crypto: caam - Add API's to allocate/free Job Rings

With each of the Job Ring available as a platform device, the
Job Ring driver needs to take care of allocation/deallocation
of the Job Rings to the above interface layers. Added APIs
in Job Ring Driver to allocate/free Job rings

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Reviewed-by: Garg Vakul-B16394 <vakul@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 57 insertions, 3 deletions

diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index cdeaf2519b48..636bb53125ab 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -97,10 +97,9 @@ static int caam_jr_remove(struct platform_device *pdev)
         jrpriv = dev_get_drvdata(jrdev);
 
         /*
-         * Make sure ring is empty before release
+         * Return EBUSY if job ring already allocated.
          */
-        if (rd_reg32(&jrpriv->rregs->outring_used) ||
-            (rd_reg32(&jrpriv->rregs->inpring_avail) != JOBR_DEPTH)) {
+        if (atomic_read(&jrpriv->tfm_count)) {
                 dev_err(jrdev, "Device is busy\n");
                 return -EBUSY;
         }
@@ -234,6 +233,59 @@ static void caam_jr_dequeue(unsigned long devarg)
 }
 
 /**
+ * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
+ *
+ * returns :  pointer to the newly allocated physical
+ *            JobR dev can be written to if successful.
+ **/
+struct device *caam_jr_alloc(void)
+{
+        struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
+        struct device *dev = NULL;
+        int min_tfm_cnt = INT_MAX;
+        int tfm_cnt;
+
+        spin_lock(&driver_data.jr_alloc_lock);
+
+        if (list_empty(&driver_data.jr_list)) {
+                spin_unlock(&driver_data.jr_alloc_lock);
+                return ERR_PTR(-ENODEV);
+        }
+
+        list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
+                tfm_cnt = atomic_read(&jrpriv->tfm_count);
+                if (tfm_cnt < min_tfm_cnt) {
+                        min_tfm_cnt = tfm_cnt;
+                        min_jrpriv = jrpriv;
+                }
+                if (!min_tfm_cnt)
+                        break;
+        }
+
+        if (min_jrpriv) {
+                atomic_inc(&min_jrpriv->tfm_count);
+                dev = min_jrpriv->dev;
+        }
+        spin_unlock(&driver_data.jr_alloc_lock);
+
+        return dev;
+}
+EXPORT_SYMBOL(caam_jr_alloc);
+
+/**
+ * caam_jr_free() - Free the Job Ring
+ * @rdev     - points to the dev that identifies the Job ring to
+ *             be released.
+ **/
+void caam_jr_free(struct device *rdev)
+{
+        struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
+
+        atomic_dec(&jrpriv->tfm_count);
+}
+EXPORT_SYMBOL(caam_jr_free);
+
+/**
  * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
  * -EBUSY if the queue is full, -EIO if it cannot map the caller's
  * descriptor.
@@ -442,6 +494,8 @@ static int caam_jr_probe(struct platform_device *pdev)
         list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
         spin_unlock(&driver_data.jr_alloc_lock);
 
+        atomic_set(&jrpriv->tfm_count, 0);
+
         return 0;
 }