diff options
Diffstat (limited to 'arch/blackfin/cpu/interrupt.S')
| -rw-r--r-- | arch/blackfin/cpu/interrupt.S | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/arch/blackfin/cpu/interrupt.S b/arch/blackfin/cpu/interrupt.S new file mode 100644 index 0000000..69bba3f --- /dev/null +++ b/arch/blackfin/cpu/interrupt.S @@ -0,0 +1,152 @@ +/* + * interrupt.S - trampoline default exceptions/interrupts to C handlers + * + * Copyright (c) 2005-2009 Analog Devices Inc. + * Licensed under the GPL-2 or later. + */ + +#include <config.h> +#include <asm/blackfin.h> +#include <asm/entry.h> +#include <asm/ptrace.h> +#include <asm/deferred.h> +#include <asm/mach-common/bits/core.h> + +.text + +/* default entry point for exceptions */ +ENTRY(_trap) + CONFIG_BFIN_SCRATCH_REG = sp; + sp.l = LO(L1_SRAM_SCRATCH_END - 20); + sp.h = HI(L1_SRAM_SCRATCH_END - 20); + SAVE_ALL_SYS + + r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */ + r1 = 3; /* EVT3 space */ + sp += -12; + call _trap_c; + sp += 12; + +#ifdef CONFIG_EXCEPTION_DEFER + CC = R0 == 0; + IF CC JUMP .Lexit_trap; + + /* To avoid double faults, lower our priority to IRQ5 */ + p4.l = lo(COREMMR_BASE); + p4.h = hi(COREMMR_BASE); + + r7.h = _exception_to_level5; + r7.l = _exception_to_level5; + [p4 + (EVT5 - COREMMR_BASE)] = r7; + + /* + * Save these registers, as they are only valid in exception context + * (where we are now - as soon as we defer to IRQ5, they can change) + */ + p5.l = _deferred_regs; + p5.h = _deferred_regs; + r6 = [p4 + (DCPLB_FAULT_ADDR - COREMMR_BASE)]; + [p5 + (deferred_regs_DCPLB_FAULT_ADDR * 4)] = r6; + + r6 = [p4 + (ICPLB_FAULT_ADDR - COREMMR_BASE)]; + [p5 + (deferred_regs_ICPLB_FAULT_ADDR * 4)] = r6; + + /* Save the state of single stepping */ + r6 = SYSCFG; + [p5 + (deferred_regs_SYSCFG * 4)] = r6; + /* Clear it while we handle the exception in IRQ5 mode + * RESTORE_ALL_SYS will load it, so all we need to do is store it + * in the right place + */ + BITCLR(r6, SYSCFG_SSSTEP_P); + [SP + PT_SYSCFG] = r6; + + /* Since we are going to clobber RETX, we need to save it */ + r6 = retx; + [p5 + (deferred_regs_retx * 4)] = r6; + + /* Save the current IMASK, since we change in order to jump to level 5 */ + cli r6; + [p5 + (deferred_regs_IMASK * 4)] = r6; + + /* Disable all interrupts, but make sure level 5 is enabled so + * we can switch to that level. + */ + r6 = 0x3f; + sti r6; + + /* Clobber RETX so we don't end up back at a faulting instruction */ + [sp + PT_RETX] = r7; + + /* In case interrupts are disabled IPEND[4] (global interrupt disable bit) + * clear it (re-enabling interrupts again) by the special sequence of pushing + * RETI onto the stack. This way we can lower ourselves to IVG5 even if the + * exception was taken after the interrupt handler was called but before it + * got a chance to enable global interrupts itself. + */ + [--sp] = reti; + sp += 4; + + RAISE 5; +.Lexit_trap: +#endif + +#if ANOMALY_05000257 + R7 = LC0; + LC0 = R7; + R7 = LC1; + LC1 = R7; +#endif + + RESTORE_ALL_SYS + sp = CONFIG_BFIN_SCRATCH_REG; + rtx; +ENDPROC(_trap) + +#ifdef CONFIG_EXCEPTION_DEFER +/* Deferred (IRQ5) exceptions */ +ENTRY(_exception_to_level5) + SAVE_ALL_SYS + + /* Now we have to fix things up */ + p4.l = lo(EVT5); + p4.h = hi(EVT5); + r0.l = _evt_default; + r0.h = _evt_default; + [p4] = r0; + csync; + + p4.l = _deferred_regs; + p4.h = _deferred_regs; + r0 = [p4 + (deferred_regs_retx * 4)]; + [sp + PT_PC] = r0; + + r0 = [p4 + (deferred_regs_SYSCFG * 4)]; + [sp + PT_SYSCFG] = r0; + + r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */ + r1 = 5; /* EVT5 space */ + sp += -12; + call _trap_c; + sp += 12; + + /* Restore IMASK */ + r0 = [p4 + (deferred_regs_IMASK * 4)]; + sti r0; + + RESTORE_ALL_SYS + + rti; +ENDPROC(_exception_to_level5) +#endif + +/* default entry point for interrupts */ +ENTRY(_evt_default) + SAVE_ALL_SYS + r0 = sp; /* stack frame pt_regs pointer argument ==> r0 */ + sp += -12; + call _bfin_panic; + sp += 12; + RESTORE_ALL_SYS + rti; +ENDPROC(_evt_default) |