--- /dev/null
+/*
+ * 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_COMPACT_H
+#define __ASM_ARC_ENTRY_COMPACT_H
+
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h> /* For THREAD_SIZE */
+
+/*--------------------------------------------------------------
+ * 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
+
+ ld r9, [sp, PT_status32]
+ bic r9, r9, (STATUS_U_MASK|STATUS_DE_MASK)
+ bset r9, r9, STATUS_L_BIT
+ sr r9, [erstatus]
+ mov r9, 55f
+ sr r9, [eret]
+
+ rtie
+55:
+.endm
+
+/*--------------------------------------------------------------
+ * For early Exception/ISR 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 PROLOG_FREEUP_REG reg, mem
+#ifdef CONFIG_SMP
+ sr \reg, [ARC_REG_SCRATCH_DATA0]
+#else
+ st \reg, [\mem]
+#endif
+.endm
+
+.macro PROLOG_RESTORE_REG reg, mem
+#ifdef CONFIG_SMP
+ lr \reg, [ARC_REG_SCRATCH_DATA0]
+#else
+ ld \reg, [\mem]
+#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 */
+ PROLOG_FREEUP_REG r9, @ex_saved_reg1
+
+ /* 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
+
+ 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 */
+ PROLOG_RESTORE_REG r9, @ex_saved_reg1
+
+ 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 EXCEPTION_EPILOGUE
+ 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
+
+/* Dummy ECR values for Interrupts */
+#define event_IRQ1 0x0031abcd
+#define event_IRQ2 0x0032abcd
+
+.macro INTERRUPT_PROLOGUE LVL
+
+ /* free up r9 as scratchpad */
+ PROLOG_FREEUP_REG r9, @int\LVL\()_saved_reg
+
+ /* Which mode (user/kernel) was the system in when intr occured */
+ lr r9, [status32_l\LVL\()]
+
+ SWITCH_TO_KERNEL_STK
+
+ /* restore original r9 */
+ PROLOG_RESTORE_REG r9, @int\LVL\()_saved_reg
+
+ /* now we are ready to save the remaining context */
+ st 0x003\LVL\()abcd, [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 ilink\LVL\()
+ PUSHAX status32_l\LVL\()
+ PUSH lp_count
+ PUSHAX lp_end
+ PUSHAX lp_start
+ PUSHAX bta_l\LVL\()
+.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 INTERRUPT_EPILOGUE LVL
+ POPAX bta_l\LVL\()
+ POPAX lp_start
+ POPAX lp_end
+
+ POP r9
+ mov lp_count, r9 ;LD to lp_count is not allowed
+
+ POPAX status32_l\LVL\()
+ POP ilink\LVL\()
+ 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 thread_info of "current" tsk */
+.macro GET_CURR_THR_INFO_FROM_SP reg
+ bic \reg, sp, (THREAD_SIZE - 1)
+.endm
+
+/* Get CPU-ID of this core */
+.macro GET_CPU_ID reg
+ lr \reg, [identity]
+ lsr \reg, \reg, 8
+ bmsk \reg, \reg, 7
+.endm
+
+#endif /* __ASM_ARC_ENTRY_COMPACT_H */
/*
+ * 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>
+#include <asm/entry-compact.h> /* ISA specific bits */
+
/* Note on the LD/ST addr modes with addr reg wback
*
* LD.a same as LD.aw
.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
-
- ld r9, [sp, PT_status32]
- bic r9, r9, (STATUS_U_MASK|STATUS_DE_MASK)
- bset r9, r9, STATUS_L_BIT
- sr r9, [erstatus]
- mov r9, 55f
- sr r9, [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"
*/
ld \reg, [\reg, THREAD_INFO_FLAGS]
.endm
-/*--------------------------------------------------------------
- * For early Exception/ISR 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 PROLOG_FREEUP_REG reg, mem
-#ifdef CONFIG_SMP
- sr \reg, [ARC_REG_SCRATCH_DATA0]
-#else
- st \reg, [\mem]
-#endif
-.endm
-
-.macro PROLOG_RESTORE_REG reg, mem
-#ifdef CONFIG_SMP
- lr \reg, [ARC_REG_SCRATCH_DATA0]
-#else
- ld \reg, [\mem]
-#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 */
- PROLOG_FREEUP_REG r9, @ex_saved_reg1
-
- /* 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
-
- 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 */
- PROLOG_RESTORE_REG r9, @ex_saved_reg1
-
- 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 EXCEPTION_EPILOGUE
- 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
-
-/* Dummy ECR values for Interrupts */
-#define event_IRQ1 0x0031abcd
-#define event_IRQ2 0x0032abcd
-
-.macro INTERRUPT_PROLOGUE LVL
-
- /* free up r9 as scratchpad */
- PROLOG_FREEUP_REG r9, @int\LVL\()_saved_reg
-
- /* Which mode (user/kernel) was the system in when intr occurred */
- lr r9, [status32_l\LVL\()]
-
- SWITCH_TO_KERNEL_STK
-
- /* restore original r9 */
- PROLOG_RESTORE_REG r9, @int\LVL\()_saved_reg
-
- /* now we are ready to save the remaining context */
- st 0x003\LVL\()abcd, [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 ilink\LVL\()
- PUSHAX status32_l\LVL\()
- PUSH lp_count
- PUSHAX lp_end
- PUSHAX lp_start
- PUSHAX bta_l\LVL\()
-.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 INTERRUPT_EPILOGUE LVL
- POPAX bta_l\LVL\()
- POPAX lp_start
- POPAX lp_end
-
- POP r9
- mov lp_count, r9 ;LD to lp_count is not allowed
-
- POPAX status32_l\LVL\()
- POP ilink\LVL\()
- 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
/*-------------------------------------------------
#endif /* CONFIG_ARC_CURR_IN_REG */
-#endif /* __ASSEMBLY__ */
-
#endif /* __ASM_ARC_ENTRY_H */
# Pass UTS_MACHINE for user_regset definition
CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"'
-obj-y := arcksyms.o setup.o irq.o time.o reset.o ptrace.o entry.o process.o
+obj-y := arcksyms.o setup.o irq.o time.o reset.o ptrace.o process.o devtree.o
obj-y += signal.o traps.o sys.o troubleshoot.o stacktrace.o disasm.o clk.o
-obj-y += devtree.o
+obj-y += entry-compact.o
obj-$(CONFIG_MODULES) += arcksyms.o module.o
obj-$(CONFIG_SMP) += smp.o
--- /dev/null
+/*
+ * Low Level Interrupts/Traps/Exceptions(non-TLB) Handling for ARCompact ISA
+ *
+ * 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: May 2011
+ * -Userspace unaligned access emulation
+ *
+ * vineetg: Feb 2011 (ptrace low level code fixes)
+ * -traced syscall return code (r0) was not saved into pt_regs for restoring
+ * into user reg-file when traded task rets to user space.
+ * -syscalls needing arch-wrappers (mainly for passing sp as pt_regs)
+ * were not invoking post-syscall trace hook (jumping directly into
+ * ret_from_system_call)
+ *
+ * vineetg: Nov 2010:
+ * -Vector table jumps (@8 bytes) converted into branches (@4 bytes)
+ * -To maintain the slot size of 8 bytes/vector, added nop, which is
+ * not executed at runtime.
+ *
+ * vineetg: Nov 2009 (Everything needed for TIF_RESTORE_SIGMASK)
+ * -do_signal()invoked upon TIF_RESTORE_SIGMASK as well
+ * -Wrappers for sys_{,rt_}sigsuspend() nolonger needed as they don't
+ * need ptregs anymore
+ *
+ * Vineetg: Oct 2009
+ * -In a rare scenario, Process gets a Priv-V exception and gets scheduled
+ * out. Since we don't do FAKE RTIE for Priv-V, CPU excpetion state remains
+ * active (AE bit enabled). This causes a double fault for a subseq valid
+ * exception. Thus FAKE RTIE needed in low level Priv-Violation handler.
+ * Instr Error could also cause similar scenario, so same there as well.
+ *
+ * Vineetg: March 2009 (Supporting 2 levels of Interrupts)
+ *
+ * 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 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". Since it is Loop INHIBIT Bit,
+ * setting it and not clearing it clears ZOL context
+ *
+ * Vineetg: May 16th, 2008
+ * - r25 now contains the Current Task when in kernel
+ *
+ * Vineetg: Dec 22, 2007
+ * Minor Surgery of Low Level ISR to make it SMP safe
+ * - MMU_SCRATCH0 Reg used for freeing up r9 in Level 1 ISR
+ * - _current_task is made an array of NR_CPUS
+ * - Access of _current_task wrapped inside a macro so that if hardware
+ * team agrees for a dedicated reg, no other code is touched
+ *
+ * Amit Bhor, Rahul Trivedi, Kanika Nema, Sameer Dhavale : Codito Tech 2004
+ */
+
+#include <linux/errno.h>
+#include <linux/linkage.h> /* {EXTRY,EXIT} */
+#include <asm/entry.h>
+#include <asm/irqflags.h>
+
+ .cpu A7
+
+;############################ Vector Table #################################
+
+.macro VECTOR lbl
+#if 1 /* Just in case, build breaks */
+ j \lbl
+#else
+ b \lbl
+ nop
+#endif
+.endm
+
+ .section .vector, "ax",@progbits
+ .align 4
+
+/* Each entry in the vector table must occupy 2 words. Since it is a jump
+ * across sections (.vector to .text) we are gauranteed that 'j somewhere'
+ * will use the 'j limm' form of the intrsuction as long as somewhere is in
+ * a section other than .vector.
+ */
+
+; ********* Critical System Events **********************
+VECTOR res_service ; 0x0, Restart Vector (0x0)
+VECTOR mem_service ; 0x8, Mem exception (0x1)
+VECTOR instr_service ; 0x10, Instrn Error (0x2)
+
+; ******************** Device ISRs **********************
+#ifdef CONFIG_ARC_IRQ3_LV2
+VECTOR handle_interrupt_level2
+#else
+VECTOR handle_interrupt_level1
+#endif
+
+VECTOR handle_interrupt_level1
+
+#ifdef CONFIG_ARC_IRQ5_LV2
+VECTOR handle_interrupt_level2
+#else
+VECTOR handle_interrupt_level1
+#endif
+
+#ifdef CONFIG_ARC_IRQ6_LV2
+VECTOR handle_interrupt_level2
+#else
+VECTOR handle_interrupt_level1
+#endif
+
+.rept 25
+VECTOR handle_interrupt_level1 ; Other devices
+.endr
+
+/* FOR ARC600: timer = 0x3, uart = 0x8, emac = 0x10 */
+
+; ******************** Exceptions **********************
+VECTOR EV_MachineCheck ; 0x100, Fatal Machine check (0x20)
+VECTOR EV_TLBMissI ; 0x108, Intruction TLB miss (0x21)
+VECTOR EV_TLBMissD ; 0x110, Data TLB miss (0x22)
+VECTOR EV_TLBProtV ; 0x118, Protection Violation (0x23)
+ ; or Misaligned Access
+VECTOR EV_PrivilegeV ; 0x120, Privilege Violation (0x24)
+VECTOR EV_Trap ; 0x128, Trap exception (0x25)
+VECTOR EV_Extension ; 0x130, Extn Intruction Excp (0x26)
+
+.rept 24
+VECTOR reserved ; Reserved Exceptions
+.endr
+
+
+;##################### Scratch Mem for IRQ stack switching #############
+
+ARCFP_DATA int1_saved_reg
+ .align 32
+ .type int1_saved_reg, @object
+ .size int1_saved_reg, 4
+int1_saved_reg:
+ .zero 4
+
+/* Each Interrupt level needs its own scratch */
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+
+ARCFP_DATA int2_saved_reg
+ .type int2_saved_reg, @object
+ .size int2_saved_reg, 4
+int2_saved_reg:
+ .zero 4
+
+#endif
+
+; ---------------------------------------------
+ .section .text, "ax",@progbits
+
+res_service: ; processor restart
+ flag 0x1 ; not implemented
+ nop
+ nop
+
+reserved: ; processor restart
+ rtie ; jump to processor initializations
+
+;##################### Interrupt Handling ##############################
+
+#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
+; ---------------------------------------------
+; Level 2 ISR: Can interrupt a Level 1 ISR
+; ---------------------------------------------
+ENTRY(handle_interrupt_level2)
+
+ INTERRUPT_PROLOGUE 2
+
+ ;------------------------------------------------------
+ ; if L2 IRQ interrupted a L1 ISR, disable preemption
+ ;------------------------------------------------------
+
+ ld r9, [sp, PT_status32] ; get statu32_l2 (saved in pt_regs)
+ bbit0 r9, STATUS_A1_BIT, 1f ; L1 not active when L2 IRQ, so normal
+
+ ; A1 is set in status32_l2
+ ; bump thread_info->preempt_count (Disable preemption)
+ GET_CURR_THR_INFO_FROM_SP r10
+ ld r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+ add r9, r9, 1
+ st r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+
+1:
+ ;------------------------------------------------------
+ ; setup params for Linux common ISR and invoke it
+ ;------------------------------------------------------
+ lr r0, [icause2]
+ and r0, r0, 0x1f
+
+ bl.d @arch_do_IRQ
+ mov r1, sp
+
+ mov r8,0x2
+ sr r8, [AUX_IRQ_LV12] ; clear bit in Sticky Status Reg
+
+ b ret_from_exception
+
+END(handle_interrupt_level2)
+
+#endif
+
+; ---------------------------------------------
+; Level 1 ISR
+; ---------------------------------------------
+ENTRY(handle_interrupt_level1)
+
+ INTERRUPT_PROLOGUE 1
+
+ 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
+
+ mov r8,0x1
+ sr r8, [AUX_IRQ_LV12] ; clear bit in Sticky Status Reg
+
+ b ret_from_exception
+END(handle_interrupt_level1)
+
+;################### Non TLB Exception Handling #############################
+
+; ---------------------------------------------
+; Protection Violation Exception Handler
+; ---------------------------------------------
+
+ENTRY(EV_TLBProtV)
+
+ EXCEPTION_PROLOGUE
+
+ lr r2, [ecr]
+ lr r0, [efa] ; Faulting Data address (not part of pt_regs saved above)
+
+ ; Exception auto-disables further Intr/exceptions.
+ ; Re-enable them by pretending to return from exception
+ ; (so rest of handler executes in pure K mode)
+
+ FAKE_RET_FROM_EXCPN
+
+ mov r1, sp ; Handle to pt_regs
+
+ ;------ (5) Type of Protection Violation? ----------
+ ;
+ ; ProtV Hardware Exception is triggered for Access Faults of 2 types
+ ; -Access Violaton : 00_23_(00|01|02|03)_00
+ ; x r w r+w
+ ; -Unaligned Access : 00_23_04_00
+ ;
+ bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f
+
+ ;========= (6a) Access Violation Processing ========
+ bl do_page_fault
+ b ret_from_exception
+
+ ;========== (6b) Non aligned access ============
+4:
+
+ SAVE_CALLEE_SAVED_USER
+ mov r2, sp ; callee_regs
+
+ bl do_misaligned_access
+
+ ; 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
+
+ b ret_from_exception
+
+END(EV_TLBProtV)
+
+; Wrapper for Linux page fault handler called from EV_TLBMiss*
+; Very similar to ProtV handler case (6a) above, but avoids the extra checks
+; for Misaligned access
+;
+ENTRY(call_do_page_fault)
+
+ EXCEPTION_PROLOGUE
+ lr r0, [efa] ; Faulting Data address
+ mov r1, sp
+ FAKE_RET_FROM_EXCPN
+
+ mov blink, ret_from_exception
+ b do_page_fault
+
+END(call_do_page_fault)
+
+;############# Common Handlers for ARCompact and ARCv2 ##############
+
+#include "entry.S"
+
+;############# Return from Intr/Excp/Trap (ARC Specifics) ##############
+;
+; 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
+
+.Lrestore_regs:
+
+ 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
+ ; Note that we use realtime STATUS32 (not pt_regs->status32) to
+ ; decide that.
+
+ ; if Returning from Exception
+ bbit0 r10, STATUS_AE_BIT, not_exception
+ EXCEPTION_EPILOGUE
+ rtie
+
+ ; Not Exception so maybe Interrupts (Level 1 or 2)
+
+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 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
+ ;----------------------------------------------------------------
+
+ 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
+
+ ; 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 because we would have incremented it.
+ ; If this does happen we simply HALT as it means a BUG !!!
+ cmp r9, 0
+ bnz 2f
+ flag 1
+
+2:
+ sub r9, r9, 1
+ st r9, [r10, THREAD_INFO_PREEMPT_COUNT]
+
+149:
+ ;return from level 2
+ INTERRUPT_EPILOGUE 2
+debug_marker_l2:
+ rtie
+
+not_level2_interrupt:
+
+#endif
+
+ bbit0 r10, STATUS_A1_BIT, not_level1_interrupt
+
+ ;return from level 1
+ INTERRUPT_EPILOGUE 1
+debug_marker_l1:
+ rtie
+
+not_level1_interrupt:
+
+ ;this case is for syscalls or Exceptions (with fake rtie)
+
+ EXCEPTION_EPILOGUE
+debug_marker_syscall:
+ rtie
/*
- * Low Level Interrupts/Traps/Exceptions(non-TLB) Handling for ARC
+ * Common Low Level Interrupts/Traps/Exceptions(non-TLB) Handling for ARC
+ * (included from entry-<isa>.S
*
+ * 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: May 2011
- * -Userspace unaligned access emulation
- *
- * vineetg: Feb 2011 (ptrace low level code fixes)
- * -traced syscall return code (r0) was not saved into pt_regs for restoring
- * into user reg-file when traded task rets to user space.
- * -syscalls needing arch-wrappers (mainly for passing sp as pt_regs)
- * were not invoking post-syscall trace hook (jumping directly into
- * ret_from_system_call)
- *
- * vineetg: Nov 2010:
- * -Vector table jumps (@8 bytes) converted into branches (@4 bytes)
- * -To maintain the slot size of 8 bytes/vector, added nop, which is
- * not executed at runtime.
- *
- * vineetg: Nov 2009 (Everything needed for TIF_RESTORE_SIGMASK)
- * -do_signal()invoked upon TIF_RESTORE_SIGMASK as well
- * -Wrappers for sys_{,rt_}sigsuspend() nolonger needed as they don't
- * need ptregs anymore
- *
- * Vineetg: Oct 2009
- * -In a rare scenario, Process gets a Priv-V exception and gets scheduled
- * out. Since we don't do FAKE RTIE for Priv-V, CPU excpetion state remains
- * active (AE bit enabled). This causes a double fault for a subseq valid
- * exception. Thus FAKE RTIE needed in low level Priv-Violation handler.
- * Instr Error could also cause similar scenario, so same there as well.
- *
- * Vineetg: March 2009 (Supporting 2 levels of Interrupts)
- *
- * 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 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". Since it is Loop INHIBIT Bit,
- * setting it and not clearing it clears ZOL context
- *
- * Vineetg: May 16th, 2008
- * - r25 now contains the Current Task when in kernel
- *
- * Vineetg: Dec 22, 2007
- * Minor Surgery of Low Level ISR to make it SMP safe
- * - MMU_SCRATCH0 Reg used for freeing up r9 in Level 1 ISR
- * - _current_task is made an array of NR_CPUS
- * - Access of _current_task wrapped inside a macro so that if hardware
- * team agrees for a dedicated reg, no other code is touched
- *
- * Amit Bhor, Rahul Trivedi, Kanika Nema, Sameer Dhavale : Codito Tech 2004
*/
/*------------------------------------------------------------------
* Global Pointer (gp) r26
* Frame Pointer (fp) r27
* Stack Pointer (sp) r28
- * Interrupt link register (ilink1) r29
- * Interrupt link register (ilink2) r30
* Branch link register (blink) r31
*------------------------------------------------------------------
*/
- .cpu A7
-
-;############################ Vector Table #################################
-
-.macro VECTOR lbl
-#if 1 /* Just in case, build breaks */
- j \lbl
-#else
- b \lbl
- nop
-#endif
-.endm
-
- .section .vector, "ax",@progbits
- .align 4
-
-/* Each entry in the vector table must occupy 2 words. Since it is a jump
- * across sections (.vector to .text) we are gauranteed that 'j somewhere'
- * will use the 'j limm' form of the intrsuction as long as somewhere is in
- * a section other than .vector.
- */
-
-; ********* Critical System Events **********************
-VECTOR res_service ; 0x0, Restart Vector (0x0)
-VECTOR mem_service ; 0x8, Mem exception (0x1)
-VECTOR instr_service ; 0x10, Instrn Error (0x2)
-
-; ******************** Device ISRs **********************
-#ifdef CONFIG_ARC_IRQ3_LV2
-VECTOR handle_interrupt_level2
-#else
-VECTOR handle_interrupt_level1
-#endif
-
-VECTOR handle_interrupt_level1
-
-#ifdef CONFIG_ARC_IRQ5_LV2
-VECTOR handle_interrupt_level2
-#else
-VECTOR handle_interrupt_level1
-#endif
-
-#ifdef CONFIG_ARC_IRQ6_LV2
-VECTOR handle_interrupt_level2
-#else
-VECTOR handle_interrupt_level1
-#endif
-
-.rept 25
-VECTOR handle_interrupt_level1 ; Other devices
-.endr
-
-/* FOR ARC600: timer = 0x3, uart = 0x8, emac = 0x10 */
-
-; ******************** Exceptions **********************
-VECTOR EV_MachineCheck ; 0x100, Fatal Machine check (0x20)
-VECTOR EV_TLBMissI ; 0x108, Intruction TLB miss (0x21)
-VECTOR EV_TLBMissD ; 0x110, Data TLB miss (0x22)
-VECTOR EV_TLBProtV ; 0x118, Protection Violation (0x23)
- ; or Misaligned Access
-VECTOR EV_PrivilegeV ; 0x120, Privilege Violation (0x24)
-VECTOR EV_Trap ; 0x128, Trap exception (0x25)
-VECTOR EV_Extension ; 0x130, Extn Intruction Excp (0x26)
-
-.rept 24
-VECTOR reserved ; Reserved Exceptions
-.endr
-
-#include <linux/linkage.h> /* {EXTRY,EXIT} */
-#include <asm/entry.h> /* SAVE_ALL_{INT1,INT2,SYS...} */
-#include <asm/errno.h>
-#include <asm/arcregs.h>
-#include <asm/irqflags.h>
-
-;##################### Scratch Mem for IRQ stack switching #############
-
-ARCFP_DATA int1_saved_reg
- .align 32
- .type int1_saved_reg, @object
- .size int1_saved_reg, 4
-int1_saved_reg:
- .zero 4
-
-/* Each Interrupt level needs its own scratch */
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-
-ARCFP_DATA int2_saved_reg
- .type int2_saved_reg, @object
- .size int2_saved_reg, 4
-int2_saved_reg:
- .zero 4
-
-#endif
-
-; ---------------------------------------------
- .section .text, "ax",@progbits
-
-res_service: ; processor restart
- flag 0x1 ; not implemented
- nop
- nop
-
-reserved: ; processor restart
- rtie ; jump to processor initializations
-
-;##################### Interrupt Handling ##############################
-
-#ifdef CONFIG_ARC_COMPACT_IRQ_LEVELS
-; ---------------------------------------------
-; Level 2 ISR: Can interrupt a Level 1 ISR
-; ---------------------------------------------
-ENTRY(handle_interrupt_level2)
-
- INTERRUPT_PROLOGUE 2
-
- ;------------------------------------------------------
- ; if L2 IRQ interrupted a L1 ISR, disable preemption
- ;------------------------------------------------------
-
- ld r9, [sp, PT_status32] ; get statu32_l2 (saved in pt_regs)
- bbit0 r9, STATUS_A1_BIT, 1f ; L1 not active when L2 IRQ, so normal
-
- ; A1 is set in status32_l2
- ; bump thread_info->preempt_count (Disable preemption)
- GET_CURR_THR_INFO_FROM_SP r10
- ld r9, [r10, THREAD_INFO_PREEMPT_COUNT]
- add r9, r9, 1
- st r9, [r10, THREAD_INFO_PREEMPT_COUNT]
-
-1:
- ;------------------------------------------------------
- ; setup params for Linux common ISR and invoke it
- ;------------------------------------------------------
- lr r0, [icause2]
- and r0, r0, 0x1f
-
- bl.d @arch_do_IRQ
- mov r1, sp
-
- mov r8,0x2
- sr r8, [AUX_IRQ_LV12] ; clear bit in Sticky Status Reg
-
- b ret_from_exception
-
-END(handle_interrupt_level2)
-
-#endif
-
-; ---------------------------------------------
-; Level 1 ISR
-; ---------------------------------------------
-ENTRY(handle_interrupt_level1)
-
- INTERRUPT_PROLOGUE 1
-
- 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
-
- mov r8,0x1
- sr r8, [AUX_IRQ_LV12] ; clear bit in Sticky Status Reg
-
- b ret_from_exception
-END(handle_interrupt_level1)
-
;################### Non TLB Exception Handling #############################
; ---------------------------------------------
END(EV_MachineCheck)
-; ---------------------------------------------
-; Protection Violation Exception Handler
-; ---------------------------------------------
-
-ENTRY(EV_TLBProtV)
-
- EXCEPTION_PROLOGUE
-
- lr r2, [ecr]
- lr r0, [efa] ; Faulting Data addr (not part of pt_regs saved above)
-
- ; Exception auto-disables further Intr/exceptions.
- ; Re-enable them by pretending to return from exception
- ; (so rest of handler executes in pure K mode)
-
- FAKE_RET_FROM_EXCPN
-
- mov r1, sp ; Handle to pt_regs
-
- ;------ (5) Type of Protection Violation? ----------
- ;
- ; ProtV Hardware Exception is triggered for Access Faults of 2 types
- ; -Access Violaton : 00_23_(00|01|02|03)_00
- ; x r w r+w
- ; -Unaligned Access : 00_23_04_00
- ;
- bbit1 r2, ECR_C_BIT_PROTV_MISALIG_DATA, 4f
-
- ;========= (6a) Access Violation Processing ========
- bl do_page_fault
- b ret_from_exception
-
- ;========== (6b) Non aligned access ============
-4:
-
- SAVE_CALLEE_SAVED_USER
- mov r2, sp ; callee_regs
-
- bl do_misaligned_access
-
- ; 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
-
- b ret_from_exception
-
-END(EV_TLBProtV)
-
-; Wrapper for Linux page fault handler called from EV_TLBMiss*
-; Very similar to ProtV handler case (6a) above, but avoids the extra checks
-; for Misaligned access
-;
-ENTRY(call_do_page_fault)
-
- EXCEPTION_PROLOGUE
- lr r0, [efa] ; Faulting Data address
- mov r1, sp
- FAKE_RET_FROM_EXCPN
-
- mov blink, ret_from_exception
- b do_page_fault
-
-END(call_do_page_fault)
-
; ---------------------------------------------
; Privilege Violation Exception Handler
; ---------------------------------------------
; preempt_schedule_irq() always returns with IRQ disabled
#endif
- ; fall through
-
-;############# Return from Intr/Excp/Trap (ARC Specifics) ##############
-;
-; 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
-
-.Lrestore_regs:
-
- 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
- ; Note that we use realtime STATUS32 (not pt_regs->status32) to
- ; decide that.
-
- ; if Returning from Exception
- bbit0 r10, STATUS_AE_BIT, not_exception
- EXCEPTION_EPILOGUE
- rtie
-
- ; Not Exception so maybe Interrupts (Level 1 or 2)
-
-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 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
- ;----------------------------------------------------------------
-
- 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
-
- ; 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 because we would have incremented it.
- ; If this does happen we simply HALT as it means a BUG !!!
- cmp r9, 0
- bnz 2f
- flag 1
-
-2:
- sub r9, r9, 1
- st r9, [r10, THREAD_INFO_PREEMPT_COUNT]
-
-149:
- ;return from level 2
- INTERRUPT_EPILOGUE 2
-debug_marker_l2:
- rtie
-
-not_level2_interrupt:
-
-#endif
-
- bbit0 r10, STATUS_A1_BIT, not_level1_interrupt
-
- ;return from level 1
- INTERRUPT_EPILOGUE 1
-debug_marker_l1:
- rtie
-
-not_level1_interrupt:
-
- ;this case is for syscalls or Exceptions (with fake rtie)
-
- EXCEPTION_EPILOGUE
-debug_marker_syscall:
- rtie
-
+ b .Lrestore_regs
END(ret_from_exception)
ENTRY(ret_from_fork)
; This also fixes STAR 9000487933 where the prev-workaround (objcopy --setflag)
; would not work after a clean build due to kernel build system dependencies.
.section .debug_frame, "wa",@progbits
+
+; Reset to .text as this file is included in entry-<isa>.S
+.section .text, "ax",@progbits
#endif
projects / platform / kernel / linux-rpi.git / commitdiff