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authorMichal Simek <monstr@monstr.eu>2010-10-22 15:48:58 +1000
committerMichal Simek <monstr@monstr.eu>2010-11-18 13:13:52 +0100
commit9da6345885e4f33437d74314f9db592da157d65d (patch)
tree23c79db4cf878eb1ac469721a5c83efbb6b76ac4
parent8cb473da3fe634fb30c1e5be8840b00f499103a8 (diff)
Revert "microblaze: Simplify syscall rutine"
This reverts commit 0e41c90908881a1b8205c66a66becec7d8d4eb4a. Break jffs2 rootfs because the patch removes syscall calling from kernel space. Signed-off-by: Michal Simek <monstr@monstr.eu>
-rw-r--r--arch/microblaze/kernel/entry.S46
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;