diff options
Diffstat (limited to 'arch/microblaze/kernel/entry.S')
| -rw-r--r-- | arch/microblaze/kernel/entry.S | 106 |
1 files changed, 57 insertions, 49 deletions
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S index 5a5cb5842938..304882e56459 100644 --- a/arch/microblaze/kernel/entry.S +++ b/arch/microblaze/kernel/entry.S @@ -745,11 +745,8 @@ IRQ_return: /* MS: Make global symbol for debugging */ 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 + * Debug trap for KGDB. Enter to _debug_exception by brki r16, 0x18 + * and call handling function with saved pt_regs */ C_ENTRY(_debug_exception): /* BIP bit is set on entry, no interrupts can occur */ @@ -759,18 +756,44 @@ C_ENTRY(_debug_exception): nop andi r1, r1, MSR_UMS bnei r1, 1f - /* Kernel-mode state save. */ +/* MS: Kernel-mode state save - kgdb */ lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/ - tophys(r1,r1); - addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */ + /* BIP bit is set on entry, no interrupts can occur */ + addik r1, r1, CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - STATE_SAVE_SIZE; SAVE_REGS; + /* save all regs to pt_reg structure */ + swi r0, r1, PTO+PT_R0; /* R0 must be saved too */ + swi r14, r1, PTO+PT_R14 /* rewrite saved R14 value */ + swi r16, r1, PTO+PT_R16 + swi r16, r1, PTO+PT_PC; /* PC and r16 are the same */ + swi r17, r1, PTO+PT_R17 + /* save special purpose registers to pt_regs */ + mfs r11, rear; + swi r11, r1, PTO+PT_EAR; + mfs r11, resr; + swi r11, r1, PTO+PT_ESR; + mfs r11, rfsr; + swi r11, r1, PTO+PT_FSR; + + /* stack pointer is in physical address at it is decrease + * by STATE_SAVE_SIZE but we need to get correct R1 value */ + addik r11, r1, CONFIG_KERNEL_START - CONFIG_KERNEL_BASE_ADDR + STATE_SAVE_SIZE; + swi r11, r1, PTO+PT_R1 + /* MS: r31 - current pointer isn't changed */ + tovirt(r1,r1) +#ifdef CONFIG_KGDB + addi r5, r1, PTO /* pass pt_reg address as the first arg */ + la r15, r0, dbtrap_call; /* return address */ + rtbd r0, microblaze_kgdb_break + nop; +#endif + /* MS: Place handler for brki from kernel space if KGDB is OFF. + * It is very unlikely that another brki instruction is called. */ + bri 0 - swi r1, r1, PTO + PT_MODE; - brid 2f; - nop; /* Fill delay slot */ -1: /* User-mode state save. */ - lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */ +/* MS: User-mode state save - gdb */ +1: 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 */ @@ -781,36 +804,32 @@ C_ENTRY(_debug_exception): swi r17, r1, PTO+PT_R17; swi r16, r1, PTO+PT_R16; swi r16, r1, PTO+PT_PC; /* Save LP */ - 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)); + lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); tovirt(r1,r1) - set_vms; addik r5, r1, PTO; addik r15, r0, dbtrap_call; -dbtrap_call: /* return point for kernel/user entry */ +dbtrap_call: /* Return point for kernel/user entry + 8 because of rtsd r15, 8 */ rtbd r0, sw_exception nop - set_bip; /* Ints masked for state restore*/ + /* MS: The first instruction for the second part of the gdb/kgdb */ + set_bip; /* Ints masked for state restore */ lwi r11, r1, PTO + PT_MODE; bnei r11, 2f; - +/* MS: Return to user space - gdb */ /* 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. */ - + /* 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 */ @@ -818,48 +837,37 @@ dbtrap_call: /* return point for kernel/user entry */ 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. */ - addik 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 */ +1: swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */ VM_OFF; tophys(r1,r1); - + /* MS: Restore all regs */ RESTORE_REGS lwi r17, r1, PTO+PT_R17; lwi r16, r1, PTO+PT_R16; - addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ - - - lwi r1, r1, PT_R1 - PT_SIZE; - /* Restore user stack pointer. */ - bri 6f; + addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space */ + lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer */ +DBTRAP_return_user: /* MS: Make global symbol for debugging */ + rtbd r16, 0; /* MS: Instructions to return from a debug trap */ + nop; -/* Return to kernel state. */ +/* MS: Return to kernel state - kgdb */ 2: VM_OFF; tophys(r1,r1); + /* MS: Restore all regs */ RESTORE_REGS - addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */ - + lwi r14, r1, PTO+PT_R14; + lwi r16, r1, PTO+PT_PC; + lwi r17, r1, PTO+PT_R17; + addik r1, r1, STATE_SAVE_SIZE; /* MS: Clean up stack space */ tovirt(r1,r1); -6: -DBTRAP_return: /* Make global symbol for debugging */ - rtbd r16, 0; /* Instructions to return from an IRQ */ +DBTRAP_return_kernel: /* MS: Make global symbol for debugging */ + rtbd r16, 0; /* MS: Instructions to return from a debug trap */ nop; |