crypto: caam - split RNG4 instantiation function

[karo-tx-linux.git] / drivers / crypto / caam / ctrl.c

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index d5fe5f57108c6ffffea606630138bbe2e8e8fa21..3ad032f570aee13d9906893daaf2e08506929c43 100644 (file)
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -13,39 +13,6 @@
 #include "error.h"
 #include "ctrl.h"
 
-static int caam_remove(struct platform_device *pdev)
-{
-       struct device *ctrldev;
-       struct caam_drv_private *ctrlpriv;
-       struct caam_drv_private_jr *jrpriv;
-       struct caam_full __iomem *topregs;
-       int ring, ret = 0;
-
-       ctrldev = &pdev->dev;
-       ctrlpriv = dev_get_drvdata(ctrldev);
-       topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
-
-       /* shut down JobRs */
-       for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
-               ret |= caam_jr_shutdown(ctrlpriv->jrdev[ring]);
-               jrpriv = dev_get_drvdata(ctrlpriv->jrdev[ring]);
-               irq_dispose_mapping(jrpriv->irq);
-       }
-
-       /* Shut down debug views */
-#ifdef CONFIG_DEBUG_FS
-       debugfs_remove_recursive(ctrlpriv->dfs_root);
-#endif
-
-       /* Unmap controller region */
-       iounmap(&topregs->ctrl);
-
-       kfree(ctrlpriv->jrdev);
-       kfree(ctrlpriv);
-
-       return ret;
-}
-
 /*
  * Descriptor to instantiate RNG State Handle 0 in normal mode and
  * load the JDKEK, TDKEK and TDSK registers
@@ -77,21 +44,23 @@ static void build_instantiation_desc(u32 *desc)
        append_jump(desc, JUMP_CLASS_CLASS1 | JUMP_TYPE_HALT);
 }
 
-static int instantiate_rng(struct device *ctrldev)
+
+/*
+ * run_descriptor_deco0 - runs a descriptor on DECO0, under direct control of
+ *                       the software (no JR/QI used).
+ * @ctrldev - pointer to device
+ * Return: - 0 if no error occurred
+ *        - -ENODEV if the DECO couldn't be acquired
+ *        - -EAGAIN if an error occurred while executing the descriptor
+ */
+static inline int run_descriptor_deco0(struct device *ctrldev, u32 *desc)
 {
        struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
        struct caam_full __iomem *topregs;
        unsigned int timeout = 100000;
-       u32 *desc, deco_dbg_reg;
+       u32 deco_dbg_reg, flags;
        int i, ret = 0;
 
-       desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL | GFP_DMA);
-       if (!desc) {
-               dev_err(ctrldev, "can't allocate RNG init descriptor memory\n");
-               return -ENOMEM;
-       }
-       build_instantiation_desc(desc);
-
        /* Set the bit to request direct access to DECO0 */
        topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
        setbits32(&topregs->ctrl.deco_rq, DECORR_RQD0ENABLE);
@@ -102,14 +71,23 @@ static int instantiate_rng(struct device *ctrldev)
 
        if (!timeout) {
                dev_err(ctrldev, "failed to acquire DECO 0\n");
-               ret = -EIO;
-               goto out;
+               clrbits32(&topregs->ctrl.deco_rq, DECORR_RQD0ENABLE);
+               return -ENODEV;
        }
 
        for (i = 0; i < desc_len(desc); i++)
-               topregs->deco.descbuf[i] = *(desc + i);
+               wr_reg32(&topregs->deco.descbuf[i], *(desc + i));
 
-       wr_reg32(&topregs->deco.jr_ctl_hi, DECO_JQCR_WHL | DECO_JQCR_FOUR);
+       flags = DECO_JQCR_WHL;
+       /*
+        * If the descriptor length is longer than 4 words, then the
+        * FOUR bit in JRCTRL register must be set.
+        */
+       if (desc_len(desc) >= 4)
+               flags |= DECO_JQCR_FOUR;
+
+       /* Instruct the DECO to execute it */
+       wr_reg32(&topregs->deco.jr_ctl_hi, flags);
 
        timeout = 10000000;
        do {
@@ -129,9 +107,75 @@ static int instantiate_rng(struct device *ctrldev)
                ret = -EIO;
        }
 
+       /* Mark the DECO as free */
        clrbits32(&topregs->ctrl.deco_rq, DECORR_RQD0ENABLE);
-out:
+
+       if (!timeout)
+               return -EAGAIN;
+
+       return 0;
+}
+
+/*
+ * instantiate_rng - builds and executes a descriptor on DECO0,
+ *                  which initializes the RNG block.
+ * @ctrldev - pointer to device
+ * Return: - 0 if no error occurred
+ *        - -ENOMEM if there isn't enough memory to allocate the descriptor
+ *        - -ENODEV if DECO0 couldn't be acquired
+ *        - -EAGAIN if an error occurred when executing the descriptor
+ *           f.i. there was a RNG hardware error due to not "good enough"
+ *           entropy being aquired.
+ */
+static int instantiate_rng(struct device *ctrldev)
+{
+       u32 *desc;
+       int ret = 0;
+
+       desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL);
+       if (!desc)
+               return -ENOMEM;
+       /* Create the descriptor for instantiating RNG State Handle 0 */
+       build_instantiation_desc(desc);
+
+       /* Try to run it through DECO0 */
+       ret = run_descriptor_deco0(ctrldev, desc);
+
        kfree(desc);
+
+       return ret;
+}
+
+static int caam_remove(struct platform_device *pdev)
+{
+       struct device *ctrldev;
+       struct caam_drv_private *ctrlpriv;
+       struct caam_drv_private_jr *jrpriv;
+       struct caam_full __iomem *topregs;
+       int ring, ret = 0;
+
+       ctrldev = &pdev->dev;
+       ctrlpriv = dev_get_drvdata(ctrldev);
+       topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
+
+       /* shut down JobRs */
+       for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
+               ret |= caam_jr_shutdown(ctrlpriv->jrdev[ring]);
+               jrpriv = dev_get_drvdata(ctrlpriv->jrdev[ring]);
+               irq_dispose_mapping(jrpriv->irq);
+       }
+
+       /* Shut down debug views */
+#ifdef CONFIG_DEBUG_FS
+       debugfs_remove_recursive(ctrlpriv->dfs_root);
+#endif
+
+       /* Unmap controller region */
+       iounmap(&topregs->ctrl);
+
+       kfree(ctrlpriv->jrdev);
+       kfree(ctrlpriv);
+
        return ret;
 }
 
@@ -333,7 +377,7 @@ static int caam_probe(struct platform_device *pdev)
                        kick_trng(pdev, ent_delay);
                        ret = instantiate_rng(dev);
                        ent_delay += 400;
-               } while ((ret == -EIO) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
+               } while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
                if (ret) {
                        dev_err(dev, "failed to instantiate RNG");
                        caam_remove(pdev);