| Message ID | 20240806-e810-live-migration-rd32-poll-timeout-v1-1-b5ada29ce703@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Anthony Nguyen |
| Headers | show |
| Series | ice: refactor and cleanup control queue logic | expand |
> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Jacob Keller > Sent: Wednesday, August 7, 2024 2:16 AM > To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Intel Wired LAN <intel-wired-lan@lists.osuosl.org>; "netdev netdev"@vger.kernel.org > Cc: Temerkhanov, Sergey <sergey.temerkhanov@intel.com>; Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; Kolacinski, Karol <karol.kolacinski@intel.com>; Wierzbicki, Jacek <jacek.wierzbicki@intel.com> > Subject: [Intel-wired-lan] [PATCH iwl-next 1/7] ice: implement and use rd32_poll_timeout for ice_sq_done timeout > > 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@intel.com> > Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> > --- > drivers/net/ethernet/intel/ice/ice_controlq.h | 2 +- > drivers/net/ethernet/intel/ice/ice_osdep.h | 4 +++ > drivers/net/ethernet/intel/ice/ice_controlq.c | 38 +++++++++++++-------------- > 3 files changed, 23 insertions(+), 21 deletions(-) > Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
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)) 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) {