Recent patches added basic support for the Apple NVMe controller but
still cause resets and data corruption on that particular controller
when a specific pattern of read/flush commands occurs. Limiting the
queue depth to 2 works around that issue.

This patch enforces that limit only for the Apple controller and is
considered a temporary fix until we find the root source of that
problem.

Signed-off-by: Stephan Günther <guenther@tum.de>
Signed-off-by: Maurice Leclaire <leclaire@in.tum.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

The get_bb_tbl function takes ppa as a generic address, which is
converted to the ppa device address within the device driver. When
the update_bbtbl callback is called from get_bb_tbl, the device
specific ppa is used, instead of the generic ppa.

Make sure to pass the generic ppa.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

The QEMU NVMe implementation uses Intel vendor, Intel device id, and the
first vendor specific byte to identify a LightNVM compatible nvme
instance.

Instead of using the Intel specific, use a preallocated from CNEX Labs
instead. This lets us uniquely identify a QEMU lightnvm device without
breaking other vendor specific work in the qemu device driver.

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

We shouldn't compile an object file to get empty implementations;
conforms to linux coding style on conditional compilation.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

When we fail various metadata related operations in nvme_queue_rq we
need to unmap the data SGL.

Cc: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

We received a bug report recently when DDW (64-bit direct DMA on Power)
is not enabled for NVMe devices. In that case, we fall back to 32-bit
DMA via the IOMMU, which is always done via 4K TCEs (Translation Control
Entries).

The NVMe device driver, though, assumes that the DMA alignment for the
PRP entries will match the device's page size, and that the DMA aligment
matches the kernel's page aligment. On Power, the the IOMMU page size,
as mentioned above, can be 4K, while the device can have a page size of
8K, while the kernel has a page size of 64K. This eventually trips the
BUG_ON in nvme_setup_prps(), as we have a 'dma_len' that is a multiple
of 4K but not 8K (e.g., 0xF000).

In this particular case of page sizes, we clearly want to use the
IOMMU's page size in the driver. And generally, the NVMe driver in this
function should be using the IOMMU's page size for the default device
page size, rather than the kernel's page size. There is not currently an
API to obtain the IOMMU's page size across all architectures and in the
interest of a stop-gap fix to this functional issue, default the NVMe
device page size to 4K, with the intent of adding such an API and
implementation across all architectures in the next merge window.

With the functionally equivalent v3 of this patch, our hardware test
exerciser survives when using 32-bit DMA; without the patch, the kernel
will BUG within a few minutes.

Signed-off-by: Nishanth Aravamudan <nacc at linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

Make sure that there are no unprocesssed entries on a completion
queue before deleting it, and check for validity of the CQ
door bell before writing completions to it.

This fixes problems with doing a sysfs reset of the device while
it's handling IO.

Tested-by: Jon Derrick <jonathan.derrick@intel.com>

Signed-off-by: Jens Axboe <axboe@fb.com>

According to the Open-Channel SSD Specification, the NVMe-NVM admin
commands use vendor specific opcodes of NVMe, so use the NVMe admin
queue to dispatch these commands.

Signed-off-by: Wenwei Tao <ww.tao0320@gmail.com>
Updated by me to include set bad block table as well and also use
the admin queue for l2p len calculation.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

Reported-by: Paul Grabinar <paul.grabinar@ranbarg.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

The specification was updated the remove the double word just after
number of configuration groups and capabilities. Update the identify
structure to reflect it.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>