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authorDavid S. Miller <davem@davemloft.net>2008-05-19 23:46:00 -0700
committerDavid S. Miller <davem@davemloft.net>2008-05-20 00:33:45 -0700
commit93dae5b70e7c1c8e927d22e1c20a941ca376906a (patch)
treef255087706b9d176455b17e4384f4632f59f4cde /arch/sparc64/mm
parent88278ca27a43ae503572b52ea2c171fbf45db5a2 (diff)
downloadblackbird-op-linux-93dae5b70e7c1c8e927d22e1c20a941ca376906a.tar.gz
blackbird-op-linux-93dae5b70e7c1c8e927d22e1c20a941ca376906a.zip
sparc64: Add global register dumping facility.
When a cpu really is stuck in the kernel, it can be often impossible to figure out which cpu is stuck where. The worst case is when the stuck cpu has interrupts disabled. Therefore, implement a global cpu state capture that uses SMP message interrupts which are not disabled by the normal IRQ enable/disable APIs of the kernel. As long as we can get a sysrq 'y' to the kernel, we can get a dump. Even if the console interrupt cpu is wedged, we can trigger it from userspace using /proc/sysrq-trigger The output is made compact so that this facility is more useful on high cpu count systems, which is where this facility will likely find itself the most useful :) Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/mm')
-rw-r--r--arch/sparc64/mm/ultra.S29
1 files changed, 28 insertions, 1 deletions
diff --git a/arch/sparc64/mm/ultra.S b/arch/sparc64/mm/ultra.S
index 15d124963f68..9bb2d90a9df6 100644
--- a/arch/sparc64/mm/ultra.S
+++ b/arch/sparc64/mm/ultra.S
@@ -1,7 +1,7 @@
/*
* ultra.S: Don't expand these all over the place...
*
- * Copyright (C) 1997, 2000 David S. Miller (davem@redhat.com)
+ * Copyright (C) 1997, 2000, 2008 David S. Miller (davem@davemloft.net)
*/
#include <asm/asi.h>
@@ -15,6 +15,7 @@
#include <asm/thread_info.h>
#include <asm/cacheflush.h>
#include <asm/hypervisor.h>
+#include <asm/cpudata.h>
/* Basically, most of the Spitfire vs. Cheetah madness
* has to do with the fact that Cheetah does not support
@@ -514,6 +515,32 @@ xcall_report_regs:
b rtrap_xcall
ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
+#ifdef CONFIG_MAGIC_SYSRQ
+ .globl xcall_fetch_glob_regs
+xcall_fetch_glob_regs:
+ sethi %hi(global_reg_snapshot), %g1
+ or %g1, %lo(global_reg_snapshot), %g1
+ __GET_CPUID(%g2)
+ sllx %g2, 6, %g3
+ add %g1, %g3, %g1
+ rdpr %tstate, %g7
+ stx %g7, [%g1 + GR_SNAP_TSTATE]
+ rdpr %tpc, %g7
+ stx %g7, [%g1 + GR_SNAP_TPC]
+ rdpr %tnpc, %g7
+ stx %g7, [%g1 + GR_SNAP_TNPC]
+ stx %o7, [%g1 + GR_SNAP_O7]
+ stx %i7, [%g1 + GR_SNAP_I7]
+ sethi %hi(trap_block), %g7
+ or %g7, %lo(trap_block), %g7
+ sllx %g2, TRAP_BLOCK_SZ_SHIFT, %g2
+ add %g7, %g2, %g7
+ ldx [%g7 + TRAP_PER_CPU_THREAD], %g3
+ membar #StoreStore
+ stx %g3, [%g1 + GR_SNAP_THREAD]
+ retry
+#endif /* CONFIG_MAGIC_SYSRQ */
+
#ifdef DCACHE_ALIASING_POSSIBLE
.align 32
.globl xcall_flush_dcache_page_cheetah
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