[PATCH v2 00/11] Consolidate asm/fixmap.h files

[PATCH v2 00/11] Consolidate asm/fixmap.h files

[Mark Salter]

Many architectures provide an asm/fixmap.h which defines support for
compile-time 'special' virtual mappings which need to be made before
paging_init() has run. This suport is also used for early ioremap
on x86. Much of this support is identical across the architectures.
This patch consolidates all of the common bits into asm-generic/fixmap.h
which is intended to be included from arch/*/include/asm/fixmap.h.

This has been compiled on x86, arm, powerpc, and sh, but tested
on x86 only.

This is version two of the patch series:

   git://github.com/mosalter/linux.git#fixmap-v2

Version 1 is here:

   git://github.com/mosalter/linux.git#fixmap

Changes from v1:

  * Added acks from feedback.
  * Use BUILD_BUG_ON in fix_to_virt()
  * Fixed ARM patch to make FIXMAP_TOP inclusive of fixmap
    range as is the case in the other architectures.

Mark Salter (11):
  Add generic fixmap.h
  x86: use generic fixmap.h
  arm: use generic fixmap.h
  hexagon: use generic fixmap.h
  metag: use generic fixmap.h
  microblaze: use generic fixmap.h
  mips: use generic fixmap.h
  powerpc: use generic fixmap.h
  sh: use generic fixmap.h
  tile: use generic fixmap.h
  um: use generic fixmap.h

 arch/arm/include/asm/fixmap.h        | 29 +++--------
 arch/arm/mm/init.c                   |  2 +-
 arch/hexagon/include/asm/fixmap.h    | 40 +--------------
 arch/metag/include/asm/fixmap.h      | 32 +-----------
 arch/microblaze/include/asm/fixmap.h | 44 +---------------
 arch/mips/include/asm/fixmap.h       | 33 +-----------
 arch/powerpc/include/asm/fixmap.h    | 44 +---------------
 arch/sh/include/asm/fixmap.h         | 39 +--------------
 arch/tile/include/asm/fixmap.h       | 33 +-----------
 arch/um/include/asm/fixmap.h         | 40 +--------------
 arch/x86/include/asm/fixmap.h        | 59 +---------------------
 include/asm-generic/fixmap.h         | 97 ++++++++++++++++++++++++++++++++++++
 12 files changed, 118 insertions(+), 374 deletions(-)
 create mode 100644 include/asm-generic/fixmap.h

-- 
1.8.3.1

[PATCH v2 01/11] Add generic fixmap.h

[Mark Salter]

Many architectures provide an asm/fixmap.h which defines support for
compile-time 'special' virtual mappings which need to be made before
paging_init() has run. This support is also used for early ioremap
on x86. Much of this support is identical across the architectures.
This patch consolidates all of the common bits into asm-generic/fixmap.h
which is intended to be included from arch/*/include/asm/fixmap.h.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
CC: linux-arch@vger.kernel.org
CC: Russell King <linux@arm.linux.org.uk>
CC: linux-arm-kernel@lists.infradead.org
CC: Richard Kuo <rkuo@codeaurora.org>
CC: linux-hexagon@vger.kernel.org
CC: James Hogan <james.hogan@imgtec.com>
CC: linux-metag@vger.kernel.org
CC: Michal Simek <monstr@monstr.eu>
CC: microblaze-uclinux@itee.uq.edu.au
CC: linux-mips@linux-mips.org
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>
CC: linuxppc-dev@lists.ozlabs.org
---
 include/asm-generic/fixmap.h | 97 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 include/asm-generic/fixmap.h

diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h
new file mode 100644
index 0000000..5a64ca4
--- /dev/null
+++ b/include/asm-generic/fixmap.h
@@ -0,0 +1,97 @@
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1998 Ingo Molnar
+ *
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
+ * Break out common bits to asm-generic by Mark Salter, November 2013
+ */
+
+#ifndef __ASM_GENERIC_FIXMAP_H
+#define __ASM_GENERIC_FIXMAP_H
+
+#include <linux/bug.h>
+
+#define __fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))
+#define __virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
+
+#ifndef __ASSEMBLY__
+/*
+ * 'index to address' translation. If anyone tries to use the idx
+ * directly without translation, we catch the bug with a NULL-deference
+ * kernel oops. Illegal ranges of incoming indices are caught too.
+ */
+static __always_inline unsigned long fix_to_virt(const unsigned int idx)
+{
+	BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
+	return __fix_to_virt(idx);
+}
+
+static inline unsigned long virt_to_fix(const unsigned long vaddr)
+{
+	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
+	return __virt_to_fix(vaddr);
+}
+
+/*
+ * Provide some reasonable defaults for page flags.
+ * Not all architectures use all of these different types and some
+ * architectures use different names.
+ */
+#ifndef FIXMAP_PAGE_NORMAL
+#define FIXMAP_PAGE_NORMAL PAGE_KERNEL
+#endif
+#ifndef FIXMAP_PAGE_NOCACHE
+#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
+#endif
+#ifndef FIXMAP_PAGE_IO
+#define FIXMAP_PAGE_IO PAGE_KERNEL_IO
+#endif
+#ifndef FIXMAP_PAGE_CLEAR
+#define FIXMAP_PAGE_CLEAR __pgprot(0)
+#endif
+
+#ifndef set_fixmap
+#define set_fixmap(idx, phys)				\
+	__set_fixmap(idx, phys, FIXMAP_PAGE_NORMAL)
+#endif
+
+#ifndef clear_fixmap
+#define clear_fixmap(idx)			\
+	__set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR)
+#endif
+
+/* Return a pointer with offset calculated */
+#define __set_fixmap_offset(idx, phys, flags)		      \
+({							      \
+	unsigned long addr;				      \
+	__set_fixmap(idx, phys, flags);			      \
+	addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1)); \
+	addr;						      \
+})
+
+#define set_fixmap_offset(idx, phys) \
+	__set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL)
+
+/*
+ * Some hardware wants to get fixmapped without caching.
+ */
+#define set_fixmap_nocache(idx, phys) \
+	__set_fixmap(idx, phys, FIXMAP_PAGE_NOCACHE)
+
+#define set_fixmap_offset_nocache(idx, phys) \
+	__set_fixmap_offset(idx, phys, FIXMAP_PAGE_NOCACHE)
+
+/*
+ * Some fixmaps are for IO
+ */
+#define set_fixmap_io(idx, phys) \
+	__set_fixmap(idx, phys, FIXMAP_PAGE_IO)
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_GENERIC_FIXMAP_H */
-- 
1.8.3.1

[PATCH v2 04/11] hexagon: use generic fixmap.h

[Mark Salter]

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Richard Kuo <rkuo@codeaurora.org>
CC: linux-hexagon@vger.kernel.org
---
 arch/hexagon/include/asm/fixmap.h | 40 +--------------------------------------
 1 file changed, 1 insertion(+), 39 deletions(-)

diff --git a/arch/hexagon/include/asm/fixmap.h b/arch/hexagon/include/asm/fixmap.h
index b75b6bf..1387f84 100644
--- a/arch/hexagon/include/asm/fixmap.h
+++ b/arch/hexagon/include/asm/fixmap.h
@@ -26,45 +26,7 @@
  */
 #include <asm/mem-layout.h>
 
-/*
- * Full fixmap support involves set_fixmap() functions, but
- * these may not be needed if all we're after is an area for
- * highmem kernel mappings.
- */
-#define	__fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))
-#define	__virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
-
-extern void __this_fixmap_does_not_exist(void);
-
-/**
- * fix_to_virt -- "index to address" translation.
- *
- * If anyone tries to use the idx directly without translation,
- * we catch the bug with a NULL-deference kernel oops. Illegal
- * ranges of incoming indices are caught too.
- */
-static inline unsigned long fix_to_virt(const unsigned int idx)
-{
-	/*
-	 * This branch gets completely eliminated after inlining,
-	 * except when someone tries to use fixaddr indices in an
-	 * illegal way. (such as mixing up address types or using
-	 * out-of-range indices).
-	 *
-	 * If it doesn't get removed, the linker will complain
-	 * loudly with a reasonably clear error message..
-	 */
-	if (idx >= __end_of_fixed_addresses)
-		__this_fixmap_does_not_exist();
-
-	return __fix_to_virt(idx);
-}
-
-static inline unsigned long virt_to_fix(const unsigned long vaddr)
-{
-	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
-	return __virt_to_fix(vaddr);
-}
+#include <asm-generic/fixmap.h>
 
 #define kmap_get_fixmap_pte(vaddr) \
 	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), \
-- 
1.8.3.1

Re: [PATCH v2 00/11] Consolidate asm/fixmap.h files

[Jonas Bonn]

Hi Mark,

Is there some reason you've excluded OpenRISC here?  Did you just miss
it, or does the implementation diverage too much to be usable with
your generic version?

Regards,
Jonas

On 25 November 2013 17:13, Mark Salter <msalter@redhat.com> wrote:
> Many architectures provide an asm/fixmap.h which defines support for
> compile-time 'special' virtual mappings which need to be made before
> paging_init() has run. This suport is also used for early ioremap
> on x86. Much of this support is identical across the architectures.
> This patch consolidates all of the common bits into asm-generic/fixmap.h
> which is intended to be included from arch/*/include/asm/fixmap.h.
>
> This has been compiled on x86, arm, powerpc, and sh, but tested
> on x86 only.
>
> This is version two of the patch series:
>
>    git://github.com/mosalter/linux.git#fixmap-v2
>
> Version 1 is here:
>
>    git://github.com/mosalter/linux.git#fixmap
>
> Changes from v1:
>
>   * Added acks from feedback.
>   * Use BUILD_BUG_ON in fix_to_virt()
>   * Fixed ARM patch to make FIXMAP_TOP inclusive of fixmap
>     range as is the case in the other architectures.
>
> Mark Salter (11):
>   Add generic fixmap.h
>   x86: use generic fixmap.h
>   arm: use generic fixmap.h
>   hexagon: use generic fixmap.h
>   metag: use generic fixmap.h
>   microblaze: use generic fixmap.h
>   mips: use generic fixmap.h
>   powerpc: use generic fixmap.h
>   sh: use generic fixmap.h
>   tile: use generic fixmap.h
>   um: use generic fixmap.h
>
>  arch/arm/include/asm/fixmap.h        | 29 +++--------
>  arch/arm/mm/init.c                   |  2 +-
>  arch/hexagon/include/asm/fixmap.h    | 40 +--------------
>  arch/metag/include/asm/fixmap.h      | 32 +-----------
>  arch/microblaze/include/asm/fixmap.h | 44 +---------------
>  arch/mips/include/asm/fixmap.h       | 33 +-----------
>  arch/powerpc/include/asm/fixmap.h    | 44 +---------------
>  arch/sh/include/asm/fixmap.h         | 39 +--------------
>  arch/tile/include/asm/fixmap.h       | 33 +-----------
>  arch/um/include/asm/fixmap.h         | 40 +--------------
>  arch/x86/include/asm/fixmap.h        | 59 +---------------------
>  include/asm-generic/fixmap.h         | 97 ++++++++++++++++++++++++++++++++++++
>  12 files changed, 118 insertions(+), 374 deletions(-)
>  create mode 100644 include/asm-generic/fixmap.h
>
> --
> 1.8.3.1
>
> --
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-- 
Jonas Bonn
Stockholm, Sweden