traps.c

linux-2.6.15.6

#endif

	if ((fp->un.fmt7.wb2s & WBV_040) &&
	    !(fp->un.fmt7.wb2s & WBTT_040)) {
		res = do_040writeback1(fp->un.fmt7.wb2s, fp->un.fmt7.wb2a,
				       fp->un.fmt7.wb2d);
		if (res)
			fix_xframe040(fp, fp->un.fmt7.wb2a, fp->un.fmt7.wb2s);
		else
			fp->un.fmt7.wb2s = 0;
	}

	/* do the 2nd wb only if the first one was successful (except for a kernel wb) */
	if (fp->un.fmt7.wb3s & WBV_040 && (!res || fp->un.fmt7.wb3s & 4)) {
		res = do_040writeback1(fp->un.fmt7.wb3s, fp->un.fmt7.wb3a,
				       fp->un.fmt7.wb3d);
		if (res)
		    {
			fix_xframe040(fp, fp->un.fmt7.wb3a, fp->un.fmt7.wb3s);

			fp->un.fmt7.wb2s = fp->un.fmt7.wb3s;
			fp->un.fmt7.wb3s &= (~WBV_040);
			fp->un.fmt7.wb2a = fp->un.fmt7.wb3a;
			fp->un.fmt7.wb2d = fp->un.fmt7.wb3d;
		    }
		else
			fp->un.fmt7.wb3s = 0;
	}

	if (res)
		send_fault_sig(&fp->ptregs);
}

/*
 * called from sigreturn(), must ensure userspace code didn't
 * manipulate exception frame to circumvent protection, then complete
 * pending writebacks
 * we just clear TM2 to turn it into an userspace access
 */
asmlinkage void berr_040cleanup(struct frame *fp)
{
	fp->un.fmt7.wb2s &= ~4;
	fp->un.fmt7.wb3s &= ~4;

	do_040writebacks(fp);
}

static inline void access_error040(struct frame *fp)
{
	unsigned short ssw = fp->un.fmt7.ssw;
	unsigned long mmusr;

#ifdef DEBUG
	printk("ssw=%#x, fa=%#lx\n", ssw, fp->un.fmt7.faddr);
        printk("wb1s=%#x, wb2s=%#x, wb3s=%#x\n", fp->un.fmt7.wb1s,
		fp->un.fmt7.wb2s, fp->un.fmt7.wb3s);
	printk ("wb2a=%lx, wb3a=%lx, wb2d=%lx, wb3d=%lx\n",
		fp->un.fmt7.wb2a, fp->un.fmt7.wb3a,
		fp->un.fmt7.wb2d, fp->un.fmt7.wb3d);
#endif

	if (ssw & ATC_040) {
		unsigned long addr = fp->un.fmt7.faddr;
		unsigned long errorcode;

		/*
		 * The MMU status has to be determined AFTER the address
		 * has been corrected if there was a misaligned access (MA).
		 */
		if (ssw & MA_040)
			addr = (addr + 7) & -8;

		/* MMU error, get the MMUSR info for this access */
		mmusr = probe040(!(ssw & RW_040), addr, ssw);
#ifdef DEBUG
		printk("mmusr = %lx\n", mmusr);
#endif
		errorcode = 1;
		if (!(mmusr & MMU_R_040)) {
			/* clear the invalid atc entry */
			__flush_tlb040_one(addr);
			errorcode = 0;
		}

		/* despite what documentation seems to say, RMW
		 * accesses have always both the LK and RW bits set */
		if (!(ssw & RW_040) || (ssw & LK_040))
			errorcode |= 2;

		if (do_page_fault(&fp->ptregs, addr, errorcode)) {
#ifdef DEBUG
		        printk("do_page_fault() !=0 \n");
#endif
			if (user_mode(&fp->ptregs)){
				/* delay writebacks after signal delivery */
#ifdef DEBUG
			        printk(".. was usermode - return\n");
#endif
				return;
			}
			/* disable writeback into user space from kernel
			 * (if do_page_fault didn't fix the mapping,
                         * the writeback won't do good)
			 */
#ifdef DEBUG
			printk(".. disabling wb2\n");
#endif
			if (fp->un.fmt7.wb2a == fp->un.fmt7.faddr)
				fp->un.fmt7.wb2s &= ~WBV_040;
		}
	} else if (send_fault_sig(&fp->ptregs) > 0) {
		printk("68040 access error, ssw=%x\n", ssw);
		trap_c(fp);
	}

	do_040writebacks(fp);
}
#endif /* CONFIG_M68040 */

#if defined(CONFIG_SUN3)
#include <asm/sun3mmu.h>

extern int mmu_emu_handle_fault (unsigned long, int, int);

/* sun3 version of bus_error030 */

static inline void bus_error030 (struct frame *fp)
{
	unsigned char buserr_type = sun3_get_buserr ();
	unsigned long addr, errorcode;
	unsigned short ssw = fp->un.fmtb.ssw;
	extern unsigned long _sun3_map_test_start, _sun3_map_test_end;

#ifdef DEBUG
	if (ssw & (FC | FB))
		printk ("Instruction fault at %#010lx\n",
			ssw & FC ?
			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
			:
			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
	if (ssw & DF)
		printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
			ssw & RW ? "read" : "write",
			fp->un.fmtb.daddr,
			space_names[ssw & DFC], fp->ptregs.pc);
#endif

	/*
	 * Check if this page should be demand-mapped. This needs to go before
	 * the testing for a bad kernel-space access (demand-mapping applies
	 * to kernel accesses too).
	 */

	if ((ssw & DF)
	    && (buserr_type & (SUN3_BUSERR_PROTERR | SUN3_BUSERR_INVALID))) {
		if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 0))
			return;
	}

	/* Check for kernel-space pagefault (BAD). */
	if (fp->ptregs.sr & PS_S) {
		/* kernel fault must be a data fault to user space */
		if (! ((ssw & DF) && ((ssw & DFC) == USER_DATA))) {
		     // try checking the kernel mappings before surrender
		     if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 1))
			  return;
			/* instruction fault or kernel data fault! */
			if (ssw & (FC | FB))
				printk ("Instruction fault at %#010lx\n",
					fp->ptregs.pc);
			if (ssw & DF) {
				/* was this fault incurred testing bus mappings? */
				if((fp->ptregs.pc >= (unsigned long)&_sun3_map_test_start) &&
				   (fp->ptregs.pc <= (unsigned long)&_sun3_map_test_end)) {
					send_fault_sig(&fp->ptregs);
					return;
				}

				printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
					ssw & RW ? "read" : "write",
					fp->un.fmtb.daddr,
					space_names[ssw & DFC], fp->ptregs.pc);
			}
			printk ("BAD KERNEL BUSERR\n");

			die_if_kernel("Oops", &fp->ptregs,0);
			force_sig(SIGKILL, current);
			return;
		}
	} else {
		/* user fault */
		if (!(ssw & (FC | FB)) && !(ssw & DF))
			/* not an instruction fault or data fault! BAD */
			panic ("USER BUSERR w/o instruction or data fault");
	}


	/* First handle the data fault, if any.  */
	if (ssw & DF) {
		addr = fp->un.fmtb.daddr;

// errorcode bit 0:	0 -> no page		1 -> protection fault
// errorcode bit 1:	0 -> read fault		1 -> write fault

// (buserr_type & SUN3_BUSERR_PROTERR)	-> protection fault
// (buserr_type & SUN3_BUSERR_INVALID)	-> invalid page fault

		if (buserr_type & SUN3_BUSERR_PROTERR)
			errorcode = 0x01;
		else if (buserr_type & SUN3_BUSERR_INVALID)
			errorcode = 0x00;
		else {
#ifdef DEBUG
			printk ("*** unexpected busfault type=%#04x\n", buserr_type);
			printk ("invalid %s access at %#lx from pc %#lx\n",
				!(ssw & RW) ? "write" : "read", addr,
				fp->ptregs.pc);
#endif
			die_if_kernel ("Oops", &fp->ptregs, buserr_type);
			force_sig (SIGBUS, current);
			return;
		}

//todo: wtf is RM bit? --m
		if (!(ssw & RW) || ssw & RM)
			errorcode |= 0x02;

		/* Handle page fault. */
		do_page_fault (&fp->ptregs, addr, errorcode);

		/* Retry the data fault now. */
		return;
	}

	/* Now handle the instruction fault. */

	/* Get the fault address. */
	if (fp->ptregs.format == 0xA)
		addr = fp->ptregs.pc + 4;
	else
		addr = fp->un.fmtb.baddr;
	if (ssw & FC)
		addr -= 2;

	if (buserr_type & SUN3_BUSERR_INVALID) {
		if (!mmu_emu_handle_fault (fp->un.fmtb.daddr, 1, 0))
			do_page_fault (&fp->ptregs, addr, 0);
       } else {
#ifdef DEBUG
		printk ("protection fault on insn access (segv).\n");
#endif
		force_sig (SIGSEGV, current);
       }
}
#else
#if defined(CPU_M68020_OR_M68030)
static inline void bus_error030 (struct frame *fp)
{
	volatile unsigned short temp;
	unsigned short mmusr;
	unsigned long addr, errorcode;
	unsigned short ssw = fp->un.fmtb.ssw;
#ifdef DEBUG
	unsigned long desc;

	printk ("pid = %x  ", current->pid);
	printk ("SSW=%#06x  ", ssw);

	if (ssw & (FC | FB))
		printk ("Instruction fault at %#010lx\n",
			ssw & FC ?
			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
			:
			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
	if (ssw & DF)
		printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
			ssw & RW ? "read" : "write",
			fp->un.fmtb.daddr,
			space_names[ssw & DFC], fp->ptregs.pc);
#endif

	/* ++andreas: If a data fault and an instruction fault happen
	   at the same time map in both pages.  */

	/* First handle the data fault, if any.  */
	if (ssw & DF) {
		addr = fp->un.fmtb.daddr;

#ifdef DEBUG
		asm volatile ("ptestr %3,%2@,#7,%0\n\t"
			      "pmove %%psr,%1@"
			      : "=a&" (desc)
			      : "a" (&temp), "a" (addr), "d" (ssw));
#else
		asm volatile ("ptestr %2,%1@,#7\n\t"
			      "pmove %%psr,%0@"
			      : : "a" (&temp), "a" (addr), "d" (ssw));
#endif
		mmusr = temp;

#ifdef DEBUG
		printk("mmusr is %#x for addr %#lx in task %p\n",
		       mmusr, addr, current);
		printk("descriptor address is %#lx, contents %#lx\n",
		       __va(desc), *(unsigned long *)__va(desc));
#endif

		errorcode = (mmusr & MMU_I) ? 0 : 1;
		if (!(ssw & RW) || (ssw & RM))
			errorcode |= 2;

		if (mmusr & (MMU_I | MMU_WP)) {
			if (ssw & 4) {
				printk("Data %s fault at %#010lx in %s (pc=%#lx)\n",
				       ssw & RW ? "read" : "write",
				       fp->un.fmtb.daddr,
				       space_names[ssw & DFC], fp->ptregs.pc);
				goto buserr;
			}
			/* Don't try to do anything further if an exception was
			   handled. */
			if (do_page_fault (&fp->ptregs, addr, errorcode) < 0)
				return;
		} else if (!(mmusr & MMU_I)) {
			/* probably a 020 cas fault */
			if (!(ssw & RM) && send_fault_sig(&fp->ptregs) > 0)
				printk("unexpected bus error (%#x,%#x)\n", ssw, mmusr);
		} else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
			printk("invalid %s access at %#lx from pc %#lx\n",
			       !(ssw & RW) ? "write" : "read", addr,
			       fp->ptregs.pc);
			die_if_kernel("Oops",&fp->ptregs,mmusr);
			force_sig(SIGSEGV, current);
			return;
		} else {
#if 0
			static volatile long tlong;
#endif

			printk("weird %s access at %#lx from pc %#lx (ssw is %#x)\n",
			       !(ssw & RW) ? "write" : "read", addr,
			       fp->ptregs.pc, ssw);
			asm volatile ("ptestr #1,%1@,#0\n\t"
				      "pmove %%psr,%0@"
				      : /* no outputs */
				      : "a" (&temp), "a" (addr));
			mmusr = temp;

			printk ("level 0 mmusr is %#x\n", mmusr);
#if 0
			asm volatile ("pmove %%tt0,%0@"
				      : /* no outputs */
				      : "a" (&tlong));
			printk("tt0 is %#lx, ", tlong);
			asm volatile ("pmove %%tt1,%0@"
				      : /* no outputs */
				      : "a" (&tlong));
			printk("tt1 is %#lx\n", tlong);
#endif
#ifdef DEBUG
			printk("Unknown SIGSEGV - 1\n");
#endif
			die_if_kernel("Oops",&fp->ptregs,mmusr);
			force_sig(SIGSEGV, current);
			return;
		}

		/* setup an ATC entry for the access about to be retried */
		if (!(ssw & RW) || (ssw & RM))
			asm volatile ("ploadw %1,%0@" : /* no outputs */
				      : "a" (addr), "d" (ssw));
		else
			asm volatile ("ploadr %1,%0@" : /* no outputs */
				      : "a" (addr), "d" (ssw));
	}

	/* Now handle the instruction fault. */

	if (!(ssw & (FC|FB)))
		return;

	if (fp->ptregs.sr & PS_S) {
		printk("Instruction fault at %#010lx\n",
			fp->ptregs.pc);
	buserr:
		printk ("BAD KERNEL BUSERR\n");
		die_if_kernel("Oops",&fp->ptregs,0);
		force_sig(SIGKILL, current);
		return;
	}

	/* get the fault address */
	if (fp->ptregs.format == 10)
		addr = fp->ptregs.pc + 4;
	else
		addr = fp->un.fmtb.baddr;
	if (ssw & FC)
		addr -= 2;

	if ((ssw & DF) && ((addr ^ fp->un.fmtb.daddr) & PAGE_MASK) == 0)
		/* Insn fault on same page as data fault.  But we
		   should still create the ATC entry.  */
		goto create_atc_entry;

#ifdef DEBUG
	asm volatile ("ptestr #1,%2@,#7,%0\n\t"
		      "pmove %%psr,%1@"
		      : "=a&" (desc)
		      : "a" (&temp), "a" (addr));
#else