[PATCH v5 0/6] powerpc: switch VDSO to C implementation.

From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	nathanl@linux.ibm.com, arnd@arndb.de, tglx@linutronix.de,
	vincenzo.frascino@arm.com, luto@kernel.org
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org,
	x86@kernel.org
Subject: [PATCH v5 0/6] powerpc: switch VDSO to C implementation.
Date: Thu, 30 Jan 2020 16:08:34 +0000 (UTC)	[thread overview]
Message-ID: <cover.1580399657.git.christophe.leroy@c-s.fr> (raw)

This is a fifth version of a series to switch powerpc VDSO to generic
C implementation. All previous where RFCs. This one has reached a
mature status.

It is tested on PPC32 (mpc885 and mpc8321E).
It is build tested on kisskb
(http://kisskb.ellerman.id.au/kisskb/head/abf15916bd65f808b07fe9a2377db965a37071e4/)
In PPC64 mode it now builds both VDSO64 and VDSO32.

The two first patches are optimisation around the way vdso datapage is
handled. They are worth merging now even if we want to wait a little
more for the entire series.

The next three patches are optimisations to the GENERIC C VDSO code.
Without them, the performance of the VDSO time functions are too
degraded compared to the current ASM version to be worth switching
the C VDSO.

This series applies on today's powerpc/merge branch.

See the last patch for details on changes and performance.

Christophe Leroy (6):
  powerpc/vdso64: Switch from __get_datapage() to get_datapage inline
    macro
  powerpc/vdso: Remove __kernel_datapage_offset and simplify
    __get_datapage()
  lib/vdso: Allow architectures to provide the vdso data pointer
  lib/vdso: Allow fixed clock mode
  lib/vdso: Allow architectures to override the ns shift operation
  powerpc/vdso: Switch VDSO to generic C implementation.

 arch/powerpc/Kconfig                         |   2 +
 arch/powerpc/include/asm/vdso/gettimeofday.h | 158 ++++++++++
 arch/powerpc/include/asm/vdso/vsyscall.h     |  25 ++
 arch/powerpc/include/asm/vdso_datapage.h     |  51 ++--
 arch/powerpc/kernel/asm-offsets.c            |  49 +---
 arch/powerpc/kernel/time.c                   |  90 ------
 arch/powerpc/kernel/vdso.c                   |  58 +---
 arch/powerpc/kernel/vdso32/Makefile          |  32 +-
 arch/powerpc/kernel/vdso32/cacheflush.S      |   2 +-
 arch/powerpc/kernel/vdso32/config-fake32.h   |  34 +++
 arch/powerpc/kernel/vdso32/datapage.S        |   7 +-
 arch/powerpc/kernel/vdso32/gettimeofday.S    | 291 +------------------
 arch/powerpc/kernel/vdso32/vdso32.lds.S      |   7 +-
 arch/powerpc/kernel/vdso32/vgettimeofday.c   |  29 ++
 arch/powerpc/kernel/vdso64/Makefile          |  23 +-
 arch/powerpc/kernel/vdso64/cacheflush.S      |   9 +-
 arch/powerpc/kernel/vdso64/datapage.S        |  31 +-
 arch/powerpc/kernel/vdso64/gettimeofday.S    | 243 +---------------
 arch/powerpc/kernel/vdso64/vdso64.lds.S      |   7 +-
 arch/powerpc/kernel/vdso64/vgettimeofday.c   |  29 ++
 lib/vdso/gettimeofday.c                      |  98 +++++--
 21 files changed, 467 insertions(+), 808 deletions(-)
 create mode 100644 arch/powerpc/include/asm/vdso/gettimeofday.h
 create mode 100644 arch/powerpc/include/asm/vdso/vsyscall.h
 create mode 100644 arch/powerpc/kernel/vdso32/config-fake32.h
 create mode 100644 arch/powerpc/kernel/vdso32/vgettimeofday.c
 create mode 100644 arch/powerpc/kernel/vdso64/vgettimeofday.c

-- 
2.25.0