[PATCH 0/5] mm: generic early_ioremap support

From: Mark Salter
Date: Tue Mar 04 2014 - 15:10:10 EST


To: linux-kernel@xxxxxxxxxxxxxxx
CC: x86@xxxxxxxxxx
CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: Arnd Bergmann <arnd@xxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
CC: Russell King <linux@xxxxxxxxxxxxxxxx>
CC: Catalin Marinas <catalin.marinas@xxxxxxx>
CC: Will Deacon <will.deacon@xxxxxxx>
CC: Dave Young <dyoung@xxxxxxxxxx>
CC: Rob Herring <robherring2@xxxxxxxxx>
CC: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
CC: patches@xxxxxxxxxx

This patch series takes the common bits from the x86 early ioremap
implementation and creates a generic implementation which may be used
by other architectures. The early ioremap interfaces are intended for
situations where boot code needs to make temporary virtual mappings
before the normal ioremap interfaces are available. Typically, this
means before paging_init() has run.

These patches are layered on top of generic fixmap patches which
were pulled into upstream 3.14-rc kernels.

This is version 5 of the patch series. These patches fixmap patches
may be found at:

git://github.com/mosalter/linux.git (early-ioremap-v5 branch)

Changes from version 4:

* Dropped arm bits from this series. There is work to be done to
support permanent fixmap mappings on ARM and that will be part
of a separate arm-only patch series.

* Added Acks for common, x86, and arm64 bits.

Changes from version 3:

* Removed dependency on MMU. In the case of no-MMU, the early remap
functions return the address passed in. This helps simplify use of
early_ioremap functions on architectures such as ARM which have
optional MMU support.

* Added L_PTE_XN to arm page flags so mappings are non-executable.

* Include linux/io.h rather than asm/io.h in arm setup.c

* Moved early_ioremap_init() before setup_machine_fdt() in arm
setup_arch().

* Fixed mispelling in config EARLY_IOREMAP help text.

Changes from version 2:

* Added some Acks

* Incorporated a patch from Dave Young to change the signature
of early_memremap() (dropping __iomem from returned pointer)
which is the first patch in a larger series:

https://lkml.org/lkml/2013/12/22/69

This allows the change of just the x86 function signature
to be bisected.

Changes from version 1:

* Moved the generic code into linux/mm instead of linux/lib

* Have early_memremap() return normal pointer instead of __iomem
This is in response to sparse warning cleanups being made in
an unrelated patch series:

https://lkml.org/lkml/2013/12/22/69

* Added arm64 patch to call init_mem_pgprot() earlier so that
the pgprot macros are valid in time for early_ioremap use

* Added validity checking for early_ioremap pgd, pud, and pmd
in arm64

Dave Young (1):
x86/mm: sparse warning fix for early_memremap

Mark Salter (4):
mm: create generic early_ioremap() support
x86: use generic early_ioremap
arm64: initialize pgprot info earlier in boot
arm64: add early_ioremap support

Documentation/arm64/memory.txt | 4 +-
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/Kbuild | 1 +
arch/arm64/include/asm/fixmap.h | 67 +++++++++
arch/arm64/include/asm/io.h | 1 +
arch/arm64/include/asm/memory.h | 2 +-
arch/arm64/include/asm/mmu.h | 1 +
arch/arm64/kernel/early_printk.c | 8 +-
arch/arm64/kernel/head.S | 9 +-
arch/arm64/kernel/setup.c | 4 +
arch/arm64/mm/ioremap.c | 85 +++++++++++
arch/arm64/mm/mmu.c | 44 +-----
arch/x86/Kconfig | 1 +
arch/x86/include/asm/Kbuild | 1 +
arch/x86/include/asm/fixmap.h | 6 +
arch/x86/include/asm/io.h | 14 +-
arch/x86/mm/ioremap.c | 224 +----------------------------
arch/x86/mm/pgtable_32.c | 2 +-
include/asm-generic/early_ioremap.h | 42 ++++++
mm/Kconfig | 3 +
mm/Makefile | 1 +
mm/early_ioremap.c | 271 ++++++++++++++++++++++++++++++++++++
22 files changed, 503 insertions(+), 289 deletions(-)
create mode 100644 arch/arm64/include/asm/fixmap.h
create mode 100644 include/asm-generic/early_ioremap.h
create mode 100644 mm/early_ioremap.c

--
1.8.5.3

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