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* [RFC v2 00/24] Re-use nvram module
@ 2015-06-14  7:46 ` Finn Thain
  0 siblings, 0 replies; 87+ messages in thread
From: Finn Thain @ 2015-06-14  7:46 UTC (permalink / raw)
  To: linux-kernel, linux-m68k, linuxppc-dev


The generic NVRAM module, drivers/char/generic_nvram, implements a
/dev/nvram misc device. It is used only by 32-bit PowerPC platforms and
isn't generic enough to be more widely used.

The RTC NVRAM module, drivers/char/nvram, also implements a /dev/nvram
misc device. It is used by x86, ARM and m68k.

The former module cannot be used on x86, ARM or m68k because it
cannot co-exist with the latter module, partly due to the Kconfig logic.

It is possible to modify the modules so that one kernel binary could
have either, neither or both. However, automatically loading the
appropriate module is then impossible; if both provide the
char-major-10-144 alias then the wrong module will end up being loaded.
Hence a multi-platform kernel binary needs a single generic nvram module
with alias char-major-10-144.

Therefore, drivers/char/nvram.c should be made more generic and the
arch-specific code therein should be moved to a more appropriate
place under arch/. Also, drivers/char/generic_nvram.c should be removed
to reduce code duplication.

In this patch series, Atari-specific code is moved from the nvram module
to arch/m68k/atari. More arch-specific code in the nvram module could
be moved, probably to arch/x86, but it is difficult to determine just
what code is relevant to ARM platforms and what code is x86-only.

In addressing code duplication, this patch series removes three
inconsistent /dev/nvram misc device implementations. One of these,
drivers/macintosh/nvram.c is entirely unused already. The other two,
drivers/char/generic_nvram.c and the misc device implementation in
arch/powerpc/kernel/nvram_64.c, are replaced by drivers/char/nvram.c.

A benefit of this work is better consistency -- between PPC32 and PPC64
as well as between PPC_PMAC and MAC. This new uniformity does have
implications for userspace, that is, some error codes for some ioctl calls
become consistent on all PowerPC platforms.

The drivers/char/nvram module becomes sufficiently generic to be useful
to other platforms and architectures, besides those with "CMOS" RTC. At the
end of this patch series the module is adopted by the m68k Mac port, which
already has PRAM access functions but lacks the /dev/nvram misc device.

This patch series has been compile-tested for arm, m68k, powerpc and x86.
The nvram and thinkpad_acpi modules were regression tested on a ThinkPad T43.
The /dev/nvram functionality was also regression tested on a G3 PowerMac.
The nvram module was also tested on a PowerBook 520 and Quadra 650.
Note that my testing doesn't cover PPC64 or Atari.

---
 arch/m68k/Kconfig                          |    3 
 arch/m68k/atari/Makefile                   |    2 
 arch/m68k/atari/nvram.c                    |  291 +++++++++++
 arch/m68k/kernel/setup_mm.c                |  107 ++++
 arch/m68k/mac/misc.c                       |  144 +++--
 arch/powerpc/Kconfig                       |    5 
 arch/powerpc/include/asm/nvram.h           |    9 
 arch/powerpc/kernel/nvram_64.c             |  203 +------
 arch/powerpc/kernel/setup_32.c             |   27 -
 arch/powerpc/platforms/chrp/Makefile       |    2 
 arch/powerpc/platforms/chrp/nvram.c        |   14 
 arch/powerpc/platforms/chrp/setup.c        |    2 
 arch/powerpc/platforms/powermac/Makefile   |    5 
 arch/powerpc/platforms/powermac/nvram.c    |    9 
 arch/powerpc/platforms/powermac/setup.c    |    3 
 drivers/char/Kconfig                       |   13 
 drivers/char/Makefile                      |    6 
 drivers/char/generic_nvram.c               |  174 ------
 drivers/char/nvram.c                       |  742 ++++++++++++-----------------
 drivers/macintosh/nvram.c                  |  130 -----
 drivers/platform/x86/thinkpad_acpi.c       |   20 
 drivers/scsi/Kconfig                       |    6 
 drivers/scsi/atari_scsi.c                  |   16 
 drivers/video/fbdev/controlfb.c            |    4 
 drivers/video/fbdev/imsttfb.c              |    7 
 drivers/video/fbdev/matrox/matroxfb_base.c |    4 
 drivers/video/fbdev/platinumfb.c           |    4 
 drivers/video/fbdev/valkyriefb.c           |    4 
 include/linux/nvram.h                      |   23 
 include/uapi/linux/pmu.h                   |    2 
 30 files changed, 937 insertions(+), 1044 deletions(-)





^ permalink raw reply	[flat|nested] 87+ messages in thread

end of thread, other threads:[~2015-06-18 16:52 UTC | newest]

Thread overview: 87+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-06-14  7:46 [RFC v2 00/24] Re-use nvram module Finn Thain
2015-06-14  7:46 ` Finn Thain
2015-06-14  7:46 ` [RFC v2 01/24] macintosh/nvram: Remove as unused Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-15  6:41   ` [RFC,v2,01/24] " Michael Ellerman
2015-06-15  6:41     ` Michael Ellerman
2015-06-14  7:46 ` [RFC v2 02/24] scsi/atari_scsi: Dont select CONFIG_NVRAM Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 03/24] m68k/atari: Move Atari-specific code out of drivers/char/nvram.c Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 04/24] m68k/atari: Replace nvram_{read,write}_byte with arch_nvram_ops Finn Thain
2015-06-14  7:46   ` [RFC v2 04/24] m68k/atari: Replace nvram_{read, write}_byte " Finn Thain
2015-06-14  7:46   ` [RFC v2 04/24] m68k/atari: Replace nvram_{read,write}_byte " Finn Thain
2015-06-14  7:46 ` [RFC v2 05/24] char/nvram: Re-order functions to remove forward declarations and #ifdefs Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 06/24] char/nvram: Adopt arch_nvram_ops Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 07/24] x86/thinkpad_acpi: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 08/24] char/nvram: Allow the set_checksum and initialize ioctls to be omitted Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 09/24] char/nvram: Implement NVRAM read/write methods Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 10/24] char/nvram: Use generic fixed_size_llseek() Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 11/24] m68k/atari: Implement arch_nvram_ops methods and enable CONFIG_HAVE_ARCH_NVRAM_OPS Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 12/24] char/nvram: Add "devname:nvram" module alias Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 13/24] powerpc: Cleanup nvram includes Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 14/24] powerpc: Add missing ppc_md.nvram_size for CHRP and PowerMac Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 15/24] powerpc: Implement arch_nvram_ops.get_size() and remove old nvram_* exports Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 16/24] powerpc: Implement nvram sync ioctl Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 17/24] powerpc, fbdev: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` [RFC v2 17/24] powerpc, fbdev: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_wri Finn Thain
2015-06-14  7:46   ` [RFC v2 17/24] powerpc, fbdev: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2015-06-14  7:46 ` [RFC v2 18/24] nvram: Drop nvram_* symbol exports and prototypes Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 19/24] powerpc: Remove CONFIG_GENERIC_NVRAM and adopt CONFIG_HAVE_ARCH_NVRAM_OPS Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 20/24] char/generic_nvram: Remove as unused Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 21/24] powerpc: Adopt nvram module for PPC64 Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 22/24] m68k/mac: Adopt naming and calling conventions for PRAM routines Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46 ` [RFC v2 23/24] m68k/mac: Fix PRAM accessors Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-15  8:23   ` Geert Uytterhoeven
2015-06-15  8:23     ` Geert Uytterhoeven
2015-06-16  3:10     ` Finn Thain
2015-06-16  3:10       ` Finn Thain
2015-06-18  4:49       ` Finn Thain
2015-06-18  6:59         ` Geert Uytterhoeven
2015-06-18  6:59           ` Geert Uytterhoeven
2015-06-18 16:52       ` Andreas Schwab
2015-06-18 16:52         ` Andreas Schwab
2015-06-14  7:46 ` [RFC v2 24/24] m68k: Dispatch nvram_ops calls to Atari or Mac functions Finn Thain
2015-06-14  7:46   ` Finn Thain
2015-06-14  7:46   ` Finn Thain

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