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From: Finn Thain <fthain@telegraphics.com.au>
To: "James E.J. Bottomley" <JBottomley@odin.com>,
	Michael Schmitz <schmitzmic@gmail.com>,
	<linux-m68k@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: [PATCH v2 40/72] ncr5380: Introduce NCR5380_poll_politely2
Date: Sun, 06 Dec 2015 12:32:06 +1100	[thread overview]
Message-ID: <20151206013136.935455721@telegraphics.com.au> (raw)
In-Reply-To: 20151206013126.995379403@telegraphics.com.au

[-- Attachment #1: ncr5380-poll_politely2 --]
[-- Type: text/plain, Size: 8793 bytes --]

SCSI bus protocol sometimes requires monitoring two related conditions
simultaneously. Enhance NCR5380_poll_politely() for this purpose, and
put it to use in the arbitration algorithm. It will also find use in
pseudo DMA.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>

---
 drivers/scsi/NCR5380.c       |   66 ++++++++++++++++++++++++-------------------
 drivers/scsi/atari_NCR5380.c |   62 ++++++++++++++++++++++++----------------
 2 files changed, 75 insertions(+), 53 deletions(-)

Index: linux/drivers/scsi/atari_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/atari_NCR5380.c	2015-12-06 12:30:30.000000000 +1100
+++ linux/drivers/scsi/atari_NCR5380.c	2015-12-06 12:30:32.000000000 +1100
@@ -457,11 +457,14 @@ static inline void initialize_SCp(struct
 }
 
 /**
- * NCR5380_poll_politely - wait for chip register value
+ * NCR5380_poll_politely2 - wait for two chip register values
  * @instance: controller to poll
- * @reg: 5380 register to poll
- * @bit: Bitmask to check
- * @val: Value required to exit
+ * @reg1: 5380 register to poll
+ * @bit1: Bitmask to check
+ * @val1: Expected value
+ * @reg2: Second 5380 register to poll
+ * @bit2: Second bitmask to check
+ * @val2: Second expected value
  * @wait: Time-out in jiffies
  *
  * Polls the chip in a reasonably efficient manner waiting for an
@@ -469,11 +472,12 @@ static inline void initialize_SCp(struct
  * (if possible). In irq contexts the time-out is arbitrarily limited.
  * Callers may hold locks as long as they are held in irq mode.
  *
- * Returns 0 if event occurred otherwise -ETIMEDOUT.
+ * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
  */
 
-static int NCR5380_poll_politely(struct Scsi_Host *instance,
-                                 int reg, int bit, int val, int wait)
+static int NCR5380_poll_politely2(struct Scsi_Host *instance,
+                                  int reg1, int bit1, int val1,
+                                  int reg2, int bit2, int val2, int wait)
 {
 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
 	unsigned long deadline = jiffies + wait;
@@ -482,9 +486,11 @@ static int NCR5380_poll_politely(struct
 	/* Busy-wait for up to 10 ms */
 	n = min(10000U, jiffies_to_usecs(wait));
 	n *= hostdata->accesses_per_ms;
-	n /= 1000;
+	n /= 2000;
 	do {
-		if ((NCR5380_read(reg) & bit) == val)
+		if ((NCR5380_read(reg1) & bit1) == val1)
+			return 0;
+		if ((NCR5380_read(reg2) & bit2) == val2)
 			return 0;
 		cpu_relax();
 	} while (n--);
@@ -495,13 +501,22 @@ static int NCR5380_poll_politely(struct
 	/* Repeatedly sleep for 1 ms until deadline */
 	while (time_is_after_jiffies(deadline)) {
 		schedule_timeout_uninterruptible(1);
-		if ((NCR5380_read(reg) & bit) == val)
+		if ((NCR5380_read(reg1) & bit1) == val1)
+			return 0;
+		if ((NCR5380_read(reg2) & bit2) == val2)
 			return 0;
 	}
 
 	return -ETIMEDOUT;
 }
 
+static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
+                                        int reg, int bit, int val, int wait)
+{
+	return NCR5380_poll_politely2(instance, reg, bit, val,
+	                                        reg, bit, val, wait);
+}
+
 #include <linux/delay.h>
 
 #if NDEBUG
@@ -1343,7 +1358,6 @@ static int NCR5380_select(struct Scsi_Ho
 	int len;
 	int err;
 	unsigned long flags;
-	unsigned long timeout;
 
 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 	dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
@@ -1373,20 +1387,18 @@ static int NCR5380_select(struct Scsi_Ho
 	 */
 
 	local_irq_restore(flags);
-	timeout = jiffies + HZ;
-	while (1) {
-		if (time_is_before_jiffies(timeout)) {
-			NCR5380_write(MODE_REG, MR_BASE);
-			shost_printk(KERN_ERR, instance,
-			             "select: arbitration timeout\n");
-			return -1;
-		}
-		if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
-			/* Reselection interrupt */
-			return -1;
-		}
-		if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
-			break;
+	err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
+	                INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
+	                                       ICR_ARBITRATION_PROGRESS, HZ);
+	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
+		/* Reselection interrupt */
+		return -1;
+	}
+	if (err < 0) {
+		NCR5380_write(MODE_REG, MR_BASE);
+		shost_printk(KERN_ERR, instance,
+		             "select: arbitration timeout\n");
+		return -1;
 	}
 
 	/* The SCSI-2 arbitration delay is 2.4 us */
Index: linux/drivers/scsi/NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/NCR5380.c	2015-12-06 12:30:30.000000000 +1100
+++ linux/drivers/scsi/NCR5380.c	2015-12-06 12:30:32.000000000 +1100
@@ -262,11 +262,14 @@ static inline void initialize_SCp(struct
 }
 
 /**
- * NCR5380_poll_politely - wait for chip register value
+ * NCR5380_poll_politely2 - wait for two chip register values
  * @instance: controller to poll
- * @reg: 5380 register to poll
- * @bit: Bitmask to check
- * @val: Value required to exit
+ * @reg1: 5380 register to poll
+ * @bit1: Bitmask to check
+ * @val1: Expected value
+ * @reg2: Second 5380 register to poll
+ * @bit2: Second bitmask to check
+ * @val2: Second expected value
  * @wait: Time-out in jiffies
  *
  * Polls the chip in a reasonably efficient manner waiting for an
@@ -274,11 +277,12 @@ static inline void initialize_SCp(struct
  * (if possible). In irq contexts the time-out is arbitrarily limited.
  * Callers may hold locks as long as they are held in irq mode.
  *
- * Returns 0 if event occurred otherwise -ETIMEDOUT.
+ * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
  */
 
-static int NCR5380_poll_politely(struct Scsi_Host *instance,
-                                 int reg, int bit, int val, int wait)
+static int NCR5380_poll_politely2(struct Scsi_Host *instance,
+                                  int reg1, int bit1, int val1,
+                                  int reg2, int bit2, int val2, int wait)
 {
 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
 	unsigned long deadline = jiffies + wait;
@@ -287,9 +291,11 @@ static int NCR5380_poll_politely(struct
 	/* Busy-wait for up to 10 ms */
 	n = min(10000U, jiffies_to_usecs(wait));
 	n *= hostdata->accesses_per_ms;
-	n /= 1000;
+	n /= 2000;
 	do {
-		if ((NCR5380_read(reg) & bit) == val)
+		if ((NCR5380_read(reg1) & bit1) == val1)
+			return 0;
+		if ((NCR5380_read(reg2) & bit2) == val2)
 			return 0;
 		cpu_relax();
 	} while (n--);
@@ -300,13 +306,22 @@ static int NCR5380_poll_politely(struct
 	/* Repeatedly sleep for 1 ms until deadline */
 	while (time_is_after_jiffies(deadline)) {
 		schedule_timeout_uninterruptible(1);
-		if ((NCR5380_read(reg) & bit) == val)
+		if ((NCR5380_read(reg1) & bit1) == val1)
+			return 0;
+		if ((NCR5380_read(reg2) & bit2) == val2)
 			return 0;
 	}
 
 	return -ETIMEDOUT;
 }
 
+static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
+                                        int reg, int bit, int val, int wait)
+{
+	return NCR5380_poll_politely2(instance, reg, bit, val,
+	                                        reg, bit, val, wait);
+}
+
 static struct {
 	unsigned char value;
 	const char *name;
@@ -1096,7 +1111,6 @@ static int NCR5380_select(struct Scsi_Ho
 	unsigned char *data;
 	int len;
 	int err;
-	unsigned long timeout;
 
 	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
 	dprintk(NDEBUG_ARBITRATION, "scsi%d : starting arbitration, id = %d\n", instance->host_no, instance->this_id);
@@ -1120,23 +1134,19 @@ static int NCR5380_select(struct Scsi_Ho
 	 */
 
 	spin_unlock_irq(instance->host_lock);
-	timeout = jiffies + HZ;
-	while (1) {
-		if (time_is_before_jiffies(timeout)) {
-			NCR5380_write(MODE_REG, MR_BASE);
-			shost_printk(KERN_ERR, instance,
-			             "select: arbitration timeout\n");
-			spin_lock_irq(instance->host_lock);
-			return -1;
-		}
-		spin_lock_irq(instance->host_lock);
-		if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
-			/* Reselection interrupt */
-			return -1;
-		}
-		if (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS)
-			break;
-		spin_unlock_irq(instance->host_lock);
+	err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
+	                INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
+	                                       ICR_ARBITRATION_PROGRESS, HZ);
+	spin_lock_irq(instance->host_lock);
+	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
+		/* Reselection interrupt */
+		return -1;
+	}
+	if (err < 0) {
+		NCR5380_write(MODE_REG, MR_BASE);
+		shost_printk(KERN_ERR, instance,
+		             "select: arbitration timeout\n");
+		return -1;
 	}
 
 	/* The SCSI-2 arbitration delay is 2.4 us */



  parent reply	other threads:[~2015-12-06  3:55 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-06  1:31 [PATCH v2 00/72] More fixes, cleanup and modernization for NCR5380 drivers Finn Thain
2015-12-06  1:31 ` [PATCH v2 01/72] atari_scsi: Fix SCSI host ID setting Finn Thain
2015-12-06  1:31 ` [PATCH v2 02/72] ncr5380: Remove redundant static variable initializers Finn Thain
2015-12-06  1:31 ` [PATCH v2 03/72] ncr5380: Eliminate PDEBUG*, TDEBUG* and DTCDEBUG* macros Finn Thain
2015-12-06  1:31 ` [PATCH v2 04/72] ncr5380: Remove more pointless macros Finn Thain
2015-12-06  1:31 ` [PATCH v2 05/72] ncr5380: Remove NCR5380_local_declare and NCR5380_setup macros Finn Thain
2015-12-06  1:31 ` [PATCH v2 06/72] ncr5380: Remove NCR5380_instance_name macro Finn Thain
2015-12-06  1:31 ` [PATCH v2 07/72] ncr5380: Split NCR5380_init() into two functions Finn Thain
2015-12-06  1:31 ` [PATCH v2 08/72] ncr5380: Move NCR53C400-specific code Finn Thain
2015-12-06  1:31 ` [PATCH v2 09/72] atari_NCR5380: Reset bus on driver initialization if required Finn Thain
2015-12-06  1:31 ` [PATCH v2 10/72] atari_NCR5380: Remove RESET_BOOT, CONFIG_ATARI_SCSI_TOSHIBA_DELAY and CONFIG_ATARI_SCSI_RESET_BOOT Finn Thain
2015-12-06  1:31 ` [PATCH v2 11/72] ncr5380: Simplify bus reset handlers Finn Thain
2015-12-06  1:31 ` [PATCH v2 12/72] ncr5380: Remove unused hostdata->aborted flag Finn Thain
2015-12-06  1:31 ` [PATCH v2 13/72] ncr5380: Remove redundant register writes Finn Thain
2015-12-06  1:31 ` [PATCH v2 14/72] ncr5380: Use return instead of goto in NCR5380_select() Finn Thain
2015-12-06  1:31 ` [PATCH v2 15/72] ncr5380: Always escalate bad target time-out " Finn Thain
2015-12-06  1:31 ` [PATCH v2 16/72] ncr5380: Proceed with next command after NCR5380_select() calls scsi_done Finn Thain
2015-12-06  1:31 ` [PATCH v2 17/72] ncr5380: Keep BSY asserted when entering SELECTION phase Finn Thain
2015-12-06  1:31 ` [PATCH v2 18/72] ncr5380: Eliminate USLEEP_WAITLONG delay Finn Thain
2015-12-06  1:31 ` [PATCH v2 19/72] ncr5380: Cleanup bogus {request,release}_region() calls Finn Thain
2015-12-06  1:31 ` [PATCH v2 20/72] ncr5380: Introduce unbound workqueue Finn Thain
2015-12-06  1:31 ` [PATCH v2 21/72] ncr5380: Sleep when polling, if possible Finn Thain
2015-12-06 10:18   ` Geert Uytterhoeven
2015-12-06 22:07     ` Finn Thain
2015-12-06  1:31 ` [PATCH v2 22/72] ncr5380: Eliminate selecting state Finn Thain
2015-12-06  1:31 ` [PATCH v2 23/72] ncr5380: Always retry arbitration and selection Finn Thain
2015-12-06  1:31 ` [PATCH v2 24/72] ncr5380: Implement NCR5380_dma_xfer_len and remove LIMIT_TRANSFERSIZE macro Finn Thain
2015-12-06  1:31 ` [PATCH v2 25/72] ncr5380: Rework disconnect versus poll logic Finn Thain
2015-12-06  1:31 ` [PATCH v2 26/72] ncr5380: Fix NCR5380_transfer_pio() result Finn Thain
2015-12-06  1:31 ` [PATCH v2 27/72] ncr5380: Add missing lock in eh_abort_handler Finn Thain
2015-12-06  1:31 ` [PATCH v2 28/72] ncr5380: Drop DEF_SCSI_QCMD macro Finn Thain
2015-12-06  1:31 ` [PATCH v2 29/72] ncr5380: Remove references to linked commands Finn Thain
2015-12-06  1:31 ` [PATCH v2 30/72] ncr5380: Add missing break after case MESSAGE_REJECT Finn Thain
2015-12-06  1:31 ` [PATCH v2 31/72] ncr5380: Fix !REQ timeout in do_abort() Finn Thain
2015-12-06  1:31 ` [PATCH v2 32/72] ncr5380: Fix bus phase " Finn Thain
2015-12-06  1:31 ` [PATCH v2 33/72] atari_NCR5380: Set do_abort() timeouts Finn Thain
2015-12-06  1:32 ` [PATCH v2 34/72] atari_NCR5380: Use arbitration timeout Finn Thain
2015-12-06  1:32 ` [PATCH v2 35/72] ncr5380: Dont wait for BUS FREE after disconnect Finn Thain
2015-12-06  1:32 ` [PATCH v2 36/72] ncr5380: Use work_struct instead of delayed_work Finn Thain
2015-12-06  1:32 ` [PATCH v2 37/72] ncr5380: Standardize work queueing algorithm Finn Thain
2015-12-06  1:32 ` [PATCH v2 38/72] ncr5380: Remove UNSAFE macro Finn Thain
2015-12-06  1:32 ` [PATCH v2 39/72] ncr5380: Standardize interrupt handling Finn Thain
2015-12-06  1:32 ` Finn Thain [this message]
2015-12-06  1:32 ` [PATCH v2 41/72] ncr5380: Replace redundant flags with FLAG_NO_DMA_FIXUP Finn Thain
2015-12-06  1:32 ` [PATCH v2 42/72] ncr5380: Replace READ_OVERRUNS macro with FLAG_NO_DMA_FIXUPS Finn Thain
2015-12-06  1:32 ` [PATCH v2 43/72] ncr5380: Standardize reselection handling Finn Thain
2015-12-06  1:32 ` [PATCH v2 44/72] ncr5380: Fix off-by-one bug in extended_msg[] bounds check Finn Thain
2015-12-06  1:32 ` [PATCH v2 45/72] ncr5380: Cleanup #include directives Finn Thain
2015-12-06  1:32 ` [PATCH v2 46/72] ncr5380: Fix NDEBUG_NO_DATAOUT flag Finn Thain
2015-12-06  1:32 ` [PATCH v2 47/72] ncr5380: Fix and cleanup scsi_host_template initializers Finn Thain
2015-12-06  1:32 ` [PATCH v2 48/72] atari_NCR5380: Fix queue_size limit Finn Thain
2015-12-06  1:32 ` [PATCH v2 49/72] ncr5380: Remove redundant ICR_ARBITRATION_LOST test and eliminate FLAG_DTC3181E Finn Thain
2015-12-06  1:32 ` [PATCH v2 50/72] ncr5380: Change instance->host_lock to hostdata->lock Finn Thain
2015-12-06  1:32 ` [PATCH v2 51/72] ncr5380: Remove command list debug code Finn Thain
2015-12-06  1:32 ` [PATCH v2 52/72] ncr5380: Remove H_NO macro and introduce dsprintk Finn Thain
2015-12-06  1:32 ` [PATCH v2 53/72] ncr5380: Use shost_priv helper Finn Thain
2015-12-06  1:32 ` [PATCH v2 54/72] ncr5380: Use dsprintk() for queue debugging Finn Thain
2015-12-06  1:32 ` [PATCH v2 55/72] ncr5380: Remove LIST and REMOVE macros Finn Thain
2015-12-06  1:32 ` [PATCH v2 56/72] ncr5380: Remove redundant volatile qualifiers Finn Thain
2015-12-06  1:32 ` [PATCH v2 57/72] ncr5380: Use standard list data structure Finn Thain
2015-12-06  1:32 ` [PATCH v2 58/72] ncr5380: Refactor command completion Finn Thain
2015-12-06  1:32 ` [PATCH v2 59/72] ncr5380: Fix autosense bugs Finn Thain
2015-12-06  1:32 ` [PATCH v2 60/72] ncr5380: Implement new eh_abort_handler Finn Thain
2015-12-06  1:32 ` [PATCH v2 61/72] ncr5380: Fix EH during arbitration and selection Finn Thain
2015-12-06  1:32 ` [PATCH v2 62/72] ncr5380: Implement new eh_bus_reset_handler Finn Thain
2015-12-06  1:32 ` [PATCH v2 63/72] atari_NCR5380: Remove HOSTNO macro from printk() and seq_printf() calls Finn Thain
2015-12-06  1:32 ` [PATCH v2 64/72] atari_NCR5380: Eliminate HOSTNO macro Finn Thain
2015-12-06  1:32 ` [PATCH v2 65/72] atari_scsi, sun3_scsi: Remove global Scsi_Host pointer Finn Thain
2015-12-06  1:32 ` [PATCH v2 66/72] ncr5380: Fix soft lockups Finn Thain
2015-12-06  1:32 ` [PATCH v2 67/72] ncr5380: Cleanup comments Finn Thain
2015-12-06  1:32 ` [PATCH v2 68/72] ncr5380: Fix whitespace issues using regexp Finn Thain
2015-12-06  1:32 ` [PATCH v2 69/72] ncr5380: Merge changes from atari_NCR5380.c Finn Thain
2015-12-06  1:32 ` [PATCH v2 70/72] atari_NCR5380: Merge changes from NCR5380.c Finn Thain
2015-12-06  1:32 ` [PATCH v2 71/72] ncr5380: Cleanup whitespace and parentheses Finn Thain
2015-12-06  1:32 ` [PATCH v2 72/72] ncr5380: Fix pseudo DMA transfers on 53C400 Finn Thain

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