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 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 (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); + 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", +}; -- 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
