diff options
Diffstat (limited to 'kernel/arch/arc/include/asm/entry.h')
| -rw-r--r-- | kernel/arch/arc/include/asm/entry.h | 378 |
1 files changed, 17 insertions, 361 deletions
diff --git a/kernel/arch/arc/include/asm/entry.h b/kernel/arch/arc/include/asm/entry.h index 884081099..ad7860c5c 100644 --- a/kernel/arch/arc/include/asm/entry.h +++ b/kernel/arch/arc/include/asm/entry.h @@ -1,45 +1,27 @@ /* + * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com) * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. - * - * Vineetg: March 2009 (Supporting 2 levels of Interrupts) - * Stack switching code can no longer reliably rely on the fact that - * if we are NOT in user mode, stack is switched to kernel mode. - * e.g. L2 IRQ interrupted a L1 ISR which had not yet completed - * it's prologue including stack switching from user mode - * - * Vineetg: Aug 28th 2008: Bug #94984 - * -Zero Overhead Loop Context shd be cleared when entering IRQ/EXcp/Trap - * Normally CPU does this automatically, however when doing FAKE rtie, - * we also need to explicitly do this. The problem in macros - * FAKE_RET_FROM_EXCPN and FAKE_RET_FROM_EXCPN_LOCK_IRQ was that this bit - * was being "CLEARED" rather then "SET". Actually "SET" clears ZOL context - * - * Vineetg: May 5th 2008 - * -Modified CALLEE_REG save/restore macros to handle the fact that - * r25 contains the kernel current task ptr - * - Defined Stack Switching Macro to be reused in all intr/excp hdlrs - * - Shaved off 11 instructions from RESTORE_ALL_INT1 by using the - * address Write back load ld.ab instead of seperate ld/add instn - * - * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 */ #ifndef __ASM_ARC_ENTRY_H #define __ASM_ARC_ENTRY_H -#ifdef __ASSEMBLY__ #include <asm/unistd.h> /* For NR_syscalls defination */ -#include <asm/asm-offsets.h> #include <asm/arcregs.h> #include <asm/ptrace.h> #include <asm/processor.h> /* For VMALLOC_START */ -#include <asm/thread_info.h> /* For THREAD_SIZE */ #include <asm/mmu.h> +#ifdef CONFIG_ISA_ARCOMPACT +#include <asm/entry-compact.h> /* ISA specific bits */ +#else +#include <asm/entry-arcv2.h> +#endif + /* Note on the LD/ST addr modes with addr reg wback * * LD.a same as LD.aw @@ -143,8 +125,6 @@ POP r13 .endm -#define OFF_USER_R25_FROM_R24 (SZ_CALLEE_REGS + SZ_PT_REGS - 8)/4 - /*-------------------------------------------------------------- * Collect User Mode callee regs as struct callee_regs - needed by * fork/do_signal/unaligned-access-emulation. @@ -157,12 +137,13 @@ *-------------------------------------------------------------*/ .macro SAVE_CALLEE_SAVED_USER + mov r12, sp ; save SP as ref to pt_regs SAVE_R13_TO_R24 #ifdef CONFIG_ARC_CURR_IN_REG - ; Retrieve orig r25 and save it on stack - ld.as r12, [sp, OFF_USER_R25_FROM_R24] - st.a r12, [sp, -4] + ; Retrieve orig r25 and save it with rest of callee_regs + ld.as r12, [r12, PT_user_r25] + PUSH r12 #else PUSH r25 #endif @@ -209,12 +190,16 @@ .macro RESTORE_CALLEE_SAVED_USER #ifdef CONFIG_ARC_CURR_IN_REG - ld.ab r12, [sp, 4] - st.as r12, [sp, OFF_USER_R25_FROM_R24] + POP r12 #else POP r25 #endif RESTORE_R24_TO_R13 + + ; SP is back to start of pt_regs +#ifdef CONFIG_ARC_CURR_IN_REG + st.as r12, [sp, PT_user_r25] +#endif .endm /*-------------------------------------------------------------- @@ -240,117 +225,6 @@ .endm -/*-------------------------------------------------------------- - * Switch to Kernel Mode stack if SP points to User Mode stack - * - * Entry : r9 contains pre-IRQ/exception/trap status32 - * Exit : SP is set to kernel mode stack pointer - * If CURR_IN_REG, r25 set to "current" task pointer - * Clobbers: r9 - *-------------------------------------------------------------*/ - -.macro SWITCH_TO_KERNEL_STK - - /* User Mode when this happened ? Yes: Proceed to switch stack */ - bbit1 r9, STATUS_U_BIT, 88f - - /* OK we were already in kernel mode when this event happened, thus can - * assume SP is kernel mode SP. _NO_ need to do any stack switching - */ - -#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS - /* However.... - * If Level 2 Interrupts enabled, we may end up with a corner case: - * 1. User Task executing - * 2. L1 IRQ taken, ISR starts (CPU auto-switched to KERNEL mode) - * 3. But before it could switch SP from USER to KERNEL stack - * a L2 IRQ "Interrupts" L1 - * Thay way although L2 IRQ happened in Kernel mode, stack is still - * not switched. - * To handle this, we may need to switch stack even if in kernel mode - * provided SP has values in range of USER mode stack ( < 0x7000_0000 ) - */ - brlo sp, VMALLOC_START, 88f - - /* TODO: vineetg: - * We need to be a bit more cautious here. What if a kernel bug in - * L1 ISR, caused SP to go whaco (some small value which looks like - * USER stk) and then we take L2 ISR. - * Above brlo alone would treat it as a valid L1-L2 sceanrio - * instead of shouting alound - * The only feasible way is to make sure this L2 happened in - * L1 prelogue ONLY i.e. ilink2 is less than a pre-set marker in - * L1 ISR before it switches stack - */ - -#endif - - /* Save Pre Intr/Exception KERNEL MODE SP on kernel stack - * safe-keeping not really needed, but it keeps the epilogue code - * (SP restore) simpler/uniform. - */ - b.d 66f - mov r9, sp - -88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */ - - GET_CURR_TASK_ON_CPU r9 - - /* With current tsk in r9, get it's kernel mode stack base */ - GET_TSK_STACK_BASE r9, r9 - -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, -16] ; Make room for orig_r0, ECR, user_r25 - - /* CAUTION: - * SP should be set at the very end when we are done with everything - * In case of 2 levels of interrupt we depend on value of SP to assume - * that everything else is done (loading r25 etc) - */ - - /* set SP to point to kernel mode stack */ - mov sp, r9 - - /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */ - -.endm - -/*------------------------------------------------------------ - * "FAKE" a rtie to return from CPU Exception context - * This is to re-enable Exceptions within exception - * Look at EV_ProtV to see how this is actually used - *-------------------------------------------------------------*/ - -.macro FAKE_RET_FROM_EXCPN reg - - ld \reg, [sp, PT_status32] - bic \reg, \reg, (STATUS_U_MASK|STATUS_DE_MASK) - bset \reg, \reg, STATUS_L_BIT - sr \reg, [erstatus] - mov \reg, 55f - sr \reg, [eret] - - rtie -55: -.endm - -/* - * @reg [OUT] &thread_info of "current" - */ -.macro GET_CURR_THR_INFO_FROM_SP reg - bic \reg, sp, (THREAD_SIZE - 1) -.endm - /* * @reg [OUT] thread_info->flags of "current" */ @@ -359,222 +233,6 @@ ld \reg, [\reg, THREAD_INFO_FLAGS] .endm -/*-------------------------------------------------------------- - * For early Exception Prologue, a core reg is temporarily needed to - * code the rest of prolog (stack switching). This is done by stashing - * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP). - * - * Before saving the full regfile - this reg is restored back, only - * to be saved again on kernel mode stack, as part of pt_regs. - *-------------------------------------------------------------*/ -.macro EXCPN_PROLOG_FREEUP_REG reg -#ifdef CONFIG_SMP - sr \reg, [ARC_REG_SCRATCH_DATA0] -#else - st \reg, [@ex_saved_reg1] -#endif -.endm - -.macro EXCPN_PROLOG_RESTORE_REG reg -#ifdef CONFIG_SMP - lr \reg, [ARC_REG_SCRATCH_DATA0] -#else - ld \reg, [@ex_saved_reg1] -#endif -.endm - -/*-------------------------------------------------------------- - * Exception Entry prologue - * -Switches stack to K mode (if not already) - * -Saves the register file - * - * After this it is safe to call the "C" handlers - *-------------------------------------------------------------*/ -.macro EXCEPTION_PROLOGUE - - /* Need at least 1 reg to code the early exception prologue */ - EXCPN_PROLOG_FREEUP_REG r9 - - /* U/K mode at time of exception (stack not switched if already K) */ - lr r9, [erstatus] - - /* ARC700 doesn't provide auto-stack switching */ - SWITCH_TO_KERNEL_STK - - /* save the regfile */ - SAVE_ALL_SYS -.endm - -/*-------------------------------------------------------------- - * Save all registers used by Exceptions (TLB Miss, Prot-V, Mem err etc) - * Requires SP to be already switched to kernel mode Stack - * sp points to the next free element on the stack at exit of this macro. - * Registers are pushed / popped in the order defined in struct ptregs - * in asm/ptrace.h - * Note that syscalls are implemented via TRAP which is also a exception - * from CPU's point of view - *-------------------------------------------------------------*/ -.macro SAVE_ALL_SYS - - 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_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 - -/*-------------------------------------------------------------- - * Restore all registers used by system call or Exceptions - * SP should always be pointing to the next free stack element - * when entering this macro. - * - * NOTE: - * - * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg - * for memory load operations. If used in that way interrupts are deffered - * 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 - - POPAX erstatus - POPAX eret - POP blink - POP fp - POP gp - RESTORE_R12_TO_R0 - - ld sp, [sp] /* restore original sp */ - /* orig_r0, ECR, user_r25 skipped automatically */ -.endm - - -/*-------------------------------------------------------------- - * Save all registers used by interrupt handlers. - *-------------------------------------------------------------*/ -.macro SAVE_ALL_INT1 - - /* restore original r9 to be saved as part of reg-file */ -#ifdef CONFIG_SMP - lr r9, [ARC_REG_SCRATCH_DATA0] -#else - ld r9, [@int1_saved_reg] -#endif - - /* now we are ready to save the remaining context :) */ - st event_IRQ1, [sp, 8] /* Dummy ECR */ - st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ - - 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 - - /* TODO-vineetg: SMP we can't use global nor can we use - * SCRATCH0 as we do for int1 because while int1 is using - * it, int2 can come - */ - /* retsore original r9 , saved in sys_saved_r9 */ - ld r9, [@int2_saved_reg] - - /* now we are ready to save the remaining context :) */ - st event_IRQ2, [sp, 8] /* Dummy ECR */ - st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ - - 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 - -/*-------------------------------------------------------------- - * Restore all registers used by interrupt handlers. - * - * NOTE: - * - * It is recommended that lp_count/ilink1/ilink2 not be used as a dest reg - * for memory load operations. If used in that way interrupts are deffered - * by hardware and that is not good. - *-------------------------------------------------------------*/ - -.macro RESTORE_ALL_INT1 - 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, ECR, user_r25 skipped automatically */ -.endm - -.macro RESTORE_ALL_INT2 - POPAX bta_l2 - POPAX lp_start - POPAX lp_end - - 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 - - -/* Get CPU-ID of this core */ -.macro GET_CPU_ID reg - lr \reg, [identity] - lsr \reg, \reg, 8 - bmsk \reg, \reg, 7 -.endm - #ifdef CONFIG_SMP /*------------------------------------------------- @@ -643,6 +301,4 @@ #endif /* CONFIG_ARC_CURR_IN_REG */ -#endif /* __ASSEMBLY__ */ - #endif /* __ASM_ARC_ENTRY_H */ |