kmap-atomic-i386-fix.patch

From dfcef64dff309968a1dd3f50a652dea73f847417 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:30:38 -0500
Subject: [PATCH] kmap: atomic i386 fix

commit 751675d74ac83053714021896601a3cde294a6ff in tip.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index d1c2886..42f2449 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -89,10 +89,10 @@ extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn,
  * on PREEMPT_RT kmap_atomic() is a wrapper that uses kmap():
  */
 #ifdef CONFIG_PREEMPT_RT
-# define kmap_atomic_prot(page, type, prot)	kmap(page)
-# define kmap_atomic(page, type)	kmap(page)
+# define kmap_atomic_prot(page, type, prot)	({ pagefault_disable(); kmap(page); })
+# define kmap_atomic(page, type)	({ pagefault_disable(); kmap(page); })
 # define kmap_atomic_pfn(pfn, type)	kmap(pfn_to_page(pfn))
-# define kunmap_atomic(kvaddr, type)	kunmap_virt(kvaddr)
+# define kunmap_atomic(kvaddr, type)	do { pagefault_enable(); kunmap_virt(kvaddr); } while(0)
 # define kmap_atomic_to_page(kvaddr)	kmap_to_page(kvaddr)
 #else
 # define kmap_atomic_prot(page, type, prot)	__kmap_atomic_prot(page, type, prot)
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 856a2a3..419d8f6 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,9 +4,9 @@
 
 void *kmap(struct page *page)
 {
-	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
+	might_sleep();
 	return kmap_high(page);
 }
 
-- 
1.7.1.1