.ifnc %0%1%2%3,$r13$r11$r12$r10 \n\
.err \n\
.endif \n\
-
- ;; Save the registers we'll use in the movem process
- ;; on the stack.
- subq 11*4,$sp
- movem $r10,[$sp]
-
- ;; Now we've got this:
- ;; r11 - src
- ;; r13 - dst
- ;; r12 - n
-
- ;; Update n for the first loop
- subq 44,$r12
-
-; Since the noted PC of a faulting instruction in a delay-slot of a taken
-; branch, is that of the branch target, we actually point at the from-movem
-; for this case. There is no ambiguity here; if there was a fault in that
-; instruction (meaning a kernel oops), the faulted PC would be the address
-; after *that* movem.
-
-0:
- movem [$r11+],$r10
- subq 44,$r12
- bge 0b
- movem $r10,[$r13+]
-1:
- addq 44,$r12 ;; compensate for last loop underflowing n
-
- ;; Restore registers from stack
- movem [$sp+],$r10
-2:
- .section .fixup,\"ax\"
-
-; To provide a correct count in r10 of bytes that failed to be copied,
-; we jump back into the loop if the loop-branch was taken. There is no
-; performance penalty for sany use; the program will segfault soon enough.
-
-3:
- move.d [$sp],$r10
- addq 44,$r10
- move.d $r10,[$sp]
- jump 0b
-4:
- movem [$sp+],$r10
- addq 44,$r10
- addq 44,$r12
- jump 2b
-
- .previous
- .section __ex_table,\"a\"
- .dword 0b,3b
- .dword 1b,4b
+ \n\
+ ;; Save the registers we'll use in the movem process \n\
+ ;; on the stack. \n\
+ subq 11*4,$sp \n\
+ movem $r10,[$sp] \n\
+ \n\
+ ;; Now we've got this: \n\
+ ;; r11 - src \n\
+ ;; r13 - dst \n\
+ ;; r12 - n \n\
+ \n\
+ ;; Update n for the first loop \n\
+ subq 44,$r12 \n\
+ \n\
+; Since the noted PC of a faulting instruction in a delay-slot of a taken \n\
+; branch, is that of the branch target, we actually point at the from-movem \n\
+; for this case. There is no ambiguity here; if there was a fault in that \n\
+; instruction (meaning a kernel oops), the faulted PC would be the address \n\
+; after *that* movem. \n\
+ \n\
+0: \n\
+ movem [$r11+],$r10 \n\
+ subq 44,$r12 \n\
+ bge 0b \n\
+ movem $r10,[$r13+] \n\
+1: \n\
+ addq 44,$r12 ;; compensate for last loop underflowing n \n\
+ \n\
+ ;; Restore registers from stack \n\
+ movem [$sp+],$r10 \n\
+2: \n\
+ .section .fixup,\"ax\" \n\
+ \n\
+; To provide a correct count in r10 of bytes that failed to be copied, \n\
+; we jump back into the loop if the loop-branch was taken. There is no \n\
+; performance penalty for sany use; the program will segfault soon enough.\n\
+ \n\
+3: \n\
+ move.d [$sp],$r10 \n\
+ addq 44,$r10 \n\
+ move.d $r10,[$sp] \n\
+ jump 0b \n\
+4: \n\
+ movem [$sp+],$r10 \n\
+ addq 44,$r10 \n\
+ addq 44,$r12 \n\
+ jump 2b \n\
+ \n\
+ .previous \n\
+ .section __ex_table,\"a\" \n\
+ .dword 0b,3b \n\
+ .dword 1b,4b \n\
.previous"
/* Outputs */ : "=r" (dst), "=r" (src), "=r" (n), "=r" (retn)
If you want to check that the allocation was right; then
check the equalities in the first comment. It should say
"r13=r13, r11=r11, r12=r12" */
- __asm__ volatile ("
+ __asm__ volatile ("\n\
.ifnc %0%1%2%3,$r13$r11$r12$r10 \n\
.err \n\
.endif \n\
-
- ;; Save the registers we'll use in the movem process
- ;; on the stack.
- subq 11*4,$sp
- movem $r10,[$sp]
-
- ;; Now we've got this:
- ;; r11 - src
- ;; r13 - dst
- ;; r12 - n
-
- ;; Update n for the first loop
- subq 44,$r12
-0:
- movem [$r11+],$r10
-1:
- subq 44,$r12
- bge 0b
- movem $r10,[$r13+]
-
- addq 44,$r12 ;; compensate for last loop underflowing n
-
- ;; Restore registers from stack
- movem [$sp+],$r10
-4:
- .section .fixup,\"ax\"
-
-;; Do not jump back into the loop if we fail. For some uses, we get a
-;; page fault somewhere on the line. Without checking for page limits,
-;; we don't know where, but we need to copy accurately and keep an
-;; accurate count; not just clear the whole line. To do that, we fall
-;; down in the code below, proceeding with smaller amounts. It should
-;; be kept in mind that we have to cater to code like what at one time
-;; was in fs/super.c:
-;; i = size - copy_from_user((void *)page, data, size);
-;; which would cause repeated faults while clearing the remainder of
-;; the SIZE bytes at PAGE after the first fault.
-;; A caveat here is that we must not fall through from a failing page
-;; to a valid page.
-
-3:
- movem [$sp+],$r10
- addq 44,$r12 ;; Get back count before faulting point.
- subq 44,$r11 ;; Get back pointer to faulting movem-line.
- jump 4b ;; Fall through, pretending the fault didn't happen.
-
- .previous
- .section __ex_table,\"a\"
- .dword 1b,3b
+ \n\
+ ;; Save the registers we'll use in the movem process \n\
+ ;; on the stack. \n\
+ subq 11*4,$sp \n\
+ movem $r10,[$sp] \n\
+ \n\
+ ;; Now we've got this: \n\
+ ;; r11 - src \n\
+ ;; r13 - dst \n\
+ ;; r12 - n \n\
+ \n\
+ ;; Update n for the first loop \n\
+ subq 44,$r12 \n\
+0: \n\
+ movem [$r11+],$r10 \n\
+1: \n\
+ subq 44,$r12 \n\
+ bge 0b \n\
+ movem $r10,[$r13+] \n\
+ \n\
+ addq 44,$r12 ;; compensate for last loop underflowing n \n\
+ \n\
+ ;; Restore registers from stack \n\
+ movem [$sp+],$r10 \n\
+4: \n\
+ .section .fixup,\"ax\" \n\
+ \n\
+;; Do not jump back into the loop if we fail. For some uses, we get a \n\
+;; page fault somewhere on the line. Without checking for page limits, \n\
+;; we don't know where, but we need to copy accurately and keep an \n\
+;; accurate count; not just clear the whole line. To do that, we fall \n\
+;; down in the code below, proceeding with smaller amounts. It should \n\
+;; be kept in mind that we have to cater to code like what at one time \n\
+;; was in fs/super.c: \n\
+;; i = size - copy_from_user((void *)page, data, size); \n\
+;; which would cause repeated faults while clearing the remainder of \n\
+;; the SIZE bytes at PAGE after the first fault. \n\
+;; A caveat here is that we must not fall through from a failing page \n\
+;; to a valid page. \n\
+ \n\
+3: \n\
+ movem [$sp+],$r10 \n\
+ addq 44,$r12 ;; Get back count before faulting point. \n\
+ subq 44,$r11 ;; Get back pointer to faulting movem-line. \n\
+ jump 4b ;; Fall through, pretending the fault didn't happen.\n\
+ \n\
+ .previous \n\
+ .section __ex_table,\"a\" \n\
+ .dword 1b,3b \n\
.previous"
/* Outputs */ : "=r" (dst), "=r" (src), "=r" (n), "=r" (retn)
If you want to check that the allocation was right; then
check the equalities in the first comment. It should say
something like "r13=r13, r11=r11, r12=r12". */
- __asm__ volatile ("
+ __asm__ volatile ("\n\
.ifnc %0%1%2,$r13$r12$r10 \n\
.err \n\
.endif \n\
-
- ;; Save the registers we'll clobber in the movem process
- ;; on the stack. Don't mention them to gcc, it will only be
- ;; upset.
- subq 11*4,$sp
- movem $r10,[$sp]
-
- clear.d $r0
- clear.d $r1
- clear.d $r2
- clear.d $r3
- clear.d $r4
- clear.d $r5
- clear.d $r6
- clear.d $r7
- clear.d $r8
- clear.d $r9
- clear.d $r10
- clear.d $r11
-
- ;; Now we've got this:
- ;; r13 - dst
- ;; r12 - n
-
- ;; Update n for the first loop
- subq 12*4,$r12
-0:
- subq 12*4,$r12
- bge 0b
- movem $r11,[$r13+]
-1:
- addq 12*4,$r12 ;; compensate for last loop underflowing n
-
- ;; Restore registers from stack
- movem [$sp+],$r10
-2:
- .section .fixup,\"ax\"
-3:
- move.d [$sp],$r10
- addq 12*4,$r10
- move.d $r10,[$sp]
- clear.d $r10
- jump 0b
-
-4:
- movem [$sp+],$r10
- addq 12*4,$r10
- addq 12*4,$r12
- jump 2b
-
- .previous
- .section __ex_table,\"a\"
- .dword 0b,3b
- .dword 1b,4b
+ \n\
+ ;; Save the registers we'll clobber in the movem process \n\
+ ;; on the stack. Don't mention them to gcc, it will only be \n\
+ ;; upset. \n\
+ subq 11*4,$sp \n\
+ movem $r10,[$sp] \n\
+ \n\
+ clear.d $r0 \n\
+ clear.d $r1 \n\
+ clear.d $r2 \n\
+ clear.d $r3 \n\
+ clear.d $r4 \n\
+ clear.d $r5 \n\
+ clear.d $r6 \n\
+ clear.d $r7 \n\
+ clear.d $r8 \n\
+ clear.d $r9 \n\
+ clear.d $r10 \n\
+ clear.d $r11 \n\
+ \n\
+ ;; Now we've got this: \n\
+ ;; r13 - dst \n\
+ ;; r12 - n \n\
+ \n\
+ ;; Update n for the first loop \n\
+ subq 12*4,$r12 \n\
+0: \n\
+ subq 12*4,$r12 \n\
+ bge 0b \n\
+ movem $r11,[$r13+] \n\
+1: \n\
+ addq 12*4,$r12 ;; compensate for last loop underflowing n\n\
+ \n\
+ ;; Restore registers from stack \n\
+ movem [$sp+],$r10 \n\
+2: \n\
+ .section .fixup,\"ax\" \n\
+3: \n\
+ move.d [$sp],$r10 \n\
+ addq 12*4,$r10 \n\
+ move.d $r10,[$sp] \n\
+ clear.d $r10 \n\
+ jump 0b \n\
+ \n\
+4: \n\
+ movem [$sp+],$r10 \n\
+ addq 12*4,$r10 \n\
+ addq 12*4,$r12 \n\
+ jump 2b \n\
+ \n\
+ .previous \n\
+ .section __ex_table,\"a\" \n\
+ .dword 0b,3b \n\
+ .dword 1b,4b \n\
.previous"
/* Outputs */ : "=r" (dst), "=r" (n), "=r" (retn)
projects / mirror_ubuntu-eoan-kernel.git / commitdiff