[QUEUED v0 17/19] stm class: dummy_stm: Create multiple devices

From: Alexander Shishkin
Date: Fri Feb 05 2016 - 11:43:23 EST


STM framework should be able to handle multiple STM devices at a time,
each one with its own master allocation policy.

This patch changes dummy_stm driver to create multiple STM sinks to
help testing the framework.

Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
---
drivers/hwtracing/stm/dummy_stm.c | 55 ++++++++++++++++++++++++++++++++-------
1 file changed, 46 insertions(+), 9 deletions(-)

diff --git a/drivers/hwtracing/stm/dummy_stm.c b/drivers/hwtracing/stm/dummy_stm.c
index 3709bef0b2..93de609688 100644
--- a/drivers/hwtracing/stm/dummy_stm.c
+++ b/drivers/hwtracing/stm/dummy_stm.c
@@ -40,22 +40,59 @@ dummy_stm_packet(struct stm_data *stm_data, unsigned int master,
return size;
}

-static struct stm_data dummy_stm = {
- .name = "dummy_stm",
- .sw_start = 0x0000,
- .sw_end = 0xffff,
- .sw_nchannels = 0xffff,
- .packet = dummy_stm_packet,
-};
+#define DUMMY_STM_MAX 32
+
+static struct stm_data dummy_stm[DUMMY_STM_MAX];
+
+static int nr_dummies = 4;
+
+module_param(nr_dummies, int, 0600);
+
+static unsigned int dummy_stm_nr;

static int dummy_stm_init(void)
{
- return stm_register_device(NULL, &dummy_stm, THIS_MODULE);
+ int i, ret = -ENOMEM, __nr_dummies = ACCESS_ONCE(nr_dummies);
+
+ if (__nr_dummies < 0 || __nr_dummies > DUMMY_STM_MAX)
+ return -EINVAL;
+
+ for (i = 0; i < __nr_dummies; i++) {
+ dummy_stm[i].name = kasprintf(GFP_KERNEL, "dummy_stm.%d", i);
+ if (!dummy_stm[i].name)
+ goto fail_unregister;
+
+ dummy_stm[i].sw_start = 0x0000;
+ dummy_stm[i].sw_end = 0xffff;
+ dummy_stm[i].sw_nchannels = 0xffff;
+ dummy_stm[i].packet = dummy_stm_packet;
+
+ ret = stm_register_device(NULL, &dummy_stm[i], THIS_MODULE);
+ if (ret)
+ goto fail_free;
+ }
+
+ dummy_stm_nr = __nr_dummies;
+
+ return 0;
+
+fail_unregister:
+ for (i--; i >= 0; i--) {
+ stm_unregister_device(&dummy_stm[i]);
+fail_free:
+ kfree(dummy_stm[i].name);
+ }
+
+ return ret;
+
}

static void dummy_stm_exit(void)
{
- stm_unregister_device(&dummy_stm);
+ int i;
+
+ for (i = 0; i < dummy_stm_nr; i++)
+ stm_unregister_device(&dummy_stm[i]);
}

module_init(dummy_stm_init);
--
2.7.0