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Implement hw-breakpoint interfaces for BookE processors

RFC PATCH New K.Prasad 1 participant 1 message Apr 27, 2010 1 message not in the archive

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K.Prasad

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RFC PATCH 1/1 Implement hw-breakpoint interfaces for BookE processors

Implement hardware breakpoint interfaces for PowerPC BookE processors

Signed-off-by K.Prasad <[email protected]>
---
 arch/powerpc/Kconfig                           |    2 
 arch/powerpc/include/asm/cputable.h            |    4 
 arch/powerpc/include/asm/hw_breakpoint_booke.h |   42 +++
 arch/powerpc/kernel/Makefile                   |    4 
 arch/powerpc/kernel/hw_breakpoint_booke.c      |  326 +++++++++++++++++++++++++
 arch/powerpc/kernel/ptrace.c                   |    8 
 arch/powerpc/kernel/traps.c                    |   11 
 include/linux/perf_event.h                     |    4 
 8 files changed, 398 insertions(+), 3 deletions(-)
arch/powerpc/include/asm/hw_breakpoint_booke.h new file +42 -0
Index: linux-2.6.bookE/arch/powerpc/include/asm/hw_breakpoint_booke.h
===================================================================
@@ -0,0 +1,42 @@
+#ifndef	_I386_HW_BREAKPOINT_H
+#define	_I386_HW_BREAKPOINT_H
+
+#ifdef	__KERNEL__
+#define	__ARCH_HW_BREAKPOINT_H
+
+struct arch_hw_breakpoint {
+	u8		len;
+	unsigned long	address;
+	unsigned long	type;
+};
+
+#include <linux/kdebug.h>
+#include <linux/percpu.h>
+#include <linux/list.h>
+
+/* Breakpoint length beyond which we should use 'range' breakpoints */
+#define DAC_LEN 8
+
+static inline int hw_breakpoint_slots(int type)
+{
+	return HBP_NUM;
+}
+
+struct perf_event;
+struct pmu;
+
+extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
+extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
+extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+						unsigned long val, void *data);
+extern void hw_breakpoint_handler(struct pt_regs *regs,
+				unsigned long debug_status);
+int arch_install_hw_breakpoint(struct perf_event *bp);
+void arch_uninstall_hw_breakpoint(struct perf_event *bp);
+void hw_breakpoint_pmu_read(struct perf_event *bp);
+
+extern struct pmu perf_ops_bp;
+
+#endif	/* __KERNEL__ */
+#endif	/* _I386_HW_BREAKPOINT_H */
+
arch/powerpc/kernel/hw_breakpoint_booke.c new file +326 -0

326 lines not on this page · raw message

arch/powerpc/kernel/traps.c +9 -2
Index: linux-2.6.bookE/arch/powerpc/kernel/traps.c
===================================================================
@@ -57,6 +57,9 @@
 #ifdef CONFIG_FSL_BOOKE
 #include <asm/dbell.h>
 #endif
+#ifdef CONFIG_BOOKE
+#include <asm/hw_breakpoint_booke.h>
+#endif
 
 #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
 int (*__debugger)(struct pt_regs *regs) __read_mostly;

@@ -1151,8 +1154,12 @@ void __kprobes DebugException(struct pt_
 		}
 
 		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
-	} else
-		handle_debug(regs, debug_status);
+	} else {
+		if (is_kernel_addr(regs->dar))
+			hw_breakpoint_handler(regs, debug_status);
+		else
+			handle_debug(regs, debug_status);
+	}
 }
 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
arch/powerpc/Kconfig +1 -1
Index: linux-2.6.bookE/arch/powerpc/Kconfig
===================================================================
@@ -140,7 +140,7 @@ config PPC
 	select HAVE_SYSCALL_WRAPPERS if PPC64
 	select GENERIC_ATOMIC64 if PPC32
 	select HAVE_PERF_EVENTS
-	select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
+	select HAVE_HW_BREAKPOINT if (PERF_EVENTS && PPC_BOOK3S_64) || BOOKE
 
 config EARLY_PRINTK
 	bool
arch/powerpc/kernel/Makefile +4 -0
Index: linux-2.6.bookE/arch/powerpc/kernel/Makefile
===================================================================
@@ -34,7 +34,11 @@ obj-y				+= vdso32/
 obj-$(CONFIG_PPC64)		+= setup_64.o sys_ppc32.o \
 				   signal_64.o ptrace32.o \
 				   paca.o nvram_64.o firmware.o
+ifeq ($(CONFIG_BOOKE),y)
+obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint_booke.o
+else
 obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
+endif
 obj-$(CONFIG_PPC_BOOK3S_64)	+= cpu_setup_ppc970.o cpu_setup_pa6t.o
 obj64-$(CONFIG_RELOCATABLE)	+= reloc_64.o
 obj-$(CONFIG_PPC_BOOK3E_64)	+= exceptions-64e.o
arch/powerpc/kernel/ptrace.c +8 -0
Index: linux-2.6.bookE/arch/powerpc/kernel/ptrace.c
===================================================================
@@ -787,10 +787,12 @@ int ptrace_set_debugreg(struct task_stru
 			       unsigned long data)
 {
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
+#ifndef CONFIG_BOOKE
 	int ret;
 	struct thread_struct *thread = &(task->thread);
 	struct perf_event *bp;
 	struct perf_event_attr attr;
+#endif /* CONFIG_BOOKE */
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 
 	/* For ppc64 we support one DABR and no IABR's at the moment (ppc64).

@@ -821,6 +823,11 @@ int ptrace_set_debugreg(struct task_stru
 	if (data && !(data & DABR_TRANSLATION))
 		return -EIO;
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
+/*
+ * Temporarily disable use of breakpoint interfaces through ptrace until
+ * user-space breakpoint support is enabled.
+ */
+#ifndef CONFIG_BOOKE
 	bp = thread->ptrace_bps[0];
 	if (data == 0) {
 		if (bp) {

@@ -873,6 +880,7 @@ int ptrace_set_debugreg(struct task_stru
 		return PTR_ERR(bp);
 	}
 
+#endif /* CONFIG_BOOKE */
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 
 	/* Move contents to the DABR register */
arch/powerpc/include/asm/cputable.h +4 -0
Index: linux-2.6.bookE/arch/powerpc/include/asm/cputable.h
===================================================================
@@ -512,7 +512,11 @@ static inline int cpu_has_feature(unsign
 }
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
+#ifdef CONFIG_BOOKE
+#define HBP_NUM 2
+#else
 #define HBP_NUM 1
+#endif /* CONFIG_BOOKE */
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 
 #endif /* !__ASSEMBLY__ */
include/linux/perf_event.h +4 -0
Index: linux-2.6.bookE/include/linux/perf_event.h
===================================================================
@@ -440,7 +440,11 @@ enum perf_callchain_context {
 #endif
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
+#ifdef CONFIG_BOOKE
+#include <asm/hw_breakpoint_booke.h>
+#else
 #include <asm/hw_breakpoint.h>
+#endif /* CONFIG_BOOKE */
 #endif
 
 #include <linux/list.h>