From: Dave Hansen <haveblue@us.ibm.com>
People love to do comparisons with highmem_start_page. However, where
CONFIG_HIGHMEM=y and there is no actual highmem, there's no real page at
*highmem_start_page.
That's usually not a problem, but CONFIG_NONLINEAR is a bit more strict and
catches the bogus address tranlations.
There are about a gillion different ways to find out of a 'struct page' is
highmem or not. Why not just check page_flags? Just use PageHighMem()
wherever there used to be a highmem_start_page comparison. Then, kill off
highmem_start_page.
This removes more code than it adds, and gets rid of some nasty
#ifdefs in .c files.
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/frv/mm/highmem.c | 4 ++--
25-akpm/arch/frv/mm/init.c | 5 -----
2 files changed, 2 insertions(+), 7 deletions(-)
diff -puN arch/frv/mm/highmem.c~frv-kill-off-highmem_start_page arch/frv/mm/highmem.c
--- 25/arch/frv/mm/highmem.c~frv-kill-off-highmem_start_page Wed Nov 17 14:18:55 2004
+++ 25-akpm/arch/frv/mm/highmem.c Wed Nov 17 14:18:55 2004
@@ -13,7 +13,7 @@
void *kmap(struct page *page)
{
might_sleep();
- if (page < highmem_start_page)
+ if (!PageHighMem(page))
return page_address(page);
return kmap_high(page);
}
@@ -22,7 +22,7 @@ void kunmap(struct page *page)
{
if (in_interrupt())
BUG();
- if (page < highmem_start_page)
+ if (!PageHighMem(page))
return;
kunmap_high(page);
}
diff -puN arch/frv/mm/init.c~frv-kill-off-highmem_start_page arch/frv/mm/init.c
--- 25/arch/frv/mm/init.c~frv-kill-off-highmem_start_page Wed Nov 17 14:18:55 2004
+++ 25-akpm/arch/frv/mm/init.c Wed Nov 17 14:18:55 2004
@@ -134,11 +134,6 @@ void __init paging_init(void)
free_area_init(zones_size);
#ifdef CONFIG_MMU
- /* high memory (if present) starts after the last mapped page
- * - this is used by kmap()
- */
- highmem_start_page = mem_map + num_mappedpages;
-
/* initialise init's MMU context */
init_new_context(&init_task, &init_mm);
#endif
_