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authorLey Foon Tan <lftan@altera.com>2015-04-10 11:10:08 +0800
committerLey Foon Tan <lftan@altera.com>2015-04-10 11:10:08 +0800
commit4a89c3088ff61aa24754e9cd6dc665cc719f7efe (patch)
treed280b9ad4a94a3aeec310e5764760df685c6ffca
parente3e29f990cc77c5b23280c77275812a3f010cc41 (diff)
downloadlinux-4a89c3088ff61aa24754e9cd6dc665cc719f7efe.tar.gz
nios2: fix cache coherency issue when debug with gdb
Remove the end address checking for flushda function. We need to flush
each address line for flushda instruction, from start to end address.
This is because flushda instruction only flush the cache if tag and line
fields are matched.

Change to use ldwio instruction (bypass cache) to load the instruction
that causing trap. Our interest is the actual instruction that executed
by the processor, this should be uncached.
Note, EA address might be an userspace cached address.


Signed-off-by: Ley Foon Tan <lftan@altera.com>
-rw-r--r--arch/nios2/kernel/entry.S2
-rw-r--r--arch/nios2/mm/cacheflush.c3
2 files changed, 1 insertions, 4 deletions
diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S
index 7729bd3f2e79..27b006c52e12 100644
--- a/arch/nios2/kernel/entry.S
+++ b/arch/nios2/kernel/entry.S
@@ -161,7 +161,7 @@ ENTRY(inthandler)
  ***********************************************************************
  */
 ENTRY(handle_trap)
-	ldw	r24, -4(ea)	/* instruction that caused the exception */
+	ldwio	r24, -4(ea)	/* instruction that caused the exception */
 	srli	r24, r24, 4
 	andi	r24, r24, 0x7c
 	movia	r9,trap_table
diff --git a/arch/nios2/mm/cacheflush.c b/arch/nios2/mm/cacheflush.c
index 2ae482b42669..796642932e2e 100644
--- a/arch/nios2/mm/cacheflush.c
+++ b/arch/nios2/mm/cacheflush.c
@@ -23,9 +23,6 @@ static void __flush_dcache(unsigned long start, unsigned long end)
 	end += (cpuinfo.dcache_line_size - 1);
 	end &= ~(cpuinfo.dcache_line_size - 1);
 
-	if (end > start + cpuinfo.dcache_size)
-		end = start + cpuinfo.dcache_size;
-
 	for (addr = start; addr < end; addr += cpuinfo.dcache_line_size) {
 		__asm__ __volatile__ ("   flushda 0(%0)\n"
 					: /* Outputs */