arch/ia64/kernel/unwind_i.h

   1 /*
   2  * Copyright (C) 2000, 2002-2003 Hewlett-Packard Co
   3  *      David Mosberger-Tang <davidm@hpl.hp.com>
   4  *
   5  * Kernel unwind support.
   6  */
   7
   8 #define UNW_VER(x)              ((x) >> 48)
   9 #define UNW_FLAG_MASK           0x0000ffff00000000
  10 #define UNW_FLAG_OSMASK         0x0000f00000000000
  11 #define UNW_FLAG_EHANDLER(x)    ((x) & 0x0000000100000000L)
  12 #define UNW_FLAG_UHANDLER(x)    ((x) & 0x0000000200000000L)
  13 #define UNW_LENGTH(x)           ((x) & 0x00000000ffffffffL)
  14
  15 enum unw_register_index {
  16         /* primary unat: */
  17         UNW_REG_PRI_UNAT_GR,
  18         UNW_REG_PRI_UNAT_MEM,
  19
  20         /* register stack */
  21         UNW_REG_BSP,                                    /* register stack pointer */
  22         UNW_REG_BSPSTORE,
  23         UNW_REG_PFS,                                    /* previous function state */
  24         UNW_REG_RNAT,
  25         /* memory stack */
  26         UNW_REG_PSP,                                    /* previous memory stack pointer */
  27         /* return pointer: */
  28         UNW_REG_RP,
  29
  30         /* preserved registers: */
  31         UNW_REG_R4, UNW_REG_R5, UNW_REG_R6, UNW_REG_R7,
  32         UNW_REG_UNAT, UNW_REG_PR, UNW_REG_LC, UNW_REG_FPSR,
  33         UNW_REG_B1, UNW_REG_B2, UNW_REG_B3, UNW_REG_B4, UNW_REG_B5,
  34         UNW_REG_F2, UNW_REG_F3, UNW_REG_F4, UNW_REG_F5,
  35         UNW_REG_F16, UNW_REG_F17, UNW_REG_F18, UNW_REG_F19,
  36         UNW_REG_F20, UNW_REG_F21, UNW_REG_F22, UNW_REG_F23,
  37         UNW_REG_F24, UNW_REG_F25, UNW_REG_F26, UNW_REG_F27,
  38         UNW_REG_F28, UNW_REG_F29, UNW_REG_F30, UNW_REG_F31,
  39         UNW_NUM_REGS
  40 };
  41
  42 struct unw_info_block {
  43         u64 header;
  44         u64 desc[0];            /* unwind descriptors */
  45         /* personality routine and language-specific data follow behind descriptors */
  46 };
  47
  48 struct unw_table {
  49         struct unw_table *next;         /* must be first member! */
  50         const char *name;
  51         unsigned long gp;               /* global pointer for this load-module */
  52         unsigned long segment_base;     /* base for offsets in the unwind table entries */
  53         unsigned long start;
  54         unsigned long end;
  55         const struct unw_table_entry *array;
  56         unsigned long length;
  57 };
  58
  59 enum unw_where {
  60         UNW_WHERE_NONE,                 /* register isn't saved at all */
  61         UNW_WHERE_GR,                   /* register is saved in a general register */
  62         UNW_WHERE_FR,                   /* register is saved in a floating-point register */
  63         UNW_WHERE_BR,                   /* register is saved in a branch register */
  64         UNW_WHERE_SPREL,                /* register is saved on memstack (sp-relative) */
  65         UNW_WHERE_PSPREL,               /* register is saved on memstack (psp-relative) */
  66         /*
  67          * At the end of each prologue these locations get resolved to
  68          * UNW_WHERE_PSPREL and UNW_WHERE_GR, respectively:
  69          */
  70         UNW_WHERE_SPILL_HOME,           /* register is saved in its spill home */
  71         UNW_WHERE_GR_SAVE               /* register is saved in next general register */
  72 };
  73
  74 #define UNW_WHEN_NEVER  0x7fffffff
  75
  76 struct unw_reg_info {
  77         unsigned long val;              /* save location: register number or offset */
  78         enum unw_where where;           /* where the register gets saved */
  79         int when;                       /* when the register gets saved */
  80 };
  81
  82 struct unw_reg_state {
  83         struct unw_reg_state *next;             /* next (outer) element on state stack */
  84         struct unw_reg_info reg[UNW_NUM_REGS];  /* register save locations */
  85 };
  86
  87 struct unw_labeled_state {
  88         struct unw_labeled_state *next;         /* next labeled state (or NULL) */
  89         unsigned long label;                    /* label for this state */
  90         struct unw_reg_state saved_state;
  91 };
  92
  93 struct unw_state_record {
  94         unsigned int first_region : 1;  /* is this the first region? */
  95         unsigned int done : 1;          /* are we done scanning descriptors? */
  96         unsigned int any_spills : 1;    /* got any register spills? */
  97         unsigned int in_body : 1;       /* are we inside a body (as opposed to a prologue)? */
  98         unsigned long flags;            /* see UNW_FLAG_* in unwind.h */
  99
 100         u8 *imask;                      /* imask of spill_mask record or NULL */
 101         unsigned long pr_val;           /* predicate values */
 102         unsigned long pr_mask;          /* predicate mask */
 103         long spill_offset;              /* psp-relative offset for spill base */
 104         int region_start;
 105         int region_len;
 106         int epilogue_start;
 107         int epilogue_count;
 108         int when_target;
 109
 110         u8 gr_save_loc;                 /* next general register to use for saving a register */
 111         u8 return_link_reg;             /* branch register in which the return link is passed */
 112
 113         struct unw_labeled_state *labeled_states;       /* list of all labeled states */
 114         struct unw_reg_state curr;      /* current state */
 115 };
 116
 117 enum unw_nat_type {
 118         UNW_NAT_NONE,           /* NaT not represented */
 119         UNW_NAT_VAL,            /* NaT represented by NaT value (fp reg) */
 120         UNW_NAT_MEMSTK,         /* NaT value is in unat word at offset OFF  */
 121         UNW_NAT_REGSTK          /* NaT is in rnat */
 122 };
 123
 124 enum unw_insn_opcode {
 125         UNW_INSN_ADD,                   /* s[dst] += val */
 126         UNW_INSN_ADD_PSP,               /* s[dst] = (s.psp + val) */
 127         UNW_INSN_ADD_SP,                /* s[dst] = (s.sp + val) */
 128         UNW_INSN_MOVE,                  /* s[dst] = s[val] */
 129         UNW_INSN_MOVE2,                 /* s[dst] = s[val]; s[dst+1] = s[val+1] */
 130         UNW_INSN_MOVE_STACKED,          /* s[dst] = ia64_rse_skip(*s.bsp, val) */
 131         UNW_INSN_SETNAT_MEMSTK,         /* s[dst+1].nat.type = MEMSTK;
 132                                            s[dst+1].nat.off = *s.pri_unat - s[dst] */
 133         UNW_INSN_SETNAT_TYPE,           /* s[dst+1].nat.type = val */
 134         UNW_INSN_LOAD,                  /* s[dst] = *s[val] */
 135         UNW_INSN_MOVE_SCRATCH,          /* s[dst] = scratch reg "val" */
 136         UNW_INSN_MOVE_CONST,            /* s[dst] = constant reg "val" */
 137 };
 138
 139 struct unw_insn {
 140         unsigned int opc        :  4;
 141         unsigned int dst        :  9;
 142         signed int val          : 19;
 143 };
 144
 145 /*
 146  * Preserved general static registers (r4-r7) give rise to two script
 147  * instructions; everything else yields at most one instruction; at
 148  * the end of the script, the psp gets popped, accounting for one more
 149  * instruction.
 150  */
 151 #define UNW_MAX_SCRIPT_LEN      (UNW_NUM_REGS + 5)
 152
 153 struct unw_script {
 154         unsigned long ip;               /* ip this script is for */
 155         unsigned long pr_mask;          /* mask of predicates script depends on */
 156         unsigned long pr_val;           /* predicate values this script is for */
 157         rwlock_t lock;
 158         unsigned int flags;             /* see UNW_FLAG_* in unwind.h */
 159         unsigned short lru_chain;       /* used for least-recently-used chain */
 160         unsigned short coll_chain;      /* used for hash collisions */
 161         unsigned short hint;            /* hint for next script to try (or -1) */
 162         unsigned short count;           /* number of instructions in script */
 163         struct unw_insn insn[UNW_MAX_SCRIPT_LEN];
 164 };