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microblaze: Simplify syscall rutine

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Syscall can be called only from userspace that's why
we don't need to check which space kernel come from.

Kernel syscall calling is not check and shouldn't come
throught this part of code.

Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
Michal Simek 2010-06-22 21:11:49 +02:00
parent 0a6b08fda6
commit 0e41c90908
1 changed files with 7 additions and 39 deletions
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46
arch/microblaze/kernel/entry.S
View File

@ -318,42 +318,23 @@
* 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 r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
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 */
/* 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. */
/* 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;
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. */
clear_ums;
2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
/* Save away the syscall number. */
swi r12, r1, PTO+PT_R0;
tovirt(r1,r1)
@ -423,9 +404,6 @@ 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. */
@ -468,16 +446,6 @@ 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;