diff options
Diffstat (limited to 'arch/arc/kernel/entry.S')
| -rw-r--r-- | arch/arc/kernel/entry.S | 156 |
1 files changed, 67 insertions, 89 deletions
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 1d7165156e1..83a046a7cd0 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -141,7 +141,7 @@ VECTOR EV_Extension ; 0x130, Extn Intruction Excp (0x26) VECTOR reserved ; Reserved Exceptions .endr -#include <linux/linkage.h> /* ARC_{EXTRY,EXIT} */ +#include <linux/linkage.h> /* {EXTRY,EXIT} */ #include <asm/entry.h> /* SAVE_ALL_{INT1,INT2,SYS...} */ #include <asm/errno.h> #include <asm/arcregs.h> @@ -156,7 +156,7 @@ ARCFP_DATA int1_saved_reg int1_saved_reg: .zero 4 -/* Each Interrupt level needs it's own scratch */ +/* Each Interrupt level needs its own scratch */ #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS ARCFP_DATA int2_saved_reg @@ -184,7 +184,7 @@ reserved: ; processor restart ; --------------------------------------------- ; Level 2 ISR: Can interrupt a Level 1 ISR ; --------------------------------------------- -ARC_ENTRY handle_interrupt_level2 +ENTRY(handle_interrupt_level2) ; TODO-vineetg for SMP this wont work ; free up r9 as scratchpad @@ -225,14 +225,14 @@ ARC_ENTRY handle_interrupt_level2 b ret_from_exception -ARC_EXIT handle_interrupt_level2 +END(handle_interrupt_level2) #endif ; --------------------------------------------- ; Level 1 ISR ; --------------------------------------------- -ARC_ENTRY handle_interrupt_level1 +ENTRY(handle_interrupt_level1) /* free up r9 as scratchpad */ #ifdef CONFIG_SMP @@ -250,6 +250,14 @@ ARC_ENTRY handle_interrupt_level1 lr r0, [icause1] and r0, r0, 0x1f +#ifdef CONFIG_TRACE_IRQFLAGS + ; icause1 needs to be read early, before calling tracing, which + ; can clobber scratch regs, hence use of stack to stash it + push r0 + TRACE_ASM_IRQ_DISABLE + pop r0 +#endif + bl.d @arch_do_IRQ mov r1, sp @@ -257,7 +265,7 @@ ARC_ENTRY handle_interrupt_level1 sr r8, [AUX_IRQ_LV12] ; clear bit in Sticky Status Reg b ret_from_exception -ARC_EXIT handle_interrupt_level1 +END(handle_interrupt_level1) ;################### Non TLB Exception Handling ############################# @@ -265,14 +273,9 @@ ARC_EXIT handle_interrupt_level1 ; Instruction Error Exception Handler ; --------------------------------------------- -ARC_ENTRY instr_service - - EXCPN_PROLOG_FREEUP_REG r9 +ENTRY(instr_service) - lr r9, [erstatus] - - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE lr r0, [efa] mov r1, sp @@ -281,38 +284,32 @@ ARC_ENTRY instr_service bl do_insterror_or_kprobe b ret_from_exception -ARC_EXIT instr_service +END(instr_service) ; --------------------------------------------- ; Memory Error Exception Handler ; --------------------------------------------- -ARC_ENTRY mem_service +ENTRY(mem_service) - EXCPN_PROLOG_FREEUP_REG r9 - - lr r9, [erstatus] - - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE lr r0, [efa] mov r1, sp + + FAKE_RET_FROM_EXCPN r9 + bl do_memory_error b ret_from_exception -ARC_EXIT mem_service +END(mem_service) ; --------------------------------------------- ; Machine Check Exception Handler ; --------------------------------------------- -ARC_ENTRY EV_MachineCheck - - EXCPN_PROLOG_FREEUP_REG r9 - lr r9, [erstatus] +ENTRY(EV_MachineCheck) - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE lr r2, [ecr] lr r0, [efa] @@ -334,29 +331,23 @@ ARC_ENTRY EV_MachineCheck j do_machine_check_fault -ARC_EXIT EV_MachineCheck +END(EV_MachineCheck) ; --------------------------------------------- ; Protection Violation Exception Handler ; --------------------------------------------- -ARC_ENTRY EV_TLBProtV - - EXCPN_PROLOG_FREEUP_REG r9 - - ;Which mode (user/kernel) was the system in when Exception occured - lr r9, [erstatus] +ENTRY(EV_TLBProtV) - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE ;---------(3) Save some more regs----------------- ; vineetg: Mar 6th: Random Seg Fault issue #1 ; ecr and efa were not saved in case an Intr sneaks in ; after fake rtie - ; + lr r2, [ecr] - lr r1, [efa] ; Faulting Data address + lr r0, [efa] ; Faulting Data address ; --------(4) Return from CPU Exception Mode --------- ; Fake a rtie, but rtie to next label @@ -365,6 +356,8 @@ ARC_ENTRY EV_TLBProtV FAKE_RET_FROM_EXCPN r9 + mov r1, sp + ;------ (5) Type of Protection Violation? ---------- ; ; ProtV Hardware Exception is triggered for Access Faults of 2 types @@ -375,16 +368,12 @@ ARC_ENTRY EV_TLBProtV bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f ;========= (6a) Access Violation Processing ======== - mov r0, sp ; pt_regs bl do_page_fault b ret_from_exception ;========== (6b) Non aligned access ============ 4: - mov r0, r1 - mov r1, sp ; pt_regs -#ifdef CONFIG_ARC_MISALIGN_ACCESS SAVE_CALLEE_SAVED_USER mov r2, sp ; callee_regs @@ -393,25 +382,17 @@ ARC_ENTRY EV_TLBProtV ; TBD: optimize - do this only if a callee reg was involved ; either a dst of emulated LD/ST or src with address-writeback RESTORE_CALLEE_SAVED_USER -#else - bl do_misaligned_error -#endif b ret_from_exception -ARC_EXIT EV_TLBProtV +END(EV_TLBProtV) ; --------------------------------------------- ; Privilege Violation Exception Handler ; --------------------------------------------- -ARC_ENTRY EV_PrivilegeV - - EXCPN_PROLOG_FREEUP_REG r9 +ENTRY(EV_PrivilegeV) - lr r9, [erstatus] - - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE lr r0, [efa] mov r1, sp @@ -420,24 +401,23 @@ ARC_ENTRY EV_PrivilegeV bl do_privilege_fault b ret_from_exception -ARC_EXIT EV_PrivilegeV +END(EV_PrivilegeV) ; --------------------------------------------- ; Extension Instruction Exception Handler ; --------------------------------------------- -ARC_ENTRY EV_Extension - - EXCPN_PROLOG_FREEUP_REG r9 - lr r9, [erstatus] +ENTRY(EV_Extension) - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE lr r0, [efa] mov r1, sp + + FAKE_RET_FROM_EXCPN r9 + bl do_extension_fault b ret_from_exception -ARC_EXIT EV_Extension +END(EV_Extension) ;######################### System Call Tracing ######################### @@ -493,7 +473,7 @@ trap_with_param: lr r0, [efa] mov r1, sp - ; Now that we have read EFA, its safe to do "fake" rtie + ; Now that we have read EFA, it is safe to do "fake" rtie ; and get out of CPU exception mode FAKE_RET_FROM_EXCPN r11 @@ -524,16 +504,9 @@ trap_with_param: ; (2) Break Points ;------------------------------------------------------------------ -ARC_ENTRY EV_Trap +ENTRY(EV_Trap) - ; Need at least 1 reg to code the early exception prolog - EXCPN_PROLOG_FREEUP_REG r9 - - ;Which mode (user/kernel) was the system in when intr occured - lr r9, [erstatus] - - SWITCH_TO_KERNEL_STK - SAVE_ALL_SYS + EXCEPTION_PROLOGUE ;------- (4) What caused the Trap -------------- lr r12, [ecr] @@ -561,9 +534,9 @@ ARC_ENTRY EV_Trap jl [r9] ; Entry into Sys Call Handler ; fall through to ret_from_system_call -ARC_EXIT EV_Trap +END(EV_Trap) -ARC_ENTRY ret_from_system_call +ENTRY(ret_from_system_call) st r0, [sp, PT_r0] ; sys call return value in pt_regs @@ -573,7 +546,7 @@ ARC_ENTRY ret_from_system_call ; ; If ret to user mode do we need to handle signals, schedule() et al. -ARC_ENTRY ret_from_exception +ENTRY(ret_from_exception) ; Pre-{IRQ,Trap,Exception} K/U mode from pt_regs->status32 ld r8, [sp, PT_status32] ; returning to User/Kernel Mode @@ -605,6 +578,7 @@ resume_user_mode_begin: ; --- (Slow Path #2) pending signal --- mov r0, sp ; pt_regs for arg to do_signal()/do_notify_resume() + GET_CURR_THR_INFO_FLAGS r9 bbit0 r9, TIF_SIGPENDING, .Lchk_notify_resume ; Normal Trap/IRQ entry only saves Scratch (caller-saved) regs @@ -640,6 +614,11 @@ resume_user_mode_begin: resume_kernel_mode: + ; Disable Interrupts from this point on + ; CONFIG_PREEMPT: This is a must for preempt_schedule_irq() + ; !CONFIG_PREEMPT: To ensure restore_regs is intr safe + IRQ_DISABLE r9 + #ifdef CONFIG_PREEMPT ; Can't preempt if preemption disabled @@ -651,8 +630,6 @@ resume_kernel_mode: ld r9, [r10, THREAD_INFO_FLAGS] bbit0 r9, TIF_NEED_RESCHED, restore_regs - IRQ_DISABLE r9 - ; Invoke PREEMPTION bl preempt_schedule_irq @@ -665,12 +642,13 @@ resume_kernel_mode: ; ; Restore the saved sys context (common exit-path for EXCPN/IRQ/Trap) ; IRQ shd definitely not happen between now and rtie +; All 2 entry points to here already disable interrupts restore_regs : - ; Disable Interrupts while restoring reg-file back - ; XXX can this be optimised out - IRQ_DISABLE_SAVE r9, r10 ;@r10 has prisitine (pre-disable) copy + TRACE_ASM_IRQ_ENABLE + + lr r10, [status32] ; Restore REG File. In case multiple Events outstanding, ; use the same priorty as rtie: EXCPN, L2 IRQ, L1 IRQ, None @@ -700,9 +678,9 @@ not_exception: brne r9, event_IRQ2, 149f ;------------------------------------------------------------------ - ; if L2 IRQ interrupted a L1 ISR, we'd disbaled preemption earlier - ; so that sched doesnt move to new task, causing L1 to be delayed - ; undeterministically. Now that we've achieved that, lets reset + ; if L2 IRQ interrupted an L1 ISR, we'd disabled preemption earlier + ; so that sched doesn't move to new task, causing L1 to be delayed + ; undeterministically. Now that we've achieved that, let's reset ; things to what they were, before returning from L2 context ;---------------------------------------------------------------- @@ -750,15 +728,15 @@ not_level1_interrupt: debug_marker_syscall: rtie -ARC_EXIT ret_from_exception +END(ret_from_exception) -ARC_ENTRY ret_from_fork +ENTRY(ret_from_fork) ; when the forked child comes here from the __switch_to function ; r0 has the last task pointer. ; put last task in scheduler queue bl @schedule_tail - ; If kernel thread, jump to it's entry-point + ; If kernel thread, jump to its entry-point ld r9, [sp, PT_status32] brne r9, 0, 1f @@ -769,11 +747,11 @@ ARC_ENTRY ret_from_fork ; special case of kernel_thread entry point returning back due to ; kernel_execve() - pretend return from syscall to ret to userland b ret_from_exception -ARC_EXIT ret_from_fork +END(ret_from_fork) ;################### Special Sys Call Wrappers ########################## -ARC_ENTRY sys_clone_wrapper +ENTRY(sys_clone_wrapper) SAVE_CALLEE_SAVED_USER bl @sys_clone DISCARD_CALLEE_SAVED_USER @@ -783,7 +761,7 @@ ARC_ENTRY sys_clone_wrapper bnz tracesys_exit b ret_from_system_call -ARC_EXIT sys_clone_wrapper +END(sys_clone_wrapper) #ifdef CONFIG_ARC_DW2_UNWIND ; Workaround for bug 94179 (STAR ): |