kernel/process.c b/arch/ppc64/kernel/process.c
index cdfecbeb331f..aba89554d89d 100644
--- a/arch/ppc64/kernel/process.c
+++ b/arch/ppc64/kernel/process.c
@@ -58,14 +58,6 @@ struct task_struct *last_task_used_math = NULL;
 struct task_struct *last_task_used_altivec = NULL;
 #endif
 
-struct mm_struct ioremap_mm = {
-        .pgd            = ioremap_dir,
-        .mm_users       = ATOMIC_INIT(2),
-        .mm_count       = ATOMIC_INIT(1),
-        .cpu_vm_mask    = CPU_MASK_ALL,
-        .page_table_lock = SPIN_LOCK_UNLOCKED,
-};
-
 /*
  * Make sure the floating-point register state in the
  * the thread_struct is up to date for task tsk.