mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
43 lines
1.1 KiB
ArmAsm
43 lines
1.1 KiB
ArmAsm
/*
|
|
* The ARM LDRD and Thumb LDRSB instructions use bit 20/11 (ARM/Thumb)
|
|
* differently than every other instruction, so it is set to 0 (write)
|
|
* even though the instructions are read instructions. This means that
|
|
* during an abort the instructions will be treated as a write and the
|
|
* handler will raise a signal from unwriteable locations if they
|
|
* fault. We have to specifically check for these instructions
|
|
* from the abort handlers to treat them properly.
|
|
*
|
|
*/
|
|
|
|
.macro do_thumb_abort
|
|
tst r3, #PSR_T_BIT
|
|
beq not_thumb
|
|
ldrh r3, [r2] @ Read aborted Thumb instruction
|
|
and r3, r3, # 0xfe00 @ Mask opcode field
|
|
cmp r3, # 0x5600 @ Is it ldrsb?
|
|
orreq r3, r3, #1 << 11 @ Set L-bit if yes
|
|
tst r3, #1 << 11 @ L = 0 -> write
|
|
orreq r1, r1, #1 << 11 @ yes.
|
|
mov pc, lr
|
|
not_thumb:
|
|
.endm
|
|
|
|
/*
|
|
* We check for the following insturction encoding for LDRD.
|
|
*
|
|
* [27:25] == 0
|
|
* [7:4] == 1101
|
|
* [20] == 0
|
|
*/
|
|
.macro do_ldrd_abort
|
|
tst r3, #0x0e000000 @ [27:25] == 0
|
|
bne not_ldrd
|
|
and r2, r3, #0x000000f0 @ [7:4] == 1101
|
|
cmp r2, #0x000000d0
|
|
bne not_ldrd
|
|
tst r3, #1 << 20 @ [20] == 0
|
|
moveq pc, lr
|
|
not_ldrd:
|
|
.endm
|
|
|