diff options
| -rw-r--r-- | arch/blackfin/kernel/traps.c | 8 | ||||
| -rw-r--r-- | arch/blackfin/mach-common/entry.S | 69 |
2 files changed, 62 insertions, 15 deletions
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c index 1a8a5f171bc8..ba68eb2ec929 100644 --- a/arch/blackfin/kernel/traps.c +++ b/arch/blackfin/kernel/traps.c @@ -132,6 +132,14 @@ static int printk_address(unsigned long address) } #endif +asmlinkage void double_fault_c(struct pt_regs *fp) +{ + printk(KERN_EMERG "\n" KERN_EMERG "Double Fault\n"); + dump_bfin_regs(fp, (void *)fp->retx); + panic("Double Fault - unrecoverable event\n"); + +} + asmlinkage void trap_c(struct pt_regs *fp) { #ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S index 3feca05694f8..e2239361cac3 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -29,21 +29,7 @@ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ -/* - * 25-Dec-2004 - LG Soft India - * 1. Fix in return_from_int, to make sure any pending - * system call in ILAT for this process to get - * executed, otherwise in case context switch happens, - * system call of first process (i.e in ILAT) will be - * carried forward to the switched process. - * 2. Removed Constant references for the following - * a. IPEND - * b. EXCAUSE mask - * c. PAGE Mask - */ - -/* - * NOTE: This code handles signal-recognition, which happens every time +/* NOTE: This code handles signal-recognition, which happens every time * after a timer-interrupt and after each system call. */ @@ -175,6 +161,13 @@ ENTRY(_ex_replaceable) nop; ENTRY(_ex_trap_c) + /* Make sure we are not in a double fault */ + p4.l = lo(IPEND); + p4.h = hi(IPEND); + r7 = [p4]; + CC = BITTST (r7, 5); + if CC jump _double_fault; + /* Call C code (trap_c) to handle the exception, which most * likely involves sending a signal to the current process. * To avoid double faults, lower our priority to IRQ5 first. @@ -220,6 +213,52 @@ ENTRY(_ex_trap_c) rtx; ENDPROC(_ex_trap_c) +/* We just realized we got an exception, while we were processing a different + * exception. This is a unrecoverable event, so crash + */ +ENTRY(_double_fault) + /* Turn caches & protection off, to ensure we don't get any more + * double exceptions + */ + + P4.L = LO(IMEM_CONTROL); + P4.H = HI(IMEM_CONTROL); + + R5 = [P4]; /* Control Register*/ + BITCLR(R5,ENICPLB_P); + SSYNC; /* SSYNC required before writing to IMEM_CONTROL. */ + .align 8; + [P4] = R5; + SSYNC; + + P4.L = LO(DMEM_CONTROL); + P4.H = HI(DMEM_CONTROL); + R5 = [P4]; + BITCLR(R5,ENDCPLB_P); + SSYNC; /* SSYNC required before writing to DMEM_CONTROL. */ + .align 8; + [P4] = R5; + SSYNC; + + /* Fix up the stack */ + (R7:6,P5:4) = [sp++]; + ASTAT = [sp++]; + SP = EX_SCRATCH_REG; + + /* We should be out of the exception stack, and back down into + * kernel or user space stack + */ + SAVE_ALL_SYS + + r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */ + SP += -12; + call _double_fault_c; + SP += 12; +.L_double_fault_panic: + JUMP .L_double_fault_panic + +ENDPROC(_double_fault) + ENTRY(_exception_to_level5) SAVE_ALL_SYS |