asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
{
unsigned int pending;
#ifdef CONFIG_SIBYTE_BCM1480_PROF
/* Set compare to count to silence count/compare timer interrupts */
write_c0_compare(read_c0_count());
#endif
pending = read_c0_cause() & read_c0_status();
#ifdef CONFIG_SIBYTE_BCM1480_PROF
if (pending & CAUSEF_IP7) /* Cpu performance counter interrupt */
sbprof_cpu_intr(exception_epc(regs));
else
#endif
if (pending & CAUSEF_IP4)
bcm1480_timer_interrupt(regs);
#ifdef CONFIG_SMP
else if (pending & CAUSEF_IP3)
bcm1480_mailbox_interrupt(regs);
#endif
#ifdef CONFIG_KGDB
else if (pending & CAUSEF_IP6)
bcm1480_kgdb_interrupt(regs); /* KGDB (uart 1) */
#endif
else if (pending & CAUSEF_IP2) {
unsigned long long mask_h, mask_l;
unsigned long base;
/*
* Default...we've hit an IP[2] interrupt, which means we've
* got to check the 1480 interrupt registers to figure out what
* to do. Need to detect which CPU we're on, now that
* smp_affinity is supported.
*/
base = A_BCM1480_IMR_MAPPER(smp_processor_id());
mask_h = __raw_readq(
IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
mask_l = __raw_readq(
IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
if (mask_h) {
if (mask_h ^ 1)
do_IRQ(fls64(mask_h) - 1, regs);
else
do_IRQ(63 + fls64(mask_l), regs);
}
}
}
int fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *fixup;
fixup = search_exception_tables(exception_epc(regs));
if (fixup) {
regs->cp0_epc = fixup->nextinsn;
return 1;
}
return 0;
}
int fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *fixup;
fixup = search_exception_tables(exception_epc(regs));
if (fixup) {
regs->cp0_epc = fixup->nextinsn;
return 1;
}
#ifdef CONFIG_KGDB
if (atomic_read(&debugger_active) && kgdb_may_fault)
/* Restore our previous state. */
kgdb_fault_longjmp(kgdb_fault_jmp_regs);
/* Not reached. */
#endif
return 0;
}
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
* routines.
*/
asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
unsigned long address)
{
struct vm_area_struct * vma;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
unsigned long fixup;
siginfo_t info;
/*
* We fault-in kernel-space virtual memory on-demand. The
* 'reference' page table is init_mm.pgd.
*
* NOTE! We MUST NOT take any locks for this case. We may
* be in an interrupt or a critical region, and should
* only copy the information from the master page table,
* nothing more.
*/
if (address >= VMALLOC_START)
goto vmalloc_fault;
info.si_code = SEGV_MAPERR;
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
*/
if (in_interrupt() || !mm)
goto no_context;
#if 0
printk("[%s:%d:%08lx:%ld:%08lx]\n", current->comm, current->pid,
address, write, regs->cp0_epc);
#endif
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if (!vma)
goto bad_area;
if (vma->vm_start <= address)
goto good_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:
info.si_code = SEGV_ACCERR;
if (write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto bad_area;
}
survive:
/*
* If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo
* the fault.
*/
switch (handle_mm_fault(mm, vma, address, write)) {
case 1:
tsk->min_flt++;
break;
case 2:
tsk->maj_flt++;
break;
case 0:
goto do_sigbus;
default:
goto out_of_memory;
}
up_read(&mm->mmap_sem);
return;
/*
* 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_read(&mm->mmap_sem);
bad_area_nosemaphore:
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
tsk->thread.cp0_badvaddr = address;
tsk->thread.error_code = write;
#if 0
printk("do_page_fault() #2: sending SIGSEGV to %s for illegal %s\n"
"%08lx (epc == %08lx, ra == %08lx)\n",
tsk->comm,
write ? "write access to" : "read access from",
address,
(unsigned long) regs->cp0_epc,
(unsigned long) regs->regs[31]);
#endif
info.si_signo = SIGSEGV;
info.si_errno = 0;
/* info.si_code has been set above */
info.si_addr = (void *) address;
force_sig_info(SIGSEGV, &info, tsk);
return;
}
no_context:
/* Are we prepared to handle this kernel fault? */
fixup = search_exception_table(exception_epc(regs));
if (fixup) {
long new_epc;
tsk->thread.cp0_baduaddr = address;
new_epc = fixup_exception(dpf_reg, fixup, regs->cp0_epc);
if (development_version)
printk(KERN_DEBUG "%s: Exception at [<%lx>] (%lx)\n",
tsk->comm, regs->cp0_epc, new_epc);
regs->cp0_epc = new_epc;
return;
}
/*
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
printk(KERN_ALERT "Unable to handle kernel paging request at virtual "
"address %08lx, epc == %08lx, ra == %08lx\n",
address, regs->cp0_epc, regs->regs[31]);
die("Oops", regs);
/* Game over. */
/*
* We ran out of memory, or some other thing happened to us that made
* us unable to handle the page fault gracefully.
*/
out_of_memory:
if (tsk->pid == 1) {
yield();
goto survive;
}
up_read(&mm->mmap_sem);
printk(KERN_NOTICE "VM: killing process %s\n", tsk->comm);
if (user_mode(regs))
do_exit(SIGKILL);
goto no_context;
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
tsk->thread.cp0_badvaddr = address;
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void *) address;
force_sig_info(SIGBUS, &info, tsk);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
return;
vmalloc_fault:
{
/*
* Synchronize this task's top level page-table
* with the 'reference' page table.
*/
int offset = pgd_index(address);
pgd_t *pgd, *pgd_k;
pmd_t *pmd, *pmd_k;
pgd = tsk->active_mm->pgd + offset;
pgd_k = init_mm.pgd + offset;
if (!pgd_present(*pgd)) {
if (!pgd_present(*pgd_k))
goto bad_area_nosemaphore;
set_pgd(pgd, *pgd_k);
return;
}
pmd = pmd_offset(pgd, address);
pmd_k = pmd_offset(pgd_k, address);
if (pmd_present(*pmd) || !pmd_present(*pmd_k))
goto bad_area_nosemaphore;
set_pmd(pmd, *pmd_k);
}
}
asmlinkage void do_ade(struct pt_regs *regs)
{
enum ctx_state prev_state;
unsigned int __user *pc;
mm_segment_t seg;
prev_state = exception_enter();
perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS,
1, regs, regs->cp0_badvaddr);
/*
* Did we catch a fault trying to load an instruction?
*/
if (regs->cp0_badvaddr == regs->cp0_epc)
goto sigbus;
if (user_mode(regs) && !test_thread_flag(TIF_FIXADE))
goto sigbus;
if (unaligned_action == UNALIGNED_ACTION_SIGNAL)
goto sigbus;
/*
* Do branch emulation only if we didn't forward the exception.
* This is all so but ugly ...
*/
/*
* Are we running in microMIPS mode?
*/
if (get_isa16_mode(regs->cp0_epc)) {
/*
* Did we catch a fault trying to load an instruction in
* 16-bit mode?
*/
if (regs->cp0_badvaddr == msk_isa16_mode(regs->cp0_epc))
goto sigbus;
if (unaligned_action == UNALIGNED_ACTION_SHOW)
show_registers(regs);
if (cpu_has_mmips) {
seg = get_fs();
if (!user_mode(regs))
set_fs(KERNEL_DS);
emulate_load_store_microMIPS(regs,
(void __user *)regs->cp0_badvaddr);
set_fs(seg);
return;
}
if (cpu_has_mips16) {
seg = get_fs();
if (!user_mode(regs))
set_fs(KERNEL_DS);
emulate_load_store_MIPS16e(regs,
(void __user *)regs->cp0_badvaddr);
set_fs(seg);
return;
}
goto sigbus;
}
if (unaligned_action == UNALIGNED_ACTION_SHOW)
show_registers(regs);
pc = (unsigned int __user *)exception_epc(regs);
seg = get_fs();
if (!user_mode(regs))
set_fs(KERNEL_DS);
emulate_load_store_insn(regs, (void __user *)regs->cp0_badvaddr, pc);
set_fs(seg);
return;
sigbus:
die_if_kernel("Kernel unaligned instruction access", regs);
force_sig(SIGBUS, current);
/*
* XXX On return from the signal handler we should advance the epc
*/
exception_exit(prev_state);
}
