linux-toradex.git/drivers/nvdimm, branch v4.5-rc3

libnvdimm, pfn: fix restoring memmap location

2016-01-30T01:43:16+00:00

This path was missed when turning on the memmap in pmem support.  Permit
'pmem' as a valid location for the map.

Reported-by: Jeff Moyer 
Signed-off-by: Dan Williams

libnvdimm: fix mode determination for e820 devices

2016-01-26T17:40:32+00:00

Correctly display "safe" mode when a btt is established on a e820/memmap
defined pmem namespace.

Signed-off-by: Dan Williams

mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup

2016-01-16T01:56:32+00:00

get_dev_page() enables paths like get_user_pages() to pin a dynamically
mapped pfn-range (devm_memremap_pages()) while the resulting struct page
objects are in use.  Unlike get_page() it may fail if the device is, or
is in the process of being, disabled.  While the initial lookup of the
range may be an expensive list walk, the result is cached to speed up
subsequent lookups which are likely to be in the same mapped range.

devm_memremap_pages() now requires a reference counter to be specified
at init time.  For pmem this means moving request_queue allocation into
pmem_alloc() so the existing queue usage counter can track "device
pages".

ZONE_DEVICE pages always have an elevated count and will never be on an
lru reclaim list.  That space in 'struct page' can be redirected for
other uses, but for safety introduce a poison value that will always
trip __list_add() to assert.  This allows half of the struct list_head
storage to be reclaimed with some assurance to back up the assumption
that the page count never goes to zero and a list_add() is never
attempted.

Signed-off-by: Dan Williams 
Tested-by: Logan Gunthorpe 
Cc: Dave Hansen 
Cc: Matthew Wilcox 
Cc: Ross Zwisler 
Cc: Alexander Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

libnvdimm, pmem: move request_queue allocation earlier in probe

2016-01-16T01:56:32+00:00

Before the dynamically allocated struct pages from devm_memremap_pages()
can be put to use outside the driver, we need a mechanism to track
whether they are still in use at teardown.  Towards that goal reorder
the initialization sequence to allow the 'q_usage_counter' from the
request_queue to be used by the devm_memremap_pages() implementation (in
subsequent patches).

Signed-off-by: Dan Williams 
Cc: Ross Zwisler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

libnvdimm, pfn, pmem: allocate memmap array in persistent memory

2016-01-16T01:56:32+00:00

Use the new vmem_altmap capability to enable the pmem driver to arrange
for a struct page memmap to be established in persistent memory.

[linux@roeck-us.net: mn10300: declare __pfn_to_phys() to fix build error]
Signed-off-by: Dan Williams 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Ross Zwisler 
Signed-off-by: Guenter Roeck 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86, mm: introduce vmem_altmap to augment vmemmap_populate()

2016-01-16T01:56:32+00:00

In support of providing struct page for large persistent memory
capacities, use struct vmem_altmap to change the default policy for
allocating memory for the memmap array.  The default vmemmap_populate()
allocates page table storage area from the page allocator.  Given
persistent memory capacities relative to DRAM it may not be feasible to
store the memmap in 'System Memory'.  Instead vmem_altmap represents
pre-allocated "device pages" to satisfy vmemmap_alloc_block_buf()
requests.

Signed-off-by: Dan Williams 
Reported-by: kbuild test robot 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Dave Hansen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: introduce find_dev_pagemap()

2016-01-16T01:56:32+00:00

There are several scenarios where we need to retrieve and update
metadata associated with a given devm_memremap_pages() mapping, and the
only lookup key available is a pfn in the range:

1/ We want to augment vmemmap_populate() (called via arch_add_memory())
   to allocate memmap storage from pre-allocated pages reserved by the
   device driver.  At vmemmap_alloc_block_buf() time it grabs device pages
   rather than page allocator pages.  This is in support of
   devm_memremap_pages() mappings where the memmap is too large to fit in
   main memory (i.e. large persistent memory devices).

2/ Taking a reference against the mapping when inserting device pages
   into the address_space radix of a given inode.  This facilitates
   unmap_mapping_range() and truncate_inode_pages() operations when the
   driver is tearing down the mapping.

3/ get_user_pages() operations on ZONE_DEVICE memory require taking a
   reference against the mapping so that the driver teardown path can
   revoke and drain usage of device pages.

Signed-off-by: Dan Williams 
Tested-by: Logan Gunthorpe 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Ross Zwisler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, dax, pmem: introduce pfn_t

2016-01-16T01:56:32+00:00

For the purpose of communicating the optional presence of a 'struct
page' for the pfn returned from ->direct_access(), introduce a type that
encapsulates a page-frame-number plus flags.  These flags contain the
historical "page_link" encoding for a scatterlist entry, but can also
denote "device memory".  Where "device memory" is a set of pfns that are
not part of the kernel's linear mapping by default, but are accessed via
the same memory controller as ram.

The motivation for this new type is large capacity persistent memory
that needs struct page entries in the 'memmap' to support 3rd party DMA
(i.e.  O_DIRECT I/O with a persistent memory source/target).  However,
we also need it in support of maintaining a list of mapped inodes which
need to be unmapped at driver teardown or freeze_bdev() time.

Signed-off-by: Dan Williams 
Cc: Christoph Hellwig 
Cc: Dave Hansen 
Cc: Ross Zwisler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-4.5/block-dax' into for-4.5/libnvdimm

2016-01-10T15:53:55+00:00

libnvdimm, pmem: nvdimm_read_bytes() badblocks support

2016-01-10T06:42:31+00:00

Support badblock checking in all the pmem read paths that do not go
through the block layer.  This protects info block reads (btt or pfn) as
well as data reads to a pmem namespace via a btt instance.

Signed-off-by: Dan Williams