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authorPaul Mackerras <paulus@samba.org>2005-10-28 22:48:08 +1000
committerPaul Mackerras <paulus@samba.org>2005-10-28 22:48:08 +1000
commitc032524f0ddea5fcc3a2cece0d4a61f37e5ca9cd (patch)
treec4ece990e6083cfedc640a06f908bfe33fd344bd /include/asm-powerpc/sstep.h
parentd73e0c99f5c45e7b86d38725a4ff49f6746f5353 (diff)
powerpc: Make single-stepping emulation (mostly) usable on 32-bit
The sc instruction emulation can't be done the same way on 32-bit as 64-bit yet, but this should work OK. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/asm-powerpc/sstep.h')
-rw-r--r--include/asm-powerpc/sstep.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/asm-powerpc/sstep.h b/include/asm-powerpc/sstep.h
new file mode 100644
index 00000000000..630a9889c07
--- /dev/null
+++ b/include/asm-powerpc/sstep.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+struct pt_regs;
+
+/*
+ * We don't allow single-stepping an mtmsrd that would clear
+ * MSR_RI, since that would make the exception unrecoverable.
+ * Since we need to single-step to proceed from a breakpoint,
+ * we don't allow putting a breakpoint on an mtmsrd instruction.
+ * Similarly we don't allow breakpoints on rfid instructions.
+ * These macros tell us if an instruction is a mtmsrd or rfid.
+ * Note that IS_MTMSRD returns true for both an mtmsr (32-bit)
+ * and an mtmsrd (64-bit).
+ */
+#define IS_MTMSRD(instr) (((instr) & 0xfc0007be) == 0x7c000124)
+#define IS_RFID(instr) (((instr) & 0xfc0007fe) == 0x4c000024)
+
+/* Emulate instructions that cause a transfer of control. */
+extern int emulate_step(struct pt_regs *regs, unsigned int instr);