powerpc/85xx: Fix issue found by lockdep trace in smp_85xx_kick_cpu

lockdep trace found the following:

------------[ cut here ]------------
Badness at c007baf0 [verbose debug info unavailable]
NIP: c007baf0 LR: c007bad8 CTR: 00000000
REGS: ef855e00 TRAP: 0700   Tainted: G        W
(2.6.30-06736-g12a31df-dirty)
MSR: 00021000 <ME,CE>  CR: 24044022  XER: 20000000
TASK = ef858000[1] 'swapper' THREAD: ef854000 CPU: 0
GPR00: 00000000 ef855eb0 ef858000 00000001 000000d0 f1000000 ffbc8000 ffffffff
GPR08: 000000d0 c0760000 c0710000 00000007 2fffffff 1004a388 7ffd9400 00000000
GPR16: 00000000 7ffcd100 7ffcd100 7ffcd100 c059cd78 c075c498 c057da7c ffffffff
GPR24: ffbc8000 f1000000 00000001 c00bf8b0 c07595d4 000000d0 00021000 000000d0
NIP [c007baf0] lockdep_trace_alloc+0xc0/0xf0
LR [c007bad8] lockdep_trace_alloc+0xa8/0xf0
Call Trace:
[ef855eb0] [c007ba60] lockdep_trace_alloc+0x30/0xf0 (unreliable)
[ef855ec0] [c00cb3ac] kmem_cache_alloc+0x2c/0xf0
[ef855ee0] [c00bf8b0] __get_vm_area_node+0x80/0x1c0
[ef855f10] [c0017580] __ioremap_caller+0x1d0/0x1e0
[ef855f40] [c057da7c] smp_85xx_kick_cpu+0x64/0x124
[ef855f60] [c0599180] __cpu_up+0xd0/0x1a4
[ef855f80] [c05997c4] cpu_up+0x14c/0x1e0
[ef855fc0] [c05732a0] kernel_init+0x100/0x1c4
[ef855ff0] [c0011524] kernel_thread+0x4c/0x68
Instruction dump:
8009c174 2f800000 409e0048 73c08000 40820040 4818980d 2f830000 419effa0
3d20c076 8009c388 2f800000 409eff90 <0fe00000> 4bffff88 60000000 60000000

We were calling ioremap after we local_irq_restore(flags).  A simple
reorder fixes the problem.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index cc0b0db8a6f31bc54f0fd8c483afcc8c67e68786..62c592ede641c4a374a7760fd67604cfc9b2f9de 100644 (file)
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -52,20 +52,19 @@ smp_85xx_kick_cpu(int nr)
 
        pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
 
-       local_irq_save(flags);
-
        np = of_get_cpu_node(nr, NULL);
        cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
 
        if (cpu_rel_addr == NULL) {
                printk(KERN_ERR "No cpu-release-addr for cpu %d\n", nr);
-               local_irq_restore(flags);
                return;
        }
 
        /* Map the spin table */
        bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
 
+       local_irq_save(flags);
+
        out_be32(bptr_vaddr + BOOT_ENTRY_PIR, nr);
        out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
 
@@ -73,10 +72,10 @@ smp_85xx_kick_cpu(int nr)
        while ((__secondary_hold_acknowledge != nr) && (++n < 1000))
                mdelay(1);
 
-       iounmap(bptr_vaddr);
-
        local_irq_restore(flags);
 
+       iounmap(bptr_vaddr);
+
        pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
 }