linux-stable/arch/powerpc/include/asm/fadump.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Firmware Assisted dump header file.
 *
 * Copyright 2011 IBM Corporation
 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
 */

#ifndef __PPC64_FA_DUMP_H__
#define __PPC64_FA_DUMP_H__

#ifdef CONFIG_FA_DUMP

/* Firmware provided dump sections */
#define FADUMP_CPU_STATE_DATA	0x0001
#define FADUMP_HPTE_REGION	0x0002
#define FADUMP_REAL_MODE_REGION	0x0011

/* Dump request flag */
#define FADUMP_REQUEST_FLAG	0x00000001

/* Dump status flag */
#define FADUMP_ERROR_FLAG	0x2000

#define FADUMP_CPU_ID_MASK	((1UL << 32) - 1)

#define CPU_UNKNOWN		(~((u32)0))

/* Utility macros */
#define SKIP_TO_NEXT_CPU(reg_entry)					\
({									\
	while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND"))	\
		reg_entry++;						\
	reg_entry++;							\
})

extern int crashing_cpu;

/* Kernel Dump section info */
struct fadump_section {
	__be32	request_flag;
	__be16	source_data_type;
	__be16	error_flags;
	__be64	source_address;
	__be64	source_len;
	__be64	bytes_dumped;
	__be64	destination_address;
};

/* ibm,configure-kernel-dump header. */
struct fadump_section_header {
	__be32	dump_format_version;
	__be16	dump_num_sections;
	__be16	dump_status_flag;
	__be32	offset_first_dump_section;

	/* Fields for disk dump option. */
	__be32	dd_block_size;
	__be64	dd_block_offset;
	__be64	dd_num_blocks;
	__be32	dd_offset_disk_path;

	/* Maximum time allowed to prevent an automatic dump-reboot. */
	__be32	max_time_auto;
};

/*
 * Firmware Assisted dump memory structure. This structure is required for
 * registering future kernel dump with power firmware through rtas call.
 *
 * No disk dump option. Hence disk dump path string section is not included.
 */
struct fadump_mem_struct {
	struct fadump_section_header	header;

	/* Kernel dump sections */
	struct fadump_section		cpu_state_data;
	struct fadump_section		hpte_region;
	struct fadump_section		rmr_region;
};

/*
 * Copy the ascii values for first 8 characters from a string into u64
 * variable at their respective indexes.
 * e.g.
 *  The string "FADMPINF" will be converted into 0x4641444d50494e46
 */
static inline u64 str_to_u64(const char *str)
{
	u64 val = 0;
	int i;

	for (i = 0; i < sizeof(val); i++)
		val = (*str) ? (val << 8) | *str++ : val << 8;
	return val;
}
#define STR_TO_HEX(x)	str_to_u64(x)
#define REG_ID(x)	str_to_u64(x)

#define REGSAVE_AREA_MAGIC		STR_TO_HEX("REGSAVE")

/* The firmware-assisted dump format.
 *
 * The register save area is an area in the partition's memory used to preserve
 * the register contents (CPU state data) for the active CPUs during a firmware
 * assisted dump. The dump format contains register save area header followed
 * by register entries. Each list of registers for a CPU starts with
 * "CPUSTRT" and ends with "CPUEND".
 */

/* Register save area header. */
struct fadump_reg_save_area_header {
	__be64		magic_number;
	__be32		version;
	__be32		num_cpu_offset;
};

/* Register entry. */
struct fadump_reg_entry {
	__be64		reg_id;
	__be64		reg_value;
};

extern int is_fadump_memory_area(u64 addr, ulong size);
extern int early_init_dt_scan_fw_dump(unsigned long node,
		const char *uname, int depth, void *data);
extern int fadump_reserve_mem(void);
extern int setup_fadump(void);
extern int is_fadump_active(void);
extern int should_fadump_crash(void);
extern void crash_fadump(struct pt_regs *, const char *);
extern void fadump_cleanup(void);

#else	/* CONFIG_FA_DUMP */
static inline int is_fadump_active(void) { return 0; }
static inline int should_fadump_crash(void) { return 0; }
static inline void crash_fadump(struct pt_regs *regs, const char *str) { }
static inline void fadump_cleanup(void) { }
#endif
#endif