/* SPDX-License-Identifier: GPL-2.0
 *
 * Copyright (C) 2009 Matt Fleming <matt@console-pimps.org>
 */
#ifndef __ASM_SH_DWARF_H
#define __ASM_SH_DWARF_H

#ifdef CONFIG_DWARF_UNWINDER

/*
 * DWARF expression operations
 */
#define DW_OP_addr      0x03
#define DW_OP_deref     0x06
#define DW_OP_const1u   0x08
#define DW_OP_const1s   0x09
#define DW_OP_const2u   0x0a
#define DW_OP_const2s   0x0b
#define DW_OP_const4u   0x0c
#define DW_OP_const4s   0x0d
#define DW_OP_const8u   0x0e
#define DW_OP_const8s   0x0f
#define DW_OP_constu    0x10
#define DW_OP_consts    0x11
#define DW_OP_dup       0x12
#define DW_OP_drop      0x13
#define DW_OP_over      0x14
#define DW_OP_pick      0x15
#define DW_OP_swap      0x16
#define DW_OP_rot       0x17
#define DW_OP_xderef    0x18
#define DW_OP_abs       0x19
#define DW_OP_and       0x1a
#define DW_OP_div       0x1b
#define DW_OP_minus     0x1c
#define DW_OP_mod       0x1d
#define DW_OP_mul       0x1e
#define DW_OP_neg       0x1f
#define DW_OP_not       0x20
#define DW_OP_or        0x21
#define DW_OP_plus      0x22
#define DW_OP_plus_uconst       0x23
#define DW_OP_shl       0x24
#define DW_OP_shr       0x25
#define DW_OP_shra      0x26
#define DW_OP_xor       0x27
#define DW_OP_skip      0x2f
#define DW_OP_bra       0x28
#define DW_OP_eq        0x29
#define DW_OP_ge        0x2a
#define DW_OP_gt        0x2b
#define DW_OP_le        0x2c
#define DW_OP_lt        0x2d
#define DW_OP_ne        0x2e
#define DW_OP_lit0      0x30
#define DW_OP_lit1      0x31
#define DW_OP_lit2      0x32
#define DW_OP_lit3      0x33
#define DW_OP_lit4      0x34
#define DW_OP_lit5      0x35
#define DW_OP_lit6      0x36
#define DW_OP_lit7      0x37
#define DW_OP_lit8      0x38
#define DW_OP_lit9      0x39
#define DW_OP_lit10     0x3a
#define DW_OP_lit11     0x3b
#define DW_OP_lit12     0x3c
#define DW_OP_lit13     0x3d
#define DW_OP_lit14     0x3e
#define DW_OP_lit15     0x3f
#define DW_OP_lit16     0x40
#define DW_OP_lit17     0x41
#define DW_OP_lit18     0x42
#define DW_OP_lit19     0x43
#define DW_OP_lit20     0x44
#define DW_OP_lit21     0x45
#define DW_OP_lit22     0x46
#define DW_OP_lit23     0x47
#define DW_OP_lit24     0x48
#define DW_OP_lit25     0x49
#define DW_OP_lit26     0x4a
#define DW_OP_lit27     0x4b
#define DW_OP_lit28     0x4c
#define DW_OP_lit29     0x4d
#define DW_OP_lit30     0x4e
#define DW_OP_lit31     0x4f
#define DW_OP_reg0      0x50
#define DW_OP_reg1      0x51
#define DW_OP_reg2      0x52
#define DW_OP_reg3      0x53
#define DW_OP_reg4      0x54
#define DW_OP_reg5      0x55
#define DW_OP_reg6      0x56
#define DW_OP_reg7      0x57
#define DW_OP_reg8      0x58
#define DW_OP_reg9      0x59
#define DW_OP_reg10     0x5a
#define DW_OP_reg11     0x5b
#define DW_OP_reg12     0x5c
#define DW_OP_reg13     0x5d
#define DW_OP_reg14     0x5e
#define DW_OP_reg15     0x5f
#define DW_OP_reg16     0x60
#define DW_OP_reg17     0x61
#define DW_OP_reg18     0x62
#define DW_OP_reg19     0x63
#define DW_OP_reg20     0x64
#define DW_OP_reg21     0x65
#define DW_OP_reg22     0x66
#define DW_OP_reg23     0x67
#define DW_OP_reg24     0x68
#define DW_OP_reg25     0x69
#define DW_OP_reg26     0x6a
#define DW_OP_reg27     0x6b
#define DW_OP_reg28     0x6c
#define DW_OP_reg29     0x6d
#define DW_OP_reg30     0x6e
#define DW_OP_reg31     0x6f
#define DW_OP_breg0     0x70
#define DW_OP_breg1     0x71
#define DW_OP_breg2     0x72
#define DW_OP_breg3     0x73
#define DW_OP_breg4     0x74
#define DW_OP_breg5     0x75
#define DW_OP_breg6     0x76
#define DW_OP_breg7     0x77
#define DW_OP_breg8     0x78
#define DW_OP_breg9     0x79
#define DW_OP_breg10    0x7a
#define DW_OP_breg11    0x7b
#define DW_OP_breg12    0x7c
#define DW_OP_breg13    0x7d
#define DW_OP_breg14    0x7e
#define DW_OP_breg15    0x7f
#define DW_OP_breg16    0x80
#define DW_OP_breg17    0x81
#define DW_OP_breg18    0x82
#define DW_OP_breg19    0x83
#define DW_OP_breg20    0x84
#define DW_OP_breg21    0x85
#define DW_OP_breg22    0x86
#define DW_OP_breg23    0x87
#define DW_OP_breg24    0x88
#define DW_OP_breg25    0x89
#define DW_OP_breg26    0x8a
#define DW_OP_breg27    0x8b
#define DW_OP_breg28    0x8c
#define DW_OP_breg29    0x8d
#define DW_OP_breg30    0x8e
#define DW_OP_breg31    0x8f
#define DW_OP_regx      0x90
#define DW_OP_fbreg     0x91
#define DW_OP_bregx     0x92
#define DW_OP_piece     0x93
#define DW_OP_deref_size        0x94
#define DW_OP_xderef_size       0x95
#define DW_OP_nop       0x96
#define DW_OP_push_object_address       0x97
#define DW_OP_call2     0x98
#define DW_OP_call4     0x99
#define DW_OP_call_ref  0x9a
#define DW_OP_form_tls_address  0x9b
#define DW_OP_call_frame_cfa    0x9c
#define DW_OP_bit_piece 0x9d
#define DW_OP_lo_user   0xe0
#define DW_OP_hi_user   0xff

/*
 * Addresses used in FDE entries in the .eh_frame section may be encoded
 * using one of the following encodings.
 */
#define DW_EH_PE_absptr 0x00
#define DW_EH_PE_omit   0xff
#define DW_EH_PE_uleb128        0x01
#define DW_EH_PE_udata2 0x02
#define DW_EH_PE_udata4 0x03
#define DW_EH_PE_udata8 0x04
#define DW_EH_PE_sleb128        0x09
#define DW_EH_PE_sdata2 0x0a
#define DW_EH_PE_sdata4 0x0b
#define DW_EH_PE_sdata8 0x0c
#define DW_EH_PE_signed 0x09

#define DW_EH_PE_pcrel  0x10

/*
 * The architecture-specific register number that contains the return
 * address in the .debug_frame table.
 */
#define DWARF_ARCH_RA_REG       17

#ifndef __ASSEMBLER__

#include <linux/compiler.h>
#include <linux/bug.h>
#include <linux/list.h>
#include <linux/module.h>

/*
 * Read either the frame pointer (r14) or the stack pointer (r15).
 * NOTE: this MUST be inlined.
 */
static __always_inline unsigned long dwarf_read_arch_reg(unsigned int reg)
{
        unsigned long value = 0;

        switch (reg) {
        case 14:
                __asm__ __volatile__("mov r14, %0\n" : "=r" (value));
                break;
        case 15:
                __asm__ __volatile__("mov r15, %0\n" : "=r" (value));
                break;
        default:
                BUG();
        }

        return value;
}

/**
 *      dwarf_cie - Common Information Entry
 */
struct dwarf_cie {
        unsigned long length;
        unsigned long cie_id;
        unsigned char version;
        const char *augmentation;
        unsigned int code_alignment_factor;
        int data_alignment_factor;

        /* Which column in the rule table represents return addr of func. */
        unsigned int return_address_reg;

        unsigned char *initial_instructions;
        unsigned char *instructions_end;

        unsigned char encoding;

        unsigned long cie_pointer;

        unsigned long flags;
#define DWARF_CIE_Z_AUGMENTATION        (1 << 0)

        /* linked-list entry if this CIE is from a module */
        struct list_head link;

        struct rb_node node;
};

/**
 *      dwarf_fde - Frame Description Entry
 */
struct dwarf_fde {
        unsigned long length;
        unsigned long cie_pointer;
        struct dwarf_cie *cie;
        unsigned long initial_location;
        unsigned long address_range;
        unsigned char *instructions;
        unsigned char *end;

        /* linked-list entry if this FDE is from a module */
        struct list_head link;

        struct rb_node node;
};

/**
 *      dwarf_frame - DWARF information for a frame in the call stack
 */
struct dwarf_frame {
        struct dwarf_frame *prev, *next;

        unsigned long pc;

        struct list_head reg_list;

        unsigned long cfa;

        /* Valid when DW_FRAME_CFA_REG_OFFSET is set in flags */
        unsigned int cfa_register;
        unsigned int cfa_offset;

        /* Valid when DW_FRAME_CFA_REG_EXP is set in flags */
        unsigned char *cfa_expr;
        unsigned int cfa_expr_len;

        unsigned long flags;
#define DWARF_FRAME_CFA_REG_OFFSET      (1 << 0)
#define DWARF_FRAME_CFA_REG_EXP         (1 << 1)

        unsigned long return_addr;
};

/**
 *      dwarf_reg - DWARF register
 *      @flags: Describes how to calculate the value of this register
 */
struct dwarf_reg {
        struct list_head link;

        unsigned int number;

        unsigned long addr;
        unsigned long flags;
#define DWARF_REG_OFFSET        (1 << 0)
#define DWARF_VAL_OFFSET        (1 << 1)
#define DWARF_UNDEFINED         (1 << 2)
};

/*
 * Call Frame instruction opcodes.
 */
#define DW_CFA_advance_loc      0x40
#define DW_CFA_offset           0x80
#define DW_CFA_restore          0xc0
#define DW_CFA_nop              0x00
#define DW_CFA_set_loc          0x01
#define DW_CFA_advance_loc1     0x02
#define DW_CFA_advance_loc2     0x03
#define DW_CFA_advance_loc4     0x04
#define DW_CFA_offset_extended  0x05
#define DW_CFA_restore_extended 0x06
#define DW_CFA_undefined        0x07
#define DW_CFA_same_value       0x08
#define DW_CFA_register         0x09
#define DW_CFA_remember_state   0x0a
#define DW_CFA_restore_state    0x0b
#define DW_CFA_def_cfa          0x0c
#define DW_CFA_def_cfa_register 0x0d
#define DW_CFA_def_cfa_offset   0x0e
#define DW_CFA_def_cfa_expression       0x0f
#define DW_CFA_expression       0x10
#define DW_CFA_offset_extended_sf       0x11
#define DW_CFA_def_cfa_sf       0x12
#define DW_CFA_def_cfa_offset_sf        0x13
#define DW_CFA_val_offset       0x14
#define DW_CFA_val_offset_sf    0x15
#define DW_CFA_val_expression   0x16
#define DW_CFA_lo_user          0x1c
#define DW_CFA_hi_user          0x3f

/* GNU extension opcodes  */
#define DW_CFA_GNU_args_size    0x2e
#define DW_CFA_GNU_negative_offset_extended 0x2f

/*
 * Some call frame instructions encode their operands in the opcode. We
 * need some helper functions to extract both the opcode and operands
 * from an instruction.
 */
static inline unsigned int DW_CFA_opcode(unsigned long insn)
{
        return (insn & 0xc0);
}

static inline unsigned int DW_CFA_operand(unsigned long insn)
{
        return (insn & 0x3f);
}

#define DW_EH_FRAME_CIE 0               /* .eh_frame CIE IDs are 0 */
#define DW_CIE_ID       0xffffffff
#define DW64_CIE_ID     0xffffffffffffffffULL

/*
 * DWARF FDE/CIE length field values.
 */
#define DW_EXT_LO       0xfffffff0
#define DW_EXT_HI       0xffffffff
#define DW_EXT_DWARF64  DW_EXT_HI

extern struct dwarf_frame *dwarf_unwind_stack(unsigned long,
                                              struct dwarf_frame *);
extern void dwarf_free_frame(struct dwarf_frame *);

extern int module_dwarf_finalize(const Elf_Ehdr *, const Elf_Shdr *,
                                 struct module *);
extern void module_dwarf_cleanup(struct module *);

#endif /* !__ASSEMBLER__ */

#define CFI_STARTPROC   .cfi_startproc
#define CFI_ENDPROC     .cfi_endproc
#define CFI_DEF_CFA     .cfi_def_cfa
#define CFI_REGISTER    .cfi_register
#define CFI_REL_OFFSET  .cfi_rel_offset
#define CFI_UNDEFINED   .cfi_undefined

#else

/*
 * Use the asm comment character to ignore the rest of the line.
 */
#define CFI_IGNORE      !

#define CFI_STARTPROC   CFI_IGNORE
#define CFI_ENDPROC     CFI_IGNORE
#define CFI_DEF_CFA     CFI_IGNORE
#define CFI_REGISTER    CFI_IGNORE
#define CFI_REL_OFFSET  CFI_IGNORE
#define CFI_UNDEFINED   CFI_IGNORE

#ifndef __ASSEMBLER__
static inline void dwarf_unwinder_init(void)
{
}

#define module_dwarf_finalize(hdr, sechdrs, me) (0)
#define module_dwarf_cleanup(mod)               do { } while (0)

#endif

#endif /* CONFIG_DWARF_UNWINDER */

#endif /* __ASM_SH_DWARF_H */