On 17/07/17 14:26, laurentiu.tudor@xxxxxxx wrote: > From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx> > > Split the 64-bit accesses in 32-bit accesses because there's no real > constrain in MC to do only atomic 64-bit. There's only one place > where ordering is important: when writing the MC command header the > first 32-bit part of the header must be written last. > We do this switch in order to allow compiling the driver on 32-bit. #include <linux/io-64-nonatomic-hi-lo.h> Then you can just use writeq()/writeq_relaxed()/readq_relaxed() on 32-bit platforms as well. Robin. > Signed-off-by: Laurentiu Tudor <laurentiu.tudor@xxxxxxx> > --- > drivers/staging/fsl-mc/bus/mc-sys.c | 31 ++++++++++++------------------- > 1 file changed, 12 insertions(+), 19 deletions(-) > > diff --git a/drivers/staging/fsl-mc/bus/mc-sys.c b/drivers/staging/fsl-mc/bus/mc-sys.c > index 195d9f3..dd2828e 100644 > --- a/drivers/staging/fsl-mc/bus/mc-sys.c > +++ b/drivers/staging/fsl-mc/bus/mc-sys.c > @@ -124,14 +124,15 @@ static inline void mc_write_command(struct mc_command __iomem *portal, > { > int i; > > - /* 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(); > - > - /* submit the command by writing the header */ > - __raw_writeq(cmd->header, &portal->header); > + /* > + * copy command parameters into the portal. Final write > + * triggers the submission of the command. > + */ > + for (i = sizeof(struct mc_command) / sizeof(u32) - 1; i >= 0; i--) { > + __raw_writel(((u32 *)cmd)[i], &((u32 *)portal)[i]); > + /* ensure command params are committed before submitting it */ > + wmb(); > + } > } > > /** > @@ -148,19 +149,11 @@ static inline enum mc_cmd_status mc_read_response(struct mc_command __iomem * > struct mc_command *resp) > { > int i; > - enum mc_cmd_status status; > - > - /* Copy command response header from MC portal: */ > - resp->header = __raw_readq(&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]); > + for (i = 0; i < sizeof(struct mc_command) / sizeof(u32); i++) > + ((u32 *)resp)[i] = __raw_readl(&((u32 *)portal)[i]); > > - return status; > + return mc_cmd_hdr_read_status(resp); > } > > /** > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel