Skip to content

Commit

Permalink
microblaze: Save and restore r3/r4 in SAVE/RESTORE_REGS macros
Browse files Browse the repository at this point in the history 
Save and restore R3/R4 registers in macros. This change
help to cleanup entry.S.

In ret_from_trap function we are saving returning value from
syscall to pt_regs on stack that's why we don't need to save and
restore these values before kernel functions (schedule, do_signal).

Signed-off-by: Michal Simek <monstr@monstr.eu>
  • Loading branch information
Michal Simek committed Aug 4, 2010
1 parent a4a94db commit 36f6095
Showing 1 changed file with 8 additions and 40 deletions.
48 changes: 8 additions & 40 deletions arch/microblaze/kernel/entry.S
View file
Original file line number Diff line number Diff line change
Expand Up @@ -194,6 +194,8 @@

#define SAVE_REGS \
swi r2, r1, PTO+PT_R2; /* Save SDA */ \
swi r3, r1, PTO+PT_R3; \
swi r4, r1, PTO+PT_R4; \
swi r5, r1, PTO+PT_R5; \
swi r6, r1, PTO+PT_R6; \
swi r7, r1, PTO+PT_R7; \
Expand Down Expand Up @@ -228,6 +230,8 @@
mts rmsr , r11; \
nop; \
lwi r2, r1, PTO+PT_R2; /* restore SDA */ \
lwi r3, r1, PTO+PT_R3; \
lwi r4, r1, PTO+PT_R4; \
lwi r5, r1, PTO+PT_R5; \
lwi r6, r1, PTO+PT_R6; \
lwi r7, r1, PTO+PT_R7; \
Expand Down Expand Up @@ -379,13 +383,12 @@ C_ENTRY(_user_exception):
/* We re-enable BIP bit before state restore */
C_ENTRY(ret_from_trap):
set_bip; /* Ints masked for state restore*/
lwi r11, r1, PTO+PT_MODE;
/* See if returning to kernel mode, if so, skip resched &c. */
bnei r11, 2f;

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. */
Expand Down Expand Up @@ -422,9 +425,6 @@ C_ENTRY(ret_from_trap):

/* Finally, return to user state. */
1:
lwi r3, r1, PTO + PT_R3; /* restore syscall result */
lwi r4, r1, PTO + PT_R4;

swi r0, r0, PER_CPU(KM); /* Now officially in user state. */
swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
VM_OFF;
Expand Down Expand Up @@ -522,10 +522,6 @@ C_ENTRY(sys_rt_sigreturn_wrapper):
swi r11, r1, (PT_R1-PT_SIZE); /* Save original SP. */ \
lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */\
addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\
/* store return registers separately because \
* this macros is use for others exceptions */ \
swi r3, r1, PTO + PT_R3; \
swi r4, r1, PTO + PT_R4; \
SAVE_REGS \
/* PC, before IRQ/trap - this is one instruction above */ \
swi r17, r1, PTO+PT_PC; \
Expand All @@ -543,10 +539,6 @@ C_ENTRY(sys_rt_sigreturn_wrapper):
tophys(r1,r1); \
\
addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */\
/* store return registers separately because this macros \
* is use for others exceptions */ \
swi r3, r1, PTO + PT_R3; \
swi r4, r1, PTO + PT_R4; \
SAVE_REGS \
/* PC, before IRQ/trap - this is one instruction above FIXME*/ \
swi r17, r1, PTO+PT_PC; \
Expand Down Expand Up @@ -689,9 +681,7 @@ C_ENTRY(ret_from_exc):
* 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.
* store return registers separately because this macros is use
* for others exceptions */
* (in a possibly modified form) after do_signal returns. */
la 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 */
Expand All @@ -703,8 +693,6 @@ C_ENTRY(ret_from_exc):
VM_OFF;
tophys(r1,r1);

lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
lwi r4, r1, PTO+PT_R4;
RESTORE_REGS;
addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */

Expand All @@ -713,8 +701,6 @@ C_ENTRY(ret_from_exc):
/* Return to kernel state. */
2: VM_OFF;
tophys(r1,r1);
lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
lwi r4, r1, PTO+PT_R4;
RESTORE_REGS;
addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */

Expand Down Expand Up @@ -753,10 +739,6 @@ C_ENTRY(_interrupt):
/* save registers */
/* MS: Make room on the stack -> activation record */
addik r1, r1, -STATE_SAVE_SIZE;
/* MS: store return registers separately because
* this macros is use for others exceptions */
swi r3, r1, PTO + PT_R3;
swi r4, r1, PTO + PT_R4;
SAVE_REGS
/* MS: store mode */
addi r11, r0, 1; /* MS: Was in kernel-mode. */
Expand All @@ -776,8 +758,6 @@ C_ENTRY(_interrupt):
tophys(r1,r1);
/* save registers */
addik r1, r1, -STATE_SAVE_SIZE;
swi r3, r1, PTO+PT_R3;
swi r4, r1, PTO+PT_R4;
SAVE_REGS
/* calculate mode */
swi r0, r1, PTO + PT_MODE;
Expand Down Expand Up @@ -829,8 +809,6 @@ no_intr_resched:
swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE);
VM_OFF;
tophys(r1,r1);
lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */
lwi r4, r1, PTO + PT_R4;
RESTORE_REGS
addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
lwi r1, r1, PT_R1 - PT_SIZE;
Expand Down Expand Up @@ -859,8 +837,6 @@ restore:
#endif
VM_OFF /* MS: turn off MMU */
tophys(r1,r1)
lwi r3, r1, PTO + PT_R3; /* MS: restore saved r3, r4 registers */
lwi r4, r1, PTO + PT_R4;
RESTORE_REGS
addik r1, r1, STATE_SAVE_SIZE /* MS: Clean up stack space. */
tovirt(r1,r1);
Expand Down Expand Up @@ -893,8 +869,6 @@ C_ENTRY(_debug_exception):
lwi r11, r0, TOPHYS(r0_ram + PTO + PT_R11); /* restore r11 */

addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
swi r3, r1, PTO + PT_R3;
swi r4, r1, PTO + PT_R4;
SAVE_REGS;

addi r11, r0, 1; /* Was in kernel-mode. */
Expand All @@ -910,8 +884,6 @@ C_ENTRY(_debug_exception):
tophys(r1,r1);

addik r1, r1, -STATE_SAVE_SIZE; /* Make room on the stack. */
swi r3, r1, PTO + PT_R3;
swi r4, r1, PTO + PT_R4;
SAVE_REGS;

swi r0, r1, PTO+PT_MODE; /* Was in user-mode. */
Expand Down Expand Up @@ -979,8 +951,6 @@ dbtrap_call: rtbd r11, 0;
VM_OFF;
tophys(r1,r1);

lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
lwi r4, r1, PTO+PT_R4;
RESTORE_REGS
addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */

Expand All @@ -992,8 +962,6 @@ dbtrap_call: rtbd r11, 0;
/* Return to kernel state. */
2: VM_OFF;
tophys(r1,r1);
lwi r3, r1, PTO+PT_R3; /* restore saved r3, r4 registers */
lwi r4, r1, PTO+PT_R4;
RESTORE_REGS
addik r1, r1, STATE_SAVE_SIZE /* Clean up stack space. */

Expand Down

0 comments on commit 36f6095

Please sign in to comment.