1 // SPDX-License-Identifier: GPL-2.0
2 /*---------------------------------------------------------------------------+
9  |                       Australia.  E-mail   billm@suburbia.net             |
12  +---------------------------------------------------------------------------*/
14 /*---------------------------------------------------------------------------+
19  +---------------------------------------------------------------------------*/
30 #define FPU_WRITE_BIT 0x10
43 #define REG_(x) (*(long *)(reg_offset[(x)] + (u_char *)FPU_info->regs))
56 		(reg_offset_vm86[((unsigned)x)] + (u_char *)FPU_info->regs))
69 		(reg_offset_pm[((unsigned)x)] + (u_char *)FPU_info->regs))
71 /* Decode the SIB byte. This function assumes mod != 0 */
86 	if ((mod == 0) && (base == 5))  in sib()
87 		offset = 0;	/* No base register */  in sib()
93 		/* A non-zero ss is illegal */  in sib()
109 	} else if (mod == 2 || base == 5) {	/* The second condition also has mod==0 */  in sib()
123 static unsigned long vm86_segment(u_char segment, struct address *addr)  in vm86_segment()  argument
125 	segment--;  in vm86_segment()
127 	if (segment > PREFIX_SS_) {  in vm86_segment()
128 		EXCEPTION(EX_INTERNAL | 0x130);  in vm86_segment()
132 	addr->selector = VM86_REG_(segment);  in vm86_segment()
133 	return (unsigned long)VM86_REG_(segment) << 4;  in vm86_segment()
137 static long pm_address(u_char FPU_modrm, u_char segment,  in pm_address()  argument
143 	segment--;  in pm_address()
146 	/* segment is unsigned, so this also detects if segment was 0: */  in pm_address()
147 	if (segment > PREFIX_SS_) {  in pm_address()
148 		EXCEPTION(EX_INTERNAL | 0x132);  in pm_address()
153 	switch (segment) {  in pm_address()
154 	case PREFIX_GS_ - 1:  in pm_address()
156 		savesegment(gs, addr->selector);  in pm_address()
159 		addr->selector = PM_REG_(segment);  in pm_address()
162 	descriptor = FPU_get_ldt_descriptor(addr->selector);  in pm_address()
167 	limit += base_address - 1;  in pm_address()
169 		limit = 0xffffffff;  in pm_address()
173 			seg_top = 0xffffffff;  in pm_address()
177 				seg_top = 0xffffffff;  in pm_address()
180 		    (address <= limit) || (address >= seg_top) ? 0 :  in pm_address()
181 		    ((seg_top - address) >= 255 ? 255 : seg_top - address);  in pm_address()
184 		    (address > limit) || (address < base_address) ? 0 :  in pm_address()
185 		    ((limit - address) >= 254 ? 255 : limit - address + 1);  in pm_address()
189 		access_limit = 0;  in pm_address()
198        7   6   5   4   3   2   1   0
204        7   6   5   4   3   2   1   0
216 	int address = 0;	/* Initialized just to stop compiler warnings. */  in FPU_get_address()
219 	   in `non-segmented' 32 bit protected mode. */  in FPU_get_address()
221 	    && (addr_modes.override.segment == PREFIX_CS_)) {  in FPU_get_address()
225 	addr->selector = FPU_DS;	/* Default, for 32 bit non-segmented mode. */  in FPU_get_address()
234 		case 0:  in FPU_get_address()
244 				addr->offset = address;  in FPU_get_address()
249 				addr->offset = address;  in FPU_get_address()
275 	addr->offset = address;  in FPU_get_address()
278 	case 0:  in FPU_get_address()
281 		address += vm86_segment(addr_modes.override.segment, addr);  in FPU_get_address()
285 		address = pm_address(FPU_modrm, addr_modes.override.segment,  in FPU_get_address()
289 		EXCEPTION(EX_INTERNAL | 0x133);  in FPU_get_address()
300 	int address = 0;	/* Default used for mod == 0 */  in FPU_get_address_16()
303 	   in `non-segmented' 32 bit protected mode. */  in FPU_get_address_16()
305 	    && (addr_modes.override.segment == PREFIX_CS_)) {  in FPU_get_address_16()
309 	addr->selector = FPU_DS;	/* Default, for 32 bit non-segmented mode. */  in FPU_get_address_16()
314 	case 0:  in FPU_get_address_16()
348 	case 0:  in FPU_get_address_16()
349 		address += FPU_info->regs->bx + FPU_info->regs->si;  in FPU_get_address_16()
352 		address += FPU_info->regs->bx + FPU_info->regs->di;  in FPU_get_address_16()
355 		address += FPU_info->regs->bp + FPU_info->regs->si;  in FPU_get_address_16()
356 		if (addr_modes.override.segment == PREFIX_DEFAULT)  in FPU_get_address_16()
357 			addr_modes.override.segment = PREFIX_SS_;  in FPU_get_address_16()
360 		address += FPU_info->regs->bp + FPU_info->regs->di;  in FPU_get_address_16()
361 		if (addr_modes.override.segment == PREFIX_DEFAULT)  in FPU_get_address_16()
362 			addr_modes.override.segment = PREFIX_SS_;  in FPU_get_address_16()
365 		address += FPU_info->regs->si;  in FPU_get_address_16()
368 		address += FPU_info->regs->di;  in FPU_get_address_16()
371 		address += FPU_info->regs->bp;  in FPU_get_address_16()
372 		if (addr_modes.override.segment == PREFIX_DEFAULT)  in FPU_get_address_16()
373 			addr_modes.override.segment = PREFIX_SS_;  in FPU_get_address_16()
376 		address += FPU_info->regs->bx;  in FPU_get_address_16()
381 	address &= 0xffff;  in FPU_get_address_16()
383 	addr->offset = address;  in FPU_get_address_16()
386 	case 0:  in FPU_get_address_16()
389 		address += vm86_segment(addr_modes.override.segment, addr);  in FPU_get_address_16()
393 		address = pm_address(FPU_modrm, addr_modes.override.segment,  in FPU_get_address_16()
397 		EXCEPTION(EX_INTERNAL | 0x131);  in FPU_get_address_16()