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-rw-r--r--arch/sh/kernel/entry.S442
1 files changed, 252 insertions, 190 deletions
diff --git a/arch/sh/kernel/entry.S b/arch/sh/kernel/entry.S
index 46ad20f53..00372811c 100644
--- a/arch/sh/kernel/entry.S
+++ b/arch/sh/kernel/entry.S
@@ -14,6 +14,8 @@
#include <linux/linkage.h>
#include <linux/config.h>
+#define COMPAT_OLD_SYSCALL_ABI 1
+
! NOTE:
! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address
! to be jumped is too far, but it causes illegal slot exception.
@@ -31,26 +33,24 @@
* if the order here is changed, it needs to be
* updated in ptrace.c and ptrace.h
*
- * syscall #
- * ssr
- * r0
+ * $r0
* ...
- * r15 = stack pointer
- * gbr
- * mach
- * macl
- * pr
- * spc
+ * $r15 = stack pointer
+ * $spc
+ * $pr
+ * $ssr
+ * $gbr
+ * $mach
+ * $macl
+ * syscall #
*
*/
/*
* These are offsets into the task-struct.
*/
-state = 0
flags = 4
sigpending = 8
-addr_limit = 12
need_resched = 20
PF_TRACESYS = 0x00000020
@@ -75,30 +75,35 @@ MMU_TEA = 0xff00000c ! TLB Exception Address Register
#endif
/* Offsets to the stack */
-SYSCALL_NR = 0
-SR = 4
-R0 = 8
-SP = (8+15*4)
+R0 = 0 /* Return value */
+SP = (15*4)
+SR = (16*4+8)
+SYSCALL_NR = (16*4+6*4)
+
#define k0 r0
#define k1 r1
#define k2 r2
#define k3 r3
+#define k4 r4
-#define kernel_sp r4 /* r4_bank1 */
-#define ksp r4_bank /* r4_bank1 */
+#define current r7 /* r7_bank1 */
+#define g_imask r6 /* r6_bank1 */
+#define k_current r7_bank /* r7_bank1 */
+#define k_g_imask r6_bank /* r6_bank1 */
#define k_ex_code r2_bank /* r2_bank1 */
-/* Kernel mode register usage:
- k0 scratch
- k1 scratch
- k2 scratch (Exception code)
- k3 scratch (Return address)
- k4 Stack base = current+8192
- k5 Global Interrupt Mask (0--15)
- k6 reserved
- k7 reserved
-*/
+/*
+ * Kernel mode register usage:
+ * k0 scratch
+ * k1 scratch
+ * k2 scratch (Exception code)
+ * k3 scratch (Return address)
+ * k4 scratch
+ * k5 reserved
+ * k6 Global Interrupt Mask (0--15 << 4)
+ * k7 CURRENT (pointer to current task)
+ */
!
! TLB Miss / Initial Page write exception handling
@@ -114,42 +119,60 @@ SP = (8+15*4)
! this first version depends *much* on C implementation.
!
-#define RESTORE_FLAGS() \
- mov.l @(SR,$r15), $r0; \
- and #0xf0, $r0; \
- shlr8 $r0; \
- cmp/eq #0x0f, $r0; \
- bt 9f; \
- mov.l __INV_IMASK, $r1; \
- stc $sr, $r0; \
- and $r1, $r0; \
- stc $r5_bank, $r1; \
- or $r1, $r0; \
- ldc $r0, $sr
+#define STI() \
+ mov.l __INV_IMASK, $r11; \
+ stc $sr, $r10; \
+ and $r11, $r10; \
+ stc $k_g_imask, $r11; \
+ or $r11, $r10; \
+ ldc $r10, $sr
.balign 4
-tlb_protection_violation_load:
tlb_miss_load:
- mov #-1, $r0
- mov.l $r0, @$r15 ! syscall nr = -1
mov.l 2f, $r0
mov.l @$r0, $r6
- RESTORE_FLAGS()
-9: mov $r15, $r4
+ STI()
+ mov $r15, $r4
mov.l 1f, $r0
jmp @$r0
mov #0, $r5
.balign 4
-tlb_protection_violation_store:
tlb_miss_store:
+ mov.l 2f, $r0
+ mov.l @$r0, $r6
+ STI()
+ mov $r15, $r4
+ mov.l 1f, $r0
+ jmp @$r0
+ mov #1, $r5
+
+ .balign 4
initial_page_write:
- mov #-1, $r0
- mov.l $r0, @$r15 ! syscall nr = -1
mov.l 2f, $r0
mov.l @$r0, $r6
- RESTORE_FLAGS()
-9: mov $r15, $r4
+ STI()
+ mov $r15, $r4
+ mov.l 1f, $r0
+ jmp @$r0
+ mov #1, $r5
+
+ .balign 4
+tlb_protection_violation_load:
+ mov.l 2f, $r0
+ mov.l @$r0, $r6
+ STI()
+ mov $r15, $r4
+ mov.l 1f, $r0
+ jmp @$r0
+ mov #0, $r5
+
+ .balign 4
+tlb_protection_violation_store:
+ mov.l 2f, $r0
+ mov.l @$r0, $r6
+ STI()
+ mov $r15, $r4
mov.l 1f, $r0
jmp @$r0
mov #1, $r5
@@ -162,8 +185,6 @@ initial_page_write:
.balign 4
/* Unwind the stack and jmp to the debug entry */
debug:
- add #4, $r15 ! skip syscall number
- mov.l @$r15+, $r11 ! SSR
mov.l @$r15+, $r0
mov.l @$r15+, $r1
mov.l @$r15+, $r2
@@ -172,11 +193,10 @@ debug:
mov.l @$r15+, $r5
mov.l @$r15+, $r6
mov.l @$r15+, $r7
- stc $sr, $r14
- mov.l 1f, $r9 ! BL =1, RB=1
- or $r9, $r14
- ldc $r14, $sr ! here, change the register bank
- mov $r11, $k1
+ stc $sr, $r8
+ mov.l 1f, $r9 ! BL =1, RB=1, IMASK=0x0F
+ or $r9, $r8
+ ldc $r8, $sr ! here, change the register bank
mov.l @$r15+, $r8
mov.l @$r15+, $r9
mov.l @$r15+, $r10
@@ -185,11 +205,12 @@ debug:
mov.l @$r15+, $r13
mov.l @$r15+, $r14
mov.l @$r15+, $k0
+ ldc.l @$r15+, $spc
+ lds.l @$r15+, $pr
+ mov.l @$r15+, $k1
ldc.l @$r15+, $gbr
lds.l @$r15+, $mach
lds.l @$r15+, $macl
- lds.l @$r15+, $pr
- ldc.l @$r15+, $spc
mov $k0, $r15
!
mov.l 2f, $k0
@@ -203,11 +224,10 @@ debug:
.balign 4
error:
!
- RESTORE_FLAGS()
-9: mov.l 1f, $r1
- mov #-1, $r0
- jmp @$r1
- mov.l $r0, @$r15 ! syscall nr = -1
+ STI()
+ mov.l 1f, $r0
+ jmp @$r0
+ nop
.balign 4
1: .long SYMBOL_NAME(do_exception_error)
@@ -222,76 +242,106 @@ ENTRY(ret_from_fork)
bra SYMBOL_NAME(ret_from_syscall)
add #4, $r15 ! pop down bogus r0 (see switch_to MACRO)
-!
-! The immediate value of "trapa" indicates the number of arguments
-! placed on the stack.
-!
-! Note that TRA register contains the value = Imm x 4.
-!
+/*
+ * Old syscall interface:
+ *
+ * Syscall #: R0
+ * Arguments #0 to #3: R4--R7
+ * more arguments: On the stack
+ * TRA: (number of arguments on the stack) x 4
+ *
+ * New syscall interface:
+ *
+ * Syscall #: R3
+ * Arguments #0 to #3: R4--R7
+ * Arguments #4 to #6: R0, R1, R2
+ * TRA: (number of arguments + 0x10) x 4
+ *
+ */
+
system_call:
- mov.l 1f, $r2
- mov.l @$r2, $r8
- !
- ! DEBUG DEBUG
- ! mov.l led, $r1
- ! mov $r0, $r2
- ! mov.b $r2, @$r1
+ mov.l 1f, $r9
+ mov.l @$r9, $r8
!
#ifdef CONFIG_DEBUG_KERNEL_WITH_GDB_STUB
- mov #0x20, $r1
- extu.b $r1, $r1
- shll2 $r1
- cmp/hs $r1, $r8
+ mov #0x20, $r9
+ extu.b $r9, $r9
+ shll2 $r9
+ cmp/hs $r9, $r8
bt debug
#endif
!
- mov $r0, $r2
- RESTORE_FLAGS()
-9: mov.l __n_sys, $r1
- cmp/hs $r1, $r2
+ mov #SYSCALL_NR, $r14
+ add $r15, $r14
+ !
+ mov #0x40, $r9
+#ifdef COMPAT_OLD_SYSCALL_ABI
+ cmp/hs $r9, $r8
+ mov $r0, $r10
+ bf/s 0f
+ mov $r0, $r9
+#endif
+ ! New Syscall ABI
+ sub $r9, $r8
+ shlr2 $r8
+ shll8 $r8
+ shll8 $r8
+ mov $r3, $r10
+ or $r8, $r10 ! Encode syscall # and # of arguments
+ !
+ mov $r3, $r9
+ mov #0, $r8
+0:
+ mov.l $r10, @$r14 ! set syscall_nr
+ STI()
+ mov.l __n_sys, $r10
+ cmp/hs $r10, $r9
bt badsys
!
- stc $ksp, $r1
- mov.l __tsk_flags, $r0
- add $r0, $r1 !
- mov.l @$r1, $r0 ! Is it trace?
- tst #PF_TRACESYS, $r0
+#ifdef COMPAT_OLD_SYSCALL_ABI
+ ! Build the stack frame if TRA > 0
+ mov $r8, $r10
+ cmp/pl $r10
+ bf 0f
+ mov.l @(SP,$r15), $r0 ! get original stack
+7: add #-4, $r10
+4: mov.l @($r0,$r10), $r1 ! May cause address error exception..
+ mov.l $r1, @-$r15
+ cmp/pl $r10
+ bt 7b
+#endif
+0: stc $k_current, $r11
+ mov.l @(flags,$r11), $r10 ! Is it trace?
+ mov #PF_TRACESYS, $r11
+ tst $r11, $r10
bt 5f
! Trace system call
- mov #-ENOSYS, $r1
- mov.l $r1, @(R0,$r15)
- mov.l 3f, $r1
- jsr @$r1
+ mov #-ENOSYS, $r11
+ mov.l $r11, @(R0,$r15)
+ mov.l 2f, $r11
+ jsr @$r11
nop
- mova 3f, $r0
+ mov.l __syscall_ret_trace, $r10
bra 6f
- lds $r0, $pr
+ lds $r10, $pr
!
-5: mova syscall_ret, $r0
- lds $r0, $pr
- ! Build the stack frame if TRA > 0
-6: mov $r2, $r3
- mov $r8, $r2
- cmp/pl $r8
- bf 0f
- mov #SP, $r0
- mov.l @($r0,$r15), $r0 ! get original stack
-7: add #-4, $r8
-4: mov.l @($r0,$r8), $r1 ! May cause address error exception..
- mov.l $r1, @-$r15
- cmp/pl $r8
- bt 7b
+5: mov.l __syscall_ret, $r10
+ lds $r10, $pr
!
-0: mov $r3, $r0
- shll2 $r0 ! x4
- mov.l __sct, $r1
- add $r1, $r0
- mov.l @$r0, $r1
- jmp @$r1
- mov $r2, $r8
+6: mov $r9, $r10
+ shll2 $r10 ! x4
+ mov.l __sct, $r11
+ add $r11, $r10
+ mov.l @$r10, $r11
+ jmp @$r11
+ nop
+
! In case of trace
.balign 4
-3: add $r8, $r15 ! pop off the arguments
+3:
+#ifdef COMPAT_OLD_SYSCALL_ABI
+ add $r8, $r15 ! pop off the arguments
+#endif
mov.l $r0, @(R0,$r15) ! save the return value
mov.l 2f, $r1
mova SYMBOL_NAME(ret_from_syscall), $r0
@@ -302,9 +352,12 @@ system_call:
2: .long SYMBOL_NAME(syscall_trace)
__n_sys: .long NR_syscalls
__sct: .long SYMBOL_NAME(sys_call_table)
-__tsk_flags: .long flags-8192 ! offset from stackbase to tsk->flags
-led: .long 0xa8000000 ! For my board -- gN
+__syscall_ret_trace:
+ .long 3b
+__syscall_ret:
+ .long SYMBOL_NAME(syscall_ret)
+#ifdef COMPAT_OLD_SYSCALL_ABI
.section .fixup,"ax"
fixup_syscall_argerr:
rts
@@ -316,6 +369,7 @@ fixup_syscall_argerr:
.balign 4
.long 4b,fixup_syscall_argerr
.previous
+#endif
.balign 4
reschedule:
@@ -327,23 +381,25 @@ reschedule:
1: .long SYMBOL_NAME(schedule)
ENTRY(ret_from_irq)
- mov.l @(SR,$r15), $r0 ! get status register
+ mov #SR, $r0
+ mov.l @($r0,$r15), $r0 ! get status register
shll $r0
shll $r0 ! kernel space?
bt restore_all ! Yes, it's from kernel, go back soon
!
- RESTORE_FLAGS()
-9: bra ret_with_reschedule
+ STI()
+ bra ret_with_reschedule
nop
ENTRY(ret_from_exception)
- mov.l @(SR,$r15), $r0 ! get status register
+ mov #SR, $r0
+ mov.l @($r0,$r15), $r0 ! get status register
shll $r0
shll $r0 ! kernel space?
bt restore_all ! Yes, it's from kernel, go back soon
!
- RESTORE_FLAGS()
-9: bra ret_from_syscall
+ STI()
+ bra ret_from_syscall
nop
.balign 4
__INV_IMASK:
@@ -351,7 +407,9 @@ __INV_IMASK:
.balign 4
syscall_ret:
+#ifdef COMPAT_OLD_SYSCALL_ABI
add $r8, $r15 ! pop off the arguments
+#endif
mov.l $r0, @(R0,$r15) ! save the return value
/* fall through */
@@ -366,9 +424,7 @@ handle_softirq:
jsr @$r0
nop
ret_with_reschedule:
- stc $ksp, $r1
- mov.l __minus8192, $r0
- add $r0, $r1
+ stc $k_current, $r1
mov.l @(need_resched,$r1), $r0
tst #0xff, $r0
bf reschedule
@@ -389,30 +445,14 @@ __softirq_state:
.long SYMBOL_NAME(softirq_state)
__do_softirq:
.long SYMBOL_NAME(do_softirq)
-__minus8192:
- .long -8192 ! offset from stackbase to tsk
.balign 4
restore_all:
#if defined(__SH4__)
- mov.l __fpu_prepare_fd, $r1
- jsr @$r1
+ mov.l __fpu_prepare_fd, $r0
+ jsr @$r0
stc $sr, $r4
#endif
- add #4, $r15 ! Skip syscall number
- mov.l @$r15+, $r11 ! Got SSR into R11
-#if defined(__SH4__)
- mov $r11, $r12
-#endif
- !
- mov.l 1f, $r1
- stc $sr, $r0
- and $r1, $r0 ! Get FD
- mov.l 2f, $r1
- and $r1, $r11
- or $r0, $r11 ! Inherit the FD value of SR
- stc $r5_bank, $r0
- or $r0, $r11 ! Inherit the IMASK value
!
mov.l @$r15+, $r0
mov.l @$r15+, $r1
@@ -422,14 +462,12 @@ restore_all:
mov.l @$r15+, $r5
mov.l @$r15+, $r6
mov.l @$r15+, $r7
- stc $sr, $r14
+ !
+ stc $sr, $r8
mov.l __blrb_flags, $r9 ! BL =1, RB=1
- or $r9, $r14
- ldc $r14, $sr ! here, change the register bank
- mov $r11, $k1
-#if defined(__SH4__)
- mov $r12, $k2
-#endif
+ or $r9, $r8
+ ldc $r8, $sr ! here, change the register bank
+ !
mov.l @$r15+, $r8
mov.l @$r15+, $r9
mov.l @$r15+, $r10
@@ -437,20 +475,33 @@ restore_all:
mov.l @$r15+, $r12
mov.l @$r15+, $r13
mov.l @$r15+, $r14
- mov.l @$r15+, $k0 ! original stack
+ mov.l @$r15+, $k4 ! original stack pointer
+ ldc.l @$r15+, $spc
+ lds.l @$r15+, $pr
+ mov.l @$r15+, $k3 ! original SR
ldc.l @$r15+, $gbr
lds.l @$r15+, $mach
lds.l @$r15+, $macl
- lds.l @$r15+, $pr
- ldc.l @$r15+, $spc
- ldc $k1, $ssr
+ add #4, $r15 ! Skip syscall number
+ !
+ ! Calculate new SR value
+ mov $k3, $k2 ! original SR value
+ mov.l 1f, $k1
+ stc $sr, $k0
+ and $k1, $k0 ! Get current FD-bit
+ mov.l 2f, $k1
+ and $k1, $k2 ! Mask orignal SR value
+ or $k0, $k2 ! Inherit current FD-bit
+ or $g_imask, $k2 ! Inherit the IMASK-bits
+ ldc $k2, $ssr
+ !
#if defined(__SH4__)
- shll $k1
- shll $k1
+ shll $k2
+ shll $k2
bf 9f ! user mode
/* Kernel to kernel transition */
mov.l 1f, $k1
- tst $k1, $k2
+ tst $k1, $k3
bf 9f ! it hadn't FPU
! Kernel to kernel and FPU was used
! There's the case we don't get FPU now
@@ -462,14 +513,15 @@ restore_all:
ldc $k2, $sr ! Grab FPU
mov.l __init_task_flags, $k1
mov.l @$k1, $k2
- mov.l __PF_USEDFPU, $k1
- or $k1, $k2
- mov.l __init_task_flags, $k1
+ mov.l __PF_USEDFPU, $k0
+ or $k0, $k2
mov.l $k2, @$k1 ! Set init_task.flags |= PF_USEDFPU
!
! Restoring FPU...
!
-7: fmov.s @$r15+, $fr0
+7: mov.l 3f, $k1
+ lds $k1, $fpscr
+ fmov.s @$r15+, $fr0
fmov.s @$r15+, $fr1
fmov.s @$r15+, $fr2
fmov.s @$r15+, $fr3
@@ -489,7 +541,7 @@ restore_all:
lds.l @$r15+, $fpul
9:
#endif
- mov $k0, $r15
+ mov $k4, $r15
rte
nop
@@ -505,6 +557,7 @@ __PF_USEDFPU:
#endif
1: .long 0x00008000 ! FD
2: .long 0xffff7f0f ! ~(IMASK+FD)
+3: .long 0x00080000 ! SZ=0, PR=1
! Exception Vector Base
!
@@ -569,6 +622,9 @@ handle_exception:
! /* Currently it's not the case for GCC (only udivsi3_i4, divsi3_i4) */
sts.l $fpul, @-$r15
sts.l $fpscr, @-$r15
+ mov.l 6f, $k1
+ lds $k1, $fpscr
+ mov.l 3f, $k1
fmov.s $fr15, @-$r15
fmov.s $fr14, @-$r15
fmov.s $fr13, @-$r15
@@ -584,40 +640,47 @@ handle_exception:
fmov.s $fr3, @-$r15
fmov.s $fr2, @-$r15
fmov.s $fr1, @-$r15
- fmov.s $fr0, @-$r15
bra 9f
- mov.l 3f, $k1
+ fmov.s $fr0, @-$r15
#else
mov.l 3f, $k1
bt/s 9f ! it's from kernel to kernel transition
mov $r15, $k0 ! save original stack to k0 anyway
#endif
8: /* User space to kernel */
- mov $kernel_sp, $r15 ! change to kernel stack
- mov.l 4f, $k1 ! let kernel release FPU
-9: stc.l $spc, @-$r15
- sts.l $pr, @-$r15
+ mov #0x20, $k1
+ shll8 $k1 ! $k1 <= 8192
+ add $current, $k1
+ mov $k1, $r15 ! change to kernel stack
!
- lds $k3, $pr ! Set the return address to pr
+ mov.l 4f, $k1 ! let kernel release FPU
+9: mov #-1, $k4
+ mov.l $k4, @-$r15 ! syscall_nr (default: -1)
!
sts.l $macl, @-$r15
sts.l $mach, @-$r15
stc.l $gbr, @-$r15
- mov.l $k0, @-$r15 ! save orignal stack
- mov.l $r14, @-$r15
+ stc.l $ssr, @-$r15
+ sts.l $pr, @-$r15
+ stc.l $spc, @-$r15
!
- stc $sr, $r14 ! Back to normal register bank, and
- or $k1, $r14 ! Block all interrupts, may release FPU
- mov.l 5f, $k1
- and $k1, $r14 ! ...
- ldc $r14, $sr ! ...changed here.
+ lds $k3, $pr ! Set the return address to pr
!
+ mov.l $k0, @-$r15 ! save orignal stack
+ mov.l $r14, @-$r15
mov.l $r13, @-$r15
mov.l $r12, @-$r15
mov.l $r11, @-$r15
mov.l $r10, @-$r15
mov.l $r9, @-$r15
mov.l $r8, @-$r15
+ !
+ stc $sr, $r8 ! Back to normal register bank, and
+ or $k1, $r8 ! Block all interrupts, may release FPU
+ mov.l 5f, $k1
+ and $k1, $r8 ! ...
+ ldc $r8, $sr ! ...changed here.
+ !
mov.l $r7, @-$r15
mov.l $r6, @-$r15
mov.l $r5, @-$r15
@@ -626,23 +689,22 @@ handle_exception:
mov.l $r2, @-$r15
mov.l $r1, @-$r15
mov.l $r0, @-$r15
- stc.l $ssr, @-$r15
- mov.l $r0, @-$r15 ! push $r0 again (for syscall number)
- ! Then, dispatch to the handler, according to the excepiton code.
- stc $k_ex_code, $r1
- shlr2 $r1
- shlr $r1
- mov.l 1f, $r0
- add $r1, $r0
- mov.l @$r0, $r0
- jmp @$r0
- mov.l @$r15, $r0 ! recovering $r0..
+ ! Then, dispatch to the handler, according to the exception code.
+ stc $k_ex_code, $r8
+ shlr2 $r8
+ shlr $r8
+ mov.l 1f, $r9
+ add $r8, $r9
+ mov.l @$r9, $r9
+ jmp @$r9
+ nop
.balign 4
1: .long SYMBOL_NAME(exception_handling_table)
2: .long 0x00008000 ! FD=1
3: .long 0x000000f0 ! FD=0, IMASK=15
4: .long 0x000080f0 ! FD=1, IMASK=15
5: .long 0xcfffffff ! RB=0, BL=0
+6: .long 0x00080000 ! SZ=0, PR=1
none:
rts
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 06:56:27 +0000