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-rw-r--r--arch/arm/kernel/entry-armv.S172
1 files changed, 89 insertions, 83 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index cfb5cf5e48fc..78cf84cdc2ae 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -53,46 +53,62 @@
/*
* Invalid mode handlers
*/
- .macro inv_entry, sym, reason
- sub sp, sp, #S_FRAME_SIZE @ Allocate frame size in one go
- stmia sp, {r0 - lr} @ Save XXX r0 - lr
- ldr r4, .LC\sym
+ .macro inv_entry, reason
+ sub sp, sp, #S_FRAME_SIZE
+ stmib sp, {r1 - lr}
mov r1, #\reason
.endm
__pabt_invalid:
- inv_entry abt, BAD_PREFETCH
- b 1f
+ inv_entry BAD_PREFETCH
+ b common_invalid
__dabt_invalid:
- inv_entry abt, BAD_DATA
- b 1f
+ inv_entry BAD_DATA
+ b common_invalid
__irq_invalid:
- inv_entry irq, BAD_IRQ
- b 1f
+ inv_entry BAD_IRQ
+ b common_invalid
__und_invalid:
- inv_entry und, BAD_UNDEFINSTR
+ inv_entry BAD_UNDEFINSTR
+
+ @
+ @ XXX fall through to common_invalid
+ @
+
+@
+@ common_invalid - generic code for failed exception (re-entrant version of handlers)
+@
+common_invalid:
+ zero_fp
+
+ ldmia r0, {r4 - r6}
+ add r0, sp, #S_PC @ here for interlock avoidance
+ mov r7, #-1 @ "" "" "" ""
+ str r4, [sp] @ save preserved r0
+ stmia r0, {r5 - r7} @ lr_<exception>,
+ @ cpsr_<exception>, "old_r0"
-1: zero_fp
- ldmia r4, {r5 - r7} @ Get XXX pc, cpsr, old_r0
- add r4, sp, #S_PC
- stmia r4, {r5 - r7} @ Save XXX pc, cpsr, old_r0
mov r0, sp
- and r2, r6, #31 @ int mode
+ and r2, r6, #0x1f
b bad_mode
/*
* SVC mode handlers
*/
- .macro svc_entry, sym
+ .macro svc_entry
sub sp, sp, #S_FRAME_SIZE
- stmia sp, {r0 - r12} @ save r0 - r12
- ldr r2, .LC\sym
- add r0, sp, #S_FRAME_SIZE
- ldmia r2, {r2 - r4} @ get pc, cpsr
- add r5, sp, #S_SP
+ stmib sp, {r1 - r12}
+
+ ldmia r0, {r1 - r3}
+ add r5, sp, #S_SP @ here for interlock avoidance
+ mov r4, #-1 @ "" "" "" ""
+ add r0, sp, #S_FRAME_SIZE @ "" "" "" ""
+ str r1, [sp] @ save the "real" r0 copied
+ @ from the exception stack
+
mov r1, lr
@
@@ -109,7 +125,7 @@ __und_invalid:
.align 5
__dabt_svc:
- svc_entry abt
+ svc_entry
@
@ get ready to re-enable interrupts if appropriate
@@ -156,13 +172,15 @@ __dabt_svc:
.align 5
__irq_svc:
- svc_entry irq
+ svc_entry
+
#ifdef CONFIG_PREEMPT
get_thread_info tsk
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
add r7, r8, #1 @ increment it
str r7, [tsk, #TI_PREEMPT]
#endif
+
irq_handler
#ifdef CONFIG_PREEMPT
ldr r0, [tsk, #TI_FLAGS] @ get flags
@@ -200,7 +218,7 @@ svc_preempt:
.align 5
__und_svc:
- svc_entry und
+ svc_entry
@
@ call emulation code, which returns using r9 if it has emulated
@@ -230,7 +248,7 @@ __und_svc:
.align 5
__pabt_svc:
- svc_entry abt
+ svc_entry
@
@ re-enable interrupts if appropriate
@@ -263,12 +281,6 @@ __pabt_svc:
ldmia sp, {r0 - pc}^ @ load r0 - pc, cpsr
.align 5
-.LCirq:
- .word __temp_irq
-.LCund:
- .word __temp_und
-.LCabt:
- .word __temp_abt
.LCcralign:
.word cr_alignment
#ifdef MULTI_ABORT
@@ -285,12 +297,16 @@ __pabt_svc:
/*
* User mode handlers
*/
- .macro usr_entry, sym
- sub sp, sp, #S_FRAME_SIZE @ Allocate frame size in one go
- stmia sp, {r0 - r12} @ save r0 - r12
- ldr r7, .LC\sym
- add r5, sp, #S_PC
- ldmia r7, {r2 - r4} @ Get USR pc, cpsr
+ .macro usr_entry
+ sub sp, sp, #S_FRAME_SIZE
+ stmib sp, {r1 - r12}
+
+ ldmia r0, {r1 - r3}
+ add r0, sp, #S_PC @ here for interlock avoidance
+ mov r4, #-1 @ "" "" "" ""
+
+ str r1, [sp] @ save the "real" r0 copied
+ @ from the exception stack
#if __LINUX_ARM_ARCH__ < 6
@ make sure our user space atomic helper is aborted
@@ -307,8 +323,8 @@ __pabt_svc:
@
@ Also, separately save sp_usr and lr_usr
@
- stmia r5, {r2 - r4}
- stmdb r5, {sp, lr}^
+ stmia r0, {r2 - r4}
+ stmdb r0, {sp, lr}^
@
@ Enable the alignment trap while in kernel mode
@@ -323,7 +339,7 @@ __pabt_svc:
.align 5
__dabt_usr:
- usr_entry abt
+ usr_entry
@
@ Call the processor-specific abort handler:
@@ -352,7 +368,7 @@ __dabt_usr:
.align 5
__irq_usr:
- usr_entry irq
+ usr_entry
get_thread_info tsk
#ifdef CONFIG_PREEMPT
@@ -360,6 +376,7 @@ __irq_usr:
add r7, r8, #1 @ increment it
str r7, [tsk, #TI_PREEMPT]
#endif
+
irq_handler
#ifdef CONFIG_PREEMPT
ldr r0, [tsk, #TI_PREEMPT]
@@ -367,6 +384,7 @@ __irq_usr:
teq r0, r7
strne r0, [r0, -r0]
#endif
+
mov why, #0
b ret_to_user
@@ -374,7 +392,7 @@ __irq_usr:
.align 5
__und_usr:
- usr_entry und
+ usr_entry
tst r3, #PSR_T_BIT @ Thumb mode?
bne fpundefinstr @ ignore FP
@@ -490,7 +508,7 @@ fpundefinstr:
.align 5
__pabt_usr:
- usr_entry abt
+ usr_entry
enable_irq @ Enable interrupts
mov r0, r2 @ address (pc)
@@ -749,29 +767,41 @@ __kuser_helper_end:
*
* Common stub entry macro:
* Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
+ *
+ * SP points to a minimal amount of processor-private memory, the address
+ * of which is copied into r0 for the mode specific abort handler.
*/
- .macro vector_stub, name, sym, correction=0
+ .macro vector_stub, name, correction=0
.align 5
vector_\name:
- ldr r13, .LCs\sym
.if \correction
sub lr, lr, #\correction
.endif
- str lr, [r13] @ save lr_IRQ
+
+ @
+ @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
+ @ (parent CPSR)
+ @
+ stmia sp, {r0, lr} @ save r0, lr
mrs lr, spsr
- str lr, [r13, #4] @ save spsr_IRQ
+ str lr, [sp, #8] @ save spsr
+
@
- @ now branch to the relevant MODE handling routine
+ @ Prepare for SVC32 mode. IRQs remain disabled.
@
- mrs r13, cpsr
- bic r13, r13, #MODE_MASK
- orr r13, r13, #SVC_MODE
- msr spsr_cxsf, r13 @ switch to SVC_32 mode
+ mrs r0, cpsr
+ bic r0, r0, #MODE_MASK
+ orr r0, r0, #SVC_MODE
+ msr spsr_cxsf, r0
- and lr, lr, #15
+ @
+ @ the branch table must immediately follow this code
+ @
+ mov r0, sp
+ and lr, lr, #0x0f
ldr lr, [pc, lr, lsl #2]
- movs pc, lr @ Changes mode and branches
+ movs pc, lr @ branch to handler in SVC mode
.endm
.globl __stubs_start
@@ -779,7 +809,7 @@ __stubs_start:
/*
* Interrupt dispatcher
*/
- vector_stub irq, irq, 4
+ vector_stub irq, 4
.long __irq_usr @ 0 (USR_26 / USR_32)
.long __irq_invalid @ 1 (FIQ_26 / FIQ_32)
@@ -802,7 +832,7 @@ __stubs_start:
* Data abort dispatcher
* Enter in ABT mode, spsr = USR CPSR, lr = USR PC
*/
- vector_stub dabt, abt, 8
+ vector_stub dabt, 8
.long __dabt_usr @ 0 (USR_26 / USR_32)
.long __dabt_invalid @ 1 (FIQ_26 / FIQ_32)
@@ -825,7 +855,7 @@ __stubs_start:
* Prefetch abort dispatcher
* Enter in ABT mode, spsr = USR CPSR, lr = USR PC
*/
- vector_stub pabt, abt, 4
+ vector_stub pabt, 4
.long __pabt_usr @ 0 (USR_26 / USR_32)
.long __pabt_invalid @ 1 (FIQ_26 / FIQ_32)
@@ -848,7 +878,7 @@ __stubs_start:
* Undef instr entry dispatcher
* Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
*/
- vector_stub und, und
+ vector_stub und
.long __und_usr @ 0 (USR_26 / USR_32)
.long __und_invalid @ 1 (FIQ_26 / FIQ_32)
@@ -902,13 +932,6 @@ vector_addrexcptn:
.LCvswi:
.word vector_swi
-.LCsirq:
- .word __temp_irq
-.LCsund:
- .word __temp_und
-.LCsabt:
- .word __temp_abt
-
.globl __stubs_end
__stubs_end:
@@ -930,23 +953,6 @@ __vectors_end:
.data
-/*
- * Do not reorder these, and do not insert extra data between...
- */
-
-__temp_irq:
- .word 0 @ saved lr_irq
- .word 0 @ saved spsr_irq
- .word -1 @ old_r0
-__temp_und:
- .word 0 @ Saved lr_und
- .word 0 @ Saved spsr_und
- .word -1 @ old_r0
-__temp_abt:
- .word 0 @ Saved lr_abt
- .word 0 @ Saved spsr_abt
- .word -1 @ old_r0
-
.globl cr_alignment
.globl cr_no_alignment
cr_alignment:
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