linux-stable.git/arch/x86/kernel/e820.c, branch linux-4.2.y

Merge tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm

2015-06-29T17:34:42+00:00

Pull libnvdimm subsystem from Dan Williams:
"The libnvdimm sub-system introduces, in addition to the
libnvdimm-core, 4 drivers / enabling modules:

NFIT:
Instantiates an "nvdimm bus" with the core and registers memory
devices (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware
Interface table).

After registering NVDIMMs the NFIT driver then registers "region"
devices. A libnvdimm-region defines an access mode and the
boundaries of persistent memory media. A region may span multiple
NVDIMMs that are interleaved by the hardware memory controller. In
turn, a libnvdimm-region can be carved into a "namespace" device and
bound to the PMEM or BLK driver which will attach a Linux block
device (disk) interface to the memory.

PMEM:
Initially merged in v4.1 this driver for contiguous spans of
persistent memory address ranges is re-worked to drive
PMEM-namespaces emitted by the libnvdimm-core.

In this update the PMEM driver, on x86, gains the ability to assert
that writes to persistent memory have been flushed all the way
through the caches and buffers in the platform to persistent media.
See memcpy_to_pmem() and wmb_pmem().

BLK:
This new driver enables access to persistent memory media through
"Block Data Windows" as defined by the NFIT. The primary difference
of this driver to PMEM is that only a small window of persistent
memory is mapped into system address space at any given point in
time.

Per-NVDIMM windows are reprogrammed at run time, per-I/O, to access
different portions of the media. BLK-mode, by definition, does not
support DAX.

BTT:
This is a library, optionally consumed by either PMEM or BLK, that
converts a byte-accessible namespace into a disk with atomic sector
update semantics (prevents sector tearing on crash or power loss).

The sinister aspect of sector tearing is that most applications do
not know they have a atomic sector dependency. At least today's
disk's rarely ever tear sectors and if they do one almost certainly
gets a CRC error on access. NVDIMMs will always tear and always
silently. Until an application is audited to be robust in the
presence of sector-tearing the usage of BTT is recommended.

Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig,
Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox,
Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael
Wysocki, and Bob Moore"

* tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm: (33 commits)
arch, x86: pmem api for ensuring durability of persistent memory updates
libnvdimm: Add sysfs numa_node to NVDIMM devices
libnvdimm: Set numa_node to NVDIMM devices
acpi: Add acpi_map_pxm_to_online_node()
libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only
pmem: flag pmem block devices as non-rotational
libnvdimm: enable iostat
pmem: make_request cleanups
libnvdimm, pmem: fix up max_hw_sectors
libnvdimm, blk: add support for blk integrity
libnvdimm, btt: add support for blk integrity
fs/block_dev.c: skip rw_page if bdev has integrity
libnvdimm: Non-Volatile Devices
tools/testing/nvdimm: libnvdimm unit test infrastructure
libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory
nd_btt: atomic sector updates
libnvdimm: infrastructure for btt devices
libnvdimm: write blk label set
libnvdimm: write pmem label set
libnvdimm: blk labels and namespace instantiation
...

mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute

2015-06-25T00:49:44+00:00

Some high end Intel Xeon systems report uncorrectable memory errors as a
recoverable machine check.  Linux has included code for some time to
process these and just signal the affected processes (or even recover
completely if the error was in a read only page that can be replaced by
reading from disk).

But we have no recovery path for errors encountered during kernel code
execution.  Except for some very specific cases were are unlikely to ever
be able to recover.

Enter memory mirroring. Actually 3rd generation of memory mirroing.

Gen1: All memory is mirrored
	Pro: No s/w enabling - h/w just gets good data from other side of the
	     mirror
	Con: Halves effective memory capacity available to OS/applications

Gen2: Partial memory mirror - just mirror memory begind some memory controllers
	Pro: Keep more of the capacity
	Con: Nightmare to enable. Have to choose between allocating from
	     mirrored memory for safety vs. NUMA local memory for performance

Gen3: Address range partial memory mirror - some mirror on each memory
      controller
	Pro: Can tune the amount of mirror and keep NUMA performance
	Con: I have to write memory management code to implement

The current plan is just to use mirrored memory for kernel allocations.
This has been broken into two phases:

1) This patch series - find the mirrored memory, use it for boot time
   allocations

2) Wade into mm/page_alloc.c and define a ZONE_MIRROR to pick up the
   unused mirrored memory from mm/memblock.c and only give it out to
   select kernel allocations (this is still being scoped because
   page_alloc.c is scary).

This patch (of 3):

Add extra "flags" to memblock to allow selection of memory based on
attribute.  No functional changes

Signed-off-by: Tony Luck 
Cc: Xishi Qiu 
Cc: Hanjun Guo 
Cc: Xiexiuqi 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Yinghai Lu 
Cc: Naoya Horiguchi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

e820, efi: add ACPI 6.0 persistent memory types

2015-05-28T01:46:05+00:00

ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory.
Mark it "reserved" and allow it to be claimed by a persistent memory
device driver.

This definition is in addition to the Linux kernel's existing type-12
definition that was recently added in support of shipping platforms with
NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as
OEM reserved).

Note, /proc/iomem can be consulted for differentiating legacy
"Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory"
E820_PMEM.

Cc: Boaz Harrosh 
Cc: Ingo Molnar 
Cc: Christoph Hellwig 
Cc: Andrew Morton 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Jens Axboe 
Cc: Linus Torvalds 
Cc: Matthew Wilcox 
Cc: Thomas Gleixner 
Acked-by: Jeff Moyer 
Acked-by: Andy Lutomirski 
Reviewed-by: Ross Zwisler 
Acked-by: Christoph Hellwig 
Tested-by: Toshi Kani 
Signed-off-by: Dan Williams

Merge branch 'x86-pmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-18T15:42:49+00:00

Pull PMEM driver from Ingo Molnar:
 "This is the initial support for the pmem block device driver:
  persistent non-volatile memory space mapped into the system's physical
  memory space as large physical memory regions.

  The driver is based on Intel code, written by Ross Zwisler, with fixes
  by Boaz Harrosh, integrated with x86 e820 memory resource management
  and tidied up by Christoph Hellwig.

  Note that there were two other separate pmem driver submissions to
  lkml: but apparently all parties (Ross Zwisler, Boaz Harrosh) are
  reasonably happy with this initial version.

  This version enables minimal support that enables persistent memory
  devices out in the wild to work as block devices, identified through a
  magic (non-standard) e820 flag and auto-discovered if
  CONFIG_X86_PMEM_LEGACY=y, or added explicitly through manipulating the
  memory maps via the "memmap=..." boot option with the new, special '!'
  modifier character.

  Limitations: this is a regular block device, and since the pmem areas
  are not struct page backed, they are invisible to the rest of the
  system (other than the block IO device), so direct IO to/from pmem
  areas, direct mmap() or XIP is not possible yet.  The page cache will
  also shadow and double buffer pmem contents, etc.

  Initial support is for x86"

* 'x86-pmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  drivers/block/pmem: Fix 32-bit build warning in pmem_alloc()
  drivers/block/pmem: Add a driver for persistent memory
  x86/mm: Add support for the non-standard protected e820 type

x86/mm: Add support for the non-standard protected e820 type

2015-04-01T15:02:43+00:00

Various recent BIOSes support NVDIMMs or ADR using a
non-standard e820 memory type, and Intel supplied reference
Linux code using this type to various vendors.

Wire this e820 table type up to export platform devices for the
pmem driver so that we can use it in Linux.

Based on earlier work from:

   Dave Jiang 
   Dan Williams 

Includes fixes for NUMA regions from Boaz Harrosh.

Tested-by: Ross Zwisler 
Signed-off-by: Christoph Hellwig 
Acked-by: Dan Williams 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Boaz Harrosh 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Jens Axboe 
Cc: Jens Axboe 
Cc: Keith Busch 
Cc: Linus Torvalds 
Cc: Matthew Wilcox 
Cc: Thomas Gleixner 
Cc: linux-nvdimm@ml01.01.org
Link: http://lkml.kernel.org/r/1427872339-6688-2-git-send-email-hch@lst.de
[ Minor cleanups. ]
Signed-off-by: Ingo Molnar

x86/mm: Use early_memunmap() instead of early_iounmap()

2015-02-24T14:58:06+00:00

Memory mapped via early_memremap() should be unmapped with
early_memunmap() instead of early_iounmap().

Signed-off-by: Juergen Gross 
Cc: matt.fleming@intel.com
Link: http://lkml.kernel.org/r/1424769211-11378-2-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar

x86, e820: Clean up sanitize_e820_map() users

2015-01-23T15:14:27+00:00

The argument 3 of sanitize_e820_map() will only be updated upon a
successful sanitization. Some of the callers have extra conditionals
for the same purpose. Clean them up.

default_machine_specific_memory_setup() must keep the extra
conditional because boot_params.e820_entries is an u8 and not an u32,
so the direct update would overwrite other fields in boot_params.

[ tglx: Massaged changelog ]

Signed-off-by: WANG Chao 
Acked-by: David Rientjes 
Cc: Grygorii Strashko 
Cc: Pavel Machek 
Cc: Lee Chun-Yi 
Cc: Xishi Qiu 
Link: http://lkml.kernel.org/r/1420601859-18439-1-git-send-email-chaowang@redhat.com
Signed-off-by: Thomas Gleixner

x86/mm: Use min() instead of min_t() in the e820 printout code

2014-12-11T10:35:02+00:00

The type of "MAX_DMA_PFN" and "xXx_pfn" are both unsigned long
now, so use min() instead of min_t().

Suggested-by: Andrew Morton 
Signed-off-by: Xishi Qiu 
Cc: Linux MM 
Cc: 
Cc: Rik van Riel 
Link: http://lkml.kernel.org/r/5487AB3F.7050807@huawei.com
Signed-off-by: Ingo Molnar

x86/mm, hibernate: Do not assume the first e820 area to be RAM

2014-09-16T07:54:31+00:00

In arch/x86/kernel/setup.c::trim_bios_range(), the codes
introduced by 1b5576e6 (base on d8a9e6a5), it updates the first
4Kb of memory to be E820_RESERVED region. That's because it's a
BIOS owned area but generally not listed in the E820 table:

  e820: BIOS-provided physical RAM map:
  BIOS-e820: [mem 0x0000000000000000-0x0000000000096fff] usable
  BIOS-e820: [mem 0x0000000000097000-0x0000000000097fff] reserved
  ...
  e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
  e820: remove [mem 0x000a0000-0x000fffff] usable

But the region of first 4Kb didn't register to nosave memory:

  PM: Registered nosave memory: [mem 0x00097000-0x00097fff]
  PM: Registered nosave memory: [mem 0x000a0000-0x000fffff]

The code in e820_mark_nosave_regions() assumes the first e820
area to be RAM, so it causes the first 4Kb E820_RESERVED region
ignored when register to nosave. This patch removed assumption
of the first e820 area.

Signed-off-by: Lee, Chun-Yi 
Acked-by: Pavel Machek 
Cc: "Rafael J. Wysocki" 
Cc: Len Brown 
Cc: "H. Peter Anvin" 
Cc: Linus Torvalds 
Cc: Yinghai Lu 
Cc: Takashi Iwai 
Link: http://lkml.kernel.org/r/1410491038-17576-1-git-send-email-jlee@suse.com
Signed-off-by: Ingo Molnar

x86/mm: memblock: switch to use NUMA_NO_NODE

2014-01-22T00:19:47+00:00

Update X86 code to use NUMA_NO_NODE instead of MAX_NUMNODES while
calling memblock APIs, because memblock API will be changed to use
NUMA_NO_NODE and will produce warning during boot otherwise.

See:
 https://lkml.org/lkml/2013/12/9/898

Signed-off-by: Grygorii Strashko 
Cc: Santosh Shilimkar 
Cc: Stephen Rothwell 
Cc: Tejun Heo 
Cc: Yinghai Lu 
Acked-by: David Rientjes 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds