From b064d0e6e42ed4774c42bfbec0db60f8249a9de2 Mon Sep 17 00:00:00 2001 From: Laurentiu Tudor Date: Wed, 19 Jul 2017 14:42:30 +0300 Subject: [PATCH] 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: Laurentiu Tudor Acked-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- drivers/staging/fsl-mc/bus/mc-sys.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/staging/fsl-mc/bus/mc-sys.c b/drivers/staging/fsl-mc/bus/mc-sys.c index 195d9f3..8a6dc47 100644 --- a/drivers/staging/fsl-mc/bus/mc-sys.c +++ b/drivers/staging/fsl-mc/bus/mc-sys.c @@ -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; } -- 2.7.4