linux-toradex.git/drivers/nvdimm/label.c, branch v4.20-rc7

libnvdimm, label: Fix sparse warning

2018-10-12T15:39:41+00:00

The kbuild robot reports:

drivers/nvdimm/label.c:500:32: warning: restricted __le32 degrades to integer

...read 'nslot' into a local u32.

Reported-by: kbuild test robot 
Acked-by: Alexander Duyck 
Signed-off-by: Dan Williams

nvdimm: Use namespace index data to reduce number of label reads needed

2018-10-12T15:39:31+00:00

This patch adds logic that is meant to make use of the namespace index data
to reduce the number of reads that are needed to initialize a given
namespace. The general idea is that once we have enough data to validate
the namespace index we do so and then proceed to fetch only those labels
that are not listed as being "free". By doing this I am seeing a total time
reduction from about 4-5 seconds to 2-3 seconds for 24 NVDIMM modules each
with 128K of label config area.

Reviewed-by: Toshi Kani 
Signed-off-by: Alexander Duyck 
Signed-off-by: Dan Williams

nvdimm: Split label init out from the logic for getting config data

2018-10-12T15:39:24+00:00

This patch splits the initialization of the label data into two functions.
One for doing the init, and another for reading the actual configuration
data. The idea behind this is that by doing this we create a symmetry
between the getting and setting of config data in that we have a function
for both. In addition it will make it easier for us to identify the bits
that are related to init versus the pieces that are a wrapper for reading
data from the ACPI interface.

So for example by splitting things out like this it becomes much more
obvious that we were performing checks that weren't necessarily related to
the set/get operations such as relying on ndd->data being present when the
set and get ops should not care about a locally cached copy of the label
area.

Reviewed-by: Toshi Kani 
Signed-off-by: Alexander Duyck 
Signed-off-by: Dan Williams

nvdimm: Remove empty if statement

2018-10-12T15:39:15+00:00

This patch removes an empty statement from an if expression and promotes
the else statement to the if expression with the expression logic reversed.

I feel this is more readable as the empty statement can lead to issues if
any additional logic was ever added.

Reviewed-by: Toshi Kani 
Signed-off-by: Alexander Duyck 
Signed-off-by: Dan Williams

nvdimm: Clarify comment in sizeof_namespace_index

2018-10-12T15:39:10+00:00

When working on the label code I found it rather confusing to see several
spots that reference a minimum label size of 256 while working with labels
that are 128 bytes in size.

This patch is meant to provide a clarification on one of the comments that
was at the heart of the issue. Specifically for version 1.2 and later of
the namespace specification the minimum label size is 256, prior to that
the minimum label size was 128. So we should state that as such to avoid
confusion.

Reviewed-by: Toshi Kani 
Signed-off-by: Alexander Duyck 
Signed-off-by: Dan Williams

nvdimm: Sanity check labeloff

2018-10-12T15:38:53+00:00

This patch adds validation for the labeloff field in the indexes.

Reviewed-by: Toshi Kani 
Signed-off-by: Alexander Duyck 
Signed-off-by: Dan Williams

libnvdimm, label: change nvdimm_num_label_slots per UEFI 2.7

2018-03-15T20:59:57+00:00

sizeof_namespace_index() fails when NVDIMM devices have the minimum
1024 bytes label storage area.  nvdimm_num_label_slots() returns 3
slots while the area is only big enough for 2 slots.

Change nvdimm_num_label_slots() to calculate a number of label slots
according to UEFI 2.7 spec.

Signed-off-by: Toshi Kani 
Signed-off-by: Dan Williams

libnvdimm: remove redundant func in dev_dbg

2018-03-06T16:44:17+00:00

Dynamic debug can be instructed to add the function name to the debug
output using the +f switch, so there is no need for the libnvdimm
modules to do it again. If a user decides to add the +f switch for
libnvdimm's dynamic debug this results in double prints of the function
name.

Reported-by: Johannes Thumshirn 
Reported-by: Ross Zwisler 
Signed-off-by: Dan Williams

libnvdimm, namespace: fix label initialization to use valid seq numbers

2017-09-28T16:13:06+00:00

The set of valid sequence numbers is {1,2,3}. The specification
indicates that an implementation should consider 0 a sign of a critical
error:

    UEFI 2.7: 13.19 NVDIMM Label Protocol

    Software never writes the sequence number 00, so a correctly
    check-summed Index Block with this sequence number probably indicates a
    critical error. When software discovers this case it treats it as an
    invalid Index Block indication.

While the expectation is that the invalid block is just thrown away, the
Robustness Principle says we should fix this to make both sequence
numbers valid.

Fixes: f524bf271a5c ("libnvdimm: write pmem label set")
Cc: 
Reported-by: Juston Li 
Signed-off-by: Dan Williams

libnvdimm, label: fix index block size calculation

2017-08-30T01:28:18+00:00

The old calculation assumed that the label space was 128k and the label
size is 128. With v1.2 labels where the label size is 256 this
calculation will return zero. We are saved by the fact that the
nsindex_size is always pre-initialized from a previous 128 byte
assumption and we are lucky that the index sizes turn out the same.

Fix this going forward in case we start encountering different
geometries of label areas besides 128k.

Since the label size can change from one call to the next, drop the
caching of nsindex_size.

Signed-off-by: Dan Williams