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Subject[PATCH 6/7] staging: fsl-mc: rewrite mc command send/receive to work on 32-bits
Date
From: Laurentiu Tudor <laurentiu.tudor@nxp.com>

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.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
---
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);
}

/**
--
2.9.4
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