/* $Id: fault.c,v 1.11 1997/06/01 05:46:15 davem Exp $ * arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc. * * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu) * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define ELEMENTS(arr) (sizeof (arr)/sizeof (arr[0])) extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS]; /* Nice, simple, prom library does all the sweating for us. ;) */ unsigned long prom_probe_memory (void) { register struct linux_mlist_p1275 *mlist; register unsigned long bytes, base_paddr, tally; register int i; i = 0; mlist = *prom_meminfo()->p1275_available; bytes = tally = mlist->num_bytes; base_paddr = (unsigned int) mlist->start_adr; sp_banks[0].base_addr = base_paddr; sp_banks[0].num_bytes = bytes; while (mlist->theres_more != (void *) 0){ i++; mlist = mlist->theres_more; bytes = mlist->num_bytes; tally += bytes; if (i >= SPARC_PHYS_BANKS-1) { printk ("The machine has more banks than " "this kernel can support\n" "Increase the SPARC_PHYS_BANKS " "setting (currently %d)\n", SPARC_PHYS_BANKS); i = SPARC_PHYS_BANKS-1; break; } sp_banks[i].base_addr = (unsigned long) mlist->start_adr; sp_banks[i].num_bytes = mlist->num_bytes; } i++; sp_banks[i].base_addr = 0xdeadbeef; sp_banks[i].num_bytes = 0; /* Now mask all bank sizes on a page boundary, it is all we can * use anyways. */ for(i=0; sp_banks[i].num_bytes != 0; i++) sp_banks[i].num_bytes &= PAGE_MASK; return tally; } /* Traverse the memory lists in the prom to see how much physical we * have. */ unsigned long probe_memory(void) { unsigned long total; total = prom_probe_memory(); /* Oh man, much nicer, keep the dirt in promlib. */ return total; } void unhandled_fault(unsigned long address, struct task_struct *tsk, struct pt_regs *regs) { if((unsigned long) address < PAGE_SIZE) { printk(KERN_ALERT "Unable to handle kernel NULL " "pointer dereference"); } else { printk(KERN_ALERT "Unable to handle kernel paging request " "at virtual address %016lx\n", (unsigned long)address); } printk(KERN_ALERT "tsk->mm->context = %016lx\n", (unsigned long) tsk->mm->context); printk(KERN_ALERT "tsk->mm->pgd = %016lx\n", (unsigned long) tsk->mm->pgd); die_if_kernel("Oops", regs); } asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc, unsigned long address) { unsigned long g2; int i; unsigned insn; struct pt_regs regs; i = search_exception_table (ret_pc, &g2); switch (i) { /* load & store will be handled by fixup */ case 3: return 3; /* store will be handled by fixup, load will bump out */ /* for _to_ macros */ case 1: insn = *(unsigned *)pc; if ((insn >> 21) & 1) return 1; break; /* load will be handled by fixup, store will bump out */ /* for _from_ macros */ case 2: insn = *(unsigned *)pc; if (!((insn >> 21) & 1) || ((insn>>19)&0x3f) == 15) return 2; break; default: break; } memset (®s, 0, sizeof (regs)); regs.tpc = pc; regs.tnpc = pc + 4; /* FIXME: Should set up regs->tstate? */ unhandled_fault (address, current, ®s); /* Not reached */ return 0; } /* #define FAULT_TRACER */ /* #define FAULT_TRACER_VERBOSE */ asmlinkage void do_sparc64_fault(struct pt_regs *regs, int text_fault, int write, unsigned long address, unsigned long tag, unsigned long sfsr) { struct vm_area_struct *vma; struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; unsigned long fixup; unsigned long g2; int from_user = !(regs->tstate & TSTATE_PRIV); #ifdef FAULT_TRACER static unsigned long last_addr = 0; static int rcnt = 0; #ifdef FAULT_TRACER_VERBOSE printk("FAULT(PC[%016lx],t[%d],w[%d],addr[%016lx])...", regs->tpc, text_fault, write, address); #else printk("F[%016lx:%016lx:w(%d)", regs->tpc, address, write); #endif if(address == last_addr) { if(rcnt++ > 15) { printk("Wheee lotsa bogus faults, something wrong, spinning\n"); __asm__ __volatile__("flushw"); printk("o7[%016lx] i7[%016lx]\n", regs->u_regs[UREG_I7], ((struct reg_window *)(regs->u_regs[UREG_FP]+STACK_BIAS))->ins[7]); sti(); while(1) barrier(); } } else rcnt = 0; last_addr = address; #endif lock_kernel (); down(&mm->mmap_sem); vma = find_vma(mm, address); if(!vma) goto bad_area; if(vma->vm_start <= address) goto good_area; if(!(vma->vm_flags & VM_GROWSDOWN)) goto bad_area; if(expand_stack(vma, address)) goto bad_area; /* * Ok, we have a good vm_area for this memory access, so * we can handle it.. */ good_area: if(write) { if(!(vma->vm_flags & VM_WRITE)) goto bad_area; } else { /* Allow reads even for write-only mappings */ if(!(vma->vm_flags & (VM_READ | VM_EXEC))) goto bad_area; } handle_mm_fault(current, vma, address, write); up(&mm->mmap_sem); goto out; /* * Something tried to access memory that isn't in our memory map.. * Fix it, but check if it's kernel or user first.. */ bad_area: up(&mm->mmap_sem); /* Is this in ex_table? */ g2 = regs->u_regs[UREG_G2]; if (!from_user && (fixup = search_exception_table (regs->tpc, &g2))) { printk("Exception: PC<%016lx> faddr<%016lx>\n", regs->tpc, address); printk("EX_TABLE: insn<%016lx> fixup<%016lx> g2<%016lx>\n", regs->tpc, fixup, g2); regs->tpc = fixup; regs->tnpc = regs->tpc + 4; regs->u_regs[UREG_G2] = g2; goto out; } if(from_user) { #if 1 unsigned long cpc; __asm__ __volatile__("mov %%i7, %0" : "=r" (cpc)); printk("[%s:%d] SIGSEGV pc[%016lx] addr[%016lx] w[%d] sfsr[%016lx] " "caller[%016lx]\n", current->comm, current->pid, regs->tpc, address, write, sfsr, cpc); #endif tsk->tss.sig_address = address; tsk->tss.sig_desc = SUBSIG_NOMAPPING; send_sig(SIGSEGV, tsk, 1); goto out; } unhandled_fault (address, tsk, regs); out: unlock_kernel(); #ifdef FAULT_TRACER #ifdef FAULT_TRACER_VERBOSE printk(" done\n"); #else printk("]"); #endif #endif }