MIPS : die at free_initmem() function 3.9+

[EUNBONG SONG <eunb.song@xxxxxxxxxxx>]

Hello. I try to boot my cavium board with david's patch. 
It's is not applied yet in linux tree, i got the patch from mailing list.
And the patch is as follow.


This is only very lightly tested, we need more testing before
declaring it the definitive fix.

 arch/mips/kernel/genex.S | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index ecb347c..57cda9a 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -132,12 +132,13 @@ LEAF(r4k_wait)
        .set    noreorder
        /* start of rollback region */
        LONG_L  t0, TI_FLAGS($28)
-       nop
        andi    t0, _TIF_NEED_RESCHED
        bnez    t0, 1f
         nop
-       nop
-       nop
+       /* Enable interrupts so WAIT will complete */
+       mfc0    t0, CP0_STATUS
+       ori     t0, ST0_IE
+       mtc0    t0, CP0_STATUS
        .set    mips3
        wait
        /* end of rollback region (the region size must be power of two) */

I think, it works well. But i encounter another problem at free_initmem(). 
The log messages are as follow.

[  132.134719] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W    3.9.0+ #29
[  132.141678] Stack : 0000000000000004 000000000000003f ffffffff80fa0000 ffffffff802924a8
          0000000000000000 ffffffff80fa0000 00000000000000ff ffffffff80293760
          0000000000000000 0000000000000000 ffffffff81080000 ffffffff81080000
          ffffffff80e2baf0 ffffffff80f93977 a80000004146cbb8 0000000000000020
          0000000000000003 0000000000000020 a800000041473da8 ffffffff810f0000
          a800000041473a10 ffffffff806ef910 a800000041473828 ffffffff80290920
          0000000000000000 ffffffff80293b90 000000000000000a ffffffff80e2baf0
          0000000000000000 a800000041473750 000000004146cef8 ffffffff805e7794
          0000000000000000 0000000000000000 0000000000000000 0000000000000000
          0000000000000000 ffffffff80272498 0000000000000000 0000000000000000
          ...
[  132.207201] Call Trace:
[  132.209655] [<ffffffff80272498>] show_stack+0x68/0x80
[  132.225943] [<ffffffff802bd4ac>] notifier_call_chain+0x5c/0xa8
[  132.231776] [<ffffffff802bdb84>] __atomic_notifier_call_chain+0x3c/0x58
[  132.238391] [<ffffffff802bdbe8>] notify_die+0x38/0x48
[  132.243442] [<ffffffff802716cc>] die+0x4c/0x148
[  132.247974] [<ffffffff8027f998>] do_page_fault+0x4b8/0x500
[  132.253461] [<ffffffff8026c764>] resume_userspace_check+0x0/0x10
[  132.259469] [<ffffffff80324a54>] free_reserved_area+0x8c/0x178
[  132.265304] [<ffffffff806e0dc8>] kernel_init+0x20/0x100
[  132.270529] [<ffffffff8026c7e0>] ret_from_kernel_thread+0x10/0x18

And i just changed free_initmem() functions as follow

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 9b973e0..e246e9b 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -447,7 +447,10 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 void __init_refok free_initmem(void)
 {
        prom_free_prom_memory();
-       free_initmem_default(POISON_FREE_INITMEM);
+
+       free_init_pages("unused kernel memory",
+                       __pa_symbol(&__init_begin),
+                       __pa_symbol(&__init_end));
 }

After that it works well. but i don't know why it works well.

Thanks.