From: Avri Altman <avri.altman@wdc.com>
To: "Martin K . Petersen" <martin.petersen@oracle.com>
Cc: Bart Van Assche <bvanassche@acm.org>,
Bean Huo <beanhuo@micron.com>,
Peter Wang <peter.wang@mediatek.com>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
Avri Altman <avri.altman@wdc.com>
Subject: [PATCH v5 1/3] scsi: ufs: Allow RTT negotiation
Date: Thu, 23 May 2024 15:58:24 +0300 [thread overview]
Message-ID: <20240523125827.818-2-avri.altman@wdc.com> (raw)
In-Reply-To: <20240523125827.818-1-avri.altman@wdc.com>
The rtt-upiu packets precede any data-out upiu packets, thus
synchronizing the data input to the device: this mostly applies to write
operations, but there are other operations that requires rtt as well.
There are several rules binding this rtt - data-out dialog, specifically
There can be at most outstanding bMaxNumOfRTT such packets. This might
have an effect on write performance (sequential write in particular), as
each data-out upiu must wait for its rtt sibling.
UFSHCI expects bMaxNumOfRTT to be min(bDeviceRTTCap, NORTT). However,
as of today, there does not appears to be no-one who sets it: not the
host controller nor the driver. It wasn't an issue up to now:
bMaxNumOfRTT is set to 2 after manufacturing, and wasn't limiting the
write performance.
UFS4.0, and specifically gear 5 changes this, and requires the device to
be more attentive. This doesn't come free - the device has to allocate
more resources to that end, but the sequential write performance
improvement is significant. Early measurements shows 25% gain when
moving from rtt 2 to 9. Therefore, set bMaxNumOfRTT to be
min(bDeviceRTTCap, NORTT) as UFSHCI expects.
Signed-off-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
---
drivers/ufs/core/ufshcd.c | 38 ++++++++++++++++++++++++++++++++++++++
include/ufs/ufs.h | 2 ++
include/ufs/ufshcd.h | 2 ++
include/ufs/ufshci.h | 1 +
4 files changed, 43 insertions(+)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 0819ddafe7a6..7df8bcacbe7e 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -102,6 +102,9 @@
/* Default RTC update every 10 seconds */
#define UFS_RTC_UPDATE_INTERVAL_MS (10 * MSEC_PER_SEC)
+/* bMaxNumOfRTT is equal to two after device manufacturing */
+#define DEFAULT_MAX_NUM_RTT 2
+
/* UFSHC 4.0 compliant HC support this mode. */
static bool use_mcq_mode = true;
@@ -2405,6 +2408,8 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba)
((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1;
hba->reserved_slot = hba->nutrs - 1;
+ hba->nortt = FIELD_GET(MASK_NUMBER_OUTSTANDING_RTT, hba->capabilities) + 1;
+
/* Read crypto capabilities */
err = ufshcd_hba_init_crypto_capabilities(hba);
if (err) {
@@ -8119,6 +8124,35 @@ static void ufshcd_ext_iid_probe(struct ufs_hba *hba, u8 *desc_buf)
dev_info->b_ext_iid_en = ext_iid_en;
}
+static void ufshcd_set_rtt(struct ufs_hba *hba)
+{
+ struct ufs_dev_info *dev_info = &hba->dev_info;
+ u32 rtt = 0;
+ u32 dev_rtt = 0;
+
+ /* RTT override makes sense only for UFS-4.0 and above */
+ if (dev_info->wspecversion < 0x400)
+ return;
+
+ if (ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+ QUERY_ATTR_IDN_MAX_NUM_OF_RTT, 0, 0, &dev_rtt)) {
+ dev_err(hba->dev, "failed reading bMaxNumOfRTT\n");
+ return;
+ }
+
+ /* do not override if it was already written */
+ if (dev_rtt != DEFAULT_MAX_NUM_RTT)
+ return;
+
+ rtt = min_t(int, dev_info->rtt_cap, hba->nortt);
+ if (rtt == dev_rtt)
+ return;
+
+ if (ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_WRITE_ATTR,
+ QUERY_ATTR_IDN_MAX_NUM_OF_RTT, 0, 0, &rtt))
+ dev_err(hba->dev, "failed writing bMaxNumOfRTT\n");
+}
+
void ufshcd_fixup_dev_quirks(struct ufs_hba *hba,
const struct ufs_dev_quirk *fixups)
{
@@ -8254,6 +8288,8 @@ static int ufs_get_device_desc(struct ufs_hba *hba)
desc_buf[DEVICE_DESC_PARAM_SPEC_VER + 1];
dev_info->bqueuedepth = desc_buf[DEVICE_DESC_PARAM_Q_DPTH];
+ dev_info->rtt_cap = desc_buf[DEVICE_DESC_PARAM_RTT_CAP];
+
model_index = desc_buf[DEVICE_DESC_PARAM_PRDCT_NAME];
err = ufshcd_read_string_desc(hba, model_index,
@@ -8506,6 +8542,8 @@ static int ufshcd_device_params_init(struct ufs_hba *hba)
goto out;
}
+ ufshcd_set_rtt(hba);
+
ufshcd_get_ref_clk_gating_wait(hba);
if (!ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index b6003749bc83..853e95957c31 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -592,6 +592,8 @@ struct ufs_dev_info {
enum ufs_rtc_time rtc_type;
time64_t rtc_time_baseline;
u32 rtc_update_period;
+
+ u8 rtt_cap; /* bDeviceRTTCap */
};
/*
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index bad88bd91995..d74bd2d67b06 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -819,6 +819,7 @@ enum ufshcd_mcq_opr {
* @capabilities: UFS Controller Capabilities
* @mcq_capabilities: UFS Multi Circular Queue capabilities
* @nutrs: Transfer Request Queue depth supported by controller
+ * @nortt - Max outstanding RTTs supported by controller
* @nutmrs: Task Management Queue depth supported by controller
* @reserved_slot: Used to submit device commands. Protected by @dev_cmd.lock.
* @ufs_version: UFS Version to which controller complies
@@ -957,6 +958,7 @@ struct ufs_hba {
u32 capabilities;
int nutrs;
+ int nortt;
u32 mcq_capabilities;
int nutmrs;
u32 reserved_slot;
diff --git a/include/ufs/ufshci.h b/include/ufs/ufshci.h
index 385e1c6b8d60..c50f92bf2e1d 100644
--- a/include/ufs/ufshci.h
+++ b/include/ufs/ufshci.h
@@ -68,6 +68,7 @@ enum {
/* Controller capability masks */
enum {
MASK_TRANSFER_REQUESTS_SLOTS = 0x0000001F,
+ MASK_NUMBER_OUTSTANDING_RTT = 0x0000FF00,
MASK_TASK_MANAGEMENT_REQUEST_SLOTS = 0x00070000,
MASK_EHSLUTRD_SUPPORTED = 0x00400000,
MASK_AUTO_HIBERN8_SUPPORT = 0x00800000,
--
2.34.1
next prev parent reply other threads:[~2024-05-23 12:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-23 12:58 [PATCH v5 0/3] scsi: ufs: Allow RTT negotiation Avri Altman
2024-05-23 12:58 ` Avri Altman [this message]
2024-05-23 12:58 ` [PATCH v5 2/3] scsi: ufs: Allow platform vendors to set rtt Avri Altman
2024-05-23 13:03 ` Christoph Hellwig
2024-05-23 13:09 ` Avri Altman
2024-05-23 13:11 ` hch
2024-05-24 6:06 ` Peter Wang (王信友)
2024-05-24 13:56 ` Bart Van Assche
2024-05-25 14:55 ` Avri Altman
2024-05-23 12:58 ` [PATCH v5 3/3] scsi: ufs: sysfs: Make max_number_of_rtt read-write Avri Altman
2024-05-23 23:05 ` Bart Van Assche
2024-05-24 3:54 ` Avri Altman
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