tsec: add debugfs support

add a debugfs file to read-out firmware log messages

Change-Id: I3501b117884a822bd835beecd8e3956481c37386
Signed-off-by: Mayuresh Kulkarni <mkulkarni@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvidia/+/2884815
(cherry picked from commit 590640045e9ba26914cad055000f7ce3618640b9)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2895857
Tested-by: Bharat Nihalani <bnihalani@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
GVS: Gerrit_Virtual_Submit <buildbot_gerritrpt@nvidia.com>

drivers/video/tegra/tsec/tsec.c

@@ -103,6 +103,134 @@ static void tsec_set_cg_regs(struct tsec_device_data *pdata)
 	tsec_writel(pdata, tsec_riscv_cg_r(), 0x3);
 }
 
+#ifdef CONFIG_DEBUG_FS
+
+struct nvriscv_log_buffer {
+	/* read offset updated by client RM */
+	uint32_t read_offset;
+	/* write offset updated by firmware RM */
+	uint32_t write_offset;
+	/* buffer size configured by client RM */
+	uint32_t buffer_size;
+	/* magic number for header validation in nvwatch */
+	uint32_t magic;
+};
+
+#define LOG_BUF_SIZE	((4 * SZ_1K) - sizeof(struct nvriscv_log_buffer))
+#define INFO_BUF_SIZE	(SZ_128)
+static u8 log_buf[LOG_BUF_SIZE]; /* Read from DMEM into local buffer */
+static u8 info_buf[INFO_BUF_SIZE];
+
+static int tsec_debug_show(struct seq_file *s, void *unused)
+{
+	int info_len = 0;
+	struct tsec_device_data *pdata = (struct tsec_device_data *)s->private;
+
+	/* Do not attempt to read DMEM if TSEC is power-down */
+	if (pdata->power_on) {
+#define DMEM_PORT	(0)
+		/* Offset of Log Buffer in DMEM */
+		u32 log_bug_off  = tsec_dmem_logbuf_offset_f();
+		u32 dmemC        = tsec_falcon_dmemc_r(DMEM_PORT);
+		u32 dmemD        = tsec_falcon_dmemd_r(DMEM_PORT);
+		struct nvriscv_log_buffer log_buf_info;
+
+		/* Auto Increment Read */
+		u32 loop_index = 0;
+
+		tsec_writel(pdata, dmemC, log_bug_off | 0x02000000);
+		while (loop_index < LOG_BUF_SIZE) {
+			u32 reg_val;
+
+			reg_val = tsec_readl(pdata, dmemD);
+			log_buf[loop_index++] = (u8)((reg_val >> 0) & 0xFF);
+			log_buf[loop_index++] = (u8)((reg_val >> 8) & 0xFF);
+			log_buf[loop_index++] = (u8)((reg_val >> 16) & 0xFF);
+			log_buf[loop_index++] = (u8)((reg_val >> 24) & 0xFF);
+		}
+		log_buf_info.read_offset  = tsec_readl(pdata, dmemD);
+		log_buf_info.write_offset = tsec_readl(pdata, dmemD);
+		log_buf_info.buffer_size  = tsec_readl(pdata, dmemD);
+		log_buf_info.magic        = tsec_readl(pdata, dmemD);
+
+		/*
+		* Replace any null charecter with new line because tsec ucode
+		* does the reverse before dumping the logs in the buffer
+		*/
+		for (loop_index = 0; loop_index < LOG_BUF_SIZE; loop_index++) {
+			if (log_buf[loop_index] == 0)
+				log_buf[loop_index] = 0xA;
+		}
+
+		/* Insert null charecter at end of log buffer */
+		log_buf[log_buf_info.write_offset] = 0;
+
+		/* Print log_buf */
+		info_len = sprintf(info_buf,
+			"Tsec Logs Start: read_offset=%d write_offset=%d buffer_size=%d magic=0x%x\n",
+			log_buf_info.read_offset, log_buf_info.write_offset,
+			log_buf_info.buffer_size, log_buf_info.magic);
+		if (info_len > 0)
+			seq_write(s, info_buf, info_len);
+
+		seq_write(s, log_buf,
+			(log_buf_info.write_offset - log_buf_info.read_offset));
+
+		info_len = strlen("Tsec Logs End\n");
+		strcpy(info_buf, "Tsec Logs End\n");
+		info_buf[info_len] = '\0';
+		seq_write(s, info_buf, info_len);
+	} else {
+		info_len = strlen("Tsec power-down\n");
+		strcpy(info_buf, "Tsec power-down\n");
+		info_buf[info_len] = '\0';
+		seq_write(s, info_buf, info_len);
+	}
+
+	return 0;
+}
+
+static int tsec_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, tsec_debug_show, inode->i_private);
+}
+
+static const struct file_operations tsec_debug_fops = {
+	.open		= tsec_debug_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+/*
+ * TSEC debugfs interface
+ * create: /sys/kernel/debug/tegra_tsec/fw_logs.
+ * cat /sys/kernel/debug/tegra_tsec/fw_logs will read the DMEM reserved for
+ * debug messages and print it on console.
+ */
+
+static int tsec_module_init_debugfs(struct platform_device *dev)
+{
+	struct tsec_device_data *pdata = platform_get_drvdata(dev);
+
+	pdata->debug_root = debugfs_create_dir("tegra_tsec", NULL);
+	if (!pdata->debug_root)
+		return -ENOMEM;
+
+	debugfs_create_file("fw_logs", 0444, pdata->debug_root,
+			pdata, &tsec_debug_fops);
+
+	return 0;
+}
+
+static void tsec_module_deinit_debugfs(struct platform_device *dev)
+{
+	struct tsec_device_data *pdata = platform_get_drvdata(dev);
+
+	debugfs_remove_recursive(pdata->debug_root);
+}
+#endif /* CONFIG_DEBUG_FS */
+
 /*
  * TSEC Power Management Operations
  */
@@ -286,11 +414,25 @@ static int tsec_probe(struct platform_device *dev)
 		return err;
 	}
 
+#ifdef CONFIG_DEBUG_FS
+	if (debugfs_initialized()) {
+		err = tsec_module_init_debugfs(dev);
+		if (err) {
+			dev_err(&dev->dev, "error %d in tsec_module_init_debugfs\n", err);
+			return err;
+		}
+	}
+#endif /* CONFIG_DEBUG_FS */
+
 	return tsec_kickoff_boot(dev);
 }
 
 static int tsec_remove(struct platform_device *dev)
 {
+#ifdef CONFIG_DEBUG_FS
+	tsec_module_deinit_debugfs(dev);
+#endif /* CONFIG_DEBUG_FS */
+
 	return tsec_poweroff(&dev->dev);
 }
 

drivers/video/tegra/tsec/tsec.h

@@ -47,6 +47,10 @@ struct tsec_device_data {
 	char *riscv_desc_bin;
 	/* name of riscv image binary */
 	char *riscv_image_bin;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debug_root;
+#endif /* CONFIG_DEBUG_FS */
 };
 
 /*

drivers/video/tegra/tsec/tsec_linux.h

@@ -29,5 +29,9 @@
 #include <linux/platform/tegra/tegra_mc.h> /* for mc_get_carveout_info */
 #include <asm/cacheflush.h>                /* for __flush_dcache_area */
 #endif
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>                 /* for debugfs APIs */
+#endif
+#include <linux/sizes.h>                   /* for SZ_* size macros */
 
 #endif /* TSEC_LINUX_H */

drivers/video/tegra/tsec/tsec_regs.h

@@ -251,4 +251,21 @@ static inline u32 tsec_riscv_br_retcode_result_pass_v(void)
 	return 0x00000003;
 }
 
+static inline u32 tsec_falcon_dmemc_r(u32 r)
+{
+	/* NV_PSEC_FALCON_DMEMC_0 */
+	return (0x11c0 + (r) * 8);
+}
+
+static inline u32 tsec_falcon_dmemd_r(u32 r)
+{
+	/* NV_PSEC_FALCON_DMEMD_0 */
+	return (0x11c4 + (r) * 8);
+}
+
+static inline u32 tsec_dmem_logbuf_offset_f(void)
+{
+	return 0x14000;
+}
+
 #endif /* TSEC_REGS_H */