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s390/alternatives: provide identical sized orginal/alternative sequences

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Explicitly provide identical sized original/alternative instruction
sequences. This way there is no need for the s390 specific alternatives
infrastructure to generate padding sequences.
The code which generates such sequences will be removed with a follow on
patch.

Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220511120532.2228616-2-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2022-05-11 14:05:25 +02:00
parent c9311de716
commit fad442d3ab
3 changed files with 13 additions and 13 deletions
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2
arch/s390/include/asm/spinlock.h
View File

@ -79,7 +79,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp)
typecheck(int, lp->lock);
kcsan_release();
asm_inline volatile(
ALTERNATIVE("", ".insn rre,0xb2fa0000,7,0", 49) /* NIAI 7 */
ALTERNATIVE("nop", ".insn rre,0xb2fa0000,7,0", 49) /* NIAI 7 */
" sth %1,%0\n"
: "=R" (((unsigned short *) &lp->lock)[1])
: "d" (0) : "cc", "memory");

20
arch/s390/kernel/entry.S
View File

@ -53,19 +53,19 @@ STACK_INIT = STACK_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE
_LPP_OFFSET = __LC_LPP
.macro STBEAR address
ALTERNATIVE "", ".insn s,0xb2010000,\address", 193
ALTERNATIVE "nop", ".insn s,0xb2010000,\address", 193
.endm
.macro LBEAR address
ALTERNATIVE "", ".insn s,0xb2000000,\address", 193
ALTERNATIVE "nop", ".insn s,0xb2000000,\address", 193
.endm
.macro LPSWEY address,lpswe
ALTERNATIVE "b \lpswe", ".insn siy,0xeb0000000071,\address,0", 193
ALTERNATIVE "b \lpswe; nopr", ".insn siy,0xeb0000000071,\address,0", 193
.endm
.macro MBEAR reg
ALTERNATIVE "", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), 193
ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), 193
.endm
.macro CHECK_STACK savearea
@ -121,16 +121,16 @@ _LPP_OFFSET = __LC_LPP
.endm
.macro BPOFF
ALTERNATIVE "", ".insn rrf,0xb2e80000,0,0,12,0", 82
ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", 82
.endm
.macro BPON
ALTERNATIVE "", ".insn rrf,0xb2e80000,0,0,13,0", 82
ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", 82
.endm
.macro BPENTER tif_ptr,tif_mask
ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .insn rrf,0xb2e80000,0,0,13,0", \
"", 82
"j .+12; nop; nop", 82
.endm
.macro BPEXIT tif_ptr,tif_mask
@ -226,7 +226,7 @@ ENTRY(__switch_to)
aghi %r3,__TASK_pid
mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
ALTERNATIVE "", "lpp _LPP_OFFSET", 40
ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40
BR_EX %r14
ENDPROC(__switch_to)
@ -610,7 +610,7 @@ ENTRY(mcck_int_handler)
jno 0f
BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
stpt __LC_EXIT_TIMER
0: ALTERNATIVE "", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193
0: ALTERNATIVE "nop", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193
LBEAR 0(%r12)
lmg %r11,%r15,__PT_R11(%r11)
LPSWEY __LC_RETURN_MCCK_PSW,__LC_RETURN_MCCK_LPSWE
@ -646,7 +646,7 @@ ENTRY(mcck_int_handler)
ENDPROC(mcck_int_handler)
ENTRY(restart_int_handler)
ALTERNATIVE "", "lpp _LPP_OFFSET", 40
ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40
stg %r15,__LC_SAVE_AREA_RESTART
TSTMSK __LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4
jz 0f

4
arch/s390/lib/spinlock.c
View File

@ -75,7 +75,7 @@ static inline int arch_load_niai4(int *lock)
int owner;
asm_inline volatile(
ALTERNATIVE("", ".insn rre,0xb2fa0000,4,0", 49) /* NIAI 4 */
ALTERNATIVE("nop", ".insn rre,0xb2fa0000,4,0", 49) /* NIAI 4 */
" l %0,%1\n"
: "=d" (owner) : "Q" (*lock) : "memory");
return owner;
@ -86,7 +86,7 @@ static inline int arch_cmpxchg_niai8(int *lock, int old, int new)
int expected = old;
asm_inline volatile(
ALTERNATIVE("", ".insn rre,0xb2fa0000,8,0", 49) /* NIAI 8 */
ALTERNATIVE("nop", ".insn rre,0xb2fa0000,8,0", 49) /* NIAI 8 */
" cs %0,%3,%1\n"
: "=d" (old), "=Q" (*lock)
: "0" (old), "d" (new), "Q" (*lock)