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Rework the exception entry/return functions to make them valid frames to be

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unwound through. For this we need the frame pointer (x29) to point to the
location on the stack where we stored the previous frame pointer, and link
register. To simplify this the stack pointer is only adjusted by addition
and subtraction, and not through the use of post increment on loads and
stores.

The updated frame layout is:

+------------+
| lr -- x30  |
+------------+
| fp -- x29  | <-- x29 points at this
+------------+
| Trap frame |
| ...        |
|            | <-- sp points at this
+------------+

The only difference is the first two items, and setting of x29.

Sponsored by:	ABT Systems Ltd
This commit is contained in:
Andrew Turner 2015-12-01 12:37:04 +00:00
parent 119a353e3d
commit 9d4de283d5
2 changed files with 44 additions and 36 deletions
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77
sys/arm64/arm64/exception.S
View File

@ -37,29 +37,32 @@ __FBSDID("$FreeBSD$");
mov x18, sp
sub sp, sp, #128
.endif
stp x28, x29, [sp, #-16]!
stp x26, x27, [sp, #-16]!
stp x24, x25, [sp, #-16]!
stp x22, x23, [sp, #-16]!
stp x20, x21, [sp, #-16]!
stp x18, x19, [sp, #-16]!
stp x16, x17, [sp, #-16]!
stp x14, x15, [sp, #-16]!
stp x12, x13, [sp, #-16]!
stp x10, x11, [sp, #-16]!
stp x8, x9, [sp, #-16]!
stp x6, x7, [sp, #-16]!
stp x4, x5, [sp, #-16]!
stp x2, x3, [sp, #-16]!
stp x0, x1, [sp, #-16]!
sub sp, sp, #(TF_SIZE + 16)
stp x29, x30, [sp, #(TF_SIZE)]
stp x28, x29, [sp, #(TF_X + 28 * 8)]
stp x26, x27, [sp, #(TF_X + 26 * 8)]
stp x24, x25, [sp, #(TF_X + 24 * 8)]
stp x22, x23, [sp, #(TF_X + 22 * 8)]
stp x20, x21, [sp, #(TF_X + 20 * 8)]
stp x18, x19, [sp, #(TF_X + 18 * 8)]
stp x16, x17, [sp, #(TF_X + 16 * 8)]
stp x14, x15, [sp, #(TF_X + 14 * 8)]
stp x12, x13, [sp, #(TF_X + 12 * 8)]
stp x10, x11, [sp, #(TF_X + 10 * 8)]
stp x8, x9, [sp, #(TF_X + 8 * 8)]
stp x6, x7, [sp, #(TF_X + 6 * 8)]
stp x4, x5, [sp, #(TF_X + 4 * 8)]
stp x2, x3, [sp, #(TF_X + 2 * 8)]
stp x0, x1, [sp, #(TF_X + 0 * 8)]
mrs x10, elr_el1
mrs x11, spsr_el1
.if \el == 0
mrs x18, sp_el0
.endif
stp x10, x11, [sp, #-16]!
stp x18, lr, [sp, #-16]!
stp x10, x11, [sp, #(TF_ELR)]
stp x18, lr, [sp, #(TF_SP)]
mrs x18, tpidr_el1
add x29, sp, #(TF_SIZE)
.endm
.macro restore_registers el
@ -70,33 +73,35 @@ __FBSDID("$FreeBSD$");
* handler. For EL0 exceptions, do_ast already did this.
*/
.endif
ldp x18, lr, [sp], #16
ldp x10, x11, [sp], #16
ldp x18, lr, [sp, #(TF_SP)]
ldp x10, x11, [sp, #(TF_ELR)]
.if \el == 0
msr sp_el0, x18
.endif
msr spsr_el1, x11
msr elr_el1, x10
ldp x0, x1, [sp], #16
ldp x2, x3, [sp], #16
ldp x4, x5, [sp], #16
ldp x6, x7, [sp], #16
ldp x8, x9, [sp], #16
ldp x10, x11, [sp], #16
ldp x12, x13, [sp], #16
ldp x14, x15, [sp], #16
ldp x16, x17, [sp], #16
ldp x0, x1, [sp, #(TF_X + 0 * 8)]
ldp x2, x3, [sp, #(TF_X + 2 * 8)]
ldp x4, x5, [sp, #(TF_X + 4 * 8)]
ldp x6, x7, [sp, #(TF_X + 6 * 8)]
ldp x8, x9, [sp, #(TF_X + 8 * 8)]
ldp x10, x11, [sp, #(TF_X + 10 * 8)]
ldp x12, x13, [sp, #(TF_X + 12 * 8)]
ldp x14, x15, [sp, #(TF_X + 14 * 8)]
ldp x16, x17, [sp, #(TF_X + 16 * 8)]
.if \el == 0
ldp x18, x19, [sp], #16
ldp x18, x19, [sp, #(TF_X + 18 * 8)]
.else
ldp xzr, x19, [sp], #16
ldr x19, [sp, #(TF_X + 19 * 8)]
.endif
ldp x20, x21, [sp], #16
ldp x22, x23, [sp], #16
ldp x24, x25, [sp], #16
ldp x26, x27, [sp], #16
ldp x28, x29, [sp], #16
.if \el == 1
ldp x20, x21, [sp, #(TF_X + 20 * 8)]
ldp x22, x23, [sp, #(TF_X + 22 * 8)]
ldp x24, x25, [sp, #(TF_X + 24 * 8)]
ldp x26, x27, [sp, #(TF_X + 26 * 8)]
ldp x28, x29, [sp, #(TF_X + 28 * 8)]
.if \el == 0
add sp, sp, #(TF_SIZE + 16)
.else
mov sp, x18
mrs x18, tpidr_el1
.endif

3
sys/arm64/arm64/genassym.c
View File

@ -60,4 +60,7 @@ ASSYM(TD_PCB, offsetof(struct thread, td_pcb));
ASSYM(TD_FLAGS, offsetof(struct thread, td_flags));
ASSYM(TD_LOCK, offsetof(struct thread, td_lock));
ASSYM(TF_SIZE, sizeof(struct trapframe));
ASSYM(TF_SP, offsetof(struct trapframe, tf_sp));
ASSYM(TF_ELR, offsetof(struct trapframe, tf_elr));
ASSYM(TF_X, offsetof(struct trapframe, tf_x));