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Revert "microblaze: Simplify syscall rutine"

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This reverts commit 0e41c90908.

Break jffs2 rootfs because the patch removes syscall calling
from kernel space.

Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
Michal Simek 2010-10-22 15:48:58 +10:00
parent 8cb473da3f
commit 9da6345885
1 changed files with 39 additions and 7 deletions
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46
arch/microblaze/kernel/entry.S
View File

@ -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;