[PATCH v2] drivers: net: fsl-mc: add a command which dumps the MC log

[Cosmin-Florin Aluchenesei]

Extended fsl_mc command adding an extra option dump_log

Signed-off-by: Cosmin-Florin Aluchenesei <aluchenesei.cosmin-florin at nxp.com>

Changes in v2:
- Add MC_STRUCT_BUFFER_OFFSET once to the base address of MC.
---
 drivers/net/fsl-mc/mc.c | 89 ++++++++++++++++++++++++++++++++++++++++-
 include/fsl-mc/fsl_mc.h |  9 +++++
 2 files changed, 97 insertions(+), 1 deletion(-)

diff --git a/drivers/net/fsl-mc/mc.c b/drivers/net/fsl-mc/mc.c
index 914ec001ec..33671b3d03 100644
--- a/drivers/net/fsl-mc/mc.c
+++ b/drivers/net/fsl-mc/mc.c
@@ -11,6 +11,7 @@
 #include <image.h>
 #include <log.h>
 #include <malloc.h>
+#include <mapmem.h>
 #include <asm/global_data.h>
 #include <linux/bug.h>
 #include <asm/io.h>
@@ -38,6 +39,16 @@
 #define MC_BOOT_ENV_VAR		"mcinitcmd"
 #define MC_DRAM_BLOCK_DEFAULT_SIZE (512UL * 1024 * 1024)
 
+#define MC_BUFFER_SIZE   (1024 * 1024 * 16)
+#define MAGIC_MC 0x4d430100
+#define MC_FW_ADDR_MASK_LOW 0xE0000000
+#define MC_FW_ADDR_MASK_HIGH 0X1FFFF
+#define MC_STRUCT_BUFFER_OFFSET 0x01000000
+#define MC_OFFSET_DELTA MC_STRUCT_BUFFER_OFFSET
+
+#define LOG_HEADER_FLAG_BUFFER_WRAPAROUND 0x80000000
+#define LAST_BYTE(a) ((a) & ~(LOG_HEADER_FLAG_BUFFER_WRAPAROUND))
+
 DECLARE_GLOBAL_DATA_PTR;
 static int mc_memset_resv_ram;
 static struct mc_version mc_ver_info;
@@ -1774,11 +1785,78 @@ err:
 	return err;
 }
 
+static void print_k_bytes(const void *buf, ssize_t *size)
+{
+	while (*size > 0) {
+		int count = printf("%s", (char *)buf);
+
+		buf += count;
+		*size -= count;
+	}
+}
+
+static void mc_dump_log(void)
+{
+	struct mc_ccsr_registers __iomem *mc_ccsr_regs = MC_CCSR_BASE_ADDR;
+	u64 high = in_le64(&mc_ccsr_regs->reg_mcfbahr) & MC_FW_ADDR_MASK_HIGH;
+	u64 low = in_le64(&mc_ccsr_regs->reg_mcfbalr) & MC_FW_ADDR_MASK_LOW;
+	u32 buf_len, wrapped, last_byte, magic, buf_start;
+	u64 mc_addr = (high << 32) | low;
+	struct log_header *header;
+	ssize_t size, bytes_end;
+	const void *end_of_data;
+	const void *map_addr;
+	const void *end_addr;
+	const void *cur_ptr;
+	const void *buf;
+
+	map_addr = map_sysmem(mc_addr + MC_STRUCT_BUFFER_OFFSET,
+			      MC_BUFFER_SIZE);
+	header = (struct log_header *)map_addr;
+	last_byte = in_le32(&header->last_byte);
+	buf_len = in_le32(&header->buf_length);
+	magic = in_le32(&header->magic_word);
+	buf_start = in_le32(&header->buf_start);
+	buf = map_addr + buf_start - MC_OFFSET_DELTA;
+	end_addr = buf + buf_len;
+	wrapped = last_byte & LOG_HEADER_FLAG_BUFFER_WRAPAROUND;
+	end_of_data = buf + LAST_BYTE(last_byte);
+
+	if (magic != MAGIC_MC) {
+		puts("Magic number is not valid\n");
+		printf("expected = %08x, received = %08x\n", MAGIC_MC, magic);
+		goto err_magic;
+	}
+
+	if (wrapped && end_of_data != end_addr)
+		cur_ptr = end_of_data + 1;
+	else
+		cur_ptr = buf;
+
+	if (cur_ptr <= end_of_data)
+		size = end_of_data - cur_ptr;
+	else
+		size = (end_addr - cur_ptr) + (end_of_data - buf);
+
+	bytes_end = end_addr - cur_ptr;
+	if (size > bytes_end) {
+		print_k_bytes(cur_ptr, &bytes_end);
+
+		cur_ptr = buf;
+		size -= bytes_end;
+	}
+
+	print_k_bytes(buf, &size);
+
+err_magic:
+	unmap_sysmem(map_addr);
+}
+
 static int do_fsl_mc(struct cmd_tbl *cmdtp, int flag, int argc,
 		     char *const argv[])
 {
 	int err = 0;
-	if (argc < 3)
+	if (argc < 2)
 		goto usage;
 
 	switch (argv[1][0]) {
@@ -1788,6 +1866,8 @@ static int do_fsl_mc(struct cmd_tbl *cmdtp, int flag, int argc,
 #ifdef CONFIG_SYS_LS_MC_DRAM_AIOP_IMG_OFFSET
 			u64 aiop_fw_addr;
 #endif
+			if (argc < 3)
+				goto usage;
 
 			sub_cmd = argv[2][0];
 
@@ -1919,6 +1999,12 @@ static int do_fsl_mc(struct cmd_tbl *cmdtp, int flag, int argc,
 		}
 		break;
 		}
+	case 'd':
+		if (argc > 2)
+			goto usage;
+
+		mc_dump_log();
+		break;
 	default:
 		printf("Invalid option: %s\n", argv[1]);
 		goto usage;
@@ -1937,6 +2023,7 @@ U_BOOT_CMD(
 	"fsl_mc lazyapply DPL [DPL_addr] - Apply DPL file on exit\n"
 	"fsl_mc apply spb [spb_addr] - Apply SPB Soft Parser Blob\n"
 	"fsl_mc start aiop [FW_addr] - Start AIOP\n"
+	"fsl_mc dump_log - Dump MC Log\n"
 );
 
 void mc_env_boot(void)
diff --git a/include/fsl-mc/fsl_mc.h b/include/fsl-mc/fsl_mc.h
index a8b072ad7c..07a46a4a1b 100644
--- a/include/fsl-mc/fsl_mc.h
+++ b/include/fsl-mc/fsl_mc.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Copyright (C) 2014 Freescale Semiconductor
+ * Copyright 2021 NXP
  */
 
 #ifndef __FSL_MC_H__
@@ -52,6 +53,14 @@ struct mc_ccsr_registers {
 	u32 reg_error[];
 };
 
+struct log_header {
+	u32 magic_word;
+	char reserved[4];
+	u32 buf_start;
+	u32 buf_length;
+	u32 last_byte;
+};
+
 void fdt_fsl_mc_fixup_iommu_map_entry(void *blob);
 int get_mc_boot_status(void);
 int get_dpl_apply_status(void);
-- 
2.25.1