Re: [PATCH] OProfile ia64 performance counter support

[Stephane Eranian <eranian@hpl.hp.com>]

Tony,

Please apply this to the IA-64 tree. It looks good to me.

Thanks.

On Sat, Aug 21, 2004 at 08:52:06PM +0100, John Levon wrote:
> 
> This patch provides support for IA64 hardware performance counters via
> the perfmon interface. Please consider applying.
> 
> thanks
> john
> 
> 
> Index: linux-cvs/arch/ia64/oprofile/Kconfig
> ===================================================================
> RCS file: /home/moz/cvs//linux-2.5/arch/ia64/oprofile/Kconfig,v
> retrieving revision 1.2
> diff -u -a -p -r1.2 Kconfig
> --- linux-cvs/arch/ia64/oprofile/Kconfig	9 Sep 2003 16:07:11 -0000	1.2
> +++ linux-cvs/arch/ia64/oprofile/Kconfig	21 Aug 2004 20:42:56 -0000
> @@ -16,6 +16,10 @@ config OPROFILE
>  	  whole system, include the kernel, kernel modules, libraries,
>  	  and applications.
>  
> +	  Due to firmware bugs, you may need to use the "nohalt" boot
> +	  option if you're using OProfile with the hardware performance
> +	  counters.
> +
>  	  If unsure, say N.
>  
>  endmenu
> Index: linux-cvs/arch/ia64/oprofile/Makefile
> ===================================================================
> RCS file: /home/moz/cvs//linux-2.5/arch/ia64/oprofile/Makefile,v
> retrieving revision 1.2
> diff -u -a -p -r1.2 Makefile
> --- linux-cvs/arch/ia64/oprofile/Makefile	9 Sep 2003 16:07:11 -0000	1.2
> +++ linux-cvs/arch/ia64/oprofile/Makefile	21 Aug 2004 20:37:27 -0000
> @@ -7,3 +7,4 @@ DRIVER_OBJS := $(addprefix ../../../driv
>  		timer_int.o )
>  
>  oprofile-y := $(DRIVER_OBJS) init.o
> +oprofile-$(CONFIG_PERFMON) += perfmon.o
> Index: linux-cvs/arch/ia64/oprofile/init.c
> ===================================================================
> RCS file: /home/moz/cvs//linux-2.5/arch/ia64/oprofile/init.c,v
> retrieving revision 1.2
> diff -u -a -p -r1.2 init.c
> --- linux-cvs/arch/ia64/oprofile/init.c	9 Sep 2003 16:07:11 -0000	1.2
> +++ linux-cvs/arch/ia64/oprofile/init.c	21 Aug 2004 20:37:27 -0000
> @@ -12,14 +12,21 @@
>  #include <linux/init.h>
>  #include <linux/errno.h>
>   
> -extern void timer_init(struct oprofile_operations ** ops);
> +extern int perfmon_init(struct oprofile_operations ** ops);
> +extern void perfmon_exit(void);
>  
>  int __init oprofile_arch_init(struct oprofile_operations ** ops)
>  {
> +#ifdef CONFIG_PERFMON
> +	return perfmon_init(ops);
> +#endif
>  	return -ENODEV;
>  }
>  
>  
>  void oprofile_arch_exit(void)
>  {
> +#ifdef CONFIG_PERFMON
> +	perfmon_exit();
> +#endif
>  }
> Index: linux-cvs/arch/ia64/oprofile/perfmon.c
> ===================================================================
> RCS file: linux-cvs/arch/ia64/oprofile/perfmon.c
> diff -N linux-cvs/arch/ia64/oprofile/perfmon.c
> --- /dev/null	1 Jan 1970 00:00:00 -0000
> +++ linux-cvs/arch/ia64/oprofile/perfmon.c	21 Aug 2004 20:37:27 -0000
> @@ -0,0 +1,105 @@
> +/**
> + * @file perfmon.c
> + *
> + * @remark Copyright 2003 OProfile authors
> + * @remark Read the file COPYING
> + *
> + * @author John Levon <levon@movementarian.org>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/config.h>
> +#include <linux/oprofile.h>
> +#include <linux/sched.h>
> +#include <asm/perfmon.h>
> +#include <asm/ptrace.h>
> +#include <asm/errno.h>
> +
> +static int allow_ints;
> +
> +static int
> +perfmon_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg,
> +                struct pt_regs *regs, unsigned long stamp)
> +{
> +	int cpu = smp_processor_id();
> +	unsigned long eip = instruction_pointer(regs);
> +	int event = arg->pmd_eventid;
> + 
> +	arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1;
> +
> +	/* the owner of the oprofile event buffer may have exited
> +	 * without perfmon being shutdown (e.g. SIGSEGV)
> +	 */
> +	if (allow_ints)
> +		oprofile_add_sample(eip, !user_mode(regs), event, cpu);
> +	return 0;
> +}
> +
> +
> +static int perfmon_start(void)
> +{
> +	allow_ints = 1;
> +	return 0;
> +}
> +
> +
> +static void perfmon_stop(void)
> +{
> +	allow_ints = 0;
> +}
> +
> +
> +#define OPROFILE_FMT_UUID { \
> +	0x77, 0x7a, 0x6e, 0x61, 0x20, 0x65, 0x73, 0x69, 0x74, 0x6e, 0x72, 0x20, 0x61, 0x65, 0x0a, 0x6c }
> +
> +static pfm_buffer_fmt_t oprofile_fmt = {
> + 	.fmt_name 	    = "oprofile_format",
> + 	.fmt_uuid	    = OPROFILE_FMT_UUID,
> + 	.fmt_handler	    = perfmon_handler,
> +};
> +
> +
> +static char * get_cpu_type(void)
> +{
> +	__u8 family = local_cpu_data->family;
> +
> +	switch (family) {
> +		case 0x07:
> +			return "ia64/itanium";
> +		case 0x1f:
> +			return "ia64/itanium2";
> +		default:
> +			return "ia64/ia64";
> +	}
> +}
> +
> +
> +/* all the ops are handled via userspace for IA64 perfmon */
> +static struct oprofile_operations perfmon_ops = {
> +	.start = perfmon_start,
> +	.stop = perfmon_stop,
> +};
> +
> +static int using_perfmon;
> +
> +int perfmon_init(struct oprofile_operations ** ops)
> +{
> +	int ret = pfm_register_buffer_fmt(&oprofile_fmt);
> +	if (ret)
> +		return -ENODEV;
> +
> +	perfmon_ops.cpu_type = get_cpu_type();
> +	*ops = &perfmon_ops;
> +	using_perfmon = 1;
> +	printk(KERN_INFO "oprofile: using perfmon.\n");
> +	return 0;
> +}
> +
> +
> +void perfmon_exit(void)
> +{
> +	if (!using_perfmon)
> +		return;
> +
> +	pfm_unregister_buffer_fmt(oprofile_fmt.fmt_uuid);
> +}
> -
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-- 

-Stephane