Commit 6e9f06ee authored by Helge Deller's avatar Helge Deller
Browse files

Revert "parisc: Use ldcw instruction for SMP spinlock release barrier" 



This reverts commit 9e5c6021.
No need to use the ldcw instruction as SMP spinlock release barrier.
Revert it to gain back speed again.

Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.2+
parent 462fb756

arch/parisc/include/asm/spinlock.h

+0 −4
Original line number Diff line number Diff line
@@ -37,11 +37,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *x) 
	volatile unsigned int *a;



	a = __ldcw_align(x);

#ifdef CONFIG_SMP

	(void) __ldcw(a);

#else

	mb();

#endif

	*a = 1;

}

arch/parisc/kernel/entry.S

+20 −23
Original line number Diff line number Diff line
@@ -454,9 +454,8 @@ 
	nop

	LDREG		0(\ptp),\pte

	bb,<,n		\pte,_PAGE_PRESENT_BIT,3f

	LDCW		0(\tmp),\tmp1

	b		\fault

	stw		\spc,0(\tmp)

	stw,ma		\spc,0(\tmp)

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

#endif

2:	LDREG		0(\ptp),\pte
@@ -465,22 +464,20 @@ 
	.endm



	/* Release pa_tlb_lock lock without reloading lock address. */

	.macro		tlb_unlock0	spc,tmp,tmp1

	.macro		tlb_unlock0	spc,tmp

#ifdef CONFIG_SMP

98:	or,COND(=)	%r0,\spc,%r0

	LDCW		0(\tmp),\tmp1

	or,COND(=)	%r0,\spc,%r0

	stw		\spc,0(\tmp)

	stw,ma		\spc,0(\tmp)

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

#endif

	.endm



	/* Release pa_tlb_lock lock. */

	.macro		tlb_unlock1	spc,tmp,tmp1

	.macro		tlb_unlock1	spc,tmp

#ifdef CONFIG_SMP

98:	load_pa_tlb_lock \tmp

99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)

	tlb_unlock0	\spc,\tmp,\tmp1

	tlb_unlock0	\spc,\tmp

#endif

	.endm
@@ -1163,7 +1160,7 @@ dtlb_miss_20w: 
	

	idtlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1189,7 +1186,7 @@ nadtlb_miss_20w: 


	idtlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1223,7 +1220,7 @@ dtlb_miss_11: 


	mtsp		t1, %sr1	/* Restore sr1 */



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1256,7 +1253,7 @@ nadtlb_miss_11: 


	mtsp		t1, %sr1	/* Restore sr1 */



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1285,7 +1282,7 @@ dtlb_miss_20: 


	idtlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1313,7 +1310,7 @@ nadtlb_miss_20: 
	

	idtlbt		pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1420,7 +1417,7 @@ itlb_miss_20w: 
	

	iitlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1444,7 +1441,7 @@ naitlb_miss_20w: 


	iitlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1478,7 +1475,7 @@ itlb_miss_11: 


	mtsp		t1, %sr1	/* Restore sr1 */



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1502,7 +1499,7 @@ naitlb_miss_11: 


	mtsp		t1, %sr1	/* Restore sr1 */



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1532,7 +1529,7 @@ itlb_miss_20: 


	iitlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1552,7 +1549,7 @@ naitlb_miss_20: 


	iitlbt          pte,prot



	tlb_unlock1	spc,t0,t1

	tlb_unlock1	spc,t0

	rfir

	nop
@@ -1582,7 +1579,7 @@ dbit_trap_20w: 
		

	idtlbt          pte,prot



	tlb_unlock0	spc,t0,t1

	tlb_unlock0	spc,t0

	rfir

	nop

#else
@@ -1608,7 +1605,7 @@ dbit_trap_11: 


	mtsp            t1, %sr1     /* Restore sr1 */



	tlb_unlock0	spc,t0,t1

	tlb_unlock0	spc,t0

	rfir

	nop
@@ -1628,7 +1625,7 @@ dbit_trap_20: 
	

	idtlbt		pte,prot



	tlb_unlock0	spc,t0,t1

	tlb_unlock0	spc,t0

	rfir

	nop

#endif

arch/parisc/kernel/syscall.S

+4 −12
Original line number Diff line number Diff line
@@ -640,9 +640,7 @@ cas_action: 
	sub,<>	%r28, %r25, %r0

2:	stw	%r24, 0(%r26)

	/* Free lock */

#ifdef CONFIG_SMP

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

	sync

	stw	%r20, 0(%sr2,%r20)

#if ENABLE_LWS_DEBUG

	/* Clear thread register indicator */
@@ -657,9 +655,7 @@ cas_action: 
3:		

	/* Error occurred on load or store */

	/* Free lock */

#ifdef CONFIG_SMP

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

	sync

	stw	%r20, 0(%sr2,%r20)

#if ENABLE_LWS_DEBUG

	stw	%r0, 4(%sr2,%r20)
@@ -861,9 +857,7 @@ cas2_action: 


cas2_end:

	/* Free lock */

#ifdef CONFIG_SMP

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

	sync

	stw	%r20, 0(%sr2,%r20)

	/* Enable interrupts */

	ssm	PSW_SM_I, %r0
@@ -874,9 +868,7 @@ cas2_end: 
22:

	/* Error occurred on load or store */

	/* Free lock */

#ifdef CONFIG_SMP

	LDCW	0(%sr2,%r20), %r1			/* Barrier */

#endif

	sync

	stw	%r20, 0(%sr2,%r20)

	ssm	PSW_SM_I, %r0

	ldo	1(%r0),%r28