diff --git a/arch/parisc/include/asm/alternative.h b/arch/parisc/include/asm/alternative.h
new file mode 100644
index 0000000000000000000000000000000000000000..bf485a94d0b4b8697b699e6ddc99d4e33b3d7f6a
--- /dev/null
+++ b/arch/parisc/include/asm/alternative.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_PARISC_ALTERNATIVE_H
+#define __ASM_PARISC_ALTERNATIVE_H
+
+#define ALT_COND_NO_SMP		0x01	/* when running UP instead of SMP */
+#define ALT_COND_NO_DCACHE	0x02	/* if system has no d-cache  */
+#define ALT_COND_NO_ICACHE	0x04	/* if system has no i-cache  */
+#define ALT_COND_NO_SPLIT_TLB	0x08	/* if split_tlb == 0  */
+#define ALT_COND_NO_IOC_FDC	0x10	/* if I/O cache does not need flushes */
+
+#define INSN_PxTLB	0x02		/* modify pdtlb, pitlb */
+#define INSN_NOP	0x08000240	/* nop */
+
+#ifndef __ASSEMBLY__
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/stringify.h>
+
+struct alt_instr {
+	s32 orig_offset;	/* offset to original instructions */
+	u32 len;		/* end of original instructions */
+	u32 cond;		/* see ALT_COND_XXX */
+	u32 replacement;	/* replacement instruction or code */
+};
+
+void set_kernel_text_rw(int enable_read_write);
+
+/* Alternative SMP implementation. */
+#define ALTERNATIVE(cond, replacement)		"!0:"	\
+	".section .altinstructions, \"aw\"	!"	\
+	".word (0b-4-.), 1, " __stringify(cond) ","	\
+		__stringify(replacement) "	!"	\
+	".previous"
+
+#else
+
+#define ALTERNATIVE(from, to, cond, replacement)\
+	.section .altinstructions, "aw"	!	\
+	.word (from - .), (to - from)/4	!	\
+	.word cond, replacement		!	\
+	.previous
+
+#endif  /*  __ASSEMBLY__  */
+
+#endif /* __ASM_PARISC_ALTERNATIVE_H */
diff --git a/arch/parisc/include/asm/cache.h b/arch/parisc/include/asm/cache.h
index 150b7f30ea9073f218a8f0967ab7229a5f5095aa..006fb939cac8801c20cafff55fb713b823dfac59 100644
--- a/arch/parisc/include/asm/cache.h
+++ b/arch/parisc/include/asm/cache.h
@@ -6,6 +6,7 @@
 #ifndef __ARCH_PARISC_CACHE_H
 #define __ARCH_PARISC_CACHE_H
 
+#include <asm/alternative.h>
 
 /*
  * PA 2.0 processors have 64 and 128-byte L2 cachelines; PA 1.1 processors
@@ -41,9 +42,24 @@ extern int icache_stride;
 extern struct pdc_cache_info cache_info;
 void parisc_setup_cache_timing(void);
 
-#define pdtlb(addr)         asm volatile("pdtlb 0(%%sr1,%0)" : : "r" (addr));
-#define pitlb(addr)         asm volatile("pitlb 0(%%sr1,%0)" : : "r" (addr));
-#define pdtlb_kernel(addr)  asm volatile("pdtlb 0(%0)" : : "r" (addr));
+#define pdtlb(addr)	asm volatile("pdtlb 0(%%sr1,%0)" \
+			ALTERNATIVE(ALT_COND_NO_SMP, INSN_PxTLB) \
+			: : "r" (addr))
+#define pitlb(addr)	asm volatile("pitlb 0(%%sr1,%0)" \
+			ALTERNATIVE(ALT_COND_NO_SMP, INSN_PxTLB) \
+			ALTERNATIVE(ALT_COND_NO_SPLIT_TLB, INSN_NOP) \
+			: : "r" (addr))
+#define pdtlb_kernel(addr)  asm volatile("pdtlb 0(%0)"   \
+			ALTERNATIVE(ALT_COND_NO_SMP, INSN_PxTLB) \
+			: : "r" (addr))
+
+#define asm_io_fdc(addr) asm volatile("fdc %%r0(%0)" \
+			ALTERNATIVE(ALT_COND_NO_DCACHE, INSN_NOP) \
+			ALTERNATIVE(ALT_COND_NO_IOC_FDC, INSN_NOP) \
+			: : "r" (addr))
+#define asm_io_sync()	asm volatile("sync" \
+			ALTERNATIVE(ALT_COND_NO_DCACHE, INSN_NOP) \
+			ALTERNATIVE(ALT_COND_NO_IOC_FDC, INSN_NOP) :: )
 
 #endif /* ! __ASSEMBLY__ */
 
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index b86c31291f0a59298969e5edf527a59b3da0114a..94c0ef7a9e030f78406369994d972eea1e3493f4 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -43,8 +43,7 @@ static inline void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
 {
 	mtsp(mm->context, 1);
 	pdtlb(addr);
-	if (unlikely(split_tlb))
-		pitlb(addr);
+	pitlb(addr);
 }
 
 /* Certain architectures need to do special things when PTEs
diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h
index 5a40b51df80ce1f6f5cb331975ca273575db622e..bb52aea0cb21ece34c267ddd6a9c281d63aca140 100644
--- a/arch/parisc/include/asm/sections.h
+++ b/arch/parisc/include/asm/sections.h
@@ -5,6 +5,8 @@
 /* nothing to see, move along */
 #include <asm-generic/sections.h>
 
+extern char __alt_instructions[], __alt_instructions_end[];
+
 #ifdef CONFIG_64BIT
 
 #define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
diff --git a/arch/parisc/include/asm/tlbflush.h b/arch/parisc/include/asm/tlbflush.h
index 14668bd52d6065e41d4b8b446ba984453af9a201..6804374efa66be4794f68949e073d67d3786cb2f 100644
--- a/arch/parisc/include/asm/tlbflush.h
+++ b/arch/parisc/include/asm/tlbflush.h
@@ -85,8 +85,7 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
 	purge_tlb_start(flags);
 	mtsp(sid, 1);
 	pdtlb(addr);
-	if (unlikely(split_tlb))
-		pitlb(addr);
+	pitlb(addr);
 	purge_tlb_end(flags);
 }
 #endif
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 9f1c29d06574b0182c895ad7d73968de74644ca9..56dc9791ee23f7c3fb3df3d53d643bbf135deb68 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -479,18 +479,6 @@ int __flush_tlb_range(unsigned long sid, unsigned long start,
 	/* Purge TLB entries for small ranges using the pdtlb and
 	   pitlb instructions.  These instructions execute locally
 	   but cause a purge request to be broadcast to other TLBs.  */
-	if (likely(!split_tlb)) {
-		while (start < end) {
-			purge_tlb_start(flags);
-			mtsp(sid, 1);
-			pdtlb(start);
-			purge_tlb_end(flags);
-			start += PAGE_SIZE;
-		}
-		return 0;
-	}
-
-	/* split TLB case */
 	while (start < end) {
 		purge_tlb_start(flags);
 		mtsp(sid, 1);
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 7c85a91b4710b53c10c5c9adb1d068be124b72f6..d3e2633cd688ef01a8940fec364d97eb030f12dd 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -38,6 +38,7 @@
 #include <asm/ldcw.h>
 #include <asm/traps.h>
 #include <asm/thread_info.h>
+#include <asm/alternative.h>
 
 #include <linux/linkage.h>
 
@@ -464,7 +465,7 @@
 	/* Acquire pa_tlb_lock lock and check page is present. */
 	.macro		tlb_lock	spc,ptp,pte,tmp,tmp1,fault
 #ifdef CONFIG_SMP
-	cmpib,COND(=),n	0,\spc,2f
+98:	cmpib,COND(=),n	0,\spc,2f
 	load_pa_tlb_lock \tmp
 1:	LDCW		0(\tmp),\tmp1
 	cmpib,COND(=)	0,\tmp1,1b
@@ -473,6 +474,7 @@
 	bb,<,n		\pte,_PAGE_PRESENT_BIT,3f
 	b		\fault
 	stw,ma		\spc,0(\tmp)
+99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
 #endif
 2:	LDREG		0(\ptp),\pte
 	bb,>=,n		\pte,_PAGE_PRESENT_BIT,\fault
@@ -482,15 +484,17 @@
 	/* Release pa_tlb_lock lock without reloading lock address. */
 	.macro		tlb_unlock0	spc,tmp
 #ifdef CONFIG_SMP
-	or,COND(=)	%r0,\spc,%r0
+98:	or,COND(=)	%r0,\spc,%r0
 	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
 #ifdef CONFIG_SMP
-	load_pa_tlb_lock \tmp
+98:	load_pa_tlb_lock \tmp
+99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
 	tlb_unlock0	\spc,\tmp
 #endif
 	.endm
diff --git a/arch/parisc/kernel/pacache.S b/arch/parisc/kernel/pacache.S
index f33bf2d306d607fb915c8469471793d9c1ddf2b5..b41c0136a05fb9922a03cd0fb5bc6fee8c9fe06e 100644
--- a/arch/parisc/kernel/pacache.S
+++ b/arch/parisc/kernel/pacache.S
@@ -37,6 +37,7 @@
 #include <asm/pgtable.h>
 #include <asm/cache.h>
 #include <asm/ldcw.h>
+#include <asm/alternative.h>
 #include <linux/linkage.h>
 #include <linux/init.h>
 
@@ -190,7 +191,7 @@ ENDPROC_CFI(flush_tlb_all_local)
 	.import cache_info,data
 
 ENTRY_CFI(flush_instruction_cache_local)
-	load32		cache_info, %r1
+88:	load32		cache_info, %r1
 
 	/* Flush Instruction Cache */
 
@@ -243,6 +244,7 @@ fioneloop2:
 fisync:
 	sync
 	mtsm		%r22			/* restore I-bit */
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_ICACHE, INSN_NOP)
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_instruction_cache_local)
@@ -250,7 +252,7 @@ ENDPROC_CFI(flush_instruction_cache_local)
 
 	.import cache_info, data
 ENTRY_CFI(flush_data_cache_local)
-	load32		cache_info, %r1
+88:	load32		cache_info, %r1
 
 	/* Flush Data Cache */
 
@@ -304,6 +306,7 @@ fdsync:
 	syncdma
 	sync
 	mtsm		%r22			/* restore I-bit */
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_data_cache_local)
@@ -312,6 +315,7 @@ ENDPROC_CFI(flush_data_cache_local)
 
 	.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
@@ -326,15 +330,17 @@ ENDPROC_CFI(flush_data_cache_local)
 	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
-	ldi		1,\tmp
+98:	ldi		1,\tmp
 	sync
 	stw		\tmp,0(\la)
 	mtsm		\flags
+99:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
 #endif
 	.endm
 
@@ -596,9 +602,11 @@ ENTRY_CFI(copy_user_page_asm)
 	pdtlb,l		%r0(%r29)
 #else
 	tlb_lock	%r20,%r21,%r22
-	pdtlb		%r0(%r28)
-	pdtlb		%r0(%r29)
+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
 
 #ifdef CONFIG_64BIT
@@ -736,8 +744,9 @@ ENTRY_CFI(clear_user_page_asm)
 	pdtlb,l		%r0(%r28)
 #else
 	tlb_lock	%r20,%r21,%r22
-	pdtlb		%r0(%r28)
+0:	pdtlb		%r0(%r28)
 	tlb_unlock	%r20,%r21,%r22
+	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 #endif
 
 #ifdef CONFIG_64BIT
@@ -813,11 +822,12 @@ ENTRY_CFI(flush_dcache_page_asm)
 	pdtlb,l		%r0(%r28)
 #else
 	tlb_lock	%r20,%r21,%r22
-	pdtlb		%r0(%r28)
+0:	pdtlb		%r0(%r28)
 	tlb_unlock	%r20,%r21,%r22
+	ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
 #endif
 
-	ldil		L%dcache_stride, %r1
+88:	ldil		L%dcache_stride, %r1
 	ldw		R%dcache_stride(%r1), r31
 
 #ifdef CONFIG_64BIT
@@ -847,6 +857,7 @@ ENTRY_CFI(flush_dcache_page_asm)
 	cmpb,COND(<<)	%r28, %r25,1b
 	fdc,m		r31(%r28)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
@@ -874,15 +885,19 @@ ENTRY_CFI(flush_icache_page_asm)
 
 #ifdef CONFIG_PA20
 	pdtlb,l		%r0(%r28)
-	pitlb,l         %r0(%sr4,%r28)
+1:	pitlb,l         %r0(%sr4,%r28)
+	ALTERNATIVE(1b, 1b+4, ALT_COND_NO_SPLIT_TLB, INSN_NOP)
 #else
 	tlb_lock        %r20,%r21,%r22
-	pdtlb		%r0(%r28)
-	pitlb           %r0(%sr4,%r28)
+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)
 #endif
 
-	ldil		L%icache_stride, %r1
+88:	ldil		L%icache_stride, %r1
 	ldw		R%icache_stride(%r1), %r31
 
 #ifdef CONFIG_64BIT
@@ -914,13 +929,14 @@ ENTRY_CFI(flush_icache_page_asm)
 	cmpb,COND(<<)	%r28, %r25,1b
 	fic,m		%r31(%sr4,%r28)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_ICACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_icache_page_asm)
 
 ENTRY_CFI(flush_kernel_dcache_page_asm)
-	ldil		L%dcache_stride, %r1
+88:	ldil		L%dcache_stride, %r1
 	ldw		R%dcache_stride(%r1), %r23
 
 #ifdef CONFIG_64BIT
@@ -950,13 +966,14 @@ ENTRY_CFI(flush_kernel_dcache_page_asm)
 	cmpb,COND(<<)		%r26, %r25,1b
 	fdc,m		%r23(%r26)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_kernel_dcache_page_asm)
 
 ENTRY_CFI(purge_kernel_dcache_page_asm)
-	ldil		L%dcache_stride, %r1
+88:	ldil		L%dcache_stride, %r1
 	ldw		R%dcache_stride(%r1), %r23
 
 #ifdef CONFIG_64BIT
@@ -985,13 +1002,14 @@ ENTRY_CFI(purge_kernel_dcache_page_asm)
 	cmpb,COND(<<)		%r26, %r25, 1b
 	pdc,m		%r23(%r26)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(purge_kernel_dcache_page_asm)
 
 ENTRY_CFI(flush_user_dcache_range_asm)
-	ldil		L%dcache_stride, %r1
+88:	ldil		L%dcache_stride, %r1
 	ldw		R%dcache_stride(%r1), %r23
 	ldo		-1(%r23), %r21
 	ANDCM		%r26, %r21, %r26
@@ -999,13 +1017,14 @@ ENTRY_CFI(flush_user_dcache_range_asm)
 1:      cmpb,COND(<<),n	%r26, %r25, 1b
 	fdc,m		%r23(%sr3, %r26)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_user_dcache_range_asm)
 
 ENTRY_CFI(flush_kernel_dcache_range_asm)
-	ldil		L%dcache_stride, %r1
+88:	ldil		L%dcache_stride, %r1
 	ldw		R%dcache_stride(%r1), %r23
 	ldo		-1(%r23), %r21
 	ANDCM		%r26, %r21, %r26
@@ -1014,13 +1033,14 @@ ENTRY_CFI(flush_kernel_dcache_range_asm)
 	fdc,m		%r23(%r26)
 
 	sync
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	syncdma
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_kernel_dcache_range_asm)
 
 ENTRY_CFI(purge_kernel_dcache_range_asm)
-	ldil		L%dcache_stride, %r1
+88:	ldil		L%dcache_stride, %r1
 	ldw		R%dcache_stride(%r1), %r23
 	ldo		-1(%r23), %r21
 	ANDCM		%r26, %r21, %r26
@@ -1029,13 +1049,14 @@ ENTRY_CFI(purge_kernel_dcache_range_asm)
 	pdc,m		%r23(%r26)
 
 	sync
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_DCACHE, INSN_NOP)
 	syncdma
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(purge_kernel_dcache_range_asm)
 
 ENTRY_CFI(flush_user_icache_range_asm)
-	ldil		L%icache_stride, %r1
+88:	ldil		L%icache_stride, %r1
 	ldw		R%icache_stride(%r1), %r23
 	ldo		-1(%r23), %r21
 	ANDCM		%r26, %r21, %r26
@@ -1043,13 +1064,14 @@ ENTRY_CFI(flush_user_icache_range_asm)
 1:      cmpb,COND(<<),n	%r26, %r25,1b
 	fic,m		%r23(%sr3, %r26)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_ICACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_user_icache_range_asm)
 
 ENTRY_CFI(flush_kernel_icache_page)
-	ldil		L%icache_stride, %r1
+88:	ldil		L%icache_stride, %r1
 	ldw		R%icache_stride(%r1), %r23
 
 #ifdef CONFIG_64BIT
@@ -1079,13 +1101,14 @@ ENTRY_CFI(flush_kernel_icache_page)
 	cmpb,COND(<<)		%r26, %r25, 1b
 	fic,m		%r23(%sr4, %r26)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_ICACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
 ENDPROC_CFI(flush_kernel_icache_page)
 
 ENTRY_CFI(flush_kernel_icache_range_asm)
-	ldil		L%icache_stride, %r1
+88:	ldil		L%icache_stride, %r1
 	ldw		R%icache_stride(%r1), %r23
 	ldo		-1(%r23), %r21
 	ANDCM		%r26, %r21, %r26
@@ -1093,6 +1116,7 @@ ENTRY_CFI(flush_kernel_icache_range_asm)
 1:      cmpb,COND(<<),n	%r26, %r25, 1b
 	fic,m		%r23(%sr4, %r26)
 
+89:	ALTERNATIVE(88b, 89b, ALT_COND_NO_ICACHE, INSN_NOP)
 	sync
 	bv		%r0(%r2)
 	nop
diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index 4e87c35c22b7215722aebbf6a980e2706a15c44a..db6e7957f9a3962c555bcb30d9812895d52d24eb 100644
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -305,6 +305,86 @@ static int __init parisc_init_resources(void)
 	return 0;
 }
 
+static int no_alternatives __initdata;
+static int __init setup_no_alternatives(char *str)
+{
+	no_alternatives = 1;
+	return 1;
+}
+__setup("no-alternatives", setup_no_alternatives);
+
+static void __init apply_alternatives_all(void)
+{
+	struct alt_instr *entry;
+	int index = 0, applied = 0;
+
+
+	pr_info("alternatives: %spatching kernel code\n",
+		no_alternatives ? "NOT " : "");
+	if (no_alternatives)
+		return;
+
+	set_kernel_text_rw(1);
+
+	for (entry = (struct alt_instr *) &__alt_instructions;
+		entry < (struct alt_instr *) &__alt_instructions_end;
+		entry++, index++) {
+
+		u32 *from, len, cond, replacement;
+
+		from = (u32 *)((ulong)&entry->orig_offset + entry->orig_offset);
+		len = entry->len;
+		cond = entry->cond;
+		replacement = entry->replacement;
+
+		WARN_ON(!cond);
+		pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
+			index, cond, len, from, replacement);
+
+		if ((cond & ALT_COND_NO_SMP) && (num_online_cpus() != 1))
+			continue;
+		if ((cond & ALT_COND_NO_DCACHE) && (cache_info.dc_size != 0))
+			continue;
+		if ((cond & ALT_COND_NO_ICACHE) && (cache_info.ic_size != 0))
+			continue;
+
+		/*
+		 * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit
+		 * set (bit #61, big endian), we have to flush and sync every
+		 * time IO-PDIR is changed in Ike/Astro.
+		 */
+		if ((cond & ALT_COND_NO_IOC_FDC) &&
+			(boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC))
+			continue;
+
+		/* Want to replace pdtlb by a pdtlb,l instruction? */
+		if (replacement == INSN_PxTLB) {
+			replacement = *from;
+			if (boot_cpu_data.cpu_type >= pcxu) /* >= pa2.0 ? */
+				replacement |= (1 << 10); /* set el bit */
+		}
+
+		/*
+		 * Replace instruction with NOPs?
+		 * For long distance insert a branch instruction instead.
+		 */
+		if (replacement == INSN_NOP && len > 1)
+			replacement = 0xe8000002 + (len-2)*8; /* "b,n .+8" */
+
+		pr_debug("Do    %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
+			index, cond, len, from, replacement);
+
+		/* Replace instruction */
+		*from = replacement;
+		applied++;
+	}
+
+	pr_info("alternatives: applied %d out of %d patches\n", applied, index);
+
+	set_kernel_text_rw(0);
+}
+
+
 extern void gsc_init(void);
 extern void processor_init(void);
 extern void ccio_init(void);
@@ -346,6 +426,7 @@ static int __init parisc_init(void)
 			boot_cpu_data.cpu_hz / 1000000,
 			boot_cpu_data.cpu_hz % 1000000	);
 
+	apply_alternatives_all();
 	parisc_setup_cache_timing();
 
 	/* These are in a non-obvious order, will fix when we have an iotree */
diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
index 342073f44d3f16fb6ba9cbb3fc39e2eaafd04e59..848c1934680bb4a88610f3570e75d03d55f84429 100644
--- a/arch/parisc/kernel/signal.c
+++ b/arch/parisc/kernel/signal.c
@@ -65,7 +65,6 @@
 #define INSN_LDI_R25_1	 0x34190002 /* ldi  1,%r25 (in_syscall=1) */
 #define INSN_LDI_R20	 0x3414015a /* ldi  __NR_rt_sigreturn,%r20 */
 #define INSN_BLE_SR2_R0  0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
-#define INSN_NOP	 0x08000240 /* nop */
 /* For debugging */
 #define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
 
diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S
index da2e31190efa1b98f4975c0be5e4c633e4bc6e87..c3b1b9c24ede70fd9957d646613413dea42398eb 100644
--- a/arch/parisc/kernel/vmlinux.lds.S
+++ b/arch/parisc/kernel/vmlinux.lds.S
@@ -61,6 +61,12 @@ SECTIONS
 		EXIT_DATA
 	}
 	PERCPU_SECTION(8)
+	. = ALIGN(4);
+	.altinstructions : {
+		__alt_instructions = .;
+		*(.altinstructions)
+		__alt_instructions_end = .;
+	}
 	. = ALIGN(HUGEPAGE_SIZE);
 	__init_end = .;
 	/* freed after init ends here */
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index aae9b0d71c1e1ac5fe30419f7fbab29505c044ec..e7e626bcd0bedd5da1f66ddde635aa9d31d83527 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -511,6 +511,21 @@ static void __init map_pages(unsigned long start_vaddr,
 	}
 }
 
+void __init set_kernel_text_rw(int enable_read_write)
+{
+	unsigned long start = (unsigned long)_stext;
+	unsigned long end   = (unsigned long)_etext;
+
+	map_pages(start, __pa(start), end-start,
+		PAGE_KERNEL_RWX, enable_read_write ? 1:0);
+
+	/* force the kernel to see the new TLB entries */
+	__flush_tlb_range(0, start, end);
+
+	/* dump old cached instructions */
+	flush_icache_range(start, end);
+}
+
 void __ref free_initmem(void)
 {
 	unsigned long init_begin = (unsigned long)__init_begin;
diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index 614823617b8b9d8fad74f67112db7c31761c78a2..701a7d6a74d5c4cf1ac6e0bc697ce9455c0f3519 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -609,14 +609,13 @@ ccio_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
 	**        PCX-T'? Don't know. (eg C110 or similar K-class)
 	**
 	** See PDC_MODEL/option 0/SW_CAP word for "Non-coherent IO-PDIR bit".
-	** Hopefully we can patch (NOP) these out at boot time somehow.
 	**
 	** "Since PCX-U employs an offset hash that is incompatible with
 	** the real mode coherence index generation of U2, the PDIR entry
 	** must be flushed to memory to retain coherence."
 	*/
-	asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
-	asm volatile("sync");
+	asm_io_fdc(pdir_ptr);
+	asm_io_sync();
 }
 
 /**
@@ -682,17 +681,14 @@ ccio_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
 		** FIXME: PCX_W platforms don't need FDC/SYNC. (eg C360)
 		**   PCX-U/U+ do. (eg C200/C240)
 		** See PDC_MODEL/option 0/SW_CAP for "Non-coherent IO-PDIR bit".
-		**
-		** Hopefully someone figures out how to patch (NOP) the
-		** FDC/SYNC out at boot time.
 		*/
-		asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr[7]));
+		asm_io_fdc(pdir_ptr);
 
 		iovp     += IOVP_SIZE;
 		byte_cnt -= IOVP_SIZE;
 	}
 
-	asm volatile("sync");
+	asm_io_sync();
 	ccio_clear_io_tlb(ioc, CCIO_IOVP(iova), saved_byte_cnt);
 }
 
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 11de0eccf96841b65e3e404b2031baf0bc95dd32..c1e599a429af9714fa03a50de9664e7cfb2a3837 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -587,8 +587,7 @@ sba_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
 	 * (bit #61, big endian), we have to flush and sync every time
 	 * IO-PDIR is changed in Ike/Astro.
 	 */
-	if (ioc_needs_fdc)
-		asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
+	asm_io_fdc(pdir_ptr);
 }
 
 
@@ -641,8 +640,8 @@ sba_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
 		do {
 			/* clear I/O Pdir entry "valid" bit first */
 			((u8 *) pdir_ptr)[7] = 0;
+			asm_io_fdc(pdir_ptr);
 			if (ioc_needs_fdc) {
-				asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
 #if 0
 				entries_per_cacheline = L1_CACHE_SHIFT - 3;
 #endif
@@ -661,8 +660,7 @@ sba_mark_invalid(struct ioc *ioc, dma_addr_t iova, size_t byte_cnt)
 	** could dump core on HPMC.
 	*/
 	((u8 *) pdir_ptr)[7] = 0;
-	if (ioc_needs_fdc)
-		asm volatile("fdc %%r0(%0)" : : "r" (pdir_ptr));
+	asm_io_fdc(pdir_ptr);
 
 	WRITE_REG( SBA_IOVA(ioc, iovp, 0, 0), ioc->ioc_hpa+IOC_PCOM);
 }
@@ -773,8 +771,7 @@ sba_map_single(struct device *dev, void *addr, size_t size,
 	}
 
 	/* force FDC ops in io_pdir_entry() to be visible to IOMMU */
-	if (ioc_needs_fdc)
-		asm volatile("sync" : : );
+	asm_io_sync();
 
 #ifdef ASSERT_PDIR_SANITY
 	sba_check_pdir(ioc,"Check after sba_map_single()");
@@ -858,8 +855,7 @@ sba_unmap_page(struct device *dev, dma_addr_t iova, size_t size,
 	sba_free_range(ioc, iova, size);
 
 	/* If fdc's were issued, force fdc's to be visible now */
-	if (ioc_needs_fdc)
-		asm volatile("sync" : : );
+	asm_io_sync();
 
 	READ_REG(ioc->ioc_hpa+IOC_PCOM);	/* flush purges */
 #endif /* DELAYED_RESOURCE_CNT == 0 */
@@ -1008,8 +1004,7 @@ sba_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	filled = iommu_fill_pdir(ioc, sglist, nents, 0, sba_io_pdir_entry);
 
 	/* force FDC ops in io_pdir_entry() to be visible to IOMMU */
-	if (ioc_needs_fdc)
-		asm volatile("sync" : : );
+	asm_io_sync();
 
 #ifdef ASSERT_PDIR_SANITY
 	if (sba_check_pdir(ioc,"Check after sba_map_sg()"))