1 files changed, 79 insertions, 32 deletions

diff --git a/drivers/char/hw_random/cn10k-rng.c b/drivers/char/hw_random/cn10k-rng.c
index 35001c63648b..3b4e78182e14 100644
--- a/drivers/char/hw_random/cn10k-rng.c
+++ b/drivers/char/hw_random/cn10k-rng.c
@@ -23,34 +23,66 @@
 #define RNM_PF_RANDOM		0x400
 #define RNM_TRNG_RESULT		0x408
 
+/* Extended TRNG Read and Status Registers */
+#define RNM_PF_TRNG_DAT		0x1000
+#define RNM_PF_TRNG_RES		0x1008
+
 struct cn10k_rng {
 	void __iomem *reg_base;
 	struct hwrng ops;
 	struct pci_dev *pdev;
+	/* Octeon CN10K-A A0/A1, CNF10K-A A0/A1 and CNF10K-B A0/B0
+	 * does not support extended TRNG registers
+	 */
+	bool extended_trng_regs;
 };
 
 #define PLAT_OCTEONTX_RESET_RNG_EBG_HEALTH_STATE     0xc2000b0f
 
-static int reset_rng_health_state(struct cn10k_rng *rng)
+#define PCI_SUBSYS_DEVID_CN10K_A_RNG	0xB900
+#define PCI_SUBSYS_DEVID_CNF10K_A_RNG	0xBA00
+#define PCI_SUBSYS_DEVID_CNF10K_B_RNG	0xBC00
+
+static bool cn10k_is_extended_trng_regs_supported(struct pci_dev *pdev)
+{
+	/* CN10K-A A0/A1 */
+	if ((pdev->subsystem_device == PCI_SUBSYS_DEVID_CN10K_A_RNG) &&
+	    (!pdev->revision || (pdev->revision & 0xff) == 0x50 ||
+	     (pdev->revision & 0xff) == 0x51))
+		return false;
+
+	/* CNF10K-A A0 */
+	if ((pdev->subsystem_device == PCI_SUBSYS_DEVID_CNF10K_A_RNG) &&
+	    (!pdev->revision || (pdev->revision & 0xff) == 0x60 ||
+	     (pdev->revision & 0xff) == 0x61))
+		return false;
+
+	/* CNF10K-B A0/B0 */
+	if ((pdev->subsystem_device == PCI_SUBSYS_DEVID_CNF10K_B_RNG) &&
+	    (!pdev->revision || (pdev->revision & 0xff) == 0x70 ||
+	     (pdev->revision & 0xff) == 0x74))
+		return false;
+
+	return true;
+}
+
+static unsigned long reset_rng_health_state(struct cn10k_rng *rng)
 {
 	struct arm_smccc_res res;
 
 	/* Send SMC service call to reset EBG health state */
 	arm_smccc_smc(PLAT_OCTEONTX_RESET_RNG_EBG_HEALTH_STATE, 0, 0, 0, 0, 0, 0, 0, &res);
-	if (res.a0 != 0UL)
-		return -EIO;
-
-	return 0;
+	return res.a0;
 }
 
 static int check_rng_health(struct cn10k_rng *rng)
 {
 	u64 status;
-	int err;
+	unsigned long err;
 
 	/* Skip checking health */
 	if (!rng->reg_base)
-		return 0;
+		return -ENODEV;
 
 	status = readq(rng->reg_base + RNM_PF_EBG_HEALTH);
 	if (status & BIT_ULL(20)) {
@@ -58,15 +90,31 @@ static int check_rng_health(struct cn10k_rng *rng)
 		if (err) {
 			dev_err(&rng->pdev->dev, "HWRNG: Health test failed (status=%llx)\n",
 					status);
-			dev_err(&rng->pdev->dev, "HWRNG: error during reset\n");
+			dev_err(&rng->pdev->dev, "HWRNG: error during reset (error=%lx)\n",
+					err);
+			return -EIO;
 		}
 	}
 	return 0;
 }
 
-static void cn10k_read_trng(struct cn10k_rng *rng, u64 *value)
+/* Returns true when valid data available otherwise return false */
+static bool cn10k_read_trng(struct cn10k_rng *rng, u64 *value)
 {
+	u16 retry_count = 0;
 	u64 upper, lower;
+	u64 status;
+
+	if (rng->extended_trng_regs) {
+		do {
+			*value = readq(rng->reg_base + RNM_PF_TRNG_DAT);
+			if (*value)
+				return true;
+			status = readq(rng->reg_base + RNM_PF_TRNG_RES);
+			if (!status && (retry_count++ > 0x1000))
+				return false;
+		} while (!status);
+	}
 
 	*value = readq(rng->reg_base + RNM_PF_RANDOM);
 
@@ -83,6 +131,7 @@ static void cn10k_read_trng(struct cn10k_rng *rng, u64 *value)
 
 		*value = (upper & 0xFFFFFFFF00000000) | (lower & 0xFFFFFFFF);
 	}
+	return true;
 }
 
 static int cn10k_rng_read(struct hwrng *hwrng, void *data,
@@ -90,6 +139,7 @@ static int cn10k_rng_read(struct hwrng *hwrng, void *data,
 {
 	struct cn10k_rng *rng = (struct cn10k_rng *)hwrng->priv;
 	unsigned int size;
+	u8 *pos = data;
 	int err = 0;
 	u64 value;
 
@@ -100,21 +150,27 @@ static int cn10k_rng_read(struct hwrng *hwrng, void *data,
 	size = max;
 
 	while (size >= 8) {
-		cn10k_read_trng(rng, &value);
+		if (!cn10k_read_trng(rng, &value))
+			goto out;
 
-		*((u64 *)data) = (u64)value;
+		*((u64 *)pos) = value;
 		size -= 8;
-		data += 8;
+		pos += 8;
 	}
 
-	while (size > 0) {
-		cn10k_read_trng(rng, &value);
+	if (size > 0) {
+		if (!cn10k_read_trng(rng, &value))
+			goto out;
 
-		*((u8 *)data) = (u8)value;
-		size--;
-		data++;
+		while (size > 0) {
+			*pos = (u8)value;
+			value >>= 8;
+			size--;
+			pos++;
+		}
 	}
 
+out:
 	return max - size;
 }
 
@@ -131,36 +187,28 @@ static int cn10k_rng_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	pci_set_drvdata(pdev, rng);
 
 	rng->reg_base = pcim_iomap(pdev, 0, 0);
-	if (!rng->reg_base) {
-		dev_err(&pdev->dev, "Error while mapping CSRs, exiting\n");
+	if (!rng->reg_base)
 		return -ENOMEM;
-	}
 
 	rng->ops.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
 				       "cn10k-rng-%s", dev_name(&pdev->dev));
 	if (!rng->ops.name)
 		return -ENOMEM;
 
-	rng->ops.read    = cn10k_rng_read;
-	rng->ops.quality = 1000;
+	rng->ops.read = cn10k_rng_read;
 	rng->ops.priv = (unsigned long)rng;
 
+	rng->extended_trng_regs = cn10k_is_extended_trng_regs_supported(pdev);
+
 	reset_rng_health_state(rng);
 
 	err = devm_hwrng_register(&pdev->dev, &rng->ops);
-	if (err) {
-		dev_err(&pdev->dev, "Could not register hwrng device.\n");
-		return err;
-	}
+	if (err)
+		return dev_err_probe(&pdev->dev, err, "Could not register hwrng device.\n");
 
 	return 0;
 }
 
-static void cn10k_rng_remove(struct pci_dev *pdev)
-{
-	/* Nothing to do */
-}
-
 static const struct pci_device_id cn10k_rng_id_table[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xA098) }, /* RNG PF */
 	{0,},
@@ -172,7 +220,6 @@ static struct pci_driver cn10k_rng_driver = {
 	.name		= "cn10k_rng",
 	.id_table	= cn10k_rng_id_table,
 	.probe		= cn10k_rng_probe,
-	.remove		= cn10k_rng_remove,
 };
 
 module_pci_driver(cn10k_rng_driver);