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From: Finn Thain <fthain@telegraphics.com.au>
To: <linux-kernel@vger.kernel.org>, <linux-m68k@vger.kernel.org>,
	<linuxppc-dev@lists.ozlabs.org>
Subject: [PATCH v7 00/26] Re-use nvram module
Date: Sun, 01 Nov 2015 21:42:02 +1100
Message-ID: <20151101104202.301856132@telegraphics.com.au> (raw)


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, v1 of 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, Quadra 650
and Atari Falcon. The PPC64 changes were tested on a G5 PowerMac.

Changes since v1:
- Minor changes to patches 7, 15 and 20 as described in commit logs.
- Revised patches 21 and 24 to address comments from Geert.

Changes since v2:
- Dropped patch 1, "macintosh/nvram: Remove as unused", because it has
since been merged.
- Inserted a new patch, "m68k/mac: Use macros for RTC accesses not
magic numbers".
- Revised patches 21 and 23 to address comments from Geert.

Changes since v3:
- Split the patch, "m68k/atari: Move Atari-specific code out of
drivers/char/nvram.c", as suggested by Geert.
- Revised patches 11 and 25 to address comments from Geert.
- Minor change to patch 21 as described in commit log.

Changes since v4:
- Split the patch, "powerpc, fbdev: Use arch_nvram_ops methods instead
of nvram_read_byte() and nvram_write_byte()", so as to separately address
inconsistent use of Kconfig symbols in PowerMac fbdev drivers.
- Fix possible git bisect build failure with CONFIG_PPC_PMAC=n.

Changes since v5:
- Dropped patch 2, "char/nvram: Use bitwise OR to obtain Atari video mode
data", since it has been added to Greg Kroah-Hartman's char-misc-next queue.
- In patch 15, error codes from the IOC_NVRAM_GET_OFFSET ioctl are now
consistent with the old generic_nvram module.

Changes since v6:
- In patch 21, the '#ifdef CONFIG_NVRAM' conditional was changed to
'#if defined(CONFIG_NVRAM) && defined(CONFIG_PPC32)' to avoid changing
behaviour as CONFIG_NVRAM becomes available to PPC64.
- Added a new patch (22) in response to Ben's comment about XPRAM accessors.
The patch replaces the calls to pmac_xpram_read() with calls to
arch_nvram_ops.read_byte()

---
 arch/m68k/Kconfig                          |    3 
 arch/m68k/Kconfig.machine                  |    2 
 arch/m68k/atari/Makefile                   |    2 
 arch/m68k/atari/nvram.c                    |  291 +++++++++++
 arch/m68k/include/asm/atarihw.h            |    6 
 arch/m68k/include/asm/macintosh.h          |    4 
 arch/m68k/kernel/setup_mm.c                |  100 +++
 arch/m68k/mac/misc.c                       |  207 +++++---
 arch/powerpc/Kconfig                       |    5 
 arch/powerpc/include/asm/nvram.h           |   13 
 arch/powerpc/kernel/nvram_64.c             |  206 +-------
 arch/powerpc/kernel/setup_32.c             |   30 -
 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    |   37 -
 arch/powerpc/platforms/powermac/setup.c    |    3 
 arch/powerpc/platforms/powermac/time.c     |   19 
 arch/powerpc/platforms/pseries/nvram.c     |    2 
 drivers/char/Kconfig                       |   13 
 drivers/char/Makefile                      |    6 
 drivers/char/generic_nvram.c               |  174 ------
 drivers/char/nvram.c                       |  740 ++++++++++++-----------------
 drivers/platform/x86/thinkpad_acpi.c       |   20 
 drivers/scsi/Kconfig                       |    6 
 drivers/scsi/atari_scsi.c                  |   16 
 drivers/video/fbdev/Kconfig                |    2 
 drivers/video/fbdev/controlfb.c            |    4 
 drivers/video/fbdev/imsttfb.c              |   17 
 drivers/video/fbdev/matrox/matroxfb_base.c |    6 
 drivers/video/fbdev/platinumfb.c           |    4 
 drivers/video/fbdev/valkyriefb.c           |   18 
 include/linux/nvram.h                      |   24 
 include/uapi/linux/pmu.h                   |    2 
 35 files changed, 1020 insertions(+), 985 deletions(-)





             reply index

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-01 10:42 Finn Thain [this message]
2015-11-01 10:42 ` [PATCH v7 01/26] scsi/atari_scsi: Dont select CONFIG_NVRAM Finn Thain
2015-11-01 10:42 ` [PATCH v7 02/26] m68k/atari: Move Atari-specific code out of drivers/char/nvram.c Finn Thain
2015-11-01 10:42 ` [PATCH v7 03/26] m68k/atari: Replace nvram_{read,write}_byte with arch_nvram_ops Finn Thain
2015-11-01 10:42 ` [PATCH v7 04/26] char/nvram: Re-order functions to remove forward declarations and #ifdefs Finn Thain
2015-11-01 10:42 ` [PATCH v7 05/26] char/nvram: Adopt arch_nvram_ops Finn Thain
2015-11-01 10:42 ` [PATCH v7 06/26] x86/thinkpad_acpi: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2015-11-01 10:42 ` [PATCH v7 07/26] char/nvram: Allow the set_checksum and initialize ioctls to be omitted Finn Thain
2015-11-01 10:42 ` [PATCH v7 08/26] char/nvram: Implement NVRAM read/write methods Finn Thain
2015-11-01 10:42 ` [PATCH v7 09/26] char/nvram: Use generic fixed_size_llseek() Finn Thain
2015-11-01 10:42 ` [PATCH v7 10/26] m68k/atari: Implement arch_nvram_ops methods and enable CONFIG_HAVE_ARCH_NVRAM_OPS Finn Thain
2015-11-01 10:42 ` [PATCH v7 11/26] char/nvram: Add "devname:nvram" module alias Finn Thain
2015-11-01 10:42 ` [PATCH v7 12/26] powerpc: Cleanup nvram includes Finn Thain
2015-11-01 10:42 ` [PATCH v7 13/26] powerpc: Add missing ppc_md.nvram_size for CHRP and PowerMac Finn Thain
2015-11-01 10:42 ` [PATCH v7 14/26] powerpc: Implement arch_nvram_ops.get_size() and remove old nvram_* exports Finn Thain
2015-11-01 10:42 ` [PATCH v7 15/26] powerpc: Implement nvram sync ioctl Finn Thain
2015-11-01 10:42 ` [PATCH v7 16/26] powerpc, fbdev: Use NV_CMODE and NV_VMODE only when CONFIG_PPC32 and CONFIG_PPC_PMAC and CONFIG_NVRAM Finn Thain
2015-11-01 10:42 ` [PATCH v7 17/26] powerpc, fbdev: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2015-11-01 10:42 ` [PATCH v7 18/26] nvram: Drop nvram_* symbol exports and prototypes Finn Thain
2015-11-01 10:42 ` [PATCH v7 19/26] powerpc: Remove CONFIG_GENERIC_NVRAM and adopt CONFIG_HAVE_ARCH_NVRAM_OPS Finn Thain
2015-11-01 10:42 ` [PATCH v7 20/26] char/generic_nvram: Remove as unused Finn Thain
2015-11-01 10:42 ` [PATCH v7 21/26] powerpc: Adopt nvram module for PPC64 Finn Thain
2015-11-01 10:42 ` [PATCH v7 22/26] powerpc: Remove pmac_xpram_{read,write} functions Finn Thain
2015-11-01 10:42 ` [PATCH v7 23/26] m68k/mac: Adopt naming and calling conventions for PRAM routines Finn Thain
2015-11-01 10:42 ` [PATCH v7 24/26] m68k/mac: Use macros for RTC accesses not magic numbers Finn Thain
2015-11-01 10:42 ` [PATCH v7 25/26] m68k/mac: Fix PRAM accessors Finn Thain
2015-11-01 10:42 ` [PATCH v7 26/26] m68k: Dispatch nvram_ops calls to Atari or Mac functions Finn Thain

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