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Commit b064d0e6 authored by Laurentiu Tudor's avatar Laurentiu Tudor Committed by Greg Kroah-Hartman
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staging: fsl-mc: don't use raw device io functions 



As raw device io functions are not portable and don't handle byte-order
(triggering suspicion that endianness isn't handled well) switch to
using the standard api.
Since MC expects LE byte-order and the upper layers already take care
of that, we need to trick the device io api by doing a LE -> CPU
conversion just before calling it. This way, the CPU -> LE conversion
done in the api puts the data back in the right byte-order. Obviously,
for reads the extra step is mirrored: there's a CPU -> LE conversion
following the API call.

Signed-off-by: default avatarLaurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f1027a8c

drivers/staging/fsl-mc/bus/mc-sys.c

+15 −6
Original line number Diff line number Diff line
@@ -126,12 +126,15 @@ static inline void mc_write_command(struct mc_command __iomem *portal, 


	/* copy command parameters into the portal */

	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)

		__raw_writeq(cmd->params[i], &portal->params[i]);

	/* ensure command params are committed before submitting it */

	wmb();

		/*

		 * Data is already in the expected LE byte-order. Do an

		 * extra LE -> CPU conversion so that the CPU -> LE done in

		 * the device io write api puts it back in the right order.

		 */

		writeq_relaxed(le64_to_cpu(cmd->params[i]), &portal->params[i]);



	/* submit the command by writing the header */

	__raw_writeq(cmd->header, &portal->header);

	writeq(le64_to_cpu(cmd->header), &portal->header);

}



/**
@@ -151,14 +154,20 @@ static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem * 
	enum mc_cmd_status status;



	/* Copy command response header from MC portal: */

	resp->header = __raw_readq(&portal->header);

	resp->header = cpu_to_le64(readq_relaxed(&portal->header));

	status = mc_cmd_hdr_read_status(resp);

	if (status != MC_CMD_STATUS_OK)

		return status;



	/* Copy command response data from MC portal: */

	for (i = 0; i < MC_CMD_NUM_OF_PARAMS; i++)

		resp->params[i] = __raw_readq(&portal->params[i]);

		/*

		 * Data is expected to be in LE byte-order. Do an

		 * extra CPU -> LE to revert the LE -> CPU done in

		 * the device io read api.

		 */

		resp->params[i] =

			cpu_to_le64(readq_relaxed(&portal->params[i]));



	return status;

}