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authorSuzuki K. Poulose <suzuki@in.ibm.com>2012-12-03 20:38:37 +0530
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-06-20 16:55:09 +1000
commit35fd219a268cc82cef842518cd64ea6949629ba2 (patch)
tree2226a6d0fe4a0d36d679905c5680f5ca27db0bab /arch/powerpc/include/asm/probes.h
parent85f395c5b0a26b3a80f9e2d35333981a2a75c0ae (diff)
powerpc: Move the single step enable code to a generic path
This patch moves the single step enable code used by kprobe to a generic routine header so that, it can be re-used by other code, in this case, uprobes. No functional changes. Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com> Cc: Ananth N Mavinakaynahalli <ananth@in.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@ozlabs.org Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/probes.h')
-rw-r--r--arch/powerpc/include/asm/probes.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/probes.h b/arch/powerpc/include/asm/probes.h
index 5f1e15b68704..3421637cfd7b 100644
--- a/arch/powerpc/include/asm/probes.h
+++ b/arch/powerpc/include/asm/probes.h
@@ -38,5 +38,30 @@ typedef u32 ppc_opcode_t;
#define is_trap(instr) (IS_TW(instr) || IS_TWI(instr))
#endif /* CONFIG_PPC64 */
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+#define MSR_SINGLESTEP (MSR_DE)
+#else
+#define MSR_SINGLESTEP (MSR_SE)
+#endif
+
+/* Enable single stepping for the current task */
+static inline void enable_single_step(struct pt_regs *regs)
+{
+ regs->msr |= MSR_SINGLESTEP;
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+ /*
+ * We turn off Critical Input Exception(CE) to ensure that the single
+ * step will be for the instruction we have the probe on; if we don't,
+ * it is possible we'd get the single step reported for CE.
+ */
+ regs->msr &= ~MSR_CE;
+ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
+#ifdef CONFIG_PPC_47x
+ isync();
+#endif
+#endif
+}
+
+
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_PROBES_H */