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Commit 6bb50c14 authored by Serge Semin's avatar Serge Semin Committed by Greg Kroah-Hartman
Browse files

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



[ Upstream commit f829230dd51974c1f4478900ed30bb77ba530b40 ]

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: 455a7b23 ("block: Add Sed-opal library")
Signed-off-by: default avatarSerge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221107203944.31686-1-Sergey.Semin@baikalelectronics.ru


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 8555c6c1

block/sed-opal.c

+28 −4
Original line number Diff line number Diff line
@@ -88,8 +88,8 @@ 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;
@@ -2019,6 +2019,8 @@ 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);
@@ -2031,17 +2033,39 @@ 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->data = data;

	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);