diff options
Diffstat (limited to 'arch/arc/include/asm/entry.h')
| -rw-r--r-- | arch/arc/include/asm/entry.h | 521 |
1 files changed, 211 insertions, 310 deletions
diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h index eb2ae53187d..8943c028d4b 100644 --- a/arch/arc/include/asm/entry.h +++ b/arch/arc/include/asm/entry.h @@ -50,194 +50,177 @@ * Eff Addr for load = [reg2] */ +.macro PUSH reg + st.a \reg, [sp, -4] +.endm + +.macro PUSHAX aux + lr r9, [\aux] + PUSH r9 +.endm + +.macro POP reg + ld.ab \reg, [sp, 4] +.endm + +.macro POPAX aux + POP r9 + sr r9, [\aux] +.endm + /*-------------------------------------------------------------- - * Save caller saved registers (scratch registers) ( r0 - r12 ) - * Registers are pushed / popped in the order defined in struct ptregs - * in asm/ptrace.h + * Helpers to save/restore Scratch Regs: + * used by Interrupt/Exception Prologue/Epilogue *-------------------------------------------------------------*/ -.macro SAVE_CALLER_SAVED - st.a r0, [sp, -4] - st.a r1, [sp, -4] - st.a r2, [sp, -4] - st.a r3, [sp, -4] - st.a r4, [sp, -4] - st.a r5, [sp, -4] - st.a r6, [sp, -4] - st.a r7, [sp, -4] - st.a r8, [sp, -4] - st.a r9, [sp, -4] - st.a r10, [sp, -4] - st.a r11, [sp, -4] - st.a r12, [sp, -4] +.macro SAVE_R0_TO_R12 + PUSH r0 + PUSH r1 + PUSH r2 + PUSH r3 + PUSH r4 + PUSH r5 + PUSH r6 + PUSH r7 + PUSH r8 + PUSH r9 + PUSH r10 + PUSH r11 + PUSH r12 +.endm + +.macro RESTORE_R12_TO_R0 + POP r12 + POP r11 + POP r10 + POP r9 + POP r8 + POP r7 + POP r6 + POP r5 + POP r4 + POP r3 + POP r2 + POP r1 + POP r0 + +#ifdef CONFIG_ARC_CURR_IN_REG + ld r25, [sp, 12] +#endif .endm /*-------------------------------------------------------------- - * Restore caller saved registers (scratch registers) + * Helpers to save/restore callee-saved regs: + * used by several macros below *-------------------------------------------------------------*/ -.macro RESTORE_CALLER_SAVED - ld.ab r12, [sp, 4] - ld.ab r11, [sp, 4] - ld.ab r10, [sp, 4] - ld.ab r9, [sp, 4] - ld.ab r8, [sp, 4] - ld.ab r7, [sp, 4] - ld.ab r6, [sp, 4] - ld.ab r5, [sp, 4] - ld.ab r4, [sp, 4] - ld.ab r3, [sp, 4] - ld.ab r2, [sp, 4] - ld.ab r1, [sp, 4] - ld.ab r0, [sp, 4] +.macro SAVE_R13_TO_R24 + PUSH r13 + PUSH r14 + PUSH r15 + PUSH r16 + PUSH r17 + PUSH r18 + PUSH r19 + PUSH r20 + PUSH r21 + PUSH r22 + PUSH r23 + PUSH r24 +.endm + +.macro RESTORE_R24_TO_R13 + POP r24 + POP r23 + POP r22 + POP r21 + POP r20 + POP r19 + POP r18 + POP r17 + POP r16 + POP r15 + POP r14 + POP r13 .endm +#define OFF_USER_R25_FROM_R24 (SZ_CALLEE_REGS + SZ_PT_REGS - 8)/4 /*-------------------------------------------------------------- - * Save callee saved registers (non scratch registers) ( r13 - r25 ) - * on kernel stack. - * User mode callee regs need to be saved in case of - * -fork and friends for replicating from parent to child - * -before going into do_signal( ) for ptrace/core-dump - * Special case handling is required for r25 in case it is used by kernel - * for caching task ptr. Low level exception/ISR save user mode r25 - * into task->thread.user_r25. So it needs to be retrieved from there and - * saved into kernel stack with rest of callee reg-file + * Collect User Mode callee regs as struct callee_regs - needed by + * fork/do_signal/unaligned-access-emulation. + * (By default only scratch regs are saved on entry to kernel) + * + * Special handling for r25 if used for caching Task Pointer. + * It would have been saved in task->thread.user_r25 already, but to keep + * the interface same it is copied into regular r25 placeholder in + * struct callee_regs. *-------------------------------------------------------------*/ .macro SAVE_CALLEE_SAVED_USER - st.a r13, [sp, -4] - st.a r14, [sp, -4] - st.a r15, [sp, -4] - st.a r16, [sp, -4] - st.a r17, [sp, -4] - st.a r18, [sp, -4] - st.a r19, [sp, -4] - st.a r20, [sp, -4] - st.a r21, [sp, -4] - st.a r22, [sp, -4] - st.a r23, [sp, -4] - st.a r24, [sp, -4] + + SAVE_R13_TO_R24 #ifdef CONFIG_ARC_CURR_IN_REG ; Retrieve orig r25 and save it on stack - ld r12, [r25, TASK_THREAD + THREAD_USER_R25] + ld.as r12, [sp, OFF_USER_R25_FROM_R24] st.a r12, [sp, -4] #else - st.a r25, [sp, -4] + PUSH r25 #endif - /* move up by 1 word to "create" callee_regs->"stack_place_holder" */ - sub sp, sp, 4 .endm /*-------------------------------------------------------------- - * Save callee saved registers (non scratch registers) ( r13 - r25 ) - * kernel mode callee regs needed to be saved in case of context switch - * If r25 is used for caching task pointer then that need not be saved - * as it can be re-created from current task global + * Save kernel Mode callee regs at the time of Contect Switch. + * + * Special handling for r25 if used for caching Task Pointer. + * Kernel simply skips saving it since it will be loaded with + * incoming task pointer anyways *-------------------------------------------------------------*/ .macro SAVE_CALLEE_SAVED_KERNEL - st.a r13, [sp, -4] - st.a r14, [sp, -4] - st.a r15, [sp, -4] - st.a r16, [sp, -4] - st.a r17, [sp, -4] - st.a r18, [sp, -4] - st.a r19, [sp, -4] - st.a r20, [sp, -4] - st.a r21, [sp, -4] - st.a r22, [sp, -4] - st.a r23, [sp, -4] - st.a r24, [sp, -4] + + SAVE_R13_TO_R24 + #ifdef CONFIG_ARC_CURR_IN_REG - sub sp, sp, 8 -#else - st.a r25, [sp, -4] sub sp, sp, 4 +#else + PUSH r25 #endif .endm /*-------------------------------------------------------------- - * RESTORE_CALLEE_SAVED_KERNEL: - * Loads callee (non scratch) Reg File by popping from Kernel mode stack. - * This is reverse of SAVE_CALLEE_SAVED, - * - * NOTE: - * Ideally this shd only be called in switch_to for loading - * switched-IN task's CALLEE Reg File. - * For all other cases RESTORE_CALLEE_SAVED_FAST must be used - * which simply pops the stack w/o touching regs. + * Opposite of SAVE_CALLEE_SAVED_KERNEL *-------------------------------------------------------------*/ .macro RESTORE_CALLEE_SAVED_KERNEL - #ifdef CONFIG_ARC_CURR_IN_REG - add sp, sp, 8 /* skip callee_reg gutter and user r25 placeholder */ + add sp, sp, 4 /* skip usual r25 placeholder */ #else - add sp, sp, 4 /* skip "callee_regs->stack_place_holder" */ - ld.ab r25, [sp, 4] + POP r25 #endif - - ld.ab r24, [sp, 4] - ld.ab r23, [sp, 4] - ld.ab r22, [sp, 4] - ld.ab r21, [sp, 4] - ld.ab r20, [sp, 4] - ld.ab r19, [sp, 4] - ld.ab r18, [sp, 4] - ld.ab r17, [sp, 4] - ld.ab r16, [sp, 4] - ld.ab r15, [sp, 4] - ld.ab r14, [sp, 4] - ld.ab r13, [sp, 4] - + RESTORE_R24_TO_R13 .endm /*-------------------------------------------------------------- - * RESTORE_CALLEE_SAVED_USER: - * This is called after do_signal where tracer might have changed callee regs - * thus we need to restore the reg file. - * Special case handling is required for r25 in case it is used by kernel - * for caching task ptr. Ptrace would have modified on-kernel-stack value of - * r25, which needs to be shoved back into task->thread.user_r25 where from - * Low level exception/ISR return code will retrieve to populate with rest of - * callee reg-file. + * Opposite of SAVE_CALLEE_SAVED_USER + * + * ptrace tracer or unaligned-access fixup might have changed a user mode + * callee reg which is saved back to usual r25 storage location *-------------------------------------------------------------*/ .macro RESTORE_CALLEE_SAVED_USER - add sp, sp, 4 /* skip "callee_regs->stack_place_holder" */ - #ifdef CONFIG_ARC_CURR_IN_REG ld.ab r12, [sp, 4] - st r12, [r25, TASK_THREAD + THREAD_USER_R25] + st.as r12, [sp, OFF_USER_R25_FROM_R24] #else - ld.ab r25, [sp, 4] + POP r25 #endif - - ld.ab r24, [sp, 4] - ld.ab r23, [sp, 4] - ld.ab r22, [sp, 4] - ld.ab r21, [sp, 4] - ld.ab r20, [sp, 4] - ld.ab r19, [sp, 4] - ld.ab r18, [sp, 4] - ld.ab r17, [sp, 4] - ld.ab r16, [sp, 4] - ld.ab r15, [sp, 4] - ld.ab r14, [sp, 4] - ld.ab r13, [sp, 4] + RESTORE_R24_TO_R13 .endm /*-------------------------------------------------------------- * Super FAST Restore callee saved regs by simply re-adjusting SP *-------------------------------------------------------------*/ .macro DISCARD_CALLEE_SAVED_USER - add sp, sp, 14 * 4 -.endm - -/*-------------------------------------------------------------- - * Restore User mode r25 saved in task_struct->thread.user_r25 - *-------------------------------------------------------------*/ -.macro RESTORE_USER_R25 - ld r25, [r25, TASK_THREAD + THREAD_USER_R25] + add sp, sp, SZ_CALLEE_REGS .endm /*------------------------------------------------------------- @@ -252,7 +235,7 @@ ld \out, [\tsk, TASK_THREAD_INFO] /* Go to end of page where stack begins (grows upwards) */ - add2 \out, \out, (THREAD_SIZE - 4)/4 /* one word GUTTER */ + add2 \out, \out, (THREAD_SIZE)/4 .endm @@ -305,33 +288,28 @@ * safe-keeping not really needed, but it keeps the epilogue code * (SP restore) simpler/uniform. */ - b.d 77f - - st.a sp, [sp, -12] ; Make room for orig_r0 and orig_r8 + b.d 66f + mov r9, sp 88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */ GET_CURR_TASK_ON_CPU r9 -#ifdef CONFIG_ARC_CURR_IN_REG - - /* If current task pointer cached in r25, time to - * -safekeep USER r25 in task->thread_struct->user_r25 - * -load r25 with current task ptr - */ - st.as r25, [r9, (TASK_THREAD + THREAD_USER_R25)/4] - mov r25, r9 -#endif - /* With current tsk in r9, get it's kernel mode stack base */ GET_TSK_STACK_BASE r9, r9 -#ifdef PT_REGS_CANARY - st 0xabcdabcd, [r9, 0] +66: +#ifdef CONFIG_ARC_CURR_IN_REG + /* + * Treat r25 as scratch reg, save it on stack first + * Load it with current task pointer + */ + st r25, [r9, -4] + GET_CURR_TASK_ON_CPU r25 #endif /* Save Pre Intr/Exception User SP on kernel stack */ - st.a sp, [r9, -12] ; Make room for orig_r0 and orig_r8 + st.a sp, [r9, -16] ; Make room for orig_r0, ECR, user_r25 /* CAUTION: * SP should be set at the very end when we are done with everything @@ -342,7 +320,7 @@ /* set SP to point to kernel mode stack */ mov sp, r9 -77: /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */ + /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */ .endm @@ -369,7 +347,7 @@ * @reg [OUT] &thread_info of "current" */ .macro GET_CURR_THR_INFO_FROM_SP reg - and \reg, sp, ~(THREAD_SIZE - 1) + bic \reg, sp, (THREAD_SIZE - 1) .endm /* @@ -413,62 +391,25 @@ * Note that syscalls are implemented via TRAP which is also a exception * from CPU's point of view *-------------------------------------------------------------*/ -.macro SAVE_ALL_EXCEPTION marker +.macro SAVE_ALL_SYS - st \marker, [sp, 8] /* orig_r8 */ + lr r9, [ecr] + st r9, [sp, 8] /* ECR */ st r0, [sp, 4] /* orig_r0, needed only for sys calls */ /* Restore r9 used to code the early prologue */ EXCPN_PROLOG_RESTORE_REG r9 - SAVE_CALLER_SAVED - st.a r26, [sp, -4] /* gp */ - st.a fp, [sp, -4] - st.a blink, [sp, -4] - lr r9, [eret] - st.a r9, [sp, -4] - lr r9, [erstatus] - st.a r9, [sp, -4] - st.a lp_count, [sp, -4] - lr r9, [lp_end] - st.a r9, [sp, -4] - lr r9, [lp_start] - st.a r9, [sp, -4] - lr r9, [erbta] - st.a r9, [sp, -4] - -#ifdef PT_REGS_CANARY - mov r9, 0xdeadbeef - st r9, [sp, -4] -#endif - - /* move up by 1 word to "create" pt_regs->"stack_place_holder" */ - sub sp, sp, 4 -.endm - -/*-------------------------------------------------------------- - * Save scratch regs for exceptions - *-------------------------------------------------------------*/ -.macro SAVE_ALL_SYS - SAVE_ALL_EXCEPTION orig_r8_IS_EXCPN -.endm - -/*-------------------------------------------------------------- - * Save scratch regs for sys calls - *-------------------------------------------------------------*/ -.macro SAVE_ALL_TRAP - /* - * Setup pt_regs->orig_r8. - * Encode syscall number (r8) in upper short word of event type (r9) - * N.B. #1: This is already endian safe (see ptrace.h) - * #2: Only r9 can be used as scratch as it is already clobbered - * and it's contents are no longer needed by the latter part - * of exception prologue - */ - lsl r9, r8, 16 - or r9, r9, orig_r8_IS_SCALL - - SAVE_ALL_EXCEPTION r9 + SAVE_R0_TO_R12 + PUSH gp + PUSH fp + PUSH blink + PUSHAX eret + PUSHAX erstatus + PUSH lp_count + PUSHAX lp_end + PUSHAX lp_start + PUSHAX erbta .endm /*-------------------------------------------------------------- @@ -483,28 +424,22 @@ * by hardware and that is not good. *-------------------------------------------------------------*/ .macro RESTORE_ALL_SYS + POPAX erbta + POPAX lp_start + POPAX lp_end + + POP r9 + mov lp_count, r9 ;LD to lp_count is not allowed - add sp, sp, 4 /* hop over unused "pt_regs->stack_place_holder" */ - - ld.ab r9, [sp, 4] - sr r9, [erbta] - ld.ab r9, [sp, 4] - sr r9, [lp_start] - ld.ab r9, [sp, 4] - sr r9, [lp_end] - ld.ab r9, [sp, 4] - mov lp_count, r9 - ld.ab r9, [sp, 4] - sr r9, [erstatus] - ld.ab r9, [sp, 4] - sr r9, [eret] - ld.ab blink, [sp, 4] - ld.ab fp, [sp, 4] - ld.ab r26, [sp, 4] /* gp */ - RESTORE_CALLER_SAVED + POPAX erstatus + POPAX eret + POP blink + POP fp + POP gp + RESTORE_R12_TO_R0 ld sp, [sp] /* restore original sp */ - /* orig_r0 and orig_r8 skipped automatically */ + /* orig_r0, ECR, user_r25 skipped automatically */ .endm @@ -513,9 +448,7 @@ *-------------------------------------------------------------*/ .macro SAVE_ALL_INT1 - /* restore original r9 , saved in int1_saved_reg - * It will be saved on stack in macro: SAVE_CALLER_SAVED - */ + /* restore original r9 to be saved as part of reg-file */ #ifdef CONFIG_SMP lr r9, [ARC_REG_SCRATCH_DATA0] #else @@ -523,29 +456,19 @@ #endif /* now we are ready to save the remaining context :) */ - st orig_r8_IS_IRQ1, [sp, 8] /* Event Type */ + st event_IRQ1, [sp, 8] /* Dummy ECR */ st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ - SAVE_CALLER_SAVED - st.a r26, [sp, -4] /* gp */ - st.a fp, [sp, -4] - st.a blink, [sp, -4] - st.a ilink1, [sp, -4] - lr r9, [status32_l1] - st.a r9, [sp, -4] - st.a lp_count, [sp, -4] - lr r9, [lp_end] - st.a r9, [sp, -4] - lr r9, [lp_start] - st.a r9, [sp, -4] - lr r9, [bta_l1] - st.a r9, [sp, -4] - -#ifdef PT_REGS_CANARY - mov r9, 0xdeadbee1 - st r9, [sp, -4] -#endif - /* move up by 1 word to "create" pt_regs->"stack_place_holder" */ - sub sp, sp, 4 + + SAVE_R0_TO_R12 + PUSH gp + PUSH fp + PUSH blink + PUSH ilink1 + PUSHAX status32_l1 + PUSH lp_count + PUSHAX lp_end + PUSHAX lp_start + PUSHAX bta_l1 .endm .macro SAVE_ALL_INT2 @@ -558,30 +481,19 @@ ld r9, [@int2_saved_reg] /* now we are ready to save the remaining context :) */ - st orig_r8_IS_IRQ2, [sp, 8] /* Event Type */ + st event_IRQ2, [sp, 8] /* Dummy ECR */ st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ - SAVE_CALLER_SAVED - st.a r26, [sp, -4] /* gp */ - st.a fp, [sp, -4] - st.a blink, [sp, -4] - st.a ilink2, [sp, -4] - lr r9, [status32_l2] - st.a r9, [sp, -4] - st.a lp_count, [sp, -4] - lr r9, [lp_end] - st.a r9, [sp, -4] - lr r9, [lp_start] - st.a r9, [sp, -4] - lr r9, [bta_l2] - st.a r9, [sp, -4] - -#ifdef PT_REGS_CANARY - mov r9, 0xdeadbee2 - st r9, [sp, -4] -#endif - /* move up by 1 word to "create" pt_regs->"stack_place_holder" */ - sub sp, sp, 4 + SAVE_R0_TO_R12 + PUSH gp + PUSH fp + PUSH blink + PUSH ilink2 + PUSHAX status32_l2 + PUSH lp_count + PUSHAX lp_end + PUSHAX lp_start + PUSHAX bta_l2 .endm /*-------------------------------------------------------------- @@ -595,52 +507,41 @@ *-------------------------------------------------------------*/ .macro RESTORE_ALL_INT1 - add sp, sp, 4 /* hop over unused "pt_regs->stack_place_holder" */ - - ld.ab r9, [sp, 4] /* Actual reg file */ - sr r9, [bta_l1] - ld.ab r9, [sp, 4] - sr r9, [lp_start] - ld.ab r9, [sp, 4] - sr r9, [lp_end] - ld.ab r9, [sp, 4] - mov lp_count, r9 - ld.ab r9, [sp, 4] - sr r9, [status32_l1] - ld.ab r9, [sp, 4] - mov ilink1, r9 - ld.ab blink, [sp, 4] - ld.ab fp, [sp, 4] - ld.ab r26, [sp, 4] /* gp */ - RESTORE_CALLER_SAVED + POPAX bta_l1 + POPAX lp_start + POPAX lp_end + + POP r9 + mov lp_count, r9 ;LD to lp_count is not allowed + + POPAX status32_l1 + POP ilink1 + POP blink + POP fp + POP gp + RESTORE_R12_TO_R0 ld sp, [sp] /* restore original sp */ - /* orig_r0 and orig_r8 skipped automatically */ + /* orig_r0, ECR, user_r25 skipped automatically */ .endm .macro RESTORE_ALL_INT2 - add sp, sp, 4 /* hop over unused "pt_regs->stack_place_holder" */ - - ld.ab r9, [sp, 4] - sr r9, [bta_l2] - ld.ab r9, [sp, 4] - sr r9, [lp_start] - ld.ab r9, [sp, 4] - sr r9, [lp_end] - ld.ab r9, [sp, 4] - mov lp_count, r9 - ld.ab r9, [sp, 4] - sr r9, [status32_l2] - ld.ab r9, [sp, 4] - mov ilink2, r9 - ld.ab blink, [sp, 4] - ld.ab fp, [sp, 4] - ld.ab r26, [sp, 4] /* gp */ - RESTORE_CALLER_SAVED + POPAX bta_l2 + POPAX lp_start + POPAX lp_end - ld sp, [sp] /* restore original sp */ - /* orig_r0 and orig_r8 skipped automatically */ + POP r9 + mov lp_count, r9 ;LD to lp_count is not allowed + POPAX status32_l2 + POP ilink2 + POP blink + POP fp + POP gp + RESTORE_R12_TO_R0 + + ld sp, [sp] /* restore original sp */ + /* orig_r0, ECR, user_r25 skipped automatically */ .endm |