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block: sed-opal: kmalloc the cmd/resp buffers

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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 c94b7f9bab ("nvme-hwmon:
kmalloc the NVME SMART log buffer").

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

Fixes: 455a7b238c ("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>
This commit is contained in:
Serge Semin 2022-11-07 23:39:44 +03:00 committed by Jens Axboe
parent f02be9002c
commit f829230dd5
1 changed files with 28 additions and 4 deletions
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32
block/sed-opal.c
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@ -87,8 +87,8 @@ struct opal_dev {
u64 lowest_lba;
size_t pos;
u8 cmd[IO_BUFFER_LENGTH];
u8 resp[IO_BUFFER_LENGTH];
u8 *cmd;
u8 *resp;
struct parsed_resp parsed;
size_t prev_d_len;
@ -2175,6 +2175,8 @@ void free_opal_dev(struct opal_dev *dev)
return;
clean_opal_dev(dev);
kfree(dev->resp);
kfree(dev->cmd);
kfree(dev);
}
EXPORT_SYMBOL(free_opal_dev);
@ -2187,6 +2189,18 @@ struct opal_dev *init_opal_dev(void *data, sec_send_recv *send_recv)
if (!dev)
return NULL;
/*
* Presumably DMA-able buffers must be cache-aligned. Kmalloc makes
* sure the allocated buffer is DMA-safe in that regard.
*/
dev->cmd = kmalloc(IO_BUFFER_LENGTH, GFP_KERNEL);
if (!dev->cmd)
goto err_free_dev;
dev->resp = kmalloc(IO_BUFFER_LENGTH, GFP_KERNEL);
if (!dev->resp)
goto err_free_cmd;
INIT_LIST_HEAD(&dev->unlk_lst);
mutex_init(&dev->dev_lock);
dev->flags = 0;
@ -2194,11 +2208,21 @@ struct opal_dev *init_opal_dev(void *data, sec_send_recv *send_recv)
dev->send_recv = send_recv;
if (check_opal_support(dev) != 0) {
pr_debug("Opal is not supported on this device\n");
kfree(dev);
return NULL;
goto err_free_resp;
}
return dev;
err_free_resp:
kfree(dev->resp);
err_free_cmd:
kfree(dev->cmd);
err_free_dev:
kfree(dev);
return NULL;
}
EXPORT_SYMBOL(init_opal_dev);