/* * Low-level system-call handling, trap handlers and context-switching * * Copyright (C) 2008-2009 Michal Simek * Copyright (C) 2008-2009 PetaLogix * Copyright (C) 2003 John Williams * Copyright (C) 2001,2002 NEC Corporation * Copyright (C) 2001,2002 Miles Bader * * 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 * Heavily modified by John Williams for Microblaze */ #include #include #include #include #include #include #include #include #include #include #include #include #undef DEBUG /* 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 | 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; \ nop; \ 2: /* turn off virtual protected mode save and user mode save*/ #define VM_OFF \ clear_vms_ums; \ rted r0, TOPHYS(1f); \ nop; \ 1: #define SAVE_REGS \ swi r2, r1, PTO+PT_R2; /* Save SDA */ \ swi r3, r1, PTO+PT_R3; \ swi r4, r1, PTO+PT_R4; \ 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 r3, r1, PTO+PT_R3; \ lwi r4, r1, PTO+PT_R4; \ 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 */ mfs r11, rmsr nop andi r11, r11, MSR_UMS bnei r11, 1f /* Kernel-mode state save - kernel execve */ 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. */ 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* Save away the syscall number. */ swi r12, r1, PTO+PT_R0; tovirt(r1,r1) /* 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] */ # Step into virtual mode. set_vms; addik r11, r0, 3f rtid r11, 0 nop 3: lwi r11, CURRENT_TASK, TS_THREAD_INFO /* get thread info */ lwi r11, r11, TI_FLAGS /* get flags in thread info */ andi r11, r11, _TIF_WORK_SYSCALL_MASK beqi r11, 4f addik r3, r0, -ENOSYS swi r3, r1, PTO + PT_R3 brlid r15, do_syscall_trace_enter addik r5, r1, PTO + PT_R0 # do_syscall_trace_enter returns the new syscall nr. addk r12, r0, r3 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; 4: /* 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 r11,5f; /* 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; #ifdef DEBUG /* Trac syscalls and stored them to r0_ram */ lwi r3, r12, 0x400 + r0_ram addi r3, r3, 1 swi r3, r12, 0x400 + r0_ram #endif # Find and jump into the syscall handler. lwi r12, r12, sys_call_table /* where the trap should return need -8 to adjust for rtsd r15, 8 */ la r15, r0, ret_from_trap-8 bra r12 /* The syscall number is invalid, return an error. */ 5: 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*/ swi r3, r1, PTO + PT_R3 swi r4, r1, PTO + PT_R4 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. */ /* FIXME: Restructure all these flag checks. */ lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ lwi r11, r11, TI_FLAGS; /* get flags in thread info */ andi r11, r11, _TIF_WORK_SYSCALL_MASK beqi r11, 1f brlid r15, do_syscall_trace_leave addik r5, r1, PTO + PT_R0 1: /* We're returning to user mode, so check for various conditions that * trigger rescheduling. */ /* get thread info from current task */ lwi r11, CURRENT_TASK, TS_THREAD_INFO; lwi r11, r11, TI_FLAGS; /* get flags in thread info */ andi r11, r11, _TIF_NEED_RESCHED; beqi r11, 5f; bralid r15, schedule; /* Call scheduler */ nop; /* delay slot */ /* Maybe handle a signal */ 5: /* get thread info from current task*/ lwi r11, CURRENT_TASK, TS_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 */ la r5, r1, PTO; /* Arg 1: struct pt_regs *regs */ addi r7, r0, 1; /* Arg 3: int in_syscall */ bralid r15, do_signal; /* Handle any signals */ add r6, r0, r0; /* Arg 2: sigset_t *oldset */ /* Finally, return to user state. */ 1: swi CURRENT_TASK, 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: add r10, r0, r9; /* Arg 6: (child_tidptr) */ add r9, r0, r8; /* Arg 5: (parent_tidptr) */ add r8, r0, r7; /* Arg 4: (stack_size) */ la r7, r1, PTO; /* Arg 3: pt_regs */ 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_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.*/ \ mfs r11, rmsr; \ nop; \ andi r11, r11, MSR_UMS; \ bnei r11, 1f; \ /* 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. */\ 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. */\ 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. */ \ 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); \ /* 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 mts rfsr, r0; /* Clear sticky 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. */ lwi r11, CURRENT_TASK, 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: lwi r11, CURRENT_TASK, 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 */ addi r7, r0, 0; /* Arg 3: int in_syscall */ bralid r15, do_signal; /* Handle any signals */ add r6, r0, r0; /* Arg 2: sigset_t *oldset */ /* Finally, return to user state. */ 1: swi CURRENT_TASK, 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: 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. */ mfs r11, rmsr nop andi r11, r11, MSR_UMS bnei r11, 1f /* 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; 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; SAVE_REGS /* calculate mode */ swi r0, r1, PTO + PT_MODE; lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); swi r11, r1, PTO+PT_R1; 2: lwi CURRENT_TASK, 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; lwi r11, CURRENT_TASK, 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: lwi r11, CURRENT_TASK, 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 CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); VM_OFF; tophys(r1,r1); 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: #ifdef CONFIG_PREEMPT lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* MS: get preempt_count from thread info */ lwi r5, r11, TI_PREEMPT_COUNT; bgti r5, restore; lwi r5, r11, TI_FLAGS; /* get flags in thread info */ andi r5, r5, _TIF_NEED_RESCHED; beqi r5, restore /* if zero jump over */ preempt: /* interrupts are off that's why I am calling preempt_chedule_irq */ bralid r15, preempt_schedule_irq nop lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */ lwi r5, r11, TI_FLAGS; /* get flags in thread info */ andi r5, r5, _TIF_NEED_RESCHED; bnei r5, preempt /* if non zero jump to resched */ restore: #endif VM_OFF /* MS: turn off MMU */ tophys(r1,r1) 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; mfs r11, rmsr nop andi r11, r11, MSR_UMS bnei r11, 1f /* 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; 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. */ 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. */ 2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* 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 */ lwi r11, CURRENT_TASK, 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: lwi r11, CURRENT_TASK, 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 */ addi r7, r0, 0; /* Arg 3: int in_syscall */ bralid r15, do_signal; /* Handle any signals */ add r6, r0, r0; /* Arg 2: sigset_t *oldset */ /* Finally, return to user state. */ 1: swi CURRENT_TASK, 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: 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, CURRENT_TASK /* 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-give me pointer to task which will be next */ lwi CURRENT_TASK, r6, TI_TASK /* stored it to current_save too */ swi CURRENT_TASK, 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) type_SYSCALL: .ascii "SYSCALL\0" type_IRQ: .ascii "IRQ\0" type_IRQ_PREEMPT: .ascii "IRQ (PREEMPTED)\0" type_SYSCALL_PREEMPT: .ascii " SYSCALL (PREEMPTED)\0" /* * Trap decoding for stack unwinder * Tuples are (start addr, end addr, string) * If return address lies on [start addr, end addr], * unwinder displays 'string' */ .align 4 .global microblaze_trap_handlers microblaze_trap_handlers: /* Exact matches come first */ .word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL .word ret_from_irq ; .word ret_from_irq ; .word type_IRQ /* Fuzzy matches go here */ .word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT .word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT /* End of table */ .word 0 ; .word 0 ; .word 0