[IA64] alternate perfmon handler

Patch from Charles Spirakis

Some linux customers want to optimize their applications on the latest
hardware but are not yet willing to upgrade to the latest kernel. This
patch provides a way to plug in an alternate, basic, and GPL'ed PMU
subsystem to help with their monitoring needs or for specialty work. It
can also be used in case of serious unexpected bugs in perfmon. Mutual
exclusion between the two subsystems is guaranteed, hence no conflict
can arise from both subsystem being present.

Acked-by: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/asm-ia64/perfmon.h b/include/asm-ia64/perfmon.h
index ed5416c5b1ac..7f3333dd00e4 100644
--- a/include/asm-ia64/perfmon.h
+++ b/include/asm-ia64/perfmon.h
@@ -177,6 +177,10 @@ typedef union {
 
 extern long perfmonctl(int fd, int cmd, void *arg, int narg);
 
+typedef struct {
+        void (*handler)(int irq, void *arg, struct pt_regs *regs);
+} pfm_intr_handler_desc_t;
+
 extern void pfm_save_regs (struct task_struct *);
 extern void pfm_load_regs (struct task_struct *);
 
@@ -187,6 +191,10 @@ extern void pfm_syst_wide_update_task(struct task_struct *, unsigned long info,
 extern void pfm_inherit(struct task_struct *task, struct pt_regs *regs);
 extern void pfm_init_percpu(void);
 extern void pfm_handle_work(void);
+extern int  pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *h);
+extern int  pfm_remove_alt_pmu_interrupt(pfm_intr_handler_desc_t *h);
+
+
 
 /*
  * Reset PMD register flags