drivers: crypto: caam/jr - Allow quiesce when quiesced

Issues:
- Job ring device is busy when do kexec reboot
- Failed to flush job ring when do system suspend-resume

Fix:
Flush the job ring to stop the running jobs.
Signed-off-by: Horia Geanta <horia.geanta@nxp.com>
Signed-off-by: Franck LENORMAND <franck.lenormand@nxp.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/jr.c

@@ -4,7 +4,7 @@
  * JobR backend functionality
  *
  * Copyright 2008-2012 Freescale Semiconductor, Inc.
- * Copyright 2019 NXP
+ * Copyright 2019, 2023 NXP
  */
 
 #include <linux/of_irq.h>
@@ -72,19 +72,27 @@ static void caam_jr_crypto_engine_exit(void *data)
 	crypto_engine_exit(jrpriv->engine);
 }
 
-static int caam_reset_hw_jr(struct device *dev)
+/*
+ * Put the CAAM in quiesce, ie stop
+ *
+ * Must be called with itr disabled
+ */
+static int caam_jr_stop_processing(struct device *dev, u32 jrcr_bits)
 {
 	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
 	unsigned int timeout = 100000;
 
-	/*
-	 * mask interrupts since we are going to poll
-	 * for reset completion status
-	 */
-	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JRCFG_IMSK);
+	/* Check the current status */
+	if (rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_INPROGRESS)
+		goto wait_quiesce_completion;
 
-	/* initiate flush (required prior to reset) */
-	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
+	/* Reset the field */
+	clrsetbits_32(&jrp->rregs->jrintstatus, JRINT_ERR_HALT_MASK, 0);
+
+	/* initiate flush / park (required prior to reset) */
+	wr_reg32(&jrp->rregs->jrcommand, jrcr_bits);
+
+wait_quiesce_completion:
 	while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
 		JRINT_ERR_HALT_INPROGRESS) && --timeout)
 		cpu_relax();
@@ -95,8 +103,35 @@ static int caam_reset_hw_jr(struct device *dev)
 		return -EIO;
 	}
 
+	return 0;
+}
+
+/*
+ * Flush the job ring, so the jobs running will be stopped, jobs queued will be
+ * invalidated and the CAAM will no longer fetch fron input ring.
+ *
+ * Must be called with itr disabled
+ */
+static int caam_jr_flush(struct device *dev)
+{
+	return caam_jr_stop_processing(dev, JRCR_RESET);
+}
+
+static int caam_reset_hw_jr(struct device *dev)
+{
+	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
+	unsigned int timeout = 100000;
+	int err;
+	/*
+	 * mask interrupts since we are going to poll
+	 * for reset completion status
+	 */
+	clrsetbits_32(&jrp->rregs->rconfig_lo, 0, JRCFG_IMSK);
+	err = caam_jr_flush(dev);
+	if (err)
+		return err;
+
 	/* initiate reset */
-	timeout = 100000;
 	wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
 	while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
 		cpu_relax();