parisc: Remove lock code to serialize TLB operations in pacache.S

TLB operations only need to be serialized on machines with the Merced
(Stretch) bus. The only machines in this category are L and N class, and
they require a 64-bit PA 2.0 kernel. On these machines, we use local TLB
purges in the tmpalias routines.
We don't need to serialize TLB purges on all other machines. Thus, the
lock/unlock code can be removed when CONFIG_PA20 is not defined.
Further, when CONFIG_PA20 is not defined, alternative patching converts
the TLB purges to local purges when PA 2.0 hardware has been detected.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Tested-By: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/pacache.S

@@ -311,39 +311,6 @@ fdsync:
 	nop
 ENDPROC_CFI(flush_data_cache_local)
 
-/* Macros to serialize TLB purge operations on SMP.  */
-
-	.macro	tlb_lock	la,flags,tmp
-#ifdef CONFIG_SMP
-98:
-#if __PA_LDCW_ALIGNMENT > 4
-	load32		pa_tlb_lock + __PA_LDCW_ALIGNMENT-1, \la
-	depi		0,31,__PA_LDCW_ALIGN_ORDER, \la
-#else
-	load32		pa_tlb_lock, \la
-#endif
-	rsm		PSW_SM_I,\flags
-1:	LDCW		0(\la),\tmp
-	cmpib,<>,n	0,\tmp,3f
-2:	ldw		0(\la),\tmp
-	cmpb,<>		%r0,\tmp,1b
-	nop
-	b,n		2b
-3:
-99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
-#endif
-	.endm
-
-	.macro	tlb_unlock	la,flags,tmp
-#ifdef CONFIG_SMP
-98:	ldi		1,\tmp
-	sync
-	stw		\tmp,0(\la)
-	mtsm		\flags
-99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
-#endif
-	.endm
-
 /* Clear page using kernel mapping.  */
 
 ENTRY_CFI(clear_page_asm)
@@ -601,10 +568,8 @@ ENTRY_CFI(copy_user_page_asm)
 	pdtlb,l		%r0(%r28)
 	pdtlb,l		%r0(%r29)
 #else
-	tlb_lock	%r20,%r21,%r22
 0:	pdtlb		%r0(%r28)
 1:	pdtlb		%r0(%r29)
-	tlb_unlock	%r20,%r21,%r22
 	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 	ALTERNATIVE(1b, 1b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 #endif
@@ -743,9 +708,7 @@ ENTRY_CFI(clear_user_page_asm)
 #ifdef CONFIG_PA20
 	pdtlb,l		%r0(%r28)
 #else
-	tlb_lock	%r20,%r21,%r22
 0:	pdtlb		%r0(%r28)
-	tlb_unlock	%r20,%r21,%r22
 	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 #endif
 
@@ -821,9 +784,7 @@ ENTRY_CFI(flush_dcache_page_asm)
 #ifdef CONFIG_PA20
 	pdtlb,l		%r0(%r28)
 #else
-	tlb_lock	%r20,%r21,%r22
 0:	pdtlb		%r0(%r28)
-	tlb_unlock	%r20,%r21,%r22
 	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 #endif
 
@@ -882,9 +843,7 @@ ENTRY_CFI(purge_dcache_page_asm)
 #ifdef CONFIG_PA20
 	pdtlb,l		%r0(%r28)
 #else
-	tlb_lock	%r20,%r21,%r22
 0:	pdtlb		%r0(%r28)
-	tlb_unlock	%r20,%r21,%r22
 	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 #endif
 
@@ -948,10 +907,8 @@ ENTRY_CFI(flush_icache_page_asm)
 1:	pitlb,l         %r0(%sr4,%r28)
 	ALTERNATIVE(1b, 1b+4, ALT_COND_NO_SPLIT_TLB, INSN_NOP)
 #else
-	tlb_lock        %r20,%r21,%r22
 0:	pdtlb		%r0(%r28)
 1:	pitlb           %r0(%sr4,%r28)
-	tlb_unlock      %r20,%r21,%r22
 	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 	ALTERNATIVE(1b, 1b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 	ALTERNATIVE(1b, 1b+4, ALT_COND_NO_SPLIT_TLB, INSN_NOP)