diff options
Diffstat (limited to 'arch/microblaze/kernel/entry.S')
| -rw-r--r-- | arch/microblaze/kernel/entry.S | 46 |
1 files changed, 39 insertions, 7 deletions
diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S index 819238b8a42..41c30cdb270 100644 --- a/arch/microblaze/kernel/entry.S +++ b/arch/microblaze/kernel/entry.S @@ -287,25 +287,44 @@ * are masked. This is nice, means we don't have to CLI before state save */ C_ENTRY(_user_exception): - addi r14, r14, 4 /* return address is 4 byte after call */ swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */ + addi r14, r14, 4 /* return address is 4 byte after call */ + + mfs r1, rmsr + nop + andi r1, r1, MSR_UMS + bnei r1, 1f + +/* Kernel-mode state save - kernel execve */ + 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. */ + SAVE_REGS + swi r1, r1, PTO + PT_MODE; /* pt_regs -> kernel mode */ + brid 2f; + nop; /* Fill delay slot */ + +/* User-mode state save. */ +1: 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 */ - /* MS these three instructions can be added to one */ - /* addik r1, r1, THREAD_SIZE; */ - /* tophys(r1,r1); */ - /* addik r1, r1, -STATE_SAVE_SIZE; */ - addik r1, r1, THREAD_SIZE + CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - STATE_SAVE_SIZE; +/* 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_R3 swi r0, r1, PTO + PT_R4 + 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. */ clear_ums; - lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); +2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* Save away the syscall number. */ swi r12, r1, PTO+PT_R0; tovirt(r1,r1) @@ -375,6 +394,9 @@ C_ENTRY(ret_from_trap): 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. */ @@ -417,6 +439,16 @@ C_ENTRY(ret_from_trap): 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: set_bip; /* Ints masked for state restore */ + 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; |