[RFC Patch 1/6] Prepare the PowerPC platform for HW Breakpoint infrastructure

[K.Prasad]

Prepare the PowerPC code for HW Breakpoint infrastructure patches by including
relevant constant definitions and function declarations.

Signed-off-by: K.Prasad <prasad at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/hw_breakpoint.h |   57 +++++++++++++++++++++++++++++++
 arch/powerpc/include/asm/processor.h     |    1 
 arch/powerpc/include/asm/reg.h           |    3 +
 3 files changed, 61 insertions(+)

Index: linux-2.6-tip.hbkpt/arch/powerpc/include/asm/hw_breakpoint.h
===================================================================
--- /dev/null
+++ linux-2.6-tip.hbkpt/arch/powerpc/include/asm/hw_breakpoint.h
@@ -0,0 +1,57 @@
+#ifndef	_PPC64_HW_BREAKPOINT_H
+#define	_PPC64_HW_BREAKPOINT_H
+
+#ifdef	__KERNEL__
+#define	__ARCH_HW_BREAKPOINT_H
+#ifdef CONFIG_PPC64
+
+struct arch_hw_breakpoint {
+	char		*name; /* Contains name of the symbol to set bkpt */
+	unsigned long	address;
+	u8		type;
+};
+
+#include <linux/kdebug.h>
+#include <asm/reg.h>
+#include <asm-generic/hw_breakpoint.h>
+
+#define HW_BREAKPOINT_READ DABR_DATA_READ
+#define HW_BREAKPOINT_WRITE DABR_DATA_WRITE
+#define HW_BREAKPOINT_RW (DABR_DATA_READ | DABR_DATA_WRITE)
+
+#define HW_BREAKPOINT_ALIGN 0x7
+#define HW_BREAKPOINT_LEN INSTRUCTION_LEN
+
+extern struct hw_breakpoint *hbp_kernel[HBP_NUM];
+DECLARE_PER_CPU(struct hw_breakpoint*, this_hbp_kernel[HBP_NUM]);
+extern unsigned int hbp_user_refcount[HBP_NUM];
+
+extern void arch_install_thread_hw_breakpoint(struct task_struct *tsk);
+extern void arch_uninstall_thread_hw_breakpoint(void);
+extern int arch_validate_hwbkpt_settings(struct hw_breakpoint *bp,
+						struct task_struct *tsk);
+extern void arch_update_user_hw_breakpoint(int pos, struct task_struct *tsk);
+extern void arch_flush_thread_hw_breakpoint(struct task_struct *tsk);
+extern void arch_update_kernel_hw_breakpoint(void *);
+extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+				     unsigned long val, void *data);
+
+extern void flush_thread_hw_breakpoint(struct task_struct *tsk);
+extern int copy_thread_hw_breakpoint(struct task_struct *tsk,
+		struct task_struct *child, unsigned long clone_flags);
+extern void load_debug_registers(void );
+
+static inline void hw_breakpoint_disable(void)
+{
+	set_dabr(0);
+}
+
+#else
+static inline void hw_breakpoint_disable(void)
+{
+	/* Function is defined only on PPC64 for now */
+}
+#endif	/* CONFIG_PPC64 */
+#endif	/* __KERNEL__ */
+#endif	/* _PPC64_HW_BREAKPOINT_H */
+
Index: linux-2.6-tip.hbkpt/arch/powerpc/include/asm/processor.h
===================================================================
--- linux-2.6-tip.hbkpt.orig/arch/powerpc/include/asm/processor.h
+++ linux-2.6-tip.hbkpt/arch/powerpc/include/asm/processor.h
@@ -177,6 +177,7 @@ struct thread_struct {
 #ifdef CONFIG_PPC64
 	unsigned long	start_tb;	/* Start purr when proc switched in */
 	unsigned long	accum_tb;	/* Total accumilated purr for process */
+	struct hw_breakpoint *hbp[HBP_NUM];
 #endif
 	unsigned long	dabr;		/* Data address breakpoint register */
 #ifdef CONFIG_ALTIVEC
Index: linux-2.6-tip.hbkpt/arch/powerpc/include/asm/reg.h
===================================================================
--- linux-2.6-tip.hbkpt.orig/arch/powerpc/include/asm/reg.h
+++ linux-2.6-tip.hbkpt/arch/powerpc/include/asm/reg.h
@@ -26,6 +26,8 @@
 #include <asm/reg_8xx.h>
 #endif /* CONFIG_8xx */
 
+#define INSTRUCTION_LEN	4		/* Length of any instruction */
+
 #define MSR_SF_LG	63              /* Enable 64 bit mode */
 #define MSR_ISF_LG	61              /* Interrupt 64b mode valid on 630 */
 #define MSR_HV_LG 	60              /* Hypervisor state */
@@ -184,6 +186,7 @@
 #define   CTRL_TE	0x00c00000	/* thread enable */
 #define   CTRL_RUNLATCH	0x1
 #define SPRN_DABR	0x3F5	/* Data Address Breakpoint Register */
+#define   HBP_NUM	1	/* Number of physical HW breakpoint registers */
 #define   DABR_TRANSLATION	(1UL << 2)
 #define   DABR_DATA_WRITE	(1UL << 1)
 #define   DABR_DATA_READ	(1UL << 0)