The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200319230737.GA16452@embeddedor.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of version 2 of the gnu general public license as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 64 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several places (dimm_devs.c, core.c etc) include label.h but only
label.c uses NSINDEX_SIGNATURE, so move its definition to label.c
instead.
In file included from drivers/nvdimm/dimm_devs.c:23:
drivers/nvdimm/label.h:41:19: warning: 'NSINDEX_SIGNATURE' defined but
not used [-Wunused-const-variable=]
Also, some places abuse "/**" which is only reserved for the kernel-doc.
drivers/nvdimm/bus.c:648: warning: cannot understand function prototype:
'struct attribute_group nd_device_attribute_group = '
drivers/nvdimm/bus.c:677: warning: cannot understand function prototype:
'struct attribute_group nd_numa_attribute_group = '
Those are just some member assignments for the "struct attribute_group"
instances and it can't be expressed in the kernel-doc.
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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 <toshi.kani@hpe.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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 <toshi.kani@hpe.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
UEFI 2.7 defines in page 758 that:
Initial Label Storage Area Configuration
:
The minimum size of the Label Storage Area is large enough to
hold 2 index blocks and 2 labels.
The mininum index block size is 256 bytes, and the minimum label size
is also 256 bytes.
Change ND_LABEL_MIN_SIZE to (256 * 4) so that NVDIMM devices with
the minimum label storage area do not fail with the size check in
nvdimm_init_config_data().
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The UEFI 2.7 specification defines an updated BTT metadata format,
bumping the revision to 2.0. Add support for the new format, while
retaining compatibility for the old 1.1 format.
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Linda Knippers <linda.knippers@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Starting with v1.2 labels, 'address abstractions' can be hinted via an
address abstraction id that implies an info-block format. The standard
address abstraction in the specification is the v2 format of the
Block-Translation-Table (BTT). Support for that is saved for a later
patch, for now we add support for the Linux supported address
abstractions BTT (v1), PFN, and DAX.
The new 'holder_class' attribute for namespace devices is added for
tooling to specify the 'abstraction_guid' to store in the namespace label.
For v1.1 labels this field is undefined and any setting of
'holder_class' away from the default 'none' value will only have effect
until the driver is unloaded. Setting 'holder_class' requires that
whatever device tries to claim the namespace must be of the specified
class.
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In support of improved interoperability between operating systems and pre-boot
environments the Intel proposed NVDIMM Namespace Specification [1], has been
adopted and modified to the the UEFI 2.7 NVDIMM Label Protocol [2].
Update the definitions of the namespace label data structures so that the new
format can be supported alongside the existing label format.
The new specification changes the default label size to 256 bytes, so
everywhere that relied on sizeof(struct nd_namespace_label) must now use the
sizeof_namespace_label() helper.
There should be no functional differences from these changes as the
default is still the v1.1 128-byte format. Future patches will move the
default to the v1.2 definition.
[1]: http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf
[2]: http://www.uefi.org/sites/default/files/resources/UEFI_Spec_2_7.pdf
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
After 'uuid', 'size', 'sector_size', and optionally 'alt_name' have been
set to valid values the labels on the dimm can be updated. The
difference with the pmem case is that blk namespaces are limited to one
dimm and can cover discontiguous ranges in dpa space.
Also, after allocating label slots, it is useful for userspace to know
how many slots are left. Export this information in sysfs.
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
After 'uuid', 'size', and optionally 'alt_name' have been set to valid
values the labels on the dimms can be updated.
Write procedure is:
1/ Allocate and write new labels in the "next" index
2/ Free the old labels in the working copy
3/ Write the bitmap and the label space on the dimm
4/ Write the index to make the update valid
Label ranges directly mirror the dpa resource values for the given
label_id of the namespace.
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
A complete label set is a PMEM-label per-dimm per-interleave-set where
all the UUIDs match and the interleave set cookie matches the hosting
interleave set.
Present sysfs attributes for manipulation of a PMEM-namespace's
'alt_name', 'uuid', and 'size' attributes. A later patch will make
these settings persistent by writing back the label.
Note that PMEM allocations grow forwards from the start of an interleave
set (lowest dimm-physical-address (DPA)). BLK-namespaces that alias
with a PMEM interleave set will grow allocations backward from the
highest DPA.
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This on media label format [1] consists of two index blocks followed by
an array of labels. None of these structures are ever updated in place.
A sequence number tracks the current active index and the next one to
write, while labels are written to free slots.
+------------+
| |
| nsindex0 |
| |
+------------+
| |
| nsindex1 |
| |
+------------+
| label0 |
+------------+
| label1 |
+------------+
| |
....nslot...
| |
+------------+
| labelN |
+------------+
After reading valid labels, store the dpa ranges they claim into
per-dimm resource trees.
[1]: http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf
Cc: Neil Brown <neilb@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Gustavo A. R. Silva
Thomas Gleixner
Qian Cai
Alexander Duyck
Toshi Kani
Vishal Verma
Dan Williams