[PATCH 3/7] work_on_cpu: use on drivers/firmware/dcdbas.c

From: Rusty Russell
Date: Wed Oct 22 2008 - 20:58:05 EST



Use work_on_cpu instead of cpumask games.

Doug: note one subtle change. If we can't get to CPU 0 for some
reason, the return will be -EINVAL not -EBUSY.

Doug: want me to fix this in the caller? ie:

return work_on_cpu(0, generate_smi, smi_cmd) == 0 ? 0 : -EBUSY;

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: Douglas_Warzecha@xxxxxxxx
---
drivers/firmware/dcdbas.c | 46 +++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 27 deletions(-)

diff -r 155c7f2e2e30 drivers/firmware/dcdbas.c
--- a/drivers/firmware/dcdbas.c Thu Oct 23 11:22:04 2008 +1100
+++ b/drivers/firmware/dcdbas.c Thu Oct 23 11:23:38 2008 +1100
@@ -237,31 +237,9 @@ static ssize_t host_control_on_shutdown_
return count;
}

-/**
- * smi_request: generate SMI request
- *
- * Called with smi_data_lock.
- */
-static int smi_request(struct smi_cmd *smi_cmd)
+static long generate_smi(void *_smi_cmd)
{
- cpumask_t old_mask;
- int ret = 0;
-
- if (smi_cmd->magic != SMI_CMD_MAGIC) {
- dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
- __func__);
- return -EBADR;
- }
-
- /* SMI requires CPU 0 */
- old_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(0));
- if (smp_processor_id() != 0) {
- dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
- __func__);
- ret = -EBUSY;
- goto out;
- }
+ struct smi_cmd *smi_cmd = _smi_cmd;

/* generate SMI */
asm volatile (
@@ -273,10 +251,24 @@ static int smi_request(struct smi_cmd *s
"c" (smi_cmd->ecx)
: "memory"
);
+ return 0;
+}

-out:
- set_cpus_allowed_ptr(current, &old_mask);
- return ret;
+/**
+ * smi_request: generate SMI request
+ *
+ * Called with smi_data_lock.
+ */
+static int smi_request(struct smi_cmd *smi_cmd)
+{
+ if (smi_cmd->magic != SMI_CMD_MAGIC) {
+ dev_info(&dcdbas_pdev->dev, "%s: invalid magic value\n",
+ __func__);
+ return -EBADR;
+ }
+
+ /* SMI requires CPU 0 */
+ return work_on_cpu(0, generate_smi, smi_cmd);
}

/**

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