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>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 5a1d55d06a08..5ecd0401cdb1 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