crypto: talitos - Implement done interrupt mitigation

In talitos_interrupt, upon one done interrupt, mask further done interrupts,
and ack only any error interrupt.
In talitos_done, unmask done interrupts after completing processing.
In flush_channel, ack each done channel processed.
Keep done overflow interrupts masked because even though each pkt
is ack'ed, a few done overflows still occur.

Signed-off-by: Lee Nipper <lee.nipper@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 24 insertions, 9 deletions

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index c429f684c79d..b5c2c9340a9c 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -319,9 +319,11 @@ static void flush_channel(struct device *dev, int ch, int error, int reset_ch)
 
                 /* descriptors with their done bits set don't get the error */
                 rmb();
-                if ((request->desc->hdr & DESC_HDR_DONE) == DESC_HDR_DONE)
+                if ((request->desc->hdr & DESC_HDR_DONE) == DESC_HDR_DONE) {
                         status = 0;
-                else
+                        /* Ack each pkt completed on channel */
+                        out_be32(priv->reg + TALITOS_ICR, (1 << (ch * 2)));
+                } else
                         if (!error)
                                 break;
                         else
@@ -369,6 +371,11 @@ static void talitos_done(unsigned long data)
 
         for (ch = 0; ch < priv->num_channels; ch++)
                 flush_channel(dev, ch, 0, 0);
+
+        /* At this point, all completed channels have been processed.
+         * Unmask done interrupts for channels completed later on.
+         */
+        setbits32(priv->reg + TALITOS_IMR, TALITOS_IMR_DONE);
 }
 
 /*
@@ -557,15 +564,22 @@ static irqreturn_t talitos_interrupt(int irq, void *data)
         isr = in_be32(priv->reg + TALITOS_ISR);
         isr_lo = in_be32(priv->reg + TALITOS_ISR_LO);
 
-        /* ack */
-        out_be32(priv->reg + TALITOS_ICR, isr);
-        out_be32(priv->reg + TALITOS_ICR_LO, isr_lo);
+        if (unlikely((isr & ~TALITOS_ISR_CHDONE) || isr_lo)) {
+                /*
+                 * Acknowledge error interrupts here.
+                 * Done interrupts are ack'ed as part of done_task.
+                 */
+                out_be32(priv->reg + TALITOS_ICR, isr);
+                out_be32(priv->reg + TALITOS_ICR_LO, isr_lo);
 
-        if (unlikely((isr & ~TALITOS_ISR_CHDONE) || isr_lo))
                 talitos_error((unsigned long)data, isr, isr_lo);
-        else
-                if (likely(isr & TALITOS_ISR_CHDONE))
+        } else
+                if (likely(isr & TALITOS_ISR_CHDONE)) {
+                        /* mask further done interrupts. */
+                        clrbits32(priv->reg + TALITOS_IMR, TALITOS_IMR_DONE);
+                        /* done_task will unmask done interrupts at exit */
                         tasklet_schedule(&priv->done_task);
+                }
 
         return (isr || isr_lo) ? IRQ_HANDLED : IRQ_NONE;
 }
diff --git a/drivers/crypto/talitos.h b/drivers/crypto/talitos.h
index c48a405abf70..e6b87770df03 100644
--- a/drivers/crypto/talitos.h
+++ b/drivers/crypto/talitos.h
@@ -37,7 +37,8 @@
 #define TALITOS_MCR_LO                  0x1038
 #define   TALITOS_MCR_SWR               0x1     /* s/w reset */
 #define TALITOS_IMR                     0x1008  /* interrupt mask register */
-#define   TALITOS_IMR_INIT              0x10fff /* enable channel IRQs */
+#define   TALITOS_IMR_INIT              0x100ff /* enable channel IRQs */
+#define   TALITOS_IMR_DONE              0x00055 /* done IRQs */
 #define TALITOS_IMR_LO                  0x100C
 #define   TALITOS_IMR_LO_INIT           0x20000 /* allow RNGU error IRQs */
 #define TALITOS_ISR                     0x1010  /* interrupt status register */