From 3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Tue, 26 Oct 2010 14:21:51 -0700
Subject: mm: stack based kmap_atomic()

Keep the current interface but ignore the KM_type and use a stack based
approach.

The advantage is that we get rid of crappy code like:

	#define __KM_PTE			\
		(in_nmi() ? KM_NMI_PTE : 	\
		 in_irq() ? KM_IRQ_PTE :	\
		 KM_PTE0)

and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.

The downside is that FRV kmap_atomic() gets more expensive.

For now we use a CPP trick suggested by Andrew:

  #define kmap_atomic(page, args...) __kmap_atomic(page)

to avoid having to touch all kmap_atomic() users in a single patch.

[ not compiled on:
  - mn10300: the arch doesn't actually build with highmem to begin with ]

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'drivers/gpu/drm/ttm/ttm_bo_util.c')

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 3451a82adba7..e8a73e65da69 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -170,7 +170,7 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
 
 #ifdef CONFIG_X86
-	dst = kmap_atomic_prot(d, KM_USER0, prot);
+	dst = kmap_atomic_prot(d, prot);
 #else
 	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
 		dst = vmap(&d, 1, 0, prot);
@@ -183,7 +183,7 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 	memcpy_fromio(dst, src, PAGE_SIZE);
 
 #ifdef CONFIG_X86
-	kunmap_atomic(dst, KM_USER0);
+	kunmap_atomic(dst);
 #else
 	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
 		vunmap(dst);
@@ -206,7 +206,7 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
 
 	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
 #ifdef CONFIG_X86
-	src = kmap_atomic_prot(s, KM_USER0, prot);
+	src = kmap_atomic_prot(s, prot);
 #else
 	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
 		src = vmap(&s, 1, 0, prot);
@@ -219,7 +219,7 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
 	memcpy_toio(dst, src, PAGE_SIZE);
 
 #ifdef CONFIG_X86
-	kunmap_atomic(src, KM_USER0);
+	kunmap_atomic(src);
 #else
 	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
 		vunmap(src);
-- 
cgit