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Diffstat (limited to 'arch/microblaze/kernel/entry.S')
| -rw-r--r-- | arch/microblaze/kernel/entry.S | 1092 |
1 files changed, 1092 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S new file mode 100644 index 0000000..c7353e7 --- /dev/null +++ b/arch/microblaze/kernel/entry.S @@ -0,0 +1,1092 @@ +/* + * Low-level system-call handling, trap handlers and context-switching + * + * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2003 John Williams <jwilliams@itee.uq.edu.au> + * Copyright (C) 2001,2002 NEC Corporation + * Copyright (C) 2001,2002 Miles Bader <miles@gnu.org> + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + * + * Written by Miles Bader <miles@gnu.org> + * Heavily modified by John Williams for Microblaze + */ + +#include <linux/sys.h> +#include <linux/linkage.h> + +#include <asm/entry.h> +#include <asm/current.h> +#include <asm/processor.h> +#include <asm/exceptions.h> +#include <asm/asm-offsets.h> +#include <asm/thread_info.h> + +#include <asm/page.h> +#include <asm/unistd.h> + +#include <linux/errno.h> +#include <asm/signal.h> + +/* The size of a state save frame. */ +#define STATE_SAVE_SIZE (PT_SIZE + STATE_SAVE_ARG_SPACE) + +/* The offset of the struct pt_regs in a `state save frame' on the stack. */ +#define PTO STATE_SAVE_ARG_SPACE /* 24 the space for args */ + +#define C_ENTRY(name) .globl name; .align 4; name + +/* + * Various ways of setting and clearing BIP in flags reg. + * This is mucky, but necessary using microblaze version that + * allows msr ops to write to BIP + */ +#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR + .macro clear_bip + msrclr r11, MSR_BIP + nop + .endm + + .macro set_bip + msrset r11, MSR_BIP + nop + .endm + + .macro clear_eip + msrclr r11, MSR_EIP + nop + .endm + + .macro set_ee + msrset r11, MSR_EE + nop + .endm + + .macro disable_irq + msrclr r11, MSR_IE + nop + .endm + + .macro enable_irq + msrset r11, MSR_IE + nop + .endm + + .macro set_ums + msrset r11, MSR_UMS + nop + msrclr r11, MSR_VMS + nop + .endm + + .macro set_vms + msrclr r11, MSR_UMS + nop + msrset r11, MSR_VMS + nop + .endm + + .macro clear_vms_ums + msrclr r11, MSR_VMS + nop + msrclr r11, MSR_UMS + nop + .endm +#else + .macro clear_bip + mfs r11, rmsr + nop + andi r11, r11, ~MSR_BIP + mts rmsr, r11 + nop + .endm + + .macro set_bip + mfs r11, rmsr + nop + ori r11, r11, MSR_BIP + mts rmsr, r11 + nop + .endm + + .macro clear_eip + mfs r11, rmsr + nop + andi r11, r11, ~MSR_EIP + mts rmsr, r11 + nop + .endm + + .macro set_ee + mfs r11, rmsr + nop + ori r11, r11, MSR_EE + mts rmsr, r11 + nop + .endm + + .macro disable_irq + mfs r11, rmsr + nop + andi r11, r11, ~MSR_IE + mts rmsr, r11 + nop + .endm + + .macro enable_irq + mfs r11, rmsr + nop + ori r11, r11, MSR_IE + mts rmsr, r11 + nop + .endm + + .macro set_ums + mfs r11, rmsr + nop + ori r11, r11, MSR_VMS + andni r11, r11, MSR_UMS + mts rmsr, r11 + nop + .endm + + .macro set_vms + mfs r11, rmsr + nop + ori r11, r11, MSR_VMS + andni r11, r11, MSR_UMS + mts rmsr, r11 + nop + .endm + + .macro clear_vms_ums + mfs r11, rmsr + nop + andni r11, r11, (MSR_VMS|MSR_UMS) + mts rmsr,r11 + nop + .endm +#endif + +/* Define how to call high-level functions. With MMU, virtual mode must be + * enabled when calling the high-level function. Clobbers R11. + * VM_ON, VM_OFF, DO_JUMP_BIPCLR, DO_CALL + */ + +/* turn on virtual protected mode save */ +#define VM_ON \ + set_ums; \ + rted r0, 2f; \ +2: nop; + +/* turn off virtual protected mode save and user mode save*/ +#define VM_OFF \ + clear_vms_ums; \ + rted r0, TOPHYS(1f); \ +1: nop; + +#define SAVE_REGS \ + swi r2, r1, PTO+PT_R2; /* Save SDA */ \ + swi r5, r1, PTO+PT_R5; \ + swi r6, r1, PTO+PT_R6; \ + swi r7, r1, PTO+PT_R7; \ + swi r8, r1, PTO+PT_R8; \ + swi r9, r1, PTO+PT_R9; \ + swi r10, r1, PTO+PT_R10; \ + swi r11, r1, PTO+PT_R11; /* save clobbered regs after rval */\ + swi r12, r1, PTO+PT_R12; \ + swi r13, r1, PTO+PT_R13; /* Save SDA2 */ \ + swi r14, r1, PTO+PT_PC; /* PC, before IRQ/trap */ \ + swi r15, r1, PTO+PT_R15; /* Save LP */ \ + swi r18, r1, PTO+PT_R18; /* Save asm scratch reg */ \ + swi r19, r1, PTO+PT_R19; \ + swi r20, r1, PTO+PT_R20; \ + swi r21, r1, PTO+PT_R21; \ + swi r22, r1, PTO+PT_R22; \ + swi r23, r1, PTO+PT_R23; \ + swi r24, r1, PTO+PT_R24; \ + swi r25, r1, PTO+PT_R25; \ + swi r26, r1, PTO+PT_R26; \ + swi r27, r1, PTO+PT_R27; \ + swi r28, r1, PTO+PT_R28; \ + swi r29, r1, PTO+PT_R29; \ + swi r30, r1, PTO+PT_R30; \ + swi r31, r1, PTO+PT_R31; /* Save current task reg */ \ + mfs r11, rmsr; /* save MSR */ \ + nop; \ + swi r11, r1, PTO+PT_MSR; + +#define RESTORE_REGS \ + lwi r11, r1, PTO+PT_MSR; \ + mts rmsr , r11; \ + nop; \ + lwi r2, r1, PTO+PT_R2; /* restore SDA */ \ + lwi r5, r1, PTO+PT_R5; \ + lwi r6, r1, PTO+PT_R6; \ + lwi r7, r1, PTO+PT_R7; \ + lwi r8, r1, PTO+PT_R8; \ + lwi r9, r1, PTO+PT_R9; \ + lwi r10, r1, PTO+PT_R10; \ + lwi r11, r1, PTO+PT_R11; /* restore clobbered regs after rval */\ + lwi r12, r1, PTO+PT_R12; \ + lwi r13, r1, PTO+PT_R13; /* restore SDA2 */ \ + lwi r14, r1, PTO+PT_PC; /* RESTORE_LINK PC, before IRQ/trap */\ + lwi r15, r1, PTO+PT_R15; /* restore LP */ \ + lwi r18, r1, PTO+PT_R18; /* restore asm scratch reg */ \ + lwi r19, r1, PTO+PT_R19; \ + lwi r20, r1, PTO+PT_R20; \ + lwi r21, r1, PTO+PT_R21; \ + lwi r22, r1, PTO+PT_R22; \ + lwi r23, r1, PTO+PT_R23; \ + lwi r24, r1, PTO+PT_R24; \ + lwi r25, r1, PTO+PT_R25; \ + lwi r26, r1, PTO+PT_R26; \ + lwi r27, r1, PTO+PT_R27; \ + lwi r28, r1, PTO+PT_R28; \ + lwi r29, r1, PTO+PT_R29; \ + lwi r30, r1, PTO+PT_R30; \ + lwi r31, r1, PTO+PT_R31; /* Restore cur task reg */ + +.text + +/* + * User trap. + * + * System calls are handled here. + * + * Syscall protocol: + * Syscall number in r12, args in r5-r10 + * Return value in r3 + * + * Trap entered via brki instruction, so BIP bit is set, and interrupts + * are masked. This is nice, means we don't have to CLI before state save + */ +C_ENTRY(_user_exception): + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ + addi r14, r14, 4 /* return address is 4 byte after call */ + swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ + + lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/ + beqi r11, 1f; /* Jump ahead if coming from user */ +/* Kernel-mode state save. */ + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ + tophys(r1,r11); + swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ + lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ + + addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ + SAVE_REGS + + addi r11, r0, 1; /* Was in kernel-mode. */ + swi r11, r1, PTO+PT_MODE; /* pt_regs -> kernel mode */ + brid 2f; + nop; /* Fill delay slot */ + +/* User-mode state save. */ +1: + lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ + lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ + tophys(r1,r1); + lwi r1, r1, TS_THREAD_INFO; /* get stack from task_struct */ +/* calculate kernel stack pointer from task struct 8k */ + addik r1, r1, THREAD_SIZE; + tophys(r1,r1); + + addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ + SAVE_REGS + + swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); + swi r11, r1, PTO+PT_R1; /* Store user SP. */ + addi r11, r0, 1; + swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */ +2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ + /* Save away the syscall number. */ + swi r12, r1, PTO+PT_R0; + tovirt(r1,r1) + + la r15, r0, ret_from_trap-8 +/* where the trap should return need -8 to adjust for rtsd r15, 8*/ +/* Jump to the appropriate function for the system call number in r12 + * (r12 is not preserved), or return an error if r12 is not valid. The LP + * register should point to the location where + * the called function should return. [note that MAKE_SYS_CALL uses label 1] */ + /* See if the system call number is valid. */ + addi r11, r12, -__NR_syscalls; + bgei r11,1f; + /* Figure out which function to use for this system call. */ + /* Note Microblaze barrel shift is optional, so don't rely on it */ + add r12, r12, r12; /* convert num -> ptr */ + add r12, r12, r12; + + /* Trac syscalls and stored them to r0_ram */ + lwi r3, r12, 0x400 + TOPHYS(r0_ram) + addi r3, r3, 1 + swi r3, r12, 0x400 + TOPHYS(r0_ram) + + lwi r12, r12, TOPHYS(sys_call_table); /* Function ptr */ + /* Make the system call. to r12*/ + set_vms; + rtid r12, 0; + nop; + /* The syscall number is invalid, return an error. */ +1: VM_ON; /* RETURN() expects virtual mode*/ + addi r3, r0, -ENOSYS; + rtsd r15,8; /* looks like a normal subroutine return */ + or r0, r0, r0 + + +/* Entry point used to return from a syscall/trap. */ +/* We re-enable BIP bit before state restore */ +C_ENTRY(ret_from_trap): + set_bip; /* Ints masked for state restore*/ + lwi r11, r1, PTO+PT_MODE; +/* See if returning to kernel mode, if so, skip resched &c. */ + bnei r11, 2f; + + /* We're returning to user mode, so check for various conditions that + * trigger rescheduling. */ + /* Get current task ptr into r11 */ + add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + lwi r11, r11, TS_THREAD_INFO; /* get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_NEED_RESCHED; + beqi r11, 5f; + + swi r3, r1, PTO + PT_R3; /* store syscall result */ + swi r4, r1, PTO + PT_R4; + bralid r15, schedule; /* Call scheduler */ + nop; /* delay slot */ + lwi r3, r1, PTO + PT_R3; /* restore syscall result */ + lwi r4, r1, PTO + PT_R4; + + /* Maybe handle a signal */ +5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + lwi r11, r11, TS_THREAD_INFO; /* get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_SIGPENDING; + beqi r11, 1f; /* Signals to handle, handle them */ + + swi r3, r1, PTO + PT_R3; /* store syscall result */ + swi r4, r1, PTO + PT_R4; + la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ + add r6, r0, r0; /* Arg 2: sigset_t *oldset */ + addi r7, r0, 1; /* Arg 3: int in_syscall */ + bralid r15, do_signal; /* Handle any signals */ + nop; + lwi r3, r1, PTO + PT_R3; /* restore syscall result */ + lwi r4, r1, PTO + PT_R4; + +/* Finally, return to user state. */ +1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ + add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */ + VM_OFF; + tophys(r1,r1); + RESTORE_REGS; + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ + lwi r1, r1, PT_R1 - PT_SIZE;/* Restore user stack pointer. */ + bri 6f; + +/* Return to kernel state. */ +2: VM_OFF; + tophys(r1,r1); + RESTORE_REGS; + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ + tovirt(r1,r1); +6: +TRAP_return: /* Make global symbol for debugging */ + rtbd r14, 0; /* Instructions to return from an IRQ */ + nop; + + +/* These syscalls need access to the struct pt_regs on the stack, so we + implement them in assembly (they're basically all wrappers anyway). */ + +C_ENTRY(sys_fork_wrapper): + addi r5, r0, SIGCHLD /* Arg 0: flags */ + lwi r6, r1, PTO+PT_R1 /* Arg 1: child SP (use parent's) */ + la r7, r1, PTO /* Arg 2: parent context */ + add r8. r0, r0 /* Arg 3: (unused) */ + add r9, r0, r0; /* Arg 4: (unused) */ + add r10, r0, r0; /* Arg 5: (unused) */ + brid do_fork /* Do real work (tail-call) */ + nop; + +/* This the initial entry point for a new child thread, with an appropriate + stack in place that makes it look the the child is in the middle of an + syscall. This function is actually `returned to' from switch_thread + (copy_thread makes ret_from_fork the return address in each new thread's + saved context). */ +C_ENTRY(ret_from_fork): + bralid r15, schedule_tail; /* ...which is schedule_tail's arg */ + add r3, r5, r0; /* switch_thread returns the prev task */ + /* ( in the delay slot ) */ + add r3, r0, r0; /* Child's fork call should return 0. */ + brid ret_from_trap; /* Do normal trap return */ + nop; + +C_ENTRY(sys_vfork): + brid microblaze_vfork /* Do real work (tail-call) */ + la r5, r1, PTO + +C_ENTRY(sys_clone): + bnei r6, 1f; /* See if child SP arg (arg 1) is 0. */ + lwi r6, r1, PTO+PT_R1; /* If so, use paret's stack ptr */ +1: la r7, r1, PTO; /* Arg 2: parent context */ + add r8, r0, r0; /* Arg 3: (unused) */ + add r9, r0, r0; /* Arg 4: (unused) */ + add r10, r0, r0; /* Arg 5: (unused) */ + brid do_fork /* Do real work (tail-call) */ + nop; + +C_ENTRY(sys_execve): + la r8, r1, PTO; /* add user context as 4th arg */ + brid microblaze_execve; /* Do real work (tail-call).*/ + nop; + +C_ENTRY(sys_rt_sigsuspend_wrapper): + swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + swi r4, r1, PTO+PT_R4; + la r7, r1, PTO; /* add user context as 3rd arg */ + brlid r15, sys_rt_sigsuspend; /* Do real work.*/ + nop; + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + bri ret_from_trap /* fall through will not work here due to align */ + nop; + +C_ENTRY(sys_rt_sigreturn_wrapper): + swi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + swi r4, r1, PTO+PT_R4; + la r5, r1, PTO; /* add user context as 1st arg */ + brlid r15, sys_rt_sigreturn /* Do real work */ + nop; + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + bri ret_from_trap /* fall through will not work here due to align */ + nop; + +/* + * HW EXCEPTION rutine start + */ + +#define SAVE_STATE \ + swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ \ + set_bip; /*equalize initial state for all possible entries*/\ + clear_eip; \ + enable_irq; \ + set_ee; \ + /* See if already in kernel mode.*/ \ + lwi r11, r0, TOPHYS(PER_CPU(KM)); \ + beqi r11, 1f; /* Jump ahead if coming from user */\ + /* Kernel-mode state save. */ \ + /* Reload kernel stack-ptr. */ \ + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ + tophys(r1,r11); \ + swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ \ + lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\ + addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\ + /* store return registers separately because \ + * this macros is use for others exceptions */ \ + swi r3, r1, PTO + PT_R3; \ + swi r4, r1, PTO + PT_R4; \ + SAVE_REGS \ + /* PC, before IRQ/trap - this is one instruction above */ \ + swi r17, r1, PTO+PT_PC; \ + \ + addi r11, r0, 1; /* Was in kernel-mode. */ \ + swi r11, r1, PTO+PT_MODE; \ + brid 2f; \ + nop; /* Fill delay slot */ \ +1: /* User-mode state save. */ \ + lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\ + lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\ + tophys(r1,r1); \ + lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ \ + addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */\ + tophys(r1,r1); \ + \ + addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\ + /* store return registers separately because this macros \ + * is use for others exceptions */ \ + swi r3, r1, PTO + PT_R3; \ + swi r4, r1, PTO + PT_R4; \ + SAVE_REGS \ + /* PC, before IRQ/trap - this is one instruction above FIXME*/ \ + swi r17, r1, PTO+PT_PC; \ + \ + swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ \ + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \ + swi r11, r1, PTO+PT_R1; /* Store user SP. */ \ + addi r11, r0, 1; \ + swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode.*/\ +2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\ + /* Save away the syscall number. */ \ + swi r0, r1, PTO+PT_R0; \ + tovirt(r1,r1) + +C_ENTRY(full_exception_trap): + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ + /* adjust exception address for privileged instruction + * for finding where is it */ + addik r17, r17, -4 + SAVE_STATE /* Save registers */ + /* FIXME this can be store directly in PT_ESR reg. + * I tested it but there is a fault */ + /* where the trap should return need -8 to adjust for rtsd r15, 8 */ + la r15, r0, ret_from_exc - 8 + la r5, r1, PTO /* parameter struct pt_regs * regs */ + mfs r6, resr + nop + mfs r7, rfsr; /* save FSR */ + nop + la r12, r0, full_exception + set_vms; + rtbd r12, 0; + nop; + +/* + * Unaligned data trap. + * + * Unaligned data trap last on 4k page is handled here. + * + * Trap entered via exception, so EE bit is set, and interrupts + * are masked. This is nice, means we don't have to CLI before state save + * + * The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S" + */ +C_ENTRY(unaligned_data_trap): + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ + SAVE_STATE /* Save registers.*/ + /* where the trap should return need -8 to adjust for rtsd r15, 8 */ + la r15, r0, ret_from_exc-8 + mfs r3, resr /* ESR */ + nop + mfs r4, rear /* EAR */ + nop + la r7, r1, PTO /* parameter struct pt_regs * regs */ + la r12, r0, _unaligned_data_exception + set_vms; + rtbd r12, 0; /* interrupts enabled */ + nop; + +/* + * Page fault traps. + * + * If the real exception handler (from hw_exception_handler.S) didn't find + * the mapping for the process, then we're thrown here to handle such situation. + * + * Trap entered via exceptions, so EE bit is set, and interrupts + * are masked. This is nice, means we don't have to CLI before state save + * + * Build a standard exception frame for TLB Access errors. All TLB exceptions + * will bail out to this point if they can't resolve the lightweight TLB fault. + * + * The C function called is in "arch/microblaze/mm/fault.c", declared as: + * void do_page_fault(struct pt_regs *regs, + * unsigned long address, + * unsigned long error_code) + */ +/* data and intruction trap - which is choose is resolved int fault.c */ +C_ENTRY(page_fault_data_trap): + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ + SAVE_STATE /* Save registers.*/ + /* where the trap should return need -8 to adjust for rtsd r15, 8 */ + la r15, r0, ret_from_exc-8 + la r5, r1, PTO /* parameter struct pt_regs * regs */ + mfs r6, rear /* parameter unsigned long address */ + nop + mfs r7, resr /* parameter unsigned long error_code */ + nop + la r12, r0, do_page_fault + set_vms; + rtbd r12, 0; /* interrupts enabled */ + nop; + +C_ENTRY(page_fault_instr_trap): + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ + SAVE_STATE /* Save registers.*/ + /* where the trap should return need -8 to adjust for rtsd r15, 8 */ + la r15, r0, ret_from_exc-8 + la r5, r1, PTO /* parameter struct pt_regs * regs */ + mfs r6, rear /* parameter unsigned long address */ + nop + ori r7, r0, 0 /* parameter unsigned long error_code */ + la r12, r0, do_page_fault + set_vms; + rtbd r12, 0; /* interrupts enabled */ + nop; + +/* Entry point used to return from an exception. */ +C_ENTRY(ret_from_exc): + set_bip; /* Ints masked for state restore*/ + lwi r11, r1, PTO+PT_MODE; + bnei r11, 2f; /* See if returning to kernel mode, */ + /* ... if so, skip resched &c. */ + + /* We're returning to user mode, so check for various conditions that + trigger rescheduling. */ + /* Get current task ptr into r11 */ + add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + lwi r11, r11, TS_THREAD_INFO; /* get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_NEED_RESCHED; + beqi r11, 5f; + +/* Call the scheduler before returning from a syscall/trap. */ + bralid r15, schedule; /* Call scheduler */ + nop; /* delay slot */ + + /* Maybe handle a signal */ +5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + lwi r11, r11, TS_THREAD_INFO; /* get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_SIGPENDING; + beqi r11, 1f; /* Signals to handle, handle them */ + + /* + * Handle a signal return; Pending signals should be in r18. + * + * Not all registers are saved by the normal trap/interrupt entry + * points (for instance, call-saved registers (because the normal + * C-compiler calling sequence in the kernel makes sure they're + * preserved), and call-clobbered registers in the case of + * traps), but signal handlers may want to examine or change the + * complete register state. Here we save anything not saved by + * the normal entry sequence, so that it may be safely restored + * (in a possibly modified form) after do_signal returns. + * store return registers separately because this macros is use + * for others exceptions */ + swi r3, r1, PTO + PT_R3; + swi r4, r1, PTO + PT_R4; + la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ + add r6, r0, r0; /* Arg 2: sigset_t *oldset */ + addi r7, r0, 0; /* Arg 3: int in_syscall */ + bralid r15, do_signal; /* Handle any signals */ + nop; + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + +/* Finally, return to user state. */ +1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ + add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */ + VM_OFF; + tophys(r1,r1); + + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + RESTORE_REGS; + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ + + lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */ + bri 6f; +/* Return to kernel state. */ +2: VM_OFF; + tophys(r1,r1); + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + RESTORE_REGS; + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ + + tovirt(r1,r1); +6: +EXC_return: /* Make global symbol for debugging */ + rtbd r14, 0; /* Instructions to return from an IRQ */ + nop; + +/* + * HW EXCEPTION rutine end + */ + +/* + * Hardware maskable interrupts. + * + * The stack-pointer (r1) should have already been saved to the memory + * location PER_CPU(ENTRY_SP). + */ +C_ENTRY(_interrupt): +/* MS: we are in physical address */ +/* Save registers, switch to proper stack, convert SP to virtual.*/ + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) + swi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); + /* MS: See if already in kernel mode. */ + lwi r11, r0, TOPHYS(PER_CPU(KM)); + beqi r11, 1f; /* MS: Jump ahead if coming from user */ + +/* Kernel-mode state save. */ + or r11, r1, r0 + tophys(r1,r11); /* MS: I have in r1 physical address where stack is */ +/* MS: Save original SP - position PT_R1 to next stack frame 4 *1 - 152*/ + swi r11, r1, (PT_R1 - PT_SIZE); +/* MS: restore r11 because of saving in SAVE_REGS */ + lwi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); + /* save registers */ +/* MS: Make room on the stack -> activation record */ + addik r1, r1, -STATE_SAVE_SIZE; +/* MS: store return registers separately because + * this macros is use for others exceptions */ + swi r3, r1, PTO + PT_R3; + swi r4, r1, PTO + PT_R4; + SAVE_REGS + /* MS: store mode */ + addi r11, r0, 1; /* MS: Was in kernel-mode. */ + swi r11, r1, PTO + PT_MODE; /* MS: and save it */ + brid 2f; + nop; /* MS: Fill delay slot */ + +1: +/* User-mode state save. */ +/* MS: restore r11 -> FIXME move before SAVE_REG */ + lwi r11, r0, TOPHYS(PER_CPU(R11_SAVE)); + /* MS: get the saved current */ + lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); + tophys(r1,r1); + lwi r1, r1, TS_THREAD_INFO; + addik r1, r1, THREAD_SIZE; + tophys(r1,r1); + /* save registers */ + addik r1, r1, -STATE_SAVE_SIZE; + swi r3, r1, PTO+PT_R3; + swi r4, r1, PTO+PT_R4; + SAVE_REGS + /* calculate mode */ + swi r0, r1, PTO + PT_MODE; + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); + swi r11, r1, PTO+PT_R1; + /* setup kernel mode to KM */ + addi r11, r0, 1; + swi r11, r0, TOPHYS(PER_CPU(KM)); + +2: + lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); + swi r0, r1, PTO + PT_R0; + tovirt(r1,r1) + la r5, r1, PTO; + set_vms; + la r11, r0, do_IRQ; + la r15, r0, irq_call; +irq_call:rtbd r11, 0; + nop; + +/* MS: we are in virtual mode */ +ret_from_irq: + lwi r11, r1, PTO + PT_MODE; + bnei r11, 2f; + + add r11, r0, CURRENT_TASK; + lwi r11, r11, TS_THREAD_INFO; + lwi r11, r11, TI_FLAGS; /* MS: get flags from thread info */ + andi r11, r11, _TIF_NEED_RESCHED; + beqi r11, 5f + bralid r15, schedule; + nop; /* delay slot */ + + /* Maybe handle a signal */ +5: add r11, r0, CURRENT_TASK; + lwi r11, r11, TS_THREAD_INFO; /* MS: get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_SIGPENDING; + beqid r11, no_intr_resched +/* Handle a signal return; Pending signals should be in r18. */ + addi r7, r0, 0; /* Arg 3: int in_syscall */ + la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ + bralid r15, do_signal; /* Handle any signals */ + add r6, r0, r0; /* Arg 2: sigset_t *oldset */ + +/* Finally, return to user state. */ +no_intr_resched: + /* Disable interrupts, we are now committed to the state restore */ + disable_irq + swi r0, r0, PER_CPU(KM); /* MS: Now officially in user state. */ + add r11, r0, CURRENT_TASK; + swi r11, r0, PER_CPU(CURRENT_SAVE); + VM_OFF; + tophys(r1,r1); + lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */ + lwi r4, r1, PTO + PT_R4; + RESTORE_REGS + addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */ + lwi r1, r1, PT_R1 - PT_SIZE; + bri 6f; +/* MS: Return to kernel state. */ +2: VM_OFF /* MS: turn off MMU */ + tophys(r1,r1) + lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */ + lwi r4, r1, PTO + PT_R4; + RESTORE_REGS + addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */ + tovirt(r1,r1); +6: +IRQ_return: /* MS: Make global symbol for debugging */ + rtid r14, 0 + nop + +/* + * `Debug' trap + * We enter dbtrap in "BIP" (breakpoint) mode. + * So we exit the breakpoint mode with an 'rtbd' and proceed with the + * original dbtrap. + * however, wait to save state first + */ +C_ENTRY(_debug_exception): + /* BIP bit is set on entry, no interrupts can occur */ + swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) + + swi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* Save r11 */ + set_bip; /*equalize initial state for all possible entries*/ + clear_eip; + enable_irq; + lwi r11, r0, TOPHYS(PER_CPU(KM));/* See if already in kernel mode.*/ + beqi r11, 1f; /* Jump ahead if coming from user */ + /* Kernel-mode state save. */ + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ + tophys(r1,r11); + swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ + lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ + + addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ + swi r3, r1, PTO + PT_R3; + swi r4, r1, PTO + PT_R4; + SAVE_REGS; + + addi r11, r0, 1; /* Was in kernel-mode. */ + swi r11, r1, PTO + PT_MODE; + brid 2f; + nop; /* Fill delay slot */ +1: /* User-mode state save. */ + lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */ + lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ + tophys(r1,r1); + lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ + addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */ + tophys(r1,r1); + + addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ + swi r3, r1, PTO + PT_R3; + swi r4, r1, PTO + PT_R4; + SAVE_REGS; + + swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */ + lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); + swi r11, r1, PTO+PT_R1; /* Store user SP. */ + addi r11, r0, 1; + swi r11, r0, TOPHYS(PER_CPU(KM)); /* Now we're in kernel-mode. */ +2: lwi r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ + /* Save away the syscall number. */ + swi r0, r1, PTO+PT_R0; + tovirt(r1,r1) + + addi r5, r0, SIGTRAP /* send the trap signal */ + add r6, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + addk r7, r0, r0 /* 3rd param zero */ + + set_vms; + la r11, r0, send_sig; + la r15, r0, dbtrap_call; +dbtrap_call: rtbd r11, 0; + nop; + + set_bip; /* Ints masked for state restore*/ + lwi r11, r1, PTO+PT_MODE; + bnei r11, 2f; + + /* Get current task ptr into r11 */ + add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + lwi r11, r11, TS_THREAD_INFO; /* get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_NEED_RESCHED; + beqi r11, 5f; + +/* Call the scheduler before returning from a syscall/trap. */ + + bralid r15, schedule; /* Call scheduler */ + nop; /* delay slot */ + /* XXX Is PT_DTRACE handling needed here? */ + /* XXX m68knommu also checks TASK_STATE & TASK_COUNTER here. */ + + /* Maybe handle a signal */ +5: add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + lwi r11, r11, TS_THREAD_INFO; /* get thread info */ + lwi r11, r11, TI_FLAGS; /* get flags in thread info */ + andi r11, r11, _TIF_SIGPENDING; + beqi r11, 1f; /* Signals to handle, handle them */ + +/* Handle a signal return; Pending signals should be in r18. */ + /* Not all registers are saved by the normal trap/interrupt entry + points (for instance, call-saved registers (because the normal + C-compiler calling sequence in the kernel makes sure they're + preserved), and call-clobbered registers in the case of + traps), but signal handlers may want to examine or change the + complete register state. Here we save anything not saved by + the normal entry sequence, so that it may be safely restored + (in a possibly modified form) after do_signal returns. */ + + la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ + add r6, r0, r0; /* Arg 2: sigset_t *oldset */ + addi r7, r0, 0; /* Arg 3: int in_syscall */ + bralid r15, do_signal; /* Handle any signals */ + nop; + + +/* Finally, return to user state. */ +1: swi r0, r0, PER_CPU(KM); /* Now officially in user state. */ + add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */ + swi r11, r0, PER_CPU(CURRENT_SAVE); /* save current */ + VM_OFF; + tophys(r1,r1); + + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + RESTORE_REGS + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ + + + lwi r1, r1, PT_R1 - PT_SIZE; + /* Restore user stack pointer. */ + bri 6f; + +/* Return to kernel state. */ +2: VM_OFF; + tophys(r1,r1); + lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */ + lwi r4, r1, PTO+PT_R4; + RESTORE_REGS + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ + + tovirt(r1,r1); +6: +DBTRAP_return: /* Make global symbol for debugging */ + rtbd r14, 0; /* Instructions to return from an IRQ */ + nop; + + + +ENTRY(_switch_to) + /* prepare return value */ + addk r3, r0, r31 + + /* save registers in cpu_context */ + /* use r11 and r12, volatile registers, as temp register */ + /* give start of cpu_context for previous process */ + addik r11, r5, TI_CPU_CONTEXT + swi r1, r11, CC_R1 + swi r2, r11, CC_R2 + /* skip volatile registers. + * they are saved on stack when we jumped to _switch_to() */ + /* dedicated registers */ + swi r13, r11, CC_R13 + swi r14, r11, CC_R14 + swi r15, r11, CC_R15 + swi r16, r11, CC_R16 + swi r17, r11, CC_R17 + swi r18, r11, CC_R18 + /* save non-volatile registers */ + swi r19, r11, CC_R19 + swi r20, r11, CC_R20 + swi r21, r11, CC_R21 + swi r22, r11, CC_R22 + swi r23, r11, CC_R23 + swi r24, r11, CC_R24 + swi r25, r11, CC_R25 + swi r26, r11, CC_R26 + swi r27, r11, CC_R27 + swi r28, r11, CC_R28 + swi r29, r11, CC_R29 + swi r30, r11, CC_R30 + /* special purpose registers */ + mfs r12, rmsr + nop + swi r12, r11, CC_MSR + mfs r12, rear + nop + swi r12, r11, CC_EAR + mfs r12, resr + nop + swi r12, r11, CC_ESR + mfs r12, rfsr + nop + swi r12, r11, CC_FSR + + /* update r31, the current */ + lwi r31, r6, TI_TASK/* give me pointer to task which will be next */ + /* stored it to current_save too */ + swi r31, r0, PER_CPU(CURRENT_SAVE) + + /* get new process' cpu context and restore */ + /* give me start where start context of next task */ + addik r11, r6, TI_CPU_CONTEXT + + /* non-volatile registers */ + lwi r30, r11, CC_R30 + lwi r29, r11, CC_R29 + lwi r28, r11, CC_R28 + lwi r27, r11, CC_R27 + lwi r26, r11, CC_R26 + lwi r25, r11, CC_R25 + lwi r24, r11, CC_R24 + lwi r23, r11, CC_R23 + lwi r22, r11, CC_R22 + lwi r21, r11, CC_R21 + lwi r20, r11, CC_R20 + lwi r19, r11, CC_R19 + /* dedicated registers */ + lwi r18, r11, CC_R18 + lwi r17, r11, CC_R17 + lwi r16, r11, CC_R16 + lwi r15, r11, CC_R15 + lwi r14, r11, CC_R14 + lwi r13, r11, CC_R13 + /* skip volatile registers */ + lwi r2, r11, CC_R2 + lwi r1, r11, CC_R1 + + /* special purpose registers */ + lwi r12, r11, CC_FSR + mts rfsr, r12 + nop + lwi r12, r11, CC_MSR + mts rmsr, r12 + nop + + rtsd r15, 8 + nop + +ENTRY(_reset) + brai 0x70; /* Jump back to FS-boot */ + +ENTRY(_break) + mfs r5, rmsr + nop + swi r5, r0, 0x250 + TOPHYS(r0_ram) + mfs r5, resr + nop + swi r5, r0, 0x254 + TOPHYS(r0_ram) + bri 0 + + /* These are compiled and loaded into high memory, then + * copied into place in mach_early_setup */ + .section .init.ivt, "ax" + .org 0x0 + /* this is very important - here is the reset vector */ + /* in current MMU branch you don't care what is here - it is + * used from bootloader site - but this is correct for FS-BOOT */ + brai 0x70 + nop + brai TOPHYS(_user_exception); /* syscall handler */ + brai TOPHYS(_interrupt); /* Interrupt handler */ + brai TOPHYS(_break); /* nmi trap handler */ + brai TOPHYS(_hw_exception_handler); /* HW exception handler */ + + .org 0x60 + brai TOPHYS(_debug_exception); /* debug trap handler*/ + +.section .rodata,"a" +#include "syscall_table.S" + +syscall_table_size=(.-sys_call_table) + |
