diff options
Diffstat (limited to 'drivers/FPU-emu/fpu_entry.c')
| -rw-r--r-- | drivers/FPU-emu/fpu_entry.c | 690 |
1 files changed, 0 insertions, 690 deletions
diff --git a/drivers/FPU-emu/fpu_entry.c b/drivers/FPU-emu/fpu_entry.c deleted file mode 100644 index b2777a722..000000000 --- a/drivers/FPU-emu/fpu_entry.c +++ /dev/null @@ -1,690 +0,0 @@ -/*---------------------------------------------------------------------------+ - | fpu_entry.c | - | | - | The entry function for wm-FPU-emu | - | | - | Copyright (C) 1992,1993,1994 | - | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | - | Australia. E-mail billm@vaxc.cc.monash.edu.au | - | | - | See the files "README" and "COPYING" for further copyright and warranty | - | information. | - | | - +---------------------------------------------------------------------------*/ - -/*---------------------------------------------------------------------------+ - | Note: | - | The file contains code which accesses user memory. | - | Emulator static data may change when user memory is accessed, due to | - | other processes using the emulator while swapping is in progress. | - +---------------------------------------------------------------------------*/ - -/*---------------------------------------------------------------------------+ - | math_emulate() is the sole entry point for wm-FPU-emu | - +---------------------------------------------------------------------------*/ - -#include <linux/signal.h> - -#include <asm/segment.h> - -#include "fpu_system.h" -#include "fpu_emu.h" -#include "exception.h" -#include "control_w.h" -#include "status_w.h" - -#define __BAD__ FPU_illegal /* Illegal on an 80486, causes SIGILL */ - -#ifndef NO_UNDOC_CODE /* Un-documented FPU op-codes supported by default. */ - -/* WARNING: These codes are not documented by Intel in their 80486 manual - and may not work on FPU clones or later Intel FPUs. */ - -/* Changes to support the un-doc codes provided by Linus Torvalds. */ - -#define _d9_d8_ fstp_i /* unofficial code (19) */ -#define _dc_d0_ fcom_st /* unofficial code (14) */ -#define _dc_d8_ fcompst /* unofficial code (1c) */ -#define _dd_c8_ fxch_i /* unofficial code (0d) */ -#define _de_d0_ fcompst /* unofficial code (16) */ -#define _df_c0_ ffreep /* unofficial code (07) ffree + pop */ -#define _df_c8_ fxch_i /* unofficial code (0f) */ -#define _df_d0_ fstp_i /* unofficial code (17) */ -#define _df_d8_ fstp_i /* unofficial code (1f) */ - -static FUNC const st_instr_table[64] = { - fadd__, fld_i_, __BAD__, __BAD__, fadd_i, ffree_, faddp_, _df_c0_, - fmul__, fxch_i, __BAD__, __BAD__, fmul_i, _dd_c8_, fmulp_, _df_c8_, - fcom_st, fp_nop, __BAD__, __BAD__, _dc_d0_, fst_i_, _de_d0_, _df_d0_, - fcompst, _d9_d8_, __BAD__, __BAD__, _dc_d8_, fstp_i, fcompp, _df_d8_, - fsub__, fp_etc, __BAD__, finit_, fsubri, fucom_, fsubrp, fstsw_, - fsubr_, fconst, fucompp, __BAD__, fsub_i, fucomp, fsubp_, __BAD__, - fdiv__, trig_a, __BAD__, __BAD__, fdivri, __BAD__, fdivrp, __BAD__, - fdivr_, trig_b, __BAD__, __BAD__, fdiv_i, __BAD__, fdivp_, __BAD__, -}; - -#else /* Support only documented FPU op-codes */ - -static FUNC const st_instr_table[64] = { - fadd__, fld_i_, __BAD__, __BAD__, fadd_i, ffree_, faddp_, __BAD__, - fmul__, fxch_i, __BAD__, __BAD__, fmul_i, __BAD__, fmulp_, __BAD__, - fcom_st, fp_nop, __BAD__, __BAD__, __BAD__, fst_i_, __BAD__, __BAD__, - fcompst, __BAD__, __BAD__, __BAD__, __BAD__, fstp_i, fcompp, __BAD__, - fsub__, fp_etc, __BAD__, finit_, fsubri, fucom_, fsubrp, fstsw_, - fsubr_, fconst, fucompp, __BAD__, fsub_i, fucomp, fsubp_, __BAD__, - fdiv__, trig_a, __BAD__, __BAD__, fdivri, __BAD__, fdivrp, __BAD__, - fdivr_, trig_b, __BAD__, __BAD__, fdiv_i, __BAD__, fdivp_, __BAD__, -}; - -#endif NO_UNDOC_CODE - - -#define _NONE_ 0 /* Take no special action */ -#define _REG0_ 1 /* Need to check for not empty st(0) */ -#define _REGI_ 2 /* Need to check for not empty st(0) and st(rm) */ -#define _REGi_ 0 /* Uses st(rm) */ -#define _PUSH_ 3 /* Need to check for space to push onto stack */ -#define _null_ 4 /* Function illegal or not implemented */ -#define _REGIi 5 /* Uses st(0) and st(rm), result to st(rm) */ -#define _REGIp 6 /* Uses st(0) and st(rm), result to st(rm) then pop */ -#define _REGIc 0 /* Compare st(0) and st(rm) */ -#define _REGIn 0 /* Uses st(0) and st(rm), but handle checks later */ - -#ifndef NO_UNDOC_CODE - -/* Un-documented FPU op-codes supported by default. (see above) */ - -static unsigned char const type_table[64] = { - _REGI_, _NONE_, _null_, _null_, _REGIi, _REGi_, _REGIp, _REGi_, - _REGI_, _REGIn, _null_, _null_, _REGIi, _REGI_, _REGIp, _REGI_, - _REGIc, _NONE_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_, - _REGIc, _REG0_, _null_, _null_, _REGIc, _REG0_, _REGIc, _REG0_, - _REGI_, _NONE_, _null_, _NONE_, _REGIi, _REGIc, _REGIp, _NONE_, - _REGI_, _NONE_, _REGIc, _null_, _REGIi, _REGIc, _REGIp, _null_, - _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_, - _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_ -}; - -#else /* Support only documented FPU op-codes */ - -static unsigned char const type_table[64] = { - _REGI_, _NONE_, _null_, _null_, _REGIi, _REGi_, _REGIp, _null_, - _REGI_, _REGIn, _null_, _null_, _REGIi, _null_, _REGIp, _null_, - _REGIc, _NONE_, _null_, _null_, _null_, _REG0_, _null_, _null_, - _REGIc, _null_, _null_, _null_, _null_, _REG0_, _REGIc, _null_, - _REGI_, _NONE_, _null_, _NONE_, _REGIi, _REGIc, _REGIp, _NONE_, - _REGI_, _NONE_, _REGIc, _null_, _REGIi, _REGIc, _REGIp, _null_, - _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_, - _REGI_, _NONE_, _null_, _null_, _REGIi, _null_, _REGIp, _null_ -}; - -#endif NO_UNDOC_CODE - - -#ifdef RE_ENTRANT_CHECKING -char emulating=0; -#endif RE_ENTRANT_CHECKING - -static int valid_prefix(unsigned char *Byte, unsigned char **fpu_eip, - overrides *override); - -asmlinkage void math_emulate(long arg) -{ - unsigned char FPU_modrm, byte1; - unsigned short code; - fpu_addr_modes addr_modes; - int unmasked; - FPU_REG loaded_data; - void *data_address; - struct address data_sel_off; - struct address entry_sel_off; - unsigned long code_base = 0; - unsigned long code_limit = 0; /* Initialized to stop compiler warnings */ - char st0_tag; - FPU_REG *st0_ptr; - struct desc_struct code_descriptor; - -#ifdef RE_ENTRANT_CHECKING - if ( emulating ) - { - printk("ERROR: wm-FPU-emu is not RE-ENTRANT!\n"); - } - RE_ENTRANT_CHECK_ON; -#endif RE_ENTRANT_CHECKING - - if (!current->used_math) - { - int i; - for ( i = 0; i < 8; i++ ) - { - /* Make sure that the registers are compatible - with the assumptions of the emulator. */ - regs[i].exp = 0; - regs[i].sigh = 0x80000000; - } - finit(); - current->used_math = 1; - } - - SETUP_DATA_AREA(arg); - - FPU_ORIG_EIP = FPU_EIP; - - if ( (FPU_EFLAGS & 0x00020000) != 0 ) - { - /* Virtual 8086 mode */ - addr_modes.default_mode = VM86; - FPU_EIP += code_base = FPU_CS << 4; - code_limit = code_base + 0xffff; /* Assumes code_base <= 0xffff0000 */ - } - else if ( FPU_CS == USER_CS && FPU_DS == USER_DS ) - { - addr_modes.default_mode = 0; - } - else if ( FPU_CS == KERNEL_CS ) - { - printk("math_emulate: %04x:%08lx\n",FPU_CS,FPU_EIP); - panic("Math emulation needed in kernel"); - } - else - { - - if ( (FPU_CS & 4) != 4 ) /* Must be in the LDT */ - { - /* Can only handle segmented addressing via the LDT - for now, and it must be 16 bit */ - printk("FPU emulator: Unsupported addressing mode\n"); - math_abort(FPU_info, SIGILL); - } - - if ( SEG_D_SIZE(code_descriptor = LDT_DESCRIPTOR(FPU_CS)) ) - { - /* The above test may be wrong, the book is not clear */ - /* Segmented 32 bit protected mode */ - addr_modes.default_mode = SEG32; - } - else - { - /* 16 bit protected mode */ - addr_modes.default_mode = PM16; - } - FPU_EIP += code_base = SEG_BASE_ADDR(code_descriptor); - code_limit = code_base - + (SEG_LIMIT(code_descriptor)+1) * SEG_GRANULARITY(code_descriptor) - - 1; - if ( code_limit < code_base ) code_limit = 0xffffffff; - } - - FPU_lookahead = 1; - if (current->flags & PF_PTRACED) - FPU_lookahead = 0; - - if ( !valid_prefix(&byte1, (unsigned char **)&FPU_EIP, - &addr_modes.override) ) - { - RE_ENTRANT_CHECK_OFF; - printk("FPU emulator: Unknown prefix byte 0x%02x, probably due to\n" - "FPU emulator: self-modifying code! (emulation impossible)\n", - byte1); - RE_ENTRANT_CHECK_ON; - EXCEPTION(EX_INTERNAL|0x126); - math_abort(FPU_info,SIGILL); - } - -do_another_FPU_instruction: - - no_ip_update = 0; - - FPU_EIP++; /* We have fetched the prefix and first code bytes. */ - - if ( addr_modes.default_mode ) - { - /* This checks for the minimum instruction bytes. - We also need to check any extra (address mode) code access. */ - if ( FPU_EIP > code_limit ) - math_abort(FPU_info,SIGSEGV); - } - - if ( (byte1 & 0xf8) != 0xd8 ) - { - if ( byte1 == FWAIT_OPCODE ) - { - if (partial_status & SW_Summary) - goto do_the_FPU_interrupt; - else - goto FPU_fwait_done; - } -#ifdef PARANOID - EXCEPTION(EX_INTERNAL|0x128); - math_abort(FPU_info,SIGILL); -#endif PARANOID - } - - RE_ENTRANT_CHECK_OFF; - FPU_code_verify_area(1); - FPU_modrm = get_fs_byte((unsigned char *) FPU_EIP); - RE_ENTRANT_CHECK_ON; - FPU_EIP++; - - if (partial_status & SW_Summary) - { - /* Ignore the error for now if the current instruction is a no-wait - control instruction */ - /* The 80486 manual contradicts itself on this topic, - but a real 80486 uses the following instructions: - fninit, fnstenv, fnsave, fnstsw, fnstenv, fnclex. - */ - code = (FPU_modrm << 8) | byte1; - if ( ! ( (((code & 0xf803) == 0xe003) || /* fnclex, fninit, fnstsw */ - (((code & 0x3003) == 0x3001) && /* fnsave, fnstcw, fnstenv, - fnstsw */ - ((code & 0xc000) != 0xc000))) ) ) - { - /* - * We need to simulate the action of the kernel to FPU - * interrupts here. - * Currently, the "real FPU" part of the kernel (0.99.10) - * clears the exception flags, sets the registers to empty, - * and passes information back to the interrupted process - * via the cs selector and operand selector, so we do the same. - */ - do_the_FPU_interrupt: - instruction_address.selector = status_word(); - operand_address.selector = tag_word(); - partial_status = 0; - top = 0; - { - int r; - for (r = 0; r < 8; r++) - { - regs[r].tag = TW_Empty; - } - } - - FPU_EIP = FPU_ORIG_EIP; /* Point to current FPU instruction. */ - - RE_ENTRANT_CHECK_OFF; - current->tss.trap_no = 16; - current->tss.error_code = 0; - send_sig(SIGFPE, current, 1); - return; - } - } - - entry_sel_off.offset = FPU_ORIG_EIP; - entry_sel_off.selector = FPU_CS; - entry_sel_off.opcode = (byte1 << 8) | FPU_modrm; - - FPU_rm = FPU_modrm & 7; - - if ( FPU_modrm < 0300 ) - { - /* All of these instructions use the mod/rm byte to get a data address */ - - if ( (addr_modes.default_mode & SIXTEEN) - ^ (addr_modes.override.address_size == ADDR_SIZE_PREFIX) ) - data_address = get_address_16(FPU_modrm, &FPU_EIP, &data_sel_off, - addr_modes); - else - data_address = get_address(FPU_modrm, &FPU_EIP, &data_sel_off, - addr_modes); - - if ( addr_modes.default_mode ) - { - if ( FPU_EIP-1 > code_limit ) - math_abort(FPU_info,SIGSEGV); - } - - if ( !(byte1 & 1) ) - { - unsigned short status1 = partial_status; - - st0_ptr = &st(0); - st0_tag = st0_ptr->tag; - - /* Stack underflow has priority */ - if ( NOT_EMPTY_ST0 ) - { - if ( addr_modes.default_mode & PROTECTED ) - { - /* This table works for 16 and 32 bit protected mode */ - if ( access_limit < data_sizes_16[(byte1 >> 1) & 3] ) - math_abort(FPU_info,SIGSEGV); - } - - unmasked = 0; /* Do this here to stop compiler warnings. */ - switch ( (byte1 >> 1) & 3 ) - { - case 0: - unmasked = reg_load_single((float *)data_address, - &loaded_data); - break; - case 1: - reg_load_int32((long *)data_address, &loaded_data); - break; - case 2: - unmasked = reg_load_double((double *)data_address, - &loaded_data); - break; - case 3: - reg_load_int16((short *)data_address, &loaded_data); - break; - } - - /* No more access to user memory, it is safe - to use static data now */ - - /* NaN operands have the next priority. */ - /* We have to delay looking at st(0) until after - loading the data, because that data might contain an SNaN */ - if ( (st0_tag == TW_NaN) || - (loaded_data.tag == TW_NaN) ) - { - /* Restore the status word; we might have loaded a - denormal. */ - partial_status = status1; - if ( (FPU_modrm & 0x30) == 0x10 ) - { - /* fcom or fcomp */ - EXCEPTION(EX_Invalid); - setcc(SW_C3 | SW_C2 | SW_C0); - if ( (FPU_modrm & 0x08) && (control_word & CW_Invalid) ) - pop(); /* fcomp, masked, so we pop. */ - } - else - { -#ifdef PECULIAR_486 - /* This is not really needed, but gives behaviour - identical to an 80486 */ - if ( (FPU_modrm & 0x28) == 0x20 ) - /* fdiv or fsub */ - real_2op_NaN(&loaded_data, st0_ptr, - st0_ptr); - else -#endif PECULIAR_486 - /* fadd, fdivr, fmul, or fsubr */ - real_2op_NaN(st0_ptr, &loaded_data, - st0_ptr); - } - goto reg_mem_instr_done; - } - - if ( unmasked && !((FPU_modrm & 0x30) == 0x10) ) - { - /* Is not a comparison instruction. */ - if ( (FPU_modrm & 0x38) == 0x38 ) - { - /* fdivr */ - if ( (st0_tag == TW_Zero) && - (loaded_data.tag == TW_Valid) ) - { - if ( divide_by_zero(loaded_data.sign, - st0_ptr) ) - { - /* We use the fact here that the unmasked - exception in the loaded data was for a - denormal operand */ - /* Restore the state of the denormal op bit */ - partial_status &= ~SW_Denorm_Op; - partial_status |= status1 & SW_Denorm_Op; - } - } - } - goto reg_mem_instr_done; - } - - switch ( (FPU_modrm >> 3) & 7 ) - { - case 0: /* fadd */ - clear_C1(); - reg_add(st0_ptr, &loaded_data, st0_ptr, - control_word); - break; - case 1: /* fmul */ - clear_C1(); - reg_mul(st0_ptr, &loaded_data, st0_ptr, - control_word); - break; - case 2: /* fcom */ - compare_st_data(&loaded_data); - break; - case 3: /* fcomp */ - if ( !compare_st_data(&loaded_data) && !unmasked ) - pop(); - break; - case 4: /* fsub */ - clear_C1(); - reg_sub(st0_ptr, &loaded_data, st0_ptr, - control_word); - break; - case 5: /* fsubr */ - clear_C1(); - reg_sub(&loaded_data, st0_ptr, st0_ptr, - control_word); - break; - case 6: /* fdiv */ - clear_C1(); - reg_div(st0_ptr, &loaded_data, st0_ptr, - control_word); - break; - case 7: /* fdivr */ - clear_C1(); - if ( st0_tag == TW_Zero ) - partial_status = status1; /* Undo any denorm tag, - zero-divide has priority. */ - reg_div(&loaded_data, st0_ptr, st0_ptr, - control_word); - break; - } - } - else - { - if ( (FPU_modrm & 0x30) == 0x10 ) - { - /* The instruction is fcom or fcomp */ - EXCEPTION(EX_StackUnder); - setcc(SW_C3 | SW_C2 | SW_C0); - if ( (FPU_modrm & 0x08) && (control_word & CW_Invalid) ) - pop(); /* fcomp */ - } - else - stack_underflow(); - } - reg_mem_instr_done: - operand_address = data_sel_off; - } - else - { - if ( !(no_ip_update = - load_store_instr(((FPU_modrm & 0x38) | (byte1 & 6)) >> 1, - addr_modes, data_address)) ) - { - operand_address = data_sel_off; - } - } - - } - else - { - /* None of these instructions access user memory */ - unsigned char instr_index = (FPU_modrm & 0x38) | (byte1 & 7); - -#ifdef PECULIAR_486 - /* This is supposed to be undefined, but a real 80486 seems - to do this: */ - operand_address.offset = 0; - operand_address.selector = FPU_DS; -#endif PECULIAR_486 - - st0_ptr = &st(0); - st0_tag = st0_ptr->tag; - switch ( type_table[(int) instr_index] ) - { - case _NONE_: /* also _REGIc: _REGIn */ - break; - case _REG0_: - if ( !NOT_EMPTY_ST0 ) - { - stack_underflow(); - goto FPU_instruction_done; - } - break; - case _REGIi: - if ( !NOT_EMPTY_ST0 || !NOT_EMPTY(FPU_rm) ) - { - stack_underflow_i(FPU_rm); - goto FPU_instruction_done; - } - break; - case _REGIp: - if ( !NOT_EMPTY_ST0 || !NOT_EMPTY(FPU_rm) ) - { - stack_underflow_pop(FPU_rm); - goto FPU_instruction_done; - } - break; - case _REGI_: - if ( !NOT_EMPTY_ST0 || !NOT_EMPTY(FPU_rm) ) - { - stack_underflow(); - goto FPU_instruction_done; - } - break; - case _PUSH_: /* Only used by the fld st(i) instruction */ - break; - case _null_: - FPU_illegal(); - goto FPU_instruction_done; - default: - EXCEPTION(EX_INTERNAL|0x111); - goto FPU_instruction_done; - } - (*st_instr_table[(int) instr_index])(); - -FPU_instruction_done: - ; - } - - if ( ! no_ip_update ) - instruction_address = entry_sel_off; - -FPU_fwait_done: - -#ifdef DEBUG - RE_ENTRANT_CHECK_OFF; - emu_printall(); - RE_ENTRANT_CHECK_ON; -#endif DEBUG - - if (FPU_lookahead && !need_resched) - { - FPU_ORIG_EIP = FPU_EIP - code_base; - if ( valid_prefix(&byte1, (unsigned char **)&FPU_EIP, - &addr_modes.override) ) - goto do_another_FPU_instruction; - } - - if ( addr_modes.default_mode ) - FPU_EIP -= code_base; - - RE_ENTRANT_CHECK_OFF; -} - - -/* Support for prefix bytes is not yet complete. To properly handle - all prefix bytes, further changes are needed in the emulator code - which accesses user address space. Access to separate segments is - important for msdos emulation. */ -static int valid_prefix(unsigned char *Byte, unsigned char **fpu_eip, - overrides *override) -{ - unsigned char byte; - unsigned char *ip = *fpu_eip; - - *override = (overrides) { 0, 0, PREFIX_DEFAULT }; /* defaults */ - - RE_ENTRANT_CHECK_OFF; - FPU_code_verify_area(1); - byte = get_fs_byte(ip); - RE_ENTRANT_CHECK_ON; - - while ( 1 ) - { - switch ( byte ) - { - case ADDR_SIZE_PREFIX: - override->address_size = ADDR_SIZE_PREFIX; - goto do_next_byte; - - case OP_SIZE_PREFIX: - override->operand_size = OP_SIZE_PREFIX; - goto do_next_byte; - - case PREFIX_CS: - override->segment = PREFIX_CS_; - goto do_next_byte; - case PREFIX_ES: - override->segment = PREFIX_ES_; - goto do_next_byte; - case PREFIX_SS: - override->segment = PREFIX_SS_; - goto do_next_byte; - case PREFIX_FS: - override->segment = PREFIX_FS_; - goto do_next_byte; - case PREFIX_GS: - override->segment = PREFIX_GS_; - goto do_next_byte; - case PREFIX_DS: - override->segment = PREFIX_DS_; - goto do_next_byte; - -/* lock is not a valid prefix for FPU instructions, - let the cpu handle it to generate a SIGILL. */ -/* case PREFIX_LOCK: */ - - /* rep.. prefixes have no meaning for FPU instructions */ - case PREFIX_REPE: - case PREFIX_REPNE: - - do_next_byte: - ip++; - RE_ENTRANT_CHECK_OFF; - FPU_code_verify_area(1); - byte = get_fs_byte(ip); - RE_ENTRANT_CHECK_ON; - break; - case FWAIT_OPCODE: - *Byte = byte; - return 1; - default: - if ( (byte & 0xf8) == 0xd8 ) - { - *Byte = byte; - *fpu_eip = ip; - return 1; - } - else - { - /* Not a valid sequence of prefix bytes followed by - an FPU instruction. */ - *Byte = byte; /* Needed for error message. */ - return 0; - } - } - } -} - - -void math_abort(struct info * info, unsigned int signal) -{ - FPU_EIP = FPU_ORIG_EIP; - current->tss.trap_no = 16; - current->tss.error_code = 0; - send_sig(signal,current,1); - RE_ENTRANT_CHECK_OFF; - __asm__("movl %0,%%esp ; ret": :"g" (((long) info)-4)); -#ifdef PARANOID - printk("ERROR: wm-FPU-emu math_abort failed!\n"); -#endif PARANOID -} |