1 files changed, 380 insertions, 0 deletions
diff --git a/drivers/crypto/caam/inst_rng.c b/drivers/crypto/caam/inst_rng.c
new file mode 100644
index 000000000000..51bedb9dbf6a
--- /dev/null
+++ b/drivers/crypto/caam/inst_rng.c
@@ -0,0 +1,380 @@
+/*
+ * CAAM RNG instantiation driver backend
+ *
+ * Copyright 2017-2018 NXP
+ */
+
+#include <linux/device.h>
+#include <linux/of_address.h>
+#include <linux/wait.h>
+#include "compat.h"
+#include "regs.h"
+#include "intern.h"
+#include "jr.h"
+#include "desc_constr.h"
+#include "error.h"
+#include "ctrl.h"
+#include "inst_rng.h"
+
+static DECLARE_WAIT_QUEUE_HEAD(wq_desc);
+static int desc_completed;
+static int desc_status;
+
+/*
+ * Descriptor to instantiate RNG State Handle 0 in normal mode and
+ * load the JDKEK, TDKEK and TDSK registers
+ */
+static void build_instantiation_desc(u32 *desc, int handle, int do_sk)
+{
+	u32 *jump_cmd, op_flags;
+
+	init_job_desc(desc, 0);
+
+	op_flags = OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
+			(handle << OP_ALG_AAI_SHIFT) | OP_ALG_AS_INIT;
+
+	/* INIT RNG in non-test mode */
+	append_operation(desc, op_flags);
+
+	if (!handle && do_sk) {
+		/*
+		 * For SH0, Secure Keys must be generated as well
+		 */
+
+		/* wait for done */
+		jump_cmd = append_jump(desc, JUMP_CLASS_CLASS1);
+		set_jump_tgt_here(desc, jump_cmd);
+
+		/*
+		 * load 1 to clear written reg:
+		 * resets the done interrupt and returns the RNG to idle.
+		 */
+		append_load_imm_u32(desc, 1, LDST_SRCDST_WORD_CLRW);
+
+		/* Initialize State Handle  */
+		append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
+				 OP_ALG_AAI_RNG4_SK);
+	}
+
+	append_jump(desc, JUMP_CLASS_CLASS1 | JUMP_TYPE_HALT);
+}
+
+/* Descriptor for deinstantiation of State Handle 0 of the RNG block. */
+static void build_deinstantiation_desc(u32 *desc, int handle)
+{
+	init_job_desc(desc, 0);
+
+	/* Uninstantiate State Handle 0 */
+	append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
+			 (handle << OP_ALG_AAI_SHIFT) | OP_ALG_AS_INITFINAL);
+
+	append_jump(desc, JUMP_CLASS_CLASS1 | JUMP_TYPE_HALT);
+}
+
+void cbk_jr_rng_inst(struct device *jrdev, u32 *desc,  u32 status, void *areq)
+{
+	if ((status & JRSTA_SSRC_JUMP_HALT_CC) == JRSTA_SSRC_JUMP_HALT_CC) {
+		dev_info(jrdev, "Instantiated RNG4 SH%d.\n", *((int *)areq));
+		desc_status = 0;
+	} else {
+		desc_status = -EAGAIN;
+	}
+	desc_completed = 1;
+	wake_up(&wq_desc);
+}
+
+/*
+ * run_descriptor_jr - runs a descriptor on first JR
+ * @status - descriptor status, after being run
+ *
+ * Return: - 0 if no error occurred
+ *	   - -ENODEV if the DECO couldn't be acquired
+ *	   - -EAGAIN if an error occurred while executing the descriptor
+ */
+static int run_descriptor_jr(u32 *desc, int sh_idx)
+{
+	struct device *jrdev;
+	int ret;
+
+	jrdev = caam_jr_alloc();
+	if (IS_ERR(jrdev)) {
+		pr_err("Job Ring Device allocation for transform failed\n");
+		return -ENODEV;
+	}
+	ret = caam_jr_enqueue(jrdev, desc, cbk_jr_rng_inst, &sh_idx);
+	if (ret) {
+		dev_err(jrdev, "caam_jr_enqueue() failed\n");
+		return ret;
+	}
+	/* wait for job descriptor completion */
+	wait_event(wq_desc, desc_completed != 0);
+	desc_completed = 0;
+	caam_jr_free(jrdev);
+	return desc_status;
+}
+
+/*
+ * instantiate_rng - builds and executes a descriptor on JR0,
+ *		     which initializes the RNG block.
+ * @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 acquired.
+ */
+static int instantiate_rng(int state_handle_mask, int gen_sk)
+{
+	u32 *desc;
+	int sh_idx, ret = 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 JR */
+		ret = run_descriptor_jr(desc, sh_idx);
+		if (ret)
+			pr_debug("Failed to run desc  RNG4 SH%d status (0x%x)\n",
+				 sh_idx, ret);
+		/* Clear the contents before recreating the descriptor */
+		memset(desc, 0x00, CAAM_CMD_SZ * 7);
+	}
+
+	kfree(desc);
+
+	return ret;
+}
+
+/*
+ * deinstantiate_rng - builds and executes a descriptor on JR0,
+ *		       which deinitializes the RNG block.
+ * @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
+ *
+ * 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
+ */
+int deinstantiate_rng(int state_handle_mask)
+{
+	u32 *desc;
+	int sh_idx, ret = 0;
+
+	desc = kmalloc(CAAM_CMD_SZ * 3, GFP_KERNEL);
+	if (!desc)
+		return -ENOMEM;
+
+	for (sh_idx = 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) {
+		/*
+		 * If the corresponding bit is set, then it means the state
+		 * handle was initialized by us, and thus it needs to be
+		 * deintialized as well
+		 */
+		if ((1 << sh_idx) & state_handle_mask) {
+			/*
+			 * Create the descriptor for deinstantating this state
+			 * handle
+			 */
+			build_deinstantiation_desc(desc, sh_idx);
+
+			/* Try to run it through JR */
+			ret = run_descriptor_jr(desc, sh_idx);
+			if (ret)
+				pr_debug("Failed to run desc to deinstantiate RNG4 SH%d\n",
+					 sh_idx);
+		}
+	}
+
+	kfree(desc);
+
+	return ret;
+}
+
+/*
+ * kick_trng - sets the various parameters for enabling the initialization
+ *	       of the RNG4 block in CAAM
+ * @ctrldev - pointer to the device
+ * @ent_delay - Defines the length (in system clocks) of each entropy sample.
+ */
+static void kick_trng(struct device *ctrldev, int ent_delay)
+{
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
+	struct caam_ctrl __iomem *ctrl;
+	struct rng4tst __iomem *r4tst;
+	u32 val;
+
+	ctrl = (struct caam_ctrl __iomem *)ctrlpriv->ctrl;
+	r4tst = &ctrl->r4tst[0];
+
+	/* put RNG4 into program mode */
+	clrsetbits_32(&r4tst->rtmctl, 0, RTMCTL_PRGM);
+
+	/*
+	 * Performance-wise, it does not make sense to
+	 * set the delay to a value that is lower
+	 * than the last one that worked (i.e. the state handles
+	 * were instantiated properly. Thus, instead of wasting
+	 * time trying to set the values controlling the sample
+	 * frequency, the function simply returns.
+	 */
+	val = (rd_reg32(&r4tst->rtsdctl) & RTSDCTL_ENT_DLY_MASK)
+	      >> RTSDCTL_ENT_DLY_SHIFT;
+	if (ent_delay <= val) {
+		/* put RNG4 into run mode */
+		clrsetbits_32(&r4tst->rtmctl, RTMCTL_PRGM, 0);
+		return;
+	}
+
+	val = rd_reg32(&r4tst->rtsdctl);
+	val = (val & ~RTSDCTL_ENT_DLY_MASK) |
+	      (ent_delay << RTSDCTL_ENT_DLY_SHIFT);
+	wr_reg32(&r4tst->rtsdctl, val);
+	/* min. freq. count, equal to 1/4 of the entropy sample length */
+	wr_reg32(&r4tst->rtfrqmin, ent_delay >> 2);
+	/* max. freq. count, equal to 16 times the entropy sample length */
+	wr_reg32(&r4tst->rtfrqmax, ent_delay << 4);
+	/* read the control register */
+	val = rd_reg32(&r4tst->rtmctl);
+	/*
+	 * select raw sampling in both entropy shifter
+	 * and statistical checker
+	 */
+	clrsetbits_32(&val, 0, RTMCTL_SAMP_MODE_RAW_ES_SC);
+	/* put RNG4 into run mode */
+	clrsetbits_32(&val, RTMCTL_PRGM, 0);
+	/* write back the control register */
+	wr_reg32(&r4tst->rtmctl, val);
+}
+
+/*
+ * inst_rng_imx - RNG instantiation function for i.MX6/7/8m platforms
+ * @pdev - pointer to the device
+ */
+int inst_rng_imx(struct platform_device *pdev)
+{
+	struct device *ctrldev, *dev;
+	struct caam_drv_private *ctrlpriv;
+	struct caam_ctrl __iomem *ctrl;
+	int ret = 0, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN;
+	u32 cha_vid_ls;
+
+	dev = &pdev->dev;
+	ctrldev = pdev->dev.parent;
+	ctrlpriv = dev_get_drvdata(ctrldev);
+	ctrl = (struct caam_ctrl __iomem *)ctrlpriv->ctrl;
+
+#ifndef CONFIG_ARM64
+	/*
+	 * Check if the Secure Firmware is running,
+	 * check only for i.MX6 and i.MX7
+	 */
+	if (of_find_compatible_node(NULL, NULL, "linaro,optee-tz")) {
+		pr_info("RNG Instantation done by Secure Firmware\n");
+		return ret;
+	}
+#endif
+
+	cha_vid_ls = rd_reg32(&ctrl->perfmon.cha_id_ls);
+	/*
+	 * If SEC has RNG version >= 4 and RNG state handle has not been
+	 * already instantiated, do RNG instantiation
+	 */
+	if ((cha_vid_ls & CHA_ID_LS_RNG_MASK) >> CHA_ID_LS_RNG_SHIFT >= 4) {
+		ctrlpriv->rng4_sh_init =
+			rd_reg32(&ctrl->r4tst[0].rdsta);
+		/*
+		 * If the secure keys (TDKEK, JDKEK, TDSK), were already
+		 * generated, signal this to the function that is instantiating
+		 * the state handles. An error would occur if RNG4 attempts
+		 * to regenerate these keys before the next POR.
+		 */
+		gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1;
+		ctrlpriv->rng4_sh_init &= RDSTA_IFMASK;
+		do {
+			int inst_handles =
+				rd_reg32(&ctrl->r4tst[0].rdsta) &
+								RDSTA_IFMASK;
+			/*
+			 * If either SH were instantiated by somebody else
+			 * (e.g. u-boot) then it is assumed that the entropy
+			 * parameters are properly set and thus the function
+			 * setting these (kick_trng(...)) is skipped.
+			 * Also, if a handle was instantiated, do not change
+			 * the TRNG parameters.
+			 */
+			if (!(ctrlpriv->rng4_sh_init || inst_handles)) {
+				dev_info(dev,
+					 "Entropy delay = %u\n",
+					 ent_delay);
+				kick_trng(ctrldev, ent_delay);
+				ent_delay += ENT_DELAY_STEP;
+			}
+			/*
+			 * if instantiate_rng(...) fails, the loop will rerun
+			 * and the kick_trng(...) function will modfiy the
+			 * upper and lower limits of the entropy sampling
+			 * interval, leading to a sucessful initialization of
+			 * the RNG.
+			 */
+			ret = instantiate_rng(inst_handles, gen_sk);
+			if (ret == -EAGAIN)
+				/*
+				 * if here, the loop will rerun,
+				 * so don't hog the CPU
+				 */
+				cpu_relax();
+		} while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
+		if (ret) {
+			dev_err(dev, "failed to instantiate RNG");
+			return ret;
+		}
+		/*
+		 * Set handles init'ed by this module as the complement of the
+		 * already initialized ones
+		 */
+		ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_IFMASK;
+		/* Enable RDB bit so that RNG works faster */
+		clrsetbits_32(&ctrl->scfgr, 0, SCFGR_RDBENABLE);
+	}
+	return ret;
+}
+
+/*
+ * deinst_rng - RNG de-instantiation function
+ * @pdev - pointer to the device
+ */
+int deinst_rng(struct platform_device *pdev)
+{
+	struct device *ctrldev, *dev;
+	struct caam_drv_private *ctrlpriv;
+	int ret = 0;
+
+	dev = &pdev->dev;
+	ctrldev = pdev->dev.parent;
+	ctrlpriv = dev_get_drvdata(ctrldev);
+
+	ret = deinstantiate_rng(ctrlpriv->rng4_sh_init);
+	return ret;
+}