Tarun,
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of
> Manjunatha GK
> Sent: Thursday, April 01, 2010 8:54 PM
> To: [email protected]
> Cc: DebBarma, Tarun Kanti; Siarhei Siamashka; G, Manjunath Kondaiah
> Subject: [PATCH] OMAP GPTimer for OProfile(Errata#628216)
>
> From: DebBarma, Tarun Kanti <[email protected]>
>
> [ARM Cortex-A8 Errata 628216]
> If a Perf Counter OVFL occurs simultaneously with an update to a CP14 or
> CP15 register, the OVFL status can be lost.
>
> In order to workaround problem in Cortex-A8 Performance Counter, OMAP
> GPTIMER is used by OProfile.
>
> Signed-off-by: Tarun Kanti DebBarma <[email protected]>
> Cc: Siarhei Siamashka <[email protected]>
> Cc: Manjunatha GK <[email protected]>
> ---
> arch/arm/Kconfig | 59 +++++++++++++++---
> arch/arm/oprofile/Makefile | 1 +
> arch/arm/oprofile/common.c | 4 +
> arch/arm/oprofile/op_arm_model.h | 1 +
> arch/arm/oprofile/op_model_omap_gptimer.c | 96
> +++++++++++++++++++++++++++++
> 5 files changed, 153 insertions(+), 8 deletions(-)
> create mode 100644 arch/arm/oprofile/op_model_omap_gptimer.c
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 410d3e3..a753c8c 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -175,27 +175,70 @@ config ARM_L1_CACHE_SHIFT_6
> help
> Setting ARM L1 cache line size to 64 Bytes.
>
> -if OPROFILE
> +menuconfig INSTRUMENTATION
> + bool "Instrumentation Support"
> + default y
> + ---help---
> + Say Y here to get to see options related to performance measurement,
> + system-wide debugging and testing. This option alone does not add any
> + kernel code.
> +
> + If you say N, all options in this submenu will be skipped and
> + disabled. If you're trying to debug the kernel itself, check the
> + Kernel Hacking menu.
> +
> +if INSTRUMENTATION
> +
> +config PROFILING
> + bool "Profiling support"
> + help
> + Say Y here to enable the extended profiling support mechanisms
> + used by profilers such as OProfile.
> +
> +config OPROFILE
> + tristate "OProfile system profiling"
> + depends on PROFILING
> + help
> + OProfile is a profiling system capable of profiling the
> + whole system, including the kernel, kernel modules, libraries,
> + and applications.
> +
> + If unsure, say N.
> +choice
> + prompt "Oprofile Mode"
> + depends on OPROFILE
> + default OPROFILE_OMAP_GPTIMER
>
> config OPROFILE_ARMV6
> - def_bool y
> + bool "Oprofile ARMv6"
> depends on CPU_V6 && !SMP
> select OPROFILE_ARM11_CORE
>
> config OPROFILE_MPCORE
> - def_bool y
> + bool "Oprofile MPcore"
> depends on CPU_V6 && SMP
> select OPROFILE_ARM11_CORE
>
> -config OPROFILE_ARM11_CORE
> - bool
> -
> config OPROFILE_ARMV7
> - def_bool y
> + bool "Oprofile ARMv7"
> depends on CPU_V7 && !SMP
> + help
> + Uses Performance counters for profiling
> +
> +config OPROFILE_OMAP_GPTIMER
> + bool "Oprofile GPTimer"
> + depends on ARCH_OMAP
> + select OMAP_32K_TIMER
> + select OMAP_DM_TIMER
> + help
> + Uses GPTIMER for profiling. Currently this is the preferred
> + way since Performance counters have known bugs in Cortex-A8
> +endchoice
> +
> +config OPROFILE_ARM11_CORE
> bool
>
> -endif
> +endif # INSTRUMENTATION
Do you need so many KConfig entries??
> config VECTORS_BASE
> hex
> diff --git a/arch/arm/oprofile/Makefile b/arch/arm/oprofile/Makefile
> index 88e31f5..fc2bc02 100644
> --- a/arch/arm/oprofile/Makefile
> +++ b/arch/arm/oprofile/Makefile
> @@ -8,6 +8,7 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
>
> oprofile-y := $(DRIVER_OBJS) common.o backtrace.o
> oprofile-$(CONFIG_CPU_XSCALE) += op_model_xscale.o
> +oprofile-$(CONFIG_OPROFILE_OMAP_GPTIMER) += op_model_omap_gptimer.o
> oprofile-$(CONFIG_OPROFILE_ARM11_CORE) += op_model_arm11_core.o
> oprofile-$(CONFIG_OPROFILE_ARMV6) += op_model_v6.o
> oprofile-$(CONFIG_OPROFILE_MPCORE) += op_model_mpcore.o
> diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
> index 3fcd752..9eb2b9b 100644
> --- a/arch/arm/oprofile/common.c
> +++ b/arch/arm/oprofile/common.c
> @@ -133,6 +133,10 @@ int __init oprofile_arch_init(struct oprofile_operations
> *ops)
>
> ops->backtrace = arm_backtrace;
>
> +#ifdef CONFIG_OPROFILE_OMAP_GPTIMER
> + spec = &op_omap_gptimer_spec;
> +#endif
> +
> #ifdef CONFIG_CPU_XSCALE
> spec = &op_xscale_spec;
> #endif
> diff --git a/arch/arm/oprofile/op_arm_model.h
> b/arch/arm/oprofile/op_arm_model.h
> index 8c4e4f6..55f22e4 100644
> --- a/arch/arm/oprofile/op_arm_model.h
> +++ b/arch/arm/oprofile/op_arm_model.h
> @@ -24,6 +24,7 @@ struct op_arm_model_spec {
> extern struct op_arm_model_spec op_xscale_spec;
> #endif
>
> +extern struct op_arm_model_spec op_omap_gptimer_spec;
> extern struct op_arm_model_spec op_armv6_spec;
> extern struct op_arm_model_spec op_mpcore_spec;
> extern struct op_arm_model_spec op_armv7_spec;
> diff --git a/arch/arm/oprofile/op_model_omap_gptimer.c
> b/arch/arm/oprofile/op_model_omap_gptimer.c
> new file mode 100644
> index 0000000..49bab30
> --- /dev/null
> +++ b/arch/arm/oprofile/op_model_omap_gptimer.c
> @@ -0,0 +1,96 @@
> +/**
> + * OMAP gptimer based event monitor driver for oprofile
> + *
> + * Copyright (C) 2009 Nokia Corporation
> + * Author: Siarhei Siamashka <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/types.h>
> +#include <linux/oprofile.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <plat/dmtimer.h>
> +
> +#include "op_counter.h"
> +#include "op_arm_model.h"
> +
> +static struct omap_dm_timer *gptimer;
> +
> +static int gptimer_init(void)
> +{
> + return 0;
> +}
> +
> +static int gptimer_setup(void)
> +{
> + return 0;
> +}
> +
> +static irqreturn_t gptimer_interrupt(int irq, void *arg)
> +{
> + omap_dm_timer_write_status(gptimer, OMAP_TIMER_INT_OVERFLOW);
> + oprofile_add_sample(get_irq_regs(), 0);
> + return IRQ_HANDLED;
> +}
> +
> +static int gptimer_start(void)
> +{
> + int err;
> + u32 count = counter_config[0].count;
> +
> + BUG_ON(gptimer != NULL);
> + /* First try to request timers from CORE power domain for OMAP3 */
If any timer is ok, why specific timer ?
> + if (cpu_is_omap34xx()) {
> + gptimer = omap_dm_timer_request_specific(10);
> + if (gptimer == NULL)
> + gptimer = omap_dm_timer_request_specific(11);
> + }
> + /* Just any timer would be fine */
> + if (gptimer == NULL)
> + gptimer = omap_dm_timer_request();
> +
> + if (gptimer == NULL)
> + return -ENODEV;
> +
> + omap_dm_timer_set_source(gptimer, OMAP_TIMER_SRC_32_KHZ);
With Sys clock this can give better resolution o.w any accuracy below ~30 uS is
lost.
> + err = request_irq(omap_dm_timer_get_irq(gptimer), gptimer_interrupt,
> + IRQF_DISABLED, "oprofile gptimer", NULL);
> + if (err) {
> + omap_dm_timer_free(gptimer);
> + gptimer = NULL;
> + printk(KERN_ERR "oprofile: unable to request gptimer IRQ\n");
> + return err;
> + }
> +
> + /* opcontrol sets default value as 100000 which makes the sample rate
> + * too low, hence resetting
> + */
> + if ((count < 0) || (count == 100000))
> + count = 1;
> +
> + omap_dm_timer_set_load_start(gptimer, 1, 0xffffffff - count);
> + omap_dm_timer_set_int_enable(gptimer, OMAP_TIMER_INT_OVERFLOW);
> + return 0;
> +}
> +
> +static void gptimer_stop(void)
> +{
> + omap_dm_timer_set_int_enable(gptimer, 0);
> + free_irq(omap_dm_timer_get_irq(gptimer), NULL);
> + omap_dm_timer_free(gptimer);
> + gptimer = NULL;
> +}
> +
> +struct op_arm_model_spec op_omap_gptimer_spec = {
> + .init = gptimer_init,
> + .num_counters = 1,
> + .setup_ctrs = gptimer_setup,
> + .start = gptimer_start,
> + .stop = gptimer_stop,
> + .name = "arm/armv6",
This is done for Cortex-A8 right which is armv7
> +};
> --
> 1.6.0.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
