block: sed-opal: kmalloc the cmd/resp buffers
authorSerge Semin <Sergey.Semin@baikalelectronics.ru>
Mon, 7 Nov 2022 20:39:44 +0000 (23:39 +0300)
committerJens Axboe <axboe@kernel.dk>
Tue, 8 Nov 2022 14:14:35 +0000 (07:14 -0700)
commitf829230dd51974c1f4478900ed30bb77ba530b40
tree6e892c9c2422352dc1d4991605fff2dad47fb32d
parentf02be9002c480cd3ec0fcf184ad27cf531bd6ece
block: sed-opal: kmalloc the cmd/resp buffers

In accordance with [1] the DMA-able memory buffers must be
cacheline-aligned otherwise the cache writing-back and invalidation
performed during the mapping may cause the adjacent data being lost. It's
specifically required for the DMA-noncoherent platforms [2]. Seeing the
opal_dev.{cmd,resp} buffers are implicitly used for DMAs in the NVME and
SCSI/SD drivers in framework of the nvme_sec_submit() and sd_sec_submit()
methods respectively they must be cacheline-aligned to prevent the denoted
problem. One of the option to guarantee that is to kmalloc the buffers
[2]. Let's explicitly allocate them then instead of embedding into the
opal_dev structure instance.

Note this fix was inspired by the commit c94b7f9bab22 ("nvme-hwmon:
kmalloc the NVME SMART log buffer").

[1] Documentation/core-api/dma-api.rst
[2] Documentation/core-api/dma-api-howto.rst

Fixes: 455a7b238cd6 ("block: Add Sed-opal library")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221107203944.31686-1-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/sed-opal.c