asmlinkage int do_page_fault()

in kernel/traps.c [125:177]

• 41 lines of code
• 11 McCabe index (conditional complexity)

asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
                             unsigned long error_code);
int send_fault_sig(struct pt_regs *regs);

asmlinkage void trap_c(struct frame *fp);

#if defined (CONFIG_M68060)
static inline void access_error060 (struct frame *fp)
{
	unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */

	pr_debug("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);

	if (fslw & MMU060_BPE) {
		/* branch prediction error -> clear branch cache */
		__asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
				      "orl   #0x00400000,%/d0\n\t"
				      "movec %/d0,%/cacr"
				      : : : "d0" );
		/* return if there's no other error */
		if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
			return;
	}

	if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
		unsigned long errorcode;
		unsigned long addr = fp->un.fmt4.effaddr;

		if (fslw & MMU060_MA)
			addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;

		errorcode = 1;
		if (fslw & MMU060_DESC_ERR) {
			__flush_tlb040_one(addr);
			errorcode = 0;
		}
		if (fslw & MMU060_W)
			errorcode |= 2;
		pr_debug("errorcode = %ld\n", errorcode);
		do_page_fault(&fp->ptregs, addr, errorcode);
	} else if (fslw & (MMU060_SEE)){
		/* Software Emulation Error.
		 * fault during mem_read/mem_write in ifpsp060/os.S
		 */
		send_fault_sig(&fp->ptregs);
	} else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
		   send_fault_sig(&fp->ptregs) > 0) {
		pr_err("pc=%#lx, fa=%#lx\n", fp->ptregs.pc,
		       fp->un.fmt4.effaddr);
		pr_err("68060 access error, fslw=%lx\n", fslw);
		trap_c( fp );
	}
}