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Message-ID: <20240826224655.133847-2-anthony.l.nguyen@intel.com>
Date: Mon, 26 Aug 2024 15:46:41 -0700
From: Tony Nguyen <anthony.l.nguyen@...el.com>
To: davem@...emloft.net,
kuba@...nel.org,
pabeni@...hat.com,
edumazet@...gle.com,
netdev@...r.kernel.org
Cc: Jacob Keller <jacob.e.keller@...el.com>,
anthony.l.nguyen@...el.com,
Przemek Kitszel <przemyslaw.kitszel@...el.com>,
Pucha Himasekhar Reddy <himasekharx.reddy.pucha@...el.com>
Subject: [PATCH net-next 1/8] ice: implement and use rd32_poll_timeout for ice_sq_done timeout
From: Jacob Keller <jacob.e.keller@...el.com>
The ice_sq_done function is used to check the control queue head register
and determine whether or not the control queue processing is done. This
function is called in a loop checking against jiffies for a specified
timeout.
The pattern of reading a register in a loop until a condition is true or a
timeout is reached is a relatively common pattern. In fact, the kernel
provides a read_poll_timeout function implementing this behavior in
<linux/iopoll.h>
Use of read_poll_timeout is preferred over directly coding these loops.
However, using it in the ice driver is a bit more difficult because of the
rd32 wrapper. Implement a rd32_poll_timeout wrapper based on
read_poll_timeout.
Refactor ice_sq_done to use rd32_poll_timeout, replacing the loop calling
ice_sq_done in ice_sq_send_cmd. This simplifies the logic down to a single
ice_sq_done() call.
The implementation of rd32_poll_timeout uses microseconds for its timeout
value, so update the CQ timeout macros used to be specified in microseconds
units as well instead of using HZ for jiffies.
Signed-off-by: Jacob Keller <jacob.e.keller@...el.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@...el.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@...el.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@...el.com>
---
drivers/net/ethernet/intel/ice/ice_controlq.c | 38 +++++++++----------
drivers/net/ethernet/intel/ice/ice_controlq.h | 2 +-
drivers/net/ethernet/intel/ice/ice_osdep.h | 4 ++
3 files changed, 23 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_controlq.c b/drivers/net/ethernet/intel/ice/ice_controlq.c
index ffaa6511c455..1b1b68a99bb2 100644
--- a/drivers/net/ethernet/intel/ice/ice_controlq.c
+++ b/drivers/net/ethernet/intel/ice/ice_controlq.c
@@ -933,19 +933,29 @@ static void ice_debug_cq(struct ice_hw *hw, void *desc, void *buf, u16 buf_len)
}
/**
- * ice_sq_done - check if FW has processed the Admin Send Queue (ATQ)
+ * ice_sq_done - poll until the last send on a control queue has completed
* @hw: pointer to the HW struct
* @cq: pointer to the specific Control queue
*
- * Returns true if the firmware has processed all descriptors on the
- * admin send queue. Returns false if there are still requests pending.
+ * Use read_poll_timeout to poll the control queue head, checking until it
+ * matches next_to_use. According to the control queue designers, this has
+ * better timing reliability than the DD bit.
+ *
+ * Return: true if all the descriptors on the send side of a control queue
+ * are finished processing, false otherwise.
*/
static bool ice_sq_done(struct ice_hw *hw, struct ice_ctl_q_info *cq)
{
- /* AQ designers suggest use of head for better
- * timing reliability than DD bit
+ u32 head;
+
+ /* Wait a short time before the initial check, to allow hardware time
+ * for completion.
*/
- return rd32(hw, cq->sq.head) == cq->sq.next_to_use;
+ udelay(5);
+
+ return !rd32_poll_timeout(hw, cq->sq.head,
+ head, head == cq->sq.next_to_use,
+ 20, ICE_CTL_Q_SQ_CMD_TIMEOUT);
}
/**
@@ -969,7 +979,6 @@ ice_sq_send_cmd(struct ice_hw *hw, struct ice_ctl_q_info *cq,
struct ice_aq_desc *desc_on_ring;
bool cmd_completed = false;
struct ice_sq_cd *details;
- unsigned long timeout;
int status = 0;
u16 retval = 0;
u32 val = 0;
@@ -1063,20 +1072,9 @@ ice_sq_send_cmd(struct ice_hw *hw, struct ice_ctl_q_info *cq,
wr32(hw, cq->sq.tail, cq->sq.next_to_use);
ice_flush(hw);
- /* Wait a short time before initial ice_sq_done() check, to allow
- * hardware time for completion.
+ /* Wait for the command to complete. If it finishes within the
+ * timeout, copy the descriptor back to temp.
*/
- udelay(5);
-
- timeout = jiffies + ICE_CTL_Q_SQ_CMD_TIMEOUT;
- do {
- if (ice_sq_done(hw, cq))
- break;
-
- usleep_range(100, 150);
- } while (time_before(jiffies, timeout));
-
- /* if ready, copy the desc back to temp */
if (ice_sq_done(hw, cq)) {
memcpy(desc, desc_on_ring, sizeof(*desc));
if (buf) {
diff --git a/drivers/net/ethernet/intel/ice/ice_controlq.h b/drivers/net/ethernet/intel/ice/ice_controlq.h
index 1d54b1cdb1c5..e5b6691436f5 100644
--- a/drivers/net/ethernet/intel/ice/ice_controlq.h
+++ b/drivers/net/ethernet/intel/ice/ice_controlq.h
@@ -43,7 +43,7 @@ enum ice_ctl_q {
};
/* Control Queue timeout settings - max delay 1s */
-#define ICE_CTL_Q_SQ_CMD_TIMEOUT HZ /* Wait max 1s */
+#define ICE_CTL_Q_SQ_CMD_TIMEOUT USEC_PER_SEC
#define ICE_CTL_Q_ADMIN_INIT_TIMEOUT 10 /* Count 10 times */
#define ICE_CTL_Q_ADMIN_INIT_MSEC 100 /* Check every 100msec */
diff --git a/drivers/net/ethernet/intel/ice/ice_osdep.h b/drivers/net/ethernet/intel/ice/ice_osdep.h
index a2562f04267f..9882e6f3b26d 100644
--- a/drivers/net/ethernet/intel/ice/ice_osdep.h
+++ b/drivers/net/ethernet/intel/ice/ice_osdep.h
@@ -12,6 +12,7 @@
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
+#include <linux/iopoll.h>
#include <linux/pci_ids.h>
#ifndef CONFIG_64BIT
#include <linux/io-64-nonatomic-lo-hi.h>
@@ -23,6 +24,9 @@
#define wr64(a, reg, value) writeq((value), ((a)->hw_addr + (reg)))
#define rd64(a, reg) readq((a)->hw_addr + (reg))
+#define rd32_poll_timeout(a, addr, val, cond, delay_us, timeout_us) \
+ read_poll_timeout(rd32, val, cond, delay_us, timeout_us, false, a, addr)
+
#define ice_flush(a) rd32((a), GLGEN_STAT)
#define ICE_M(m, s) ((m ## U) << (s))
--
2.42.0
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