On Jul 1, 2008, at 1:29 AM, Michael Ellerman wrote:
On Tue, 2008-07-01 at 00:32 -0500, Kumar Gala wrote:
To allow for a single kernel image on e500 v1/v2/mc we need to
fixup lwsync
at runtime. On e500v1/v2 lwsync causes an illop so we need to
patch up
the code. We default to 'sync' since that is always safe and if
the cpu
is capable we will replace 'sync' with 'lwsync'.
We introduce CPU_FTR_LWSYNC as a way to determine at runtime if
this is
needed. This flag could be moved elsewhere since we dont really
use it
for the normal CPU_FTR purpose.
Finally we only store the relative offset in the fixup section to
keep it
as small as possible rather than using a full fixup_entry.
How many entries are we talking? I guess it's not much bother to
have a
separate section.
On the order of 1000 entries for an SMP build.
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/
setup_32.c
index 9e83add..0109e7f 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -101,6 +101,10 @@ unsigned long __init early_init(unsigned long
dt_ptr)
PTRRELOC(&__start___ftr_fixup),
PTRRELOC(&__stop___ftr_fixup));
+ do_lwsync_fixups(spec->cpu_features,
+ PTRRELOC(&__start___lwsync_fixup),
+ PTRRELOC(&__stop___lwsync_fixup));
+
This could be changed to use cur_cpu_spec->cpu_features, and then all
the call sites would be passing that, which would mean
do_lwsync_fixups() could just check cur_cpu_spec->cpu_features
directly.
cur_cpu_spec and spec at this point arent the same thing.
will post a new version w/fixes.
- k
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