Hi Robin,
On 07/17/2017 04:43 PM, Robin Murphy wrote:
> 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.
>
Thanks, didn't knew of the header. This should take care of the
compilation errors i was seeing. There's one problem though: these
handle byte-ordering and i need raw accessors. :-(
---
Best Regards, Laurentiu
>> 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);
>> }
>>
>> /**
>>
>
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