sparc32: use flushi when run-time patching in per_cpu_patch

Davis S. Miller wrote:
"
The way we do that now is overkill.  We only needed to use the MMU
cache ops when we had sun4c around because sun4c lacked support for
the "flush" instruction.

But all sun4m and later chips have it so we can use it
unconditionally.

So in the per_cpu_patch() code, get rid of the cache ops invocation,
and instead execute a "flush %reg" after each of the instruction patch
assignments, where %reg is set to the address of the instruction that
was stored into.

Perhaps take the flushi() definition from asm/cacheflush_64.h and
place it into asm/cacheflush.h, then you can simply use that.
"

Implemented as per suggestion.
Moved run-time patching before we call paging_init(),
so helper methods in paging_init() may utilise run-time patching too.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 10 deletions

diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c
index d65b5a1c2209..c052313f4dc5 100644
--- a/arch/sparc/kernel/setup_32.c
+++ b/arch/sparc/kernel/setup_32.c
@@ -227,16 +227,14 @@ static void __init per_cpu_patch(void)
 			prom_halt();
 		}
 		*(unsigned int *) (addr + 0) = insns[0];
+		flushi(addr + 0);
 		*(unsigned int *) (addr + 4) = insns[1];
+		flushi(addr + 4);
 		*(unsigned int *) (addr + 8) = insns[2];
+		flushi(addr + 8);
 
 		p++;
 	}
-#ifdef CONFIG_SMP
-	local_ops->cache_all();
-#else
-	sparc32_cachetlb_ops->cache_all();
-#endif
 }
 
 enum sparc_cpu sparc_cpu_model;
@@ -340,13 +338,11 @@ void __init setup_arch(char **cmdline_p)
 	init_mm.context = (unsigned long) NO_CONTEXT;
 	init_task.thread.kregs = &fake_swapper_regs;
 
-	paging_init();
-
-	/* Now that we have the cache ops hooked up, we can patch
-	 * instructions.
-	 */
+	/* Run-time patch instructions to match the cpu model */
 	per_cpu_patch();
 
+	paging_init();
+
 	smp_setup_cpu_possible_map();
 }