From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Some architecture like ARM assign masterIDs statically at the HW design phase, making masterID manipulation in the generic STM core irrelevant. This patch adds a new 'mstatic' flag to struct stm_data that tells the core that this specific STM device doesn't need explicit masterID management. In the core sw_start/end of masterID are set to '1', i.e there is only one masterID to deal with. Also this patch depends on [1], so that the number of masterID is '1' too. Finally the lower and upper bound for masterIDs as presented in ($SYSFS)/class/stm/XYZ.stm/masters and ($SYSFS)/../stp-policy/XYZ.stm.my_policy/some_device/masters are set to '-1'. That way users can't confuse them with architecture where masterID management is required (where any other value would be valid). [1] https://lkml.org/lkml/2015/12/22/348 Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx> --- drivers/hwtracing/stm/core.c | 18 ++++++++++++++++-- drivers/hwtracing/stm/policy.c | 19 +++++++++++++++++-- include/linux/stm.h | 8 ++++++++ 3 files changed, 41 insertions(+), 4 deletions(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 86bb4e3..cd3dc19 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -44,9 +44,15 @@ static ssize_t masters_show(struct device *dev, char *buf) { struct stm_device *stm = to_stm_device(dev); - int ret; + int ret, sw_start, sw_end; + + sw_start = stm->data->sw_start; + sw_end = stm->data->sw_end; - ret = sprintf(buf, "%u %u\n", stm->data->sw_start, stm->data->sw_end); + if (stm->data->mstatic) + sw_start = sw_end = STM_STATIC_MASTERID; + + ret = sprintf(buf, "%d %d\n", sw_start, sw_end); return ret; } @@ -629,7 +635,15 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data, if (!stm_data->packet || !stm_data->sw_nchannels) return -EINVAL; + /* + * MasterIDs are statically set in HW. As such the core is + * using a single master for interaction with this device. + */ + if (stm_data->mstatic) + stm_data->sw_start = stm_data->sw_end = 1; + nmasters = stm_data->sw_end - stm_data->sw_start; + stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL); if (!stm) return -ENOMEM; diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c index 691686e..7e70ca2 100644 --- a/drivers/hwtracing/stm/policy.c +++ b/drivers/hwtracing/stm/policy.c @@ -80,10 +80,17 @@ static ssize_t stp_policy_node_masters_show(struct config_item *item, char *page) { struct stp_policy_node *policy_node = to_stp_policy_node(item); + struct stm_device *stm = policy_node->policy->stm; + int first_master, last_master; ssize_t count; - count = sprintf(page, "%u %u\n", policy_node->first_master, - policy_node->last_master); + first_master = policy_node->first_master; + last_master = policy_node->last_master; + + if (stm && stm->data->mstatic) + first_master = last_master = STM_STATIC_MASTERID; + + count = sprintf(page, "%d %d\n", first_master, last_master); return count; } @@ -106,6 +113,13 @@ stp_policy_node_masters_store(struct config_item *item, const char *page, if (!stm) goto unlock; + /* + * masterIDs are statically allocated in HW, no point in trying to + * change their values. + */ + if (stm->data->mstatic) + goto unlock; + /* must be within [sw_start..sw_end], which is an inclusive range */ if (first > INT_MAX || last > INT_MAX || first > last || first < stm->data->sw_start || @@ -325,6 +339,7 @@ stp_policies_make(struct config_group *group, const char *name) * number of dot(s) are found in the <device_name>, the * first matched STM device name would be extracted. */ + for (p = devname; ; p++) { p = strchr(p, '.'); if (!p) { diff --git a/include/linux/stm.h b/include/linux/stm.h index f351d62..c9712a7 100644 --- a/include/linux/stm.h +++ b/include/linux/stm.h @@ -18,6 +18,11 @@ #include <linux/device.h> /** + * The masterIDs are statically set in hardware and can't be queried + */ +#define STM_STATIC_MASTERID -1 + +/** * enum stp_packet_type - STP packets that an STM driver sends */ enum stp_packet_type { @@ -46,6 +51,8 @@ struct stm_device; * struct stm_data - STM device description and callbacks * @name: device name * @stm: internal structure, only used by stm class code + * @mstatic: true if masterIDs are assigned in HW. If so @sw_start + * and @sw_end are set to '1' by the core. * @sw_start: first STP master available to software * @sw_end: last STP master available to software * @sw_nchannels: number of STP channels per master @@ -71,6 +78,7 @@ struct stm_device; struct stm_data { const char *name; struct stm_device *stm; + bool mstatic; unsigned int sw_start; unsigned int sw_end; unsigned int sw_nchannels; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
