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ARC: Increase readability of entry handlers

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* use artificial PUSH/POP contructs for CORE Reg save/restore to stack
* use artificial PUSHAX/POPAX contructs for Auxiliary Space regs
* macro'ize multiple copies of callee-reg-save/restore (SAVE_R13_TO_R24)
* use BIC insn for inverse-and operation

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2013-05-28 13:24:43 +05:30
parent 16f9afe651
commit 3ebedbb2fd
2 changed files with 188 additions and 214 deletions
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398
arch/arc/include/asm/entry.h
View File

@ -50,150 +50,155 @@
* Eff Addr for load = [reg2] * Eff Addr for load = [reg2]
*/ */
/*-------------------------------------------------------------- .macro PUSH reg
* Save caller saved registers (scratch registers) ( r0 - r12 ) st.a \reg, [sp, -4]
* Registers are pushed / popped in the order defined in struct ptregs .endm
* in asm/ptrace.h
*-------------------------------------------------------------*/ .macro PUSHAX aux
.macro SAVE_CALLER_SAVED lr r9, [\aux]
st.a r0, [sp, -4] PUSH r9
st.a r1, [sp, -4] .endm
st.a r2, [sp, -4]
st.a r3, [sp, -4] .macro POP reg
st.a r4, [sp, -4] ld.ab \reg, [sp, 4]
st.a r5, [sp, -4] .endm
st.a r6, [sp, -4]
st.a r7, [sp, -4] .macro POPAX aux
st.a r8, [sp, -4] POP r9
st.a r9, [sp, -4] sr r9, [\aux]
st.a r10, [sp, -4]
st.a r11, [sp, -4]
st.a r12, [sp, -4]
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
* Restore caller saved registers (scratch registers) * Helpers to save/restore Scratch Regs:
* used by Interrupt/Exception Prologue/Epilogue
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro RESTORE_CALLER_SAVED .macro SAVE_R0_TO_R12
ld.ab r12, [sp, 4] PUSH r0
ld.ab r11, [sp, 4] PUSH r1
ld.ab r10, [sp, 4] PUSH r2
ld.ab r9, [sp, 4] PUSH r3
ld.ab r8, [sp, 4] PUSH r4
ld.ab r7, [sp, 4] PUSH r5
ld.ab r6, [sp, 4] PUSH r6
ld.ab r5, [sp, 4] PUSH r7
ld.ab r4, [sp, 4] PUSH r8
ld.ab r3, [sp, 4] PUSH r9
ld.ab r2, [sp, 4] PUSH r10
ld.ab r1, [sp, 4] PUSH r11
ld.ab r0, [sp, 4] PUSH r12
.endm
.macro RESTORE_R12_TO_R0
POP r12
POP r11
POP r10
POP r9
POP r8
POP r7
POP r6
POP r5
POP r4
POP r3
POP r2
POP r1
POP r0
.endm
/*--------------------------------------------------------------
* Helpers to save/restore callee-saved regs:
* used by several macros below
*-------------------------------------------------------------*/
.macro SAVE_R13_TO_R24
PUSH r13
PUSH r14
PUSH r15
PUSH r16
PUSH r17
PUSH r18
PUSH r19
PUSH r20
PUSH r21
PUSH r22
PUSH r23
PUSH r24
.endm
.macro RESTORE_R24_TO_R13
POP r24
POP r23
POP r22
POP r21
POP r20
POP r19
POP r18
POP r17
POP r16
POP r15
POP r14
POP r13
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
* Save callee saved registers (non scratch registers) ( r13 - r25 ) * Collect User Mode callee regs as struct callee_regs - needed by
* on kernel stack. * fork/do_signal/unaligned-access-emulation.
* User mode callee regs need to be saved in case of * (By default only scratch regs are saved on entry to kernel)
* -fork and friends for replicating from parent to child *
* -before going into do_signal( ) for ptrace/core-dump * Special handling for r25 if used for caching Task Pointer.
* Special case handling is required for r25 in case it is used by kernel * It would have been saved in task->thread.user_r25 already, but to keep
* for caching task ptr. Low level exception/ISR save user mode r25 * the interface same it is copied into regular r25 placeholder in
* into task->thread.user_r25. So it needs to be retrieved from there and * struct callee_regs.
* saved into kernel stack with rest of callee reg-file
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro SAVE_CALLEE_SAVED_USER .macro SAVE_CALLEE_SAVED_USER
st.a r13, [sp, -4]
st.a r14, [sp, -4] SAVE_R13_TO_R24
st.a r15, [sp, -4]
st.a r16, [sp, -4]
st.a r17, [sp, -4]
st.a r18, [sp, -4]
st.a r19, [sp, -4]
st.a r20, [sp, -4]
st.a r21, [sp, -4]
st.a r22, [sp, -4]
st.a r23, [sp, -4]
st.a r24, [sp, -4]
#ifdef CONFIG_ARC_CURR_IN_REG #ifdef CONFIG_ARC_CURR_IN_REG
; Retrieve orig r25 and save it on stack ; Retrieve orig r25 and save it on stack
ld r12, [r25, TASK_THREAD + THREAD_USER_R25] ld r12, [r25, TASK_THREAD + THREAD_USER_R25]
st.a r12, [sp, -4] st.a r12, [sp, -4]
#else #else
st.a r25, [sp, -4] PUSH r25
#endif #endif
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
* Save callee saved registers (non scratch registers) ( r13 - r25 ) * Save kernel Mode callee regs at the time of Contect Switch.
* kernel mode callee regs needed to be saved in case of context switch *
* If r25 is used for caching task pointer then that need not be saved * Special handling for r25 if used for caching Task Pointer.
* as it can be re-created from current task global * Kernel simply skips saving it since it will be loaded with
* incoming task pointer anyways
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro SAVE_CALLEE_SAVED_KERNEL .macro SAVE_CALLEE_SAVED_KERNEL
st.a r13, [sp, -4]
st.a r14, [sp, -4] SAVE_R13_TO_R24
st.a r15, [sp, -4]
st.a r16, [sp, -4]
st.a r17, [sp, -4]
st.a r18, [sp, -4]
st.a r19, [sp, -4]
st.a r20, [sp, -4]
st.a r21, [sp, -4]
st.a r22, [sp, -4]
st.a r23, [sp, -4]
st.a r24, [sp, -4]
#ifdef CONFIG_ARC_CURR_IN_REG #ifdef CONFIG_ARC_CURR_IN_REG
sub sp, sp, 4 sub sp, sp, 4
#else #else
st.a r25, [sp, -4] PUSH r25
#endif #endif
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
* RESTORE_CALLEE_SAVED_KERNEL: * Opposite of SAVE_CALLEE_SAVED_KERNEL
* Loads callee (non scratch) Reg File by popping from Kernel mode stack.
* This is reverse of SAVE_CALLEE_SAVED,
*
* NOTE:
* Ideally this shd only be called in switch_to for loading
* switched-IN task's CALLEE Reg File.
* For all other cases RESTORE_CALLEE_SAVED_FAST must be used
* which simply pops the stack w/o touching regs.
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro RESTORE_CALLEE_SAVED_KERNEL .macro RESTORE_CALLEE_SAVED_KERNEL
#ifdef CONFIG_ARC_CURR_IN_REG #ifdef CONFIG_ARC_CURR_IN_REG
add sp, sp, 4 /* skip usual r25 placeholder */ add sp, sp, 4 /* skip usual r25 placeholder */
#else #else
ld.ab r25, [sp, 4] POP r25
#endif #endif
ld.ab r24, [sp, 4] RESTORE_R24_TO_R13
ld.ab r23, [sp, 4]
ld.ab r22, [sp, 4]
ld.ab r21, [sp, 4]
ld.ab r20, [sp, 4]
ld.ab r19, [sp, 4]
ld.ab r18, [sp, 4]
ld.ab r17, [sp, 4]
ld.ab r16, [sp, 4]
ld.ab r15, [sp, 4]
ld.ab r14, [sp, 4]
ld.ab r13, [sp, 4]
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
* RESTORE_CALLEE_SAVED_USER: * Opposite of SAVE_CALLEE_SAVED_USER
* This is called after do_signal where tracer might have changed callee regs *
* thus we need to restore the reg file. * ptrace tracer or unaligned-access fixup might have changed a user mode
* Special case handling is required for r25 in case it is used by kernel * callee reg which is saved back to usual r25 storage location
* for caching task ptr. Ptrace would have modified on-kernel-stack value of
* r25, which needs to be shoved back into task->thread.user_r25 where from
* Low level exception/ISR return code will retrieve to populate with rest of
* callee reg-file.
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro RESTORE_CALLEE_SAVED_USER .macro RESTORE_CALLEE_SAVED_USER
@ -201,21 +206,9 @@
ld.ab r12, [sp, 4] ld.ab r12, [sp, 4]
st r12, [r25, TASK_THREAD + THREAD_USER_R25] st r12, [r25, TASK_THREAD + THREAD_USER_R25]
#else #else
ld.ab r25, [sp, 4] POP r25
#endif #endif
RESTORE_R24_TO_R13
ld.ab r24, [sp, 4]
ld.ab r23, [sp, 4]
ld.ab r22, [sp, 4]
ld.ab r21, [sp, 4]
ld.ab r20, [sp, 4]
ld.ab r19, [sp, 4]
ld.ab r18, [sp, 4]
ld.ab r17, [sp, 4]
ld.ab r16, [sp, 4]
ld.ab r15, [sp, 4]
ld.ab r14, [sp, 4]
ld.ab r13, [sp, 4]
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
@ -357,7 +350,7 @@
* @reg [OUT] &thread_info of "current" * @reg [OUT] &thread_info of "current"
*/ */
.macro GET_CURR_THR_INFO_FROM_SP reg .macro GET_CURR_THR_INFO_FROM_SP reg
and \reg, sp, ~(THREAD_SIZE - 1) bic \reg, sp, (THREAD_SIZE - 1)
.endm .endm
/* /*
@ -409,21 +402,16 @@
/* Restore r9 used to code the early prologue */ /* Restore r9 used to code the early prologue */
EXCPN_PROLOG_RESTORE_REG r9 EXCPN_PROLOG_RESTORE_REG r9
SAVE_CALLER_SAVED SAVE_R0_TO_R12
st.a r26, [sp, -4] /* gp */ PUSH gp
st.a fp, [sp, -4] PUSH fp
st.a blink, [sp, -4] PUSH blink
lr r9, [eret] PUSHAX eret
st.a r9, [sp, -4] PUSHAX erstatus
lr r9, [erstatus] PUSH lp_count
st.a r9, [sp, -4] PUSHAX lp_end
st.a lp_count, [sp, -4] PUSHAX lp_start
lr r9, [lp_end] PUSHAX erbta
st.a r9, [sp, -4]
lr r9, [lp_start]
st.a r9, [sp, -4]
lr r9, [erbta]
st.a r9, [sp, -4]
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
@ -463,22 +451,19 @@
* by hardware and that is not good. * by hardware and that is not good.
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro RESTORE_ALL_SYS .macro RESTORE_ALL_SYS
ld.ab r9, [sp, 4] POPAX erbta
sr r9, [erbta] POPAX lp_start
ld.ab r9, [sp, 4] POPAX lp_end
sr r9, [lp_start]
ld.ab r9, [sp, 4] POP r9
sr r9, [lp_end] mov lp_count, r9 ;LD to lp_count is not allowed
ld.ab r9, [sp, 4]
mov lp_count, r9 POPAX erstatus
ld.ab r9, [sp, 4] POPAX eret
sr r9, [erstatus] POP blink
ld.ab r9, [sp, 4] POP fp
sr r9, [eret] POP gp
ld.ab blink, [sp, 4] RESTORE_R12_TO_R0
ld.ab fp, [sp, 4]
ld.ab r26, [sp, 4] /* gp */
RESTORE_CALLER_SAVED
ld sp, [sp] /* restore original sp */ ld sp, [sp] /* restore original sp */
/* orig_r0 and orig_r8 skipped automatically */ /* orig_r0 and orig_r8 skipped automatically */
@ -490,9 +475,7 @@
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro SAVE_ALL_INT1 .macro SAVE_ALL_INT1
/* restore original r9 , saved in int1_saved_reg /* restore original r9 to be saved as part of reg-file */
* It will be saved on stack in macro: SAVE_CALLER_SAVED
*/
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
lr r9, [ARC_REG_SCRATCH_DATA0] lr r9, [ARC_REG_SCRATCH_DATA0]
#else #else
@ -502,20 +485,17 @@
/* now we are ready to save the remaining context :) */ /* now we are ready to save the remaining context :) */
st orig_r8_IS_IRQ1, [sp, 8] /* Event Type */ st orig_r8_IS_IRQ1, [sp, 8] /* Event Type */
st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ st 0, [sp, 4] /* orig_r0 , N/A for IRQ */
SAVE_CALLER_SAVED
st.a r26, [sp, -4] /* gp */ SAVE_R0_TO_R12
st.a fp, [sp, -4] PUSH gp
st.a blink, [sp, -4] PUSH fp
st.a ilink1, [sp, -4] PUSH blink
lr r9, [status32_l1] PUSH ilink1
st.a r9, [sp, -4] PUSHAX status32_l1
st.a lp_count, [sp, -4] PUSH lp_count
lr r9, [lp_end] PUSHAX lp_end
st.a r9, [sp, -4] PUSHAX lp_start
lr r9, [lp_start] PUSHAX bta_l1
st.a r9, [sp, -4]
lr r9, [bta_l1]
st.a r9, [sp, -4]
.endm .endm
.macro SAVE_ALL_INT2 .macro SAVE_ALL_INT2
@ -530,20 +510,17 @@
/* now we are ready to save the remaining context :) */ /* now we are ready to save the remaining context :) */
st orig_r8_IS_IRQ2, [sp, 8] /* Event Type */ st orig_r8_IS_IRQ2, [sp, 8] /* Event Type */
st 0, [sp, 4] /* orig_r0 , N/A for IRQ */ st 0, [sp, 4] /* orig_r0 , N/A for IRQ */
SAVE_CALLER_SAVED
st.a r26, [sp, -4] /* gp */ SAVE_R0_TO_R12
st.a fp, [sp, -4] PUSH gp
st.a blink, [sp, -4] PUSH fp
st.a ilink2, [sp, -4] PUSH blink
lr r9, [status32_l2] PUSH ilink2
st.a r9, [sp, -4] PUSHAX status32_l2
st.a lp_count, [sp, -4] PUSH lp_count
lr r9, [lp_end] PUSHAX lp_end
st.a r9, [sp, -4] PUSHAX lp_start
lr r9, [lp_start] PUSHAX bta_l2
st.a r9, [sp, -4]
lr r9, [bta_l2]
st.a r9, [sp, -4]
.endm .endm
/*-------------------------------------------------------------- /*--------------------------------------------------------------
@ -557,48 +534,41 @@
*-------------------------------------------------------------*/ *-------------------------------------------------------------*/
.macro RESTORE_ALL_INT1 .macro RESTORE_ALL_INT1
ld.ab r9, [sp, 4] /* Actual reg file */ POPAX bta_l1
sr r9, [bta_l1] POPAX lp_start
ld.ab r9, [sp, 4] POPAX lp_end
sr r9, [lp_start]
ld.ab r9, [sp, 4] POP r9
sr r9, [lp_end] mov lp_count, r9 ;LD to lp_count is not allowed
ld.ab r9, [sp, 4]
mov lp_count, r9 POPAX status32_l1
ld.ab r9, [sp, 4] POP ilink1
sr r9, [status32_l1] POP blink
ld.ab r9, [sp, 4] POP fp
mov ilink1, r9 POP gp
ld.ab blink, [sp, 4] RESTORE_R12_TO_R0
ld.ab fp, [sp, 4]
ld.ab r26, [sp, 4] /* gp */
RESTORE_CALLER_SAVED
ld sp, [sp] /* restore original sp */ ld sp, [sp] /* restore original sp */
/* orig_r0 and orig_r8 skipped automatically */ /* orig_r0 and orig_r8 skipped automatically */
.endm .endm
.macro RESTORE_ALL_INT2 .macro RESTORE_ALL_INT2
ld.ab r9, [sp, 4] POPAX bta_l2
sr r9, [bta_l2] POPAX lp_start
ld.ab r9, [sp, 4] POPAX lp_end
sr r9, [lp_start]
ld.ab r9, [sp, 4] POP r9
sr r9, [lp_end] mov lp_count, r9 ;LD to lp_count is not allowed
ld.ab r9, [sp, 4]
mov lp_count, r9 POPAX status32_l2
ld.ab r9, [sp, 4] POP ilink2
sr r9, [status32_l2] POP blink
ld.ab r9, [sp, 4] POP fp
mov ilink2, r9 POP gp
ld.ab blink, [sp, 4] RESTORE_R12_TO_R0
ld.ab fp, [sp, 4]
ld.ab r26, [sp, 4] /* gp */
RESTORE_CALLER_SAVED
ld sp, [sp] /* restore original sp */ ld sp, [sp] /* restore original sp */
/* orig_r0 and orig_r8 skipped automatically */ /* orig_r0 and orig_r8 skipped automatically */
.endm .endm

4
arch/arc/kernel/process.c
View File

@ -73,6 +73,10 @@ asmlinkage void ret_from_fork(void);
* ~ ~ * ~ ~
* | --to-- | (scratch Regs of user mode) * | --to-- | (scratch Regs of user mode)
* | r0 | * | r0 |
* ------------------
* | SP |
* | orig_r0 |
* | orig_r8 |
* ------------------ <===== END of PAGE * ------------------ <===== END of PAGE
*/ */
int copy_thread(unsigned long clone_flags, int copy_thread(unsigned long clone_flags,