@@ -920,14 +920,16 @@ Description: This file shows whether the configuration descriptor is locked.
What: /sys/bus/platform/drivers/ufshcd/*/attributes/max_number_of_rtt
What: /sys/bus/platform/devices/*.ufs/attributes/max_number_of_rtt
-Date: February 2018
-Contact: Stanislav Nijnikov <stanislav.nijnikov@wdc.com>
+Date: May 2024
+Contact: Avri Altman <avri.altman@wdc.com>
Description: This file provides the maximum current number of
- outstanding RTTs in device that is allowed. The full
- information about the attribute could be found at
- UFS specifications 2.1.
+ outstanding RTTs in device that is allowed. bMaxNumOfRTT is a
+ read-write persistent attribute and is equal to two after device
+ manufacturing. It shall not be set to a value greater than
+ bDeviceRTTCap value, and it may be set only when the hw queues are
+ empty.
- The file is read only.
+ The file is read write.
What: /sys/bus/platform/drivers/ufshcd/*/attributes/exception_event_control
What: /sys/bus/platform/devices/*.ufs/attributes/exception_event_control
@@ -1340,6 +1340,77 @@ static const struct attribute_group ufs_sysfs_flags_group = {
.attrs = ufs_sysfs_device_flags,
};
+static ssize_t max_number_of_rtt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+ u32 rtt;
+ int ret;
+
+ down(&hba->host_sem);
+ if (!ufshcd_is_user_access_allowed(hba)) {
+ up(&hba->host_sem);
+ return -EBUSY;
+ }
+
+ ufshcd_rpm_get_sync(hba);
+ ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+ QUERY_ATTR_IDN_MAX_NUM_OF_RTT, 0, 0, &rtt);
+ ufshcd_rpm_put_sync(hba);
+
+ if (ret)
+ goto out;
+
+ ret = sysfs_emit(buf, "0x%08X\n", rtt);
+
+out:
+ up(&hba->host_sem);
+ return ret;
+}
+
+static ssize_t max_number_of_rtt_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+ struct ufs_dev_info *dev_info = &hba->dev_info;
+ unsigned int rtt;
+ int ret;
+
+ if (kstrtouint(buf, 0, &rtt))
+ return -EINVAL;
+
+ if (rtt > dev_info->rtt_cap) {
+ dev_err(dev, "rtt can be at most bDeviceRTTCap\n");
+ return -EINVAL;
+ }
+
+ down(&hba->host_sem);
+ if (!ufshcd_is_user_access_allowed(hba)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ufshcd_rpm_get_sync(hba);
+
+ /* make sure that there are no outstanding requests when rtt is set */
+ ufshcd_scsi_block_requests(hba);
+ blk_mq_wait_quiesce_done(&hba->host->tag_set);
+
+ ret = ufshcd_query_attr(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+ QUERY_ATTR_IDN_MAX_NUM_OF_RTT, 0, 0, &rtt);
+
+ ufshcd_scsi_unblock_requests(hba);
+
+ ufshcd_rpm_put_sync(hba);
+
+out:
+ up(&hba->host_sem);
+ return ret < 0 ? ret : count;
+}
+
+static DEVICE_ATTR_RW(max_number_of_rtt);
+
static inline bool ufshcd_is_wb_attrs(enum attr_idn idn)
{
return idn >= QUERY_ATTR_IDN_WB_FLUSH_STATUS &&
@@ -1387,7 +1458,6 @@ UFS_ATTRIBUTE(max_data_in_size, _MAX_DATA_IN);
UFS_ATTRIBUTE(max_data_out_size, _MAX_DATA_OUT);
UFS_ATTRIBUTE(reference_clock_frequency, _REF_CLK_FREQ);
UFS_ATTRIBUTE(configuration_descriptor_lock, _CONF_DESC_LOCK);
-UFS_ATTRIBUTE(max_number_of_rtt, _MAX_NUM_OF_RTT);
UFS_ATTRIBUTE(exception_event_control, _EE_CONTROL);
UFS_ATTRIBUTE(exception_event_status, _EE_STATUS);
UFS_ATTRIBUTE(ffu_status, _FFU_STATUS);
@@ -32,6 +32,18 @@ static inline bool ufshcd_is_wb_buf_flush_allowed(struct ufs_hba *hba)
!(hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL);
}
+static inline void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
+{
+ if (atomic_dec_and_test(&hba->scsi_block_reqs_cnt))
+ scsi_unblock_requests(hba->host);
+}
+
+static inline void ufshcd_scsi_block_requests(struct ufs_hba *hba)
+{
+ if (atomic_inc_return(&hba->scsi_block_reqs_cnt) == 1)
+ scsi_block_requests(hba->host);
+}
+
#ifdef CONFIG_SCSI_UFS_HWMON
void ufs_hwmon_probe(struct ufs_hba *hba, u8 mask);
void ufs_hwmon_remove(struct ufs_hba *hba);
@@ -332,18 +332,6 @@ static void ufshcd_configure_wb(struct ufs_hba *hba)
ufshcd_wb_toggle_buf_flush(hba, true);
}
-static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
-{
- if (atomic_dec_and_test(&hba->scsi_block_reqs_cnt))
- scsi_unblock_requests(hba->host);
-}
-
-static void ufshcd_scsi_block_requests(struct ufs_hba *hba)
-{
- if (atomic_inc_return(&hba->scsi_block_reqs_cnt) == 1)
- scsi_block_requests(hba->host);
-}
-
static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned int tag,
enum ufs_trace_str_t str_t)
{
Given the importance of the RTT parameter, we want to be able to configure it via sysfs. This is because UFS users should be discouraged from change UFS device parameters without the UFSHCI driver being aware of these changes. Signed-off-by: Avri Altman <avri.altman@wdc.com> --- Documentation/ABI/testing/sysfs-driver-ufs | 14 +++-- drivers/ufs/core/ufs-sysfs.c | 72 +++++++++++++++++++++- drivers/ufs/core/ufshcd-priv.h | 12 ++++ drivers/ufs/core/ufshcd.c | 12 ---- 4 files changed, 91 insertions(+), 19 deletions(-)