From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 13 May 2024 10:30:14 +0000
Subject: [PATCH] modify sin led gpio

---
 kernel/drivers/char/hw_random/cavium-rng-vf.c |  191 ++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 179 insertions(+), 12 deletions(-)

diff --git a/kernel/drivers/char/hw_random/cavium-rng-vf.c b/kernel/drivers/char/hw_random/cavium-rng-vf.c
index 2d1352b..6f66919 100644
--- a/kernel/drivers/char/hw_random/cavium-rng-vf.c
+++ b/kernel/drivers/char/hw_random/cavium-rng-vf.c
@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- * Hardware Random Number Generator support for Cavium, Inc.
- * Thunder processor family.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
+ * Hardware Random Number Generator support.
+ * Cavium Thunder, Marvell OcteonTx/Tx2 processor families.
  *
  * Copyright (C) 2016 Cavium, Inc.
  */
@@ -15,16 +12,146 @@
 #include <linux/pci.h>
 #include <linux/pci_ids.h>
 
+#include <asm/arch_timer.h>
+
+/* PCI device IDs */
+#define	PCI_DEVID_CAVIUM_RNG_PF		0xA018
+#define	PCI_DEVID_CAVIUM_RNG_VF		0xA033
+
+#define HEALTH_STATUS_REG		0x38
+
+/* RST device info */
+#define PCI_DEVICE_ID_RST_OTX2		0xA085
+#define RST_BOOT_REG			0x1600ULL
+#define CLOCK_BASE_RATE			50000000ULL
+#define MSEC_TO_NSEC(x)			(x * 1000000)
+
 struct cavium_rng {
 	struct hwrng ops;
 	void __iomem *result;
+	void __iomem *pf_regbase;
+	struct pci_dev *pdev;
+	u64  clock_rate;
+	u64  prev_error;
+	u64  prev_time;
 };
+
+static inline bool is_octeontx(struct pci_dev *pdev)
+{
+	if (midr_is_cpu_model_range(read_cpuid_id(), MIDR_THUNDERX_83XX,
+				    MIDR_CPU_VAR_REV(0, 0),
+				    MIDR_CPU_VAR_REV(3, 0)) ||
+	    midr_is_cpu_model_range(read_cpuid_id(), MIDR_THUNDERX_81XX,
+				    MIDR_CPU_VAR_REV(0, 0),
+				    MIDR_CPU_VAR_REV(3, 0)) ||
+	    midr_is_cpu_model_range(read_cpuid_id(), MIDR_THUNDERX,
+				    MIDR_CPU_VAR_REV(0, 0),
+				    MIDR_CPU_VAR_REV(3, 0)))
+		return true;
+
+	return false;
+}
+
+static u64 rng_get_coprocessor_clkrate(void)
+{
+	u64 ret = CLOCK_BASE_RATE * 16; /* Assume 800Mhz as default */
+	struct pci_dev *pdev;
+	void __iomem *base;
+
+	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
+			      PCI_DEVICE_ID_RST_OTX2, NULL);
+	if (!pdev)
+		goto error;
+
+	base = pci_ioremap_bar(pdev, 0);
+	if (!base)
+		goto error_put_pdev;
+
+	/* RST: PNR_MUL * 50Mhz gives clockrate */
+	ret = CLOCK_BASE_RATE * ((readq(base + RST_BOOT_REG) >> 33) & 0x3F);
+
+	iounmap(base);
+
+error_put_pdev:
+	pci_dev_put(pdev);
+
+error:
+	return ret;
+}
+
+static int check_rng_health(struct cavium_rng *rng)
+{
+	u64 cur_err, cur_time;
+	u64 status, cycles;
+	u64 time_elapsed;
+
+
+	/* Skip checking health for OcteonTx */
+	if (!rng->pf_regbase)
+		return 0;
+
+	status = readq(rng->pf_regbase + HEALTH_STATUS_REG);
+	if (status & BIT_ULL(0)) {
+		dev_err(&rng->pdev->dev, "HWRNG: Startup health test failed\n");
+		return -EIO;
+	}
+
+	cycles = status >> 1;
+	if (!cycles)
+		return 0;
+
+	cur_time = arch_timer_read_counter();
+
+	/* RNM_HEALTH_STATUS[CYCLES_SINCE_HEALTH_FAILURE]
+	 * Number of coprocessor cycles times 2 since the last failure.
+	 * This field doesn't get cleared/updated until another failure.
+	 */
+	cycles = cycles / 2;
+	cur_err = (cycles * 1000000000) / rng->clock_rate; /* In nanosec */
+
+	/* Ignore errors that happenned a long time ago, these
+	 * are most likely false positive errors.
+	 */
+	if (cur_err > MSEC_TO_NSEC(10)) {
+		rng->prev_error = 0;
+		rng->prev_time = 0;
+		return 0;
+	}
+
+	if (rng->prev_error) {
+		/* Calculate time elapsed since last error
+		 * '1' tick of CNTVCT is 10ns, since it runs at 100Mhz.
+		 */
+		time_elapsed = (cur_time - rng->prev_time) * 10;
+		time_elapsed += rng->prev_error;
+
+		/* Check if current error is a new one or the old one itself.
+		 * If error is a new one then consider there is a persistent
+		 * issue with entropy, declare hardware failure.
+		 */
+		if (cur_err < time_elapsed) {
+			dev_err(&rng->pdev->dev, "HWRNG failure detected\n");
+			rng->prev_error = cur_err;
+			rng->prev_time = cur_time;
+			return -EIO;
+		}
+	}
+
+	rng->prev_error = cur_err;
+	rng->prev_time = cur_time;
+	return 0;
+}
 
 /* Read data from the RNG unit */
 static int cavium_rng_read(struct hwrng *rng, void *dat, size_t max, bool wait)
 {
 	struct cavium_rng *p = container_of(rng, struct cavium_rng, ops);
 	unsigned int size = max;
+	int err = 0;
+
+	err = check_rng_health(p);
+	if (err)
+		return err;
 
 	while (size >= 8) {
 		*((u64 *)dat) = readq(p->result);
@@ -39,6 +166,39 @@
 	return max;
 }
 
+static int cavium_map_pf_regs(struct cavium_rng *rng)
+{
+	struct pci_dev *pdev;
+
+	/* Health status is not supported on 83xx, skip mapping PF CSRs */
+	if (is_octeontx(rng->pdev)) {
+		rng->pf_regbase = NULL;
+		return 0;
+	}
+
+	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
+			      PCI_DEVID_CAVIUM_RNG_PF, NULL);
+	if (!pdev) {
+		dev_err(&pdev->dev, "Cannot find RNG PF device\n");
+		return -EIO;
+	}
+
+	rng->pf_regbase = ioremap(pci_resource_start(pdev, 0),
+				  pci_resource_len(pdev, 0));
+	if (!rng->pf_regbase) {
+		dev_err(&pdev->dev, "Failed to map PF CSR region\n");
+		pci_dev_put(pdev);
+		return -ENOMEM;
+	}
+
+	pci_dev_put(pdev);
+
+	/* Get co-processor clock rate */
+	rng->clock_rate = rng_get_coprocessor_clkrate();
+
+	return 0;
+}
+
 /* Map Cavium RNG to an HWRNG object */
 static int cavium_rng_probe_vf(struct	pci_dev		*pdev,
 			 const struct	pci_device_id	*id)
@@ -49,6 +209,8 @@
 	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
 	if (!rng)
 		return -ENOMEM;
+
+	rng->pdev = pdev;
 
 	/* Map the RNG result */
 	rng->result = pcim_iomap(pdev, 0, 0);
@@ -67,7 +229,12 @@
 
 	pci_set_drvdata(pdev, rng);
 
-	ret = hwrng_register(&rng->ops);
+	/* Health status is available only at PF, hence map PF registers. */
+	ret = cavium_map_pf_regs(rng);
+	if (ret)
+		return ret;
+
+	ret = devm_hwrng_register(&pdev->dev, &rng->ops);
 	if (ret) {
 		dev_err(&pdev->dev, "Error registering device as HWRNG.\n");
 		return ret;
@@ -77,17 +244,17 @@
 }
 
 /* Remove the VF */
-static void  cavium_rng_remove_vf(struct pci_dev *pdev)
+static void cavium_rng_remove_vf(struct pci_dev *pdev)
 {
 	struct cavium_rng *rng;
 
 	rng = pci_get_drvdata(pdev);
-	hwrng_unregister(&rng->ops);
+	iounmap(rng->pf_regbase);
 }
 
 static const struct pci_device_id cavium_rng_vf_id_table[] = {
-	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0},
-	{0,},
+	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_CAVIUM_RNG_VF) },
+	{ 0, }
 };
 MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table);
 
@@ -100,4 +267,4 @@
 module_pci_driver(cavium_rng_vf_driver);
 
 MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");

--
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