powerpc, hw_breakpoint: Tell generic code we have no instruction breakpoints
At present, hw_breakpoint_slots() returns 1 regardless of what
type of breakpoint is specified in the type argument. Since we
don't define CONFIG_HAVE_MIXED_BREAKPOINTS_REGS, there are
separate values for TYPE_INST and TYPE_DATA, and hw_breakpoint_slots()
returns 1 for both, effectively advertising instruction breakpoint
support which doesn't exist.
This fixes it by making hw_breakpoint_slots return 1 for TYPE_DATA
and 0 for TYPE_INST. This moves hw_breakpoint_slots() from the
powerpc hw_breakpoint.h to hw_breakpoint.c because the definitions
of TYPE_INST and TYPE_DATA aren't available in <asm/hw_breakpoint.h>.
They are defined in <linux/hw_breakpoint.h> but we can't include
that header in <asm/hw_breakpoint.h>, and nor can we rely on
<linux/hw_breakpoint.h> being included before <asm/hw_breakpoint.h>.
Since hw_breakpoint_slots() is only called at boot time, there is
no performance impact from making it a real function rather than
a static inline.
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index ea87f8a..1c33ec1 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -37,10 +37,6 @@
#include <asm/reg.h>
#include <asm/system.h>
-static inline int hw_breakpoint_slots(int type)
-{
- return HBP_NUM;
-}
struct perf_event;
struct pmu;
struct perf_sample_data;
@@ -49,6 +45,7 @@
/* Maximum permissible length of any HW Breakpoint */
#define HW_BREAKPOINT_LEN 0x8
+extern int hw_breakpoint_slots(int type);
extern int arch_bp_generic_fields(int type, int *gen_bp_type);
extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 5a1d55d..5ecd040 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -44,6 +44,16 @@
static DEFINE_PER_CPU(struct perf_event *, bp_per_reg);
/*
+ * Returns total number of data or instruction breakpoints available.
+ */
+int hw_breakpoint_slots(int type)
+{
+ if (type == TYPE_DATA)
+ return HBP_NUM;
+ return 0; /* no instruction breakpoints available */
+}
+
+/*
* Install a perf counter breakpoint.
*
* We seek a free debug address register and use it for this