+
+ if (!timeout)
+ return -EAGAIN;
+
+ return 0;
+}
+
+/*
+ * instantiate_rng - builds and executes a descriptor on DECO0,
+ * which initializes the RNG block.
+ * @ctrldev - pointer to device
+ * @state_handle_mask - bitmask containing the instantiation status
+ * for the RNG4 state handles which exist in
+ * the RNG4 block: 1 if it's been instantiated
+ * by an external entry, 0 otherwise.
+ * @gen_sk - generate data to be loaded into the JDKEK, TDKEK and TDSK;
+ * Caution: this can be done only once; if the keys need to be
+ * regenerated, a POR is required
+ *
+ * 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, int state_handle_mask,
+ int gen_sk)
+{
+ struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
+ struct caam_full __iomem *topregs;
+ struct rng4tst __iomem *r4tst;
+ u32 *desc, status, rdsta_val;
+ int ret = 0, sh_idx;
+
+ topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
+ r4tst = &topregs->ctrl.r4tst[0];
+
+ desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL);
+ if (!desc)
+ return -ENOMEM;
+
+ for (sh_idx = 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) {
+ /*
+ * If the corresponding bit is set, this state handle
+ * was initialized by somebody else, so it's left alone.
+ */
+ if ((1 << sh_idx) & state_handle_mask)
+ continue;
+
+ /* Create the descriptor for instantiating RNG State Handle */
+ build_instantiation_desc(desc, sh_idx, gen_sk);
+
+ /* Try to run it through DECO0 */
+ ret = run_descriptor_deco0(ctrldev, desc, &status);
+
+ /*
+ * If ret is not 0, or descriptor status is not 0, then
+ * something went wrong. No need to try the next state
+ * handle (if available), bail out here.
+ * Also, if for some reason, the State Handle didn't get
+ * instantiated although the descriptor has finished
+ * without any error (HW optimizations for later
+ * CAAM eras), then try again.
+ */
+ rdsta_val =
+ rd_reg32(&topregs->ctrl.r4tst[0].rdsta) & RDSTA_IFMASK;
+ if (status || !(rdsta_val & (1 << sh_idx)))
+ ret = -EAGAIN;
+ if (ret)
+ break;
+
+ dev_info(ctrldev, "Instantiated RNG4 SH%d\n", sh_idx);
+ /* Clear the contents before recreating the descriptor */
+ memset(desc, 0x00, CAAM_CMD_SZ * 7);
+ }
+