diff options
Diffstat (limited to 'arch/arc/kernel/entry.S')
-rw-r--r-- | arch/arc/kernel/entry.S | 103 |
1 files changed, 41 insertions, 62 deletions
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 0c6d664d4a8..1d7165156e1 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -142,7 +142,7 @@ VECTOR reserved ; Reserved Exceptions .endr #include <linux/linkage.h> /* ARC_{EXTRY,EXIT} */ -#include <asm/entry.h> /* SAVE_ALL_{INT1,INT2,TRAP...} */ +#include <asm/entry.h> /* SAVE_ALL_{INT1,INT2,SYS...} */ #include <asm/errno.h> #include <asm/arcregs.h> #include <asm/irqflags.h> @@ -274,10 +274,8 @@ ARC_ENTRY instr_service SWITCH_TO_KERNEL_STK SAVE_ALL_SYS - lr r0, [ecr] - lr r1, [efa] - - mov r2, sp + lr r0, [efa] + mov r1, sp FAKE_RET_FROM_EXCPN r9 @@ -298,9 +296,8 @@ ARC_ENTRY mem_service SWITCH_TO_KERNEL_STK SAVE_ALL_SYS - lr r0, [ecr] - lr r1, [efa] - mov r2, sp + lr r0, [efa] + mov r1, sp bl do_memory_error b ret_from_exception ARC_EXIT mem_service @@ -317,11 +314,14 @@ ARC_ENTRY EV_MachineCheck SWITCH_TO_KERNEL_STK SAVE_ALL_SYS - lr r0, [ecr] - lr r1, [efa] - mov r2, sp + lr r2, [ecr] + lr r0, [efa] + mov r1, sp + + lsr r3, r2, 8 + bmsk r3, r3, 7 + brne r3, ECR_C_MCHK_DUP_TLB, 1f - brne r0, 0x200100, 1f bl do_tlb_overlap_fault b ret_from_exception @@ -355,8 +355,8 @@ ARC_ENTRY EV_TLBProtV ; ecr and efa were not saved in case an Intr sneaks in ; after fake rtie ; - lr r3, [ecr] - lr r4, [efa] + lr r2, [ecr] + lr r1, [efa] ; Faulting Data address ; --------(4) Return from CPU Exception Mode --------- ; Fake a rtie, but rtie to next label @@ -368,31 +368,25 @@ ARC_ENTRY EV_TLBProtV ;------ (5) Type of Protection Violation? ---------- ; ; ProtV Hardware Exception is triggered for Access Faults of 2 types - ; -Access Violaton (WRITE to READ ONLY Page) - for linux COW - ; -Unaligned Access (READ/WRITE on odd boundary) + ; -Access Violaton : 00_23_(00|01|02|03)_00 + ; x r w r+w + ; -Unaligned Access : 00_23_04_00 ; - cmp r3, 0x230400 ; Misaligned data access ? - beq 4f + bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f ;========= (6a) Access Violation Processing ======== - cmp r3, 0x230100 - mov r1, 0x0 ; if LD exception ? write = 0 - mov.ne r1, 0x1 ; else write = 1 - - mov r2, r4 ; faulting address mov r0, sp ; pt_regs bl do_page_fault b ret_from_exception ;========== (6b) Non aligned access ============ 4: - mov r0, r3 ; cause code - mov r1, r4 ; faulting address - mov r2, sp ; pt_regs + mov r0, r1 + mov r1, sp ; pt_regs #ifdef CONFIG_ARC_MISALIGN_ACCESS SAVE_CALLEE_SAVED_USER - mov r3, sp ; callee_regs + mov r2, sp ; callee_regs bl do_misaligned_access @@ -419,9 +413,8 @@ ARC_ENTRY EV_PrivilegeV SWITCH_TO_KERNEL_STK SAVE_ALL_SYS - lr r0, [ecr] - lr r1, [efa] - mov r2, sp + lr r0, [efa] + mov r1, sp FAKE_RET_FROM_EXCPN r9 @@ -440,9 +433,8 @@ ARC_ENTRY EV_Extension SWITCH_TO_KERNEL_STK SAVE_ALL_SYS - lr r0, [ecr] - lr r1, [efa] - mov r2, sp + lr r0, [efa] + mov r1, sp bl do_extension_fault b ret_from_exception ARC_EXIT EV_Extension @@ -498,11 +490,8 @@ tracesys_exit: trap_with_param: ; stop_pc info by gdb needs this info - stw orig_r8_IS_BRKPT, [sp, PT_orig_r8] - - mov r0, r12 - lr r1, [efa] - mov r2, sp + lr r0, [efa] + mov r1, sp ; Now that we have read EFA, its safe to do "fake" rtie ; and get out of CPU exception mode @@ -544,11 +533,11 @@ ARC_ENTRY EV_Trap lr r9, [erstatus] SWITCH_TO_KERNEL_STK - SAVE_ALL_TRAP + SAVE_ALL_SYS ;------- (4) What caused the Trap -------------- lr r12, [ecr] - and.f 0, r12, ECR_PARAM_MASK + bmsk.f 0, r12, 7 bnz trap_with_param ; ======= (5a) Trap is due to System Call ======== @@ -589,11 +578,7 @@ ARC_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 -#ifdef CONFIG_PREEMPT bbit0 r8, STATUS_U_BIT, resume_kernel_mode -#else - bbit0 r8, STATUS_U_BIT, restore_regs -#endif ; Before returning to User mode check-for-and-complete any pending work ; such as rescheduling/signal-delivery etc. @@ -653,10 +638,10 @@ resume_user_mode_begin: b resume_user_mode_begin ; unconditionally back to U mode ret chks ; for single exit point from this block -#ifdef CONFIG_PREEMPT - resume_kernel_mode: +#ifdef CONFIG_PREEMPT + ; Can't preempt if preemption disabled GET_CURR_THR_INFO_FROM_SP r10 ld r8, [r10, THREAD_INFO_PREEMPT_COUNT] @@ -687,17 +672,6 @@ restore_regs : ; XXX can this be optimised out IRQ_DISABLE_SAVE r9, r10 ;@r10 has prisitine (pre-disable) copy -#ifdef CONFIG_ARC_CURR_IN_REG - ; Restore User R25 - ; Earlier this used to be only for returning to user mode - ; However with 2 levels of IRQ this can also happen even if - ; in kernel mode - ld r9, [sp, PT_sp] - brhs r9, VMALLOC_START, 8f - RESTORE_USER_R25 -8: -#endif - ; Restore REG File. In case multiple Events outstanding, ; use the same priorty as rtie: EXCPN, L2 IRQ, L1 IRQ, None ; Note that we use realtime STATUS32 (not pt_regs->status32) to @@ -714,28 +688,33 @@ not_exception: #ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS + ; Level 2 interrupt return Path - from hardware standpoint bbit0 r10, STATUS_A2_BIT, not_level2_interrupt ;------------------------------------------------------------------ + ; However the context returning might not have taken L2 intr itself + ; e.g. Task'A' user-code -> L2 intr -> schedule -> 'B' user-code ret + ; Special considerations needed for the context which took L2 intr + + ld r9, [sp, PT_event] ; Ensure this is L2 intr context + 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 ; things to what they were, before returning from L2 context ;---------------------------------------------------------------- - ldw r9, [sp, PT_orig_r8] ; get orig_r8 to make sure it is - brne r9, orig_r8_IS_IRQ2, 149f ; infact a L2 ISR ret path - ld r9, [sp, PT_status32] ; get statu32_l2 (saved in pt_regs) bbit0 r9, STATUS_A1_BIT, 149f ; L1 not active when L2 IRQ, so normal - ; A1 is set in status32_l2 ; decrement thread_info->preempt_count (re-enable preemption) GET_CURR_THR_INFO_FROM_SP r10 ld r9, [r10, THREAD_INFO_PREEMPT_COUNT] ; paranoid check, given A1 was active when A2 happened, preempt count - ; must not be 0 beccause we would have incremented it. + ; must not be 0 because we would have incremented it. ; If this does happen we simply HALT as it means a BUG !!! cmp r9, 0 bnz 2f |