[PATCH] parisc: Add alternative prefetchw() on 32-bit CPUs

[PATCH] parisc: Add alternative prefetchw() on 32-bit CPUs

[Helge Deller]

Add the ALT_COND_RUN_ON_PA1X alternative conditional to nop
out a 64-bit ldd instruction in prefetchw() when running on 32-bit CPUs.

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/include/asm/alternative.h b/arch/parisc/include/asm/alternative.h
index 0ec54f43d6d2..8b94aa4f1bd7 100644
--- a/arch/parisc/include/asm/alternative.h
+++ b/arch/parisc/include/asm/alternative.h
@@ -9,6 +9,7 @@
 #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 ALT_COND_RUN_ON_QEMU	0x20	/* if running on QEMU */
+#define ALT_COND_RUN_ON_PA1X	0x40	/* if running on PA1.x CPU */

 #define INSN_PxTLB	0x02		/* modify pdtlb, pitlb */
 #define INSN_NOP	0x08000240	/* nop */
diff --git a/arch/parisc/include/asm/prefetch.h b/arch/parisc/include/asm/prefetch.h
index 6e63f720024d..ea898362dfc0 100644
--- a/arch/parisc/include/asm/prefetch.h
+++ b/arch/parisc/include/asm/prefetch.h
@@ -17,6 +17,8 @@
 #define __ASM_PARISC_PREFETCH_H

 #ifndef __ASSEMBLY__
+#include <asm/alternative.h>
+
 #ifdef CONFIG_PREFETCH

 #define ARCH_HAS_PREFETCH
@@ -35,7 +37,9 @@ static inline void prefetch(const void *addr)
 #define ARCH_HAS_PREFETCHW
 static inline void prefetchw(const void *addr)
 {
-	__asm__("ldd 0(%0), %%r0" : : "r" (addr));
+	__asm__("ldd 0(%0), %%r0"
+		ALTERNATIVE(ALT_COND_RUN_ON_PA1X, INSN_NOP)
+		: : "r" (addr));
 }
 #endif /* CONFIG_PA20 */

diff --git a/arch/parisc/kernel/alternative.c b/arch/parisc/kernel/alternative.c
index daa1e9047275..276904ab7265 100644
--- a/arch/parisc/kernel/alternative.c
+++ b/arch/parisc/kernel/alternative.c
@@ -33,6 +33,7 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 		((cache_info.dc_size == 0) ? ALT_COND_NO_DCACHE : 0) |
 		((cache_info.ic_size == 0) ? ALT_COND_NO_ICACHE : 0) |
 		(running_on_qemu ? ALT_COND_RUN_ON_QEMU : 0) |
+		((boot_cpu_data.cpu_type < pcxu) ? ALT_COND_RUN_ON_PA1X : 0) |
 		((split_tlb == 0) ? ALT_COND_NO_SPLIT_TLB : 0) |
 		/*
 		 * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit