From: Avri Altman <avri.altman@wdc.com>
Date: Mon, 12 Jul 2021 12:50:39 +0300
Subject: [PATCH] scsi: ufs: ufshpb: Make host mode parameters configurable
Git-commit: f95f59a2bb60f917faf516f2f0a679dc4e58f490
Patch-mainline: v5.15-rc1
References: jsc#PED-818
Elaborate some more on the host control mode logic parameters, explaining
what they do and how to configure them.
Link: https://lore.kernel.org/r/20210712095039.8093-13-avri.altman@wdc.com
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
Documentation/ABI/testing/sysfs-driver-ufs | 76 +++++-
drivers/scsi/ufs/ufshpb.c | 288 +++++++++++++++++++--
drivers/scsi/ufs/ufshpb.h | 20 ++
3 files changed, 367 insertions(+), 17 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index 929460738651..ec3a7149ced5 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1449,7 +1449,7 @@ Description: This entry shows the maximum HPB data size for using a single HPB
The file is read only.
-What: /sys/bus/platform/drivers/ufshcd/*/flags/wb_enable
+What: /sys/bus/platform/drivers/ufshcd/*/flags/hpb_enable
Date: June 2021
Contact: Daejun Park <daejun7.park@samsung.com>
Description: This entry shows the status of HPB.
@@ -1460,3 +1460,77 @@ Description: This entry shows the status of HPB.
== ============================
The file is read only.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/activation_thld
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: In host control mode, reads are the major source of activation
+ trials. Once this threshold hs met, the region is added to the
+ "to-be-activated" list. Since we reset the read counter upon
+ write, this include sending a rb command updating the region
+ ppn as well.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/normalization_factor
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: In host control mode, we think of the regions as "buckets".
+ Those buckets are being filled with reads, and emptied on write.
+ We use entries_per_srgn - the amount of blocks in a subregion as
+ our bucket size. This applies because HPB1.0 only handles
+ single-block reads. Once the bucket size is crossed, we trigger
+ a normalization work - not only to avoid overflow, but mainly
+ because we want to keep those counters normalized, as we are
+ using those reads as a comparative score, to make various decisions.
+ The normalization is dividing (shift right) the read counter by
+ the normalization_factor. If during consecutive normalizations
+ an active region has exhausted its reads - inactivate it.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/eviction_thld_enter
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: Region deactivation is often due to the fact that eviction took
+ place: A region becomes active at the expense of another. This is
+ happening when the max-active-regions limit has been crossed.
+ In host mode, eviction is considered an extreme measure. We
+ want to verify that the entering region has enough reads, and
+ the exiting region has much fewer reads. eviction_thld_enter is
+ the min reads that a region must have in order to be considered
+ a candidate for evicting another region.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/eviction_thld_exit
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: Same as above for the exiting region. A region is considered to
+ be a candidate for eviction only if it has fewer reads than
+ eviction_thld_exit.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/read_timeout_ms
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: In order not to hang on to "cold" regions, we inactivate
+ a region that has no READ access for a predefined amount of
+ time - read_timeout_ms. If read_timeout_ms has expired, and the
+ region is dirty, it is less likely that we can make any use of
+ HPB reading it so we inactivate it. Still, deactivation has
+ its overhead, and we may still benefit from HPB reading this
+ region if it is clean - see read_timeout_expiries.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/read_timeout_expiries
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: If the region read timeout has expired, but the region is clean,
+ just re-wind its timer for another spin. Do that as long as it
+ is clean and did not exhaust its read_timeout_expiries threshold.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/timeout_polling_interval_ms
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: The frequency with which the delayed worker that checks the
+ read_timeouts is awakened.
+
+What: /sys/class/scsi_device/*/device/hpb_param_sysfs/inflight_map_req
+Date: February 2021
+Contact: Avri Altman <avri.altman@wdc.com>
+Description: In host control mode the host is the originator of map requests.
+ To avoid flooding the device with map requests, use a simple throttling
+ mechanism that limits the number of inflight map requests.
diff --git a/drivers/scsi/ufs/ufshpb.c b/drivers/scsi/ufs/ufshpb.c
index 49f58598dba7..54e8e019bdbe 100644
--- a/drivers/scsi/ufs/ufshpb.c
+++ b/drivers/scsi/ufs/ufshpb.c
@@ -17,7 +17,6 @@
#include "../sd.h"
#define ACTIVATION_THRESHOLD 8 /* 8 IOs */
-#define EVICTION_THRESHOLD (ACTIVATION_THRESHOLD << 5) /* 256 IOs */
#define READ_TO_MS 1000
#define READ_TO_EXPIRIES 100
#define POLLING_INTERVAL_MS 200
@@ -195,7 +194,7 @@ static void ufshpb_iterate_rgn(struct ufshpb_lu *hpb, int rgn_idx, int srgn_idx,
} else {
srgn->reads++;
rgn->reads++;
- if (srgn->reads == ACTIVATION_THRESHOLD)
+ if (srgn->reads == hpb->params.activation_thld)
activate = true;
}
spin_unlock(&rgn->rgn_lock);
@@ -744,10 +743,11 @@ static struct ufshpb_req *ufshpb_get_map_req(struct ufshpb_lu *hpb,
struct bio *bio;
if (hpb->is_hcm &&
- hpb->num_inflight_map_req >= THROTTLE_MAP_REQ_DEFAULT) {
+ hpb->num_inflight_map_req >= hpb->params.inflight_map_req) {
dev_info(&hpb->sdev_ufs_lu->sdev_dev,
"map_req throttle. inflight %d throttle %d",
- hpb->num_inflight_map_req, THROTTLE_MAP_REQ_DEFAULT);
+ hpb->num_inflight_map_req,
+ hpb->params.inflight_map_req);
return NULL;
}
@@ -1053,6 +1053,7 @@ static void ufshpb_read_to_handler(struct work_struct *work)
struct victim_select_info *lru_info = &hpb->lru_info;
struct ufshpb_region *rgn, *next_rgn;
unsigned long flags;
+ unsigned int poll;
LIST_HEAD(expired_list);
if (test_and_set_bit(TIMEOUT_WORK_RUNNING, &hpb->work_data_bits))
@@ -1071,7 +1072,7 @@ static void ufshpb_read_to_handler(struct work_struct *work)
list_add(&rgn->list_expired_rgn, &expired_list);
else
rgn->read_timeout = ktime_add_ms(ktime_get(),
- READ_TO_MS);
+ hpb->params.read_timeout_ms);
}
}
@@ -1089,8 +1090,9 @@ static void ufshpb_read_to_handler(struct work_struct *work)
clear_bit(TIMEOUT_WORK_RUNNING, &hpb->work_data_bits);
+ poll = hpb->params.timeout_polling_interval_ms;
schedule_delayed_work(&hpb->ufshpb_read_to_work,
- msecs_to_jiffies(POLLING_INTERVAL_MS));
+ msecs_to_jiffies(poll));
}
static void ufshpb_add_lru_info(struct victim_select_info *lru_info,
@@ -1100,8 +1102,11 @@ static void ufshpb_add_lru_info(struct victim_select_info *lru_info,
list_add_tail(&rgn->list_lru_rgn, &lru_info->lh_lru_rgn);
atomic_inc(&lru_info->active_cnt);
if (rgn->hpb->is_hcm) {
- rgn->read_timeout = ktime_add_ms(ktime_get(), READ_TO_MS);
- rgn->read_timeout_expiries = READ_TO_EXPIRIES;
+ rgn->read_timeout =
+ ktime_add_ms(ktime_get(),
+ rgn->hpb->params.read_timeout_ms);
+ rgn->read_timeout_expiries =
+ rgn->hpb->params.read_timeout_expiries;
}
}
@@ -1130,7 +1135,8 @@ static struct ufshpb_region *ufshpb_victim_lru_info(struct ufshpb_lu *hpb)
* in host control mode, verify that the exiting region
* has fewer reads
*/
- if (hpb->is_hcm && rgn->reads > (EVICTION_THRESHOLD >> 1))
+ if (hpb->is_hcm &&
+ rgn->reads > hpb->params.eviction_thld_exit)
continue;
victim_rgn = rgn;
@@ -1346,7 +1352,8 @@ static int ufshpb_add_region(struct ufshpb_lu *hpb, struct ufshpb_region *rgn)
* in host control mode, verify that the entering
* region has enough reads
*/
- if (hpb->is_hcm && rgn->reads < EVICTION_THRESHOLD) {
+ if (hpb->is_hcm &&
+ rgn->reads < hpb->params.eviction_thld_enter) {
ret = -EACCES;
goto out;
}
@@ -1697,6 +1704,7 @@ static void ufshpb_normalization_work_handler(struct work_struct *work)
struct ufshpb_lu *hpb = container_of(work, struct ufshpb_lu,
ufshpb_normalization_work);
int rgn_idx;
+ u8 factor = hpb->params.normalization_factor;
for (rgn_idx = 0; rgn_idx < hpb->rgns_per_lu; rgn_idx++) {
struct ufshpb_region *rgn = hpb->rgn_tbl + rgn_idx;
@@ -1707,7 +1715,7 @@ static void ufshpb_normalization_work_handler(struct work_struct *work)
for (srgn_idx = 0; srgn_idx < hpb->srgns_per_rgn; srgn_idx++) {
struct ufshpb_subregion *srgn = rgn->srgn_tbl + srgn_idx;
- srgn->reads >>= 1;
+ srgn->reads >>= factor;
rgn->reads += srgn->reads;
}
spin_unlock(&rgn->rgn_lock);
@@ -2030,8 +2038,247 @@ requeue_timeout_ms_store(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RW(requeue_timeout_ms);
+ufshpb_sysfs_param_show_func(activation_thld);
+static ssize_t
+activation_thld_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ if (val <= 0)
+ return -EINVAL;
+
+ hpb->params.activation_thld = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(activation_thld);
+
+ufshpb_sysfs_param_show_func(normalization_factor);
+static ssize_t
+normalization_factor_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ if (val <= 0 || val > ilog2(hpb->entries_per_srgn))
+ return -EINVAL;
+
+ hpb->params.normalization_factor = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(normalization_factor);
+
+ufshpb_sysfs_param_show_func(eviction_thld_enter);
+static ssize_t
+eviction_thld_enter_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ if (val <= hpb->params.eviction_thld_exit)
+ return -EINVAL;
+
+ hpb->params.eviction_thld_enter = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(eviction_thld_enter);
+
+ufshpb_sysfs_param_show_func(eviction_thld_exit);
+static ssize_t
+eviction_thld_exit_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ if (val <= hpb->params.activation_thld)
+ return -EINVAL;
+
+ hpb->params.eviction_thld_exit = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(eviction_thld_exit);
+
+ufshpb_sysfs_param_show_func(read_timeout_ms);
+static ssize_t
+read_timeout_ms_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ /* read_timeout >> timeout_polling_interval */
+ if (val < hpb->params.timeout_polling_interval_ms * 2)
+ return -EINVAL;
+
+ hpb->params.read_timeout_ms = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(read_timeout_ms);
+
+ufshpb_sysfs_param_show_func(read_timeout_expiries);
+static ssize_t
+read_timeout_expiries_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ if (val <= 0)
+ return -EINVAL;
+
+ hpb->params.read_timeout_expiries = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(read_timeout_expiries);
+
+ufshpb_sysfs_param_show_func(timeout_polling_interval_ms);
+static ssize_t
+timeout_polling_interval_ms_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ /* timeout_polling_interval << read_timeout */
+ if (val <= 0 || val > hpb->params.read_timeout_ms / 2)
+ return -EINVAL;
+
+ hpb->params.timeout_polling_interval_ms = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(timeout_polling_interval_ms);
+
+ufshpb_sysfs_param_show_func(inflight_map_req);
+static ssize_t inflight_map_req_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ufshpb_lu *hpb = ufshpb_get_hpb_data(sdev);
+ int val;
+
+ if (!hpb)
+ return -ENODEV;
+
+ if (!hpb->is_hcm)
+ return -EOPNOTSUPP;
+
+ if (kstrtouint(buf, 0, &val))
+ return -EINVAL;
+
+ if (val <= 0 || val > hpb->sdev_ufs_lu->queue_depth - 1)
+ return -EINVAL;
+
+ hpb->params.inflight_map_req = val;
+
+ return count;
+}
+static DEVICE_ATTR_RW(inflight_map_req);
+
+static void ufshpb_hcm_param_init(struct ufshpb_lu *hpb)
+{
+ hpb->params.activation_thld = ACTIVATION_THRESHOLD;
+ hpb->params.normalization_factor = 1;
+ hpb->params.eviction_thld_enter = (ACTIVATION_THRESHOLD << 5);
+ hpb->params.eviction_thld_exit = (ACTIVATION_THRESHOLD << 4);
+ hpb->params.read_timeout_ms = READ_TO_MS;
+ hpb->params.read_timeout_expiries = READ_TO_EXPIRIES;
+ hpb->params.timeout_polling_interval_ms = POLLING_INTERVAL_MS;
+ hpb->params.inflight_map_req = THROTTLE_MAP_REQ_DEFAULT;
+}
+
static struct attribute *hpb_dev_param_attrs[] = {
&dev_attr_requeue_timeout_ms.attr,
+ &dev_attr_activation_thld.attr,
+ &dev_attr_normalization_factor.attr,
+ &dev_attr_eviction_thld_enter.attr,
+ &dev_attr_eviction_thld_exit.attr,
+ &dev_attr_read_timeout_ms.attr,
+ &dev_attr_read_timeout_expiries.attr,
+ &dev_attr_timeout_polling_interval_ms.attr,
+ &dev_attr_inflight_map_req.attr,
NULL,
};
@@ -2115,6 +2362,8 @@ static void ufshpb_stat_init(struct ufshpb_lu *hpb)
static void ufshpb_param_init(struct ufshpb_lu *hpb)
{
hpb->params.requeue_timeout_ms = HPB_REQUEUE_TIME_MS;
+ if (hpb->is_hcm)
+ ufshpb_hcm_param_init(hpb);
}
static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb)
@@ -2169,9 +2418,13 @@ static int ufshpb_lu_hpb_init(struct ufs_hba *hba, struct ufshpb_lu *hpb)
ufshpb_stat_init(hpb);
ufshpb_param_init(hpb);
- if (hpb->is_hcm)
+ if (hpb->is_hcm) {
+ unsigned int poll;
+
+ poll = hpb->params.timeout_polling_interval_ms;
schedule_delayed_work(&hpb->ufshpb_read_to_work,
- msecs_to_jiffies(POLLING_INTERVAL_MS));
+ msecs_to_jiffies(poll));
+ }
return 0;
@@ -2350,10 +2603,13 @@ void ufshpb_resume(struct ufs_hba *hba)
continue;
ufshpb_set_state(hpb, HPB_PRESENT);
ufshpb_kick_map_work(hpb);
- if (hpb->is_hcm)
- schedule_delayed_work(&hpb->ufshpb_read_to_work,
- msecs_to_jiffies(POLLING_INTERVAL_MS));
+ if (hpb->is_hcm) {
+ unsigned int poll =
+ hpb->params.timeout_polling_interval_ms;
+ schedule_delayed_work(&hpb->ufshpb_read_to_work,
+ msecs_to_jiffies(poll));
+ }
}
}
diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h
index edf565e9036f..c74a6c35a446 100644
--- a/drivers/scsi/ufs/ufshpb.h
+++ b/drivers/scsi/ufs/ufshpb.h
@@ -185,8 +185,28 @@ struct victim_select_info {
atomic_t active_cnt;
};
+/**
+ * ufshpb_params - ufs hpb parameters
+ * @requeue_timeout_ms - requeue threshold of wb command (0x2)
+ * @activation_thld - min reads [IOs] to activate/update a region
+ * @normalization_factor - shift right the region's reads
+ * @eviction_thld_enter - min reads [IOs] for the entering region in eviction
+ * @eviction_thld_exit - max reads [IOs] for the exiting region in eviction
+ * @read_timeout_ms - timeout [ms] from the last read IO to the region
+ * @read_timeout_expiries - amount of allowable timeout expireis
+ * @timeout_polling_interval_ms - frequency in which timeouts are checked
+ * @inflight_map_req - number of inflight map requests
+ */
struct ufshpb_params {
unsigned int requeue_timeout_ms;
+ unsigned int activation_thld;
+ unsigned int normalization_factor;
+ unsigned int eviction_thld_enter;
+ unsigned int eviction_thld_exit;
+ unsigned int read_timeout_ms;
+ unsigned int read_timeout_expiries;
+ unsigned int timeout_polling_interval_ms;
+ unsigned int inflight_map_req;
};
struct ufshpb_stats {
--
2.35.3