[PATCH v2 0/4] pmem api, generic ioremap_cache, and memremap

From: Dan Williams
Date: Sat May 30 2015 - 15:02:29 EST


The pmem api is responsible for shepherding data out to persistent
media. The pmem driver uses this api, when available, to assert that
data is durable by the time bio_endio() is invoked. When an
architecture or cpu can not make persistence guarantees the driver warns
and falls back to "best effort" implementation.

Changes since v1 [1]:

1/ Rebase on tip/master + Toshi's ioremap_wt() patches and enable
ioremap_cache() to be used generically in drivers. Fix
devm_ioremap_resource() in the process.

2/ Rather than add yet another instance of "force cast away __iomem for
non-io-memory" take the opportunity to introduce memremap() for this use
case and fix up the current users that botch their handling of the
__iomem annotation.

3/ Mandate that consumers of the pmem api handle the case when archs, or
cpus within an arch are not able to make durability guarantees for
writes to persistent memory. See pmem_ops in drivers/block/pmem.c

4/ Drop the persistent_flush() api as there are no users until the BLK
driver is introduced, and even then it is not a "flush to persistence"
it is an invalidation of a previous mmio aperture setting
(io_flush_cache_range()).

5/ Add persistent_remap() to the pmem api for the arch to pick its
desired memory type that corresponds to the assumptions of
persistent_copy() and persistent_sync().

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-May/000929.html

This boots and processes pmem writes on x86, cross-compile 0day results
are still pending.

---

Dan Williams (3):
arch/*/asm/io.h: add ioremap_cache() to all architectures
devm: fix ioremap_cache() usage
arch: introduce memremap()

Ross Zwisler (1):
arch, x86: cache management apis for persistent memory


arch/arc/include/asm/io.h | 1
arch/arm/include/asm/io.h | 2 +
arch/arm64/include/asm/io.h | 2 +
arch/arm64/kernel/efi.c | 4 +
arch/arm64/kernel/smp_spin_table.c | 10 ++--
arch/avr32/include/asm/io.h | 1
arch/frv/include/asm/io.h | 6 ++
arch/m32r/include/asm/io.h | 1
arch/m68k/include/asm/io_mm.h | 7 +++
arch/m68k/include/asm/io_no.h | 5 ++
arch/metag/include/asm/io.h | 5 ++
arch/microblaze/include/asm/io.h | 1
arch/mn10300/include/asm/io.h | 1
arch/nios2/include/asm/io.h | 1
arch/s390/include/asm/io.h | 1
arch/sparc/include/asm/io_32.h | 1
arch/sparc/include/asm/io_64.h | 1
arch/tile/include/asm/io.h | 1
arch/x86/Kconfig | 1
arch/x86/include/asm/cacheflush.h | 24 +++++++++
arch/x86/include/asm/io.h | 7 +++
arch/x86/kernel/crash_dump_64.c | 6 +-
arch/x86/kernel/kdebugfs.c | 8 +--
arch/x86/kernel/ksysfs.c | 28 +++++-----
arch/x86/mm/ioremap.c | 10 +---
arch/xtensa/include/asm/io.h | 3 +
drivers/acpi/apei/einj.c | 8 +--
drivers/acpi/apei/erst.c | 14 +++--
drivers/block/pmem.c | 62 +++++++++++++++++++++--
drivers/firmware/google/memconsole.c | 4 +
include/asm-generic/io.h | 8 +++
include/asm-generic/iomap.h | 4 +
include/linux/device.h | 5 ++
include/linux/io.h | 38 ++++++++++++++
include/linux/pmem.h | 93 ++++++++++++++++++++++++++++++++++
lib/Kconfig | 3 +
lib/devres.c | 48 ++++++++----------
37 files changed, 347 insertions(+), 78 deletions(-)
create mode 100644 include/linux/pmem.h
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