On Wed, 2010-10-27 at 11:27 +0100, Chris Wilson wrote:
> On Sat, 18 Sep 2010 17:53:26 +0200, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
> > Next version of the kmap_atomic rework using Andrew's fancy CPP trickery to
> > avoid having to convert the whole tree at once.
> >
> > This is compile tested for i386-allmodconfig, frv, mips-sb1250-swarm,
> > powerpc-ppc6xx_defconfig, sparc32_defconfig, arm-omap3 (all with
> > HIGHEM=y).
>
> This break on x86, HIGHMEM=n:
>
> arch/x86/mm/iomap_32.c: In function âkmap_atomic_prot_pfnâ:
> arch/x86/mm/iomap_32.c:64: error: implicit declaration of function
> âkmap_atomic_idx_pushâ
> arch/x86/mm/iomap_32.c: In function âiounmap_atomicâ:
> arch/x86/mm/iomap_32.c:101: error: implicit declaration of function
> âkmap_atomic_idx_popâ
Christoph just complained about the same on IRC, the below seems to cure
things for i386-defconfig with CONFIG_HIGHMEM=n
---
Subject: mm,x86: fix kmap_atomic_push vs ioremap_32.c
It appears i386 uses kmap_atomic infrastructure regardless of
CONFIG_HIGHMEM which results in a compile error when highmem is
disabled.
Cure this by providing the needed few bits for both CONFIG_HIGHMEM and
CONFIG_X86_32.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
include/linux/highmem.h | 46 +++++++++++++++++++++++++---------------------
mm/highmem.c | 6 +++++-
2 files changed, 30 insertions(+), 22 deletions(-)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 8a85ec1..102f76b 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -37,27 +37,6 @@ extern unsigned long totalhigh_pages;
void kmap_flush_unused(void);
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
-{
- int idx = __get_cpu_var(__kmap_atomic_idx)++;
-#ifdef CONFIG_DEBUG_HIGHMEM
- WARN_ON_ONCE(in_irq() && !irqs_disabled());
- BUG_ON(idx > KM_TYPE_NR);
-#endif
- return idx;
-}
-
-static inline int kmap_atomic_idx_pop(void)
-{
- int idx = --__get_cpu_var(__kmap_atomic_idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
- BUG_ON(idx < 0);
-#endif
- return idx;
-}
-
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -95,6 +74,31 @@ static inline void __kunmap_atomic(void *addr)
#endif /* CONFIG_HIGHMEM */
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+
+DECLARE_PER_CPU(int, __kmap_atomic_idx);
+
+static inline int kmap_atomic_idx_push(void)
+{
+ int idx = __get_cpu_var(__kmap_atomic_idx)++;
+#ifdef CONFIG_DEBUG_HIGHMEM
+ WARN_ON_ONCE(in_irq() && !irqs_disabled());
+ BUG_ON(idx > KM_TYPE_NR);
+#endif
+ return idx;
+}
+
+static inline int kmap_atomic_idx_pop(void)
+{
+ int idx = --__get_cpu_var(__kmap_atomic_idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+ BUG_ON(idx < 0);
+#endif
+ return idx;
+}
+
+#endif
+
/*
* Make both: kmap_atomic(page, idx) and kmap_atomic(page) work.
*/
diff --git a/mm/highmem.c b/mm/highmem.c
index 781e754..693394d 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -29,6 +29,11 @@
#include <linux/kgdb.h>
#include <asm/tlbflush.h>
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+DEFINE_PER_CPU(int, __kmap_atomic_idx);
+#endif
+
/*
* Virtual_count is not a pure "count".
* 0 means that it is not mapped, and has not been mapped
@@ -43,7 +48,6 @@ unsigned long totalhigh_pages __read_mostly;
EXPORT_SYMBOL(totalhigh_pages);
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
unsigned int nr_free_highpages (void)
--
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