g 28, 2010 at 3:38 AM, <vishwanath.sripa...@linaro.org> wrote:
> From: Vishwanath BS <vishwanath.sripa...@linaro.org>
>
> This patch has instrumentation code for measuring latencies for
> various CPUIdle C states for OMAP. Idea here is to capture the
> timestamp at various phases of CPU Idle and then compute the sw
> latency for various c states. For OMAP, 32k clock is chosen as
> reference clock this as is an always on clock. wkup domain memory
> (scratchpad memory) is used for storing timestamps. One can see the
> worstcase latencies in below sysfs entries (after enabling
> CONFIG_CPU_IDLE_PROF
> in .config). This information can be used to correctly configure cpu idle
> latencies for various C states after adding HW latencies for each of
> these sw latencies.
> /sys/devices/system/cpu/cpu0/cpuidle/state<n>/actual_latency
> /sys/devices/system/cpu/cpu0/cpuidle/state<n>/sleep_latency
> /sys/devices/system/cpu/cpu0/cpuidle/state<n>/wkup_latency
>
> THis patch is tested on OMAP ZOOM3 using kevin's pm branch.
>
> Signed-off-by: Vishwanath BS <vishwanath.sripa...@linaro.org>
> Cc: linaro-dev@lists.linaro.org
> ---
> arch/arm/mach-omap2/cpuidle34xx.c | 58 ++++++++++++++++--
> arch/arm/mach-omap2/pm.h | 5 ++
> arch/arm/mach-omap2/sleep34xx.S | 121
> +++++++++++++++++++++++++++++++++++++
> drivers/cpuidle/Kconfig | 5 ++
> drivers/cpuidle/sysfs.c | 16 +++++-
> include/linux/cpuidle.h | 3 +
> 6 files changed, 202 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/cpuidle34xx.c
> b/arch/arm/mach-omap2/cpuidle34xx.c
> index 3d3d035..398bef8
> --- a/arch/arm/mach-omap2/cpuidle34xx.c
> +++ b/arch/arm/mach-omap2/cpuidle34xx.c
> @@ -25,6 +25,7 @@
> #include <linux/sched.h>
> #include <linux/cpuidle.h>
>
> +#include <linux/clk.h>
> #include <plat/prcm.h>
> #include <plat/irqs.h>
> #include <plat/powerdomain.h>
> @@ -86,6 +87,11 @@ static struct cpuidle_params cpuidle_params_table[] = {
> {1, 10000, 30000, 300000},
> };
>
> +#ifdef CONFIG_CPU_IDLE_PROF
> +static struct clk *clk_32k;
> +#define CONVERT_32K_USEC(lat) (lat * (USEC_PER_SEC/clk_get_rate(clk_32k)))
> +#endif
> +
> static int omap3_idle_bm_check(void)
> {
> if (!omap3_can_sleep())
> @@ -115,21 +121,28 @@ static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
> * Called from the CPUidle framework to program the device to the
> * specified target state selected by the governor.
> */
> +
> static int omap3_enter_idle(struct cpuidle_device *dev,
> struct cpuidle_state *state)
> {
> struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
> struct timespec ts_preidle, ts_postidle, ts_idle;
> u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
> +#ifdef CONFIG_CPU_IDLE_PROF
> + int idle_time, latency;
> + long sleep_time, wkup_time, total_sleep_time;
> + long preidle_time, postidle_time;
> +#endif
>
> current_cx_state = *cx;
>
> - /* Used to keep track of the total time in idle */
> - getnstimeofday(&ts_preidle);
> -
> local_irq_disable();
> local_fiq_disable();
> -
> + /* Used to keep track of the total time in idle */
> + getnstimeofday(&ts_preidle);
> +#ifdef CONFIG_CPU_IDLE_PROF
> + preidle_time = omap3_sram_get_32k_tick();
> +#endif
> pwrdm_set_next_pwrst(mpu_pd, mpu_state);
> pwrdm_set_next_pwrst(core_pd, core_state);
>
> @@ -153,9 +166,39 @@ return_sleep_time:
> getnstimeofday(&ts_postidle);
> ts_idle = timespec_sub(ts_postidle, ts_preidle);
>
> +#ifdef CONFIG_CPU_IDLE_PROF
> + postidle_time = omap3_sram_get_32k_tick();
> +#endif
> local_irq_enable();
> local_fiq_enable();
>
> +#ifdef CONFIG_CPU_IDLE_PROF
> + sleep_time = omap3_sram_get_sleep_time();
> + wkup_time = omap3_sram_get_wkup_time();
> +
> + /* take care of overflow */
> + if (postidle_time < preidle_time)
> + postidle_time += (u32) 0xffffffff;
> + if (wkup_time < sleep_time)
> + wkup_time += (u32) 0xffffffff;
> +
> + idle_time = postidle_time - preidle_time;
> + total_sleep_time = wkup_time - sleep_time;
> + latency = idle_time - total_sleep_time;
> + sleep_time = omap3_sram_get_sleep_time();
> + wkup_time = omap3_sram_get_wkup_time();
> +
> + /* calculate average latency after ignoring sprious ones */
> + if ((total_sleep_time > 0) && (latency > state->actual_latency)
> + && (latency >= 0)) {
> + state->actual_latency = CONVERT_32K_USEC(latency);
> + latency = (sleep_time - preidle_time);
> + state->sleep_latency = CONVERT_32K_USEC(latency);
> + latency = postidle_time - wkup_time;
> + state->wkup_latency = CONVERT_32K_USEC(latency);
> + }
> +#endif
> +
> return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
> }
>
> @@ -423,7 +466,9 @@ int __init omap3_idle_init(void)
> struct omap3_processor_cx *cx;
> struct cpuidle_state *state;
> struct cpuidle_device *dev;
> -
> +#ifdef CONFIG_CPU_IDLE_PROF
> + static struct device dummy_device;
> +#endif
> mpu_pd = pwrdm_lookup("mpu_pwrdm");
> core_pd = pwrdm_lookup("core_pwrdm");
>
> @@ -456,6 +501,9 @@ int __init omap3_idle_init(void)
>
> omap3_cpuidle_update_states();
>
> +#ifdef CONFIG_CPU_IDLE_PROF
> + clk_32k = clk_get(&dummy_device, "wkup_32k_fck");
> +#endif
> if (cpuidle_register_device(dev)) {
> printk(KERN_ERR "%s: CPUidle register device failed\n",
> __func__);
> diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
> index 3de6ece..e62e87d 100644
> --- a/arch/arm/mach-omap2/pm.h
> +++ b/arch/arm/mach-omap2/pm.h
> @@ -82,4 +82,9 @@ extern unsigned int save_secure_ram_context_sz;
> extern unsigned int omap24xx_cpu_suspend_sz;
> extern unsigned int omap34xx_cpu_suspend_sz;
>
> +#ifdef CONFIG_CPU_IDLE_PROF
> +extern u32 omap3_sram_get_wkup_time();
> +extern u32 omap3_sram_get_sleep_time();
> +extern u32 omap3_sram_get_32k_tick();
> +#endif
> #endif
> diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
> index d522cd7..8dec5ef 100644
> --- a/arch/arm/mach-omap2/sleep34xx.S
> +++ b/arch/arm/mach-omap2/sleep34xx.S
> @@ -59,6 +59,20 @@
> #define SDRC_DLLA_STATUS_V OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS)
> #define SDRC_DLLA_CTRL_V OMAP34XX_SDRC_REGADDR(SDRC_DLLA_CTRL)
>
> +#define TIMER_32K_SYNC_P 0x48320010
> +#define TIMER_32K_SYNC OMAP2_L4_IO_ADDRESS(TIMER_32K_SYNC_P)
> +
> +#define SCRATCHPAD_SLEEP_TIME_OFFSET 0x9f8
> +#define SCRATCHPAD_WKUP_TIME_OFFSET 0x9fc
> +#define SCRATCHPAD_SLEEP_TIME
> OMAP343X_CTRL_REGADDR(SCRATCHPAD_SLEEP_TIME_OFFSET)
> +#define SCRATCHPAD_WKUP_TIME
> OMAP343X_CTRL_REGADDR(SCRATCHPAD_WKUP_TIME_OFFSET)
> +#define SCRATCHPAD_WKUP_TIME_P OMAP343X_CTRL_BASE +
> SCRATCHPAD_WKUP_TIME_OFFSET
> +
> +#define CM_ICLKEN_WKUP OMAP34XX_CM_REGADDR(WKUP_MOD, CM_ICLKEN)
> +#define CM_ICLKEN_WKUP_P OMAP3430_CM_BASE + WKUP_MOD + CM_ICLKEN
> +#define CM_IDLEST_WKUP OMAP34XX_CM_REGADDR(WKUP_MOD, CM_IDLEST)
> +#define CM_IDLEST_WKUP_P OMAP3430_CM_BASE + WKUP_MOD + CM_IDLEST
> +
> .text
> /* Function to aquire the semaphore in scratchpad */
> ENTRY(lock_scratchpad_sem)
> @@ -183,7 +197,31 @@ api_params:
> .word 0x4, 0x0, 0x0, 0x1, 0x1
> ENTRY(save_secure_ram_context_sz)
> .word . - save_secure_ram_context
> +#ifdef CONFIG_CPU_IDLE_PROF
> +ENTRY(omap3_sram_get_wkup_time)
> + stmfd sp!, {lr} @ save registers on stack
> + ldr r0, wkup_time
> + ldr r0, [r0]
> + ldmfd sp!, {pc} @ restore regs and return
> +ENTRY(omap3_sram_get_wkup_time_sz)
> + .word . - omap3_sram_get_wkup_time
> +
> +ENTRY(omap3_sram_get_sleep_time)
> + stmfd sp!, {lr} @ save registers on stack
> + ldr r0, sleep_time
> + ldr r0, [r0]
> + ldmfd sp!, {pc} @ restore regs and return
> +ENTRY(omap3_sram_get_sleep_time_sz)
> + .word . - omap3_sram_get_sleep_time
>
> +ENTRY(omap3_sram_get_32k_tick)
> + stmfd sp!, {lr} @ save registers on stack
> + ldr r0, sync_32k_timer
> + ldr r0, [r0]
> + ldmfd sp!, {pc} @ restore regs and return
> +ENTRY(omap3_sram_get_32k_tick_sz)
> + .word . - omap3_sram_get_32k_tick
> +#endif
> /*
> * Forces OMAP into idle state
> *
> @@ -207,6 +245,13 @@ loop:
> cmp r1, #0x0
> /* If context save is required, do that and execute wfi */
> bne save_context_wfi
> +
> +#ifdef CONFIG_CPU_IDLE_PROF
> + ldr r4, sync_32k_timer
> + ldr r5, [r4]
> + ldr r6, sleep_time
> + str r5, [r6]
> +#endif
> /* Data memory barrier and Data sync barrier */
> mov r1, #0
> mcr p15, 0, r1, c7, c10, 4
> @@ -224,8 +269,25 @@ loop:
> nop
> nop
> nop
> +#ifdef CONFIG_CPU_IDLE_PROF
> + ldr r4, iclken_wkup
> + ldr r5, [r4]
> + orr r5, r5, #0x4
> + str r5, [r4]
> + ldr r4, idlest_wkup
> +wait_idlest:
> + ldr r5, [r4]
> + and r5, r5, #0x4
> + cmp r5, #0x0
> + bne wait_idlest
> + ldr r4, sync_32k_timer
> + ldr r5, [r4]
> + ldr r6, wkup_time
> + str r5, [r6]
> +#endif
> bl wait_sdrc_ok
>
> +
> ldmfd sp!, {r0-r12, pc} @ restore regs and return
> restore_es3:
> /*b restore_es3*/ @ Enable to debug restore code
> @@ -247,6 +309,23 @@ copy_to_sram:
> blx r1
> restore:
> /* b restore*/ @ Enable to debug restore code
> +#ifdef CONFIG_CPU_IDLE_PROF
> + ldr r4, iclken_wkup_p
> + ldr r5, [r4]
> + orr r5, r5, #0x4
> + str r5, [r4]
> + ldr r4, idlest_wkup_p
> +wait_idlest1:
> + ldr r5, [r4]
> + and r5, r5, #0x4
> + cmp r5, #0x0
> + bne wait_idlest1
> + ldr r4, sync_32k_timer_p
> + ldr r5, [r4]
> + ldr r6, wkup_time_p
> + str r5, [r6]
> +#endif
> +
> /* Check what was the reason for mpu reset and store the reason in
> r9*/
> /* 1 - Only L1 and logic lost */
> /* 2 - Only L2 lost - In this case, we wont be here */
> @@ -587,6 +666,12 @@ finished:
> mcr p15, 2, r10, c0, c0, 0
> isb
> skip_l2_inval:
> +#ifdef CONFIG_CPU_IDLE_PROF
> + ldr r4, sync_32k_timer
> + ldr r5, [r4]
> + ldr r6, sleep_time
> + str r5, [r6]
> +#endif
> /* Data memory barrier and Data sync barrier */
> mov r1, #0
> mcr p15, 0, r1, c7, c10, 4
> @@ -603,6 +688,22 @@ skip_l2_inval:
> nop
> nop
> nop
> +#ifdef CONFIG_CPU_IDLE_PROF
> + ldr r4, iclken_wkup
> + ldr r5, [r4]
> + orr r5, r5, #0x4
> + str r5, [r4]
> + ldr r4, idlest_wkup
> +wait_idlest2:
> + ldr r5, [r4]
> + and r5, r5, #0x4
> + cmp r5, #0x0
> + bne wait_idlest2
> + ldr r4, sync_32k_timer
> + ldr r5, [r4]
> + ldr r6, wkup_time
> + str r5, [r6]
> +#endif
> bl wait_sdrc_ok
> /* restore regs and return */
> ldmfd sp!, {r0-r12, pc}
> @@ -668,5 +769,25 @@ cache_pred_disable_mask:
> .word 0xFFFFE7FB
> control_stat:
> .word CONTROL_STAT
> +#ifdef CONFIG_CPU_IDLE_PROF
> +sync_32k_timer:
> + .word TIMER_32K_SYNC
> +sync_32k_timer_p:
> + .word TIMER_32K_SYNC_P
> +sleep_time:
> + .word SCRATCHPAD_SLEEP_TIME
> +wkup_time:
> + .word SCRATCHPAD_WKUP_TIME
> +wkup_time_p:
> + .word SCRATCHPAD_WKUP_TIME_P
> +iclken_wkup:
> + .word CM_ICLKEN_WKUP
> +iclken_wkup_p:
> + .word CM_ICLKEN_WKUP_P
> +idlest_wkup:
> + .word CM_IDLEST_WKUP
> +idlest_wkup_p:
> + .word CM_IDLEST_WKUP_P
> +#endif
> ENTRY(omap34xx_cpu_suspend_sz)
> .word . - omap34xx_cpu_suspend
> diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> index 7dbc4a8..147456d 100644
> --- a/drivers/cpuidle/Kconfig
> +++ b/drivers/cpuidle/Kconfig
> @@ -18,3 +18,8 @@ config CPU_IDLE_GOV_MENU
> bool
> depends on CPU_IDLE && NO_HZ
> default y
> +
> +config CPU_IDLE_PROF
> + bool
Should not this be something like bool "CPU idle profiling " so that
this entry shows up in
'make menuconfig' ? and this should have dependency on ARCH_OMAP3 also ?
> + depends on CPU_IDLE
> + default n
> diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
> index 0310ffa..a3e9db1 100644
> --- a/drivers/cpuidle/sysfs.c
> +++ b/drivers/cpuidle/sysfs.c
> @@ -249,6 +249,11 @@ define_show_state_ull_function(usage)
> define_show_state_ull_function(time)
> define_show_state_str_function(name)
> define_show_state_str_function(desc)
> +#ifdef CONFIG_CPU_IDLE_PROF
> +define_show_state_function(actual_latency)
> +define_show_state_function(sleep_latency)
> +define_show_state_function(wkup_latency)
> +#endif
>
> define_one_state_ro(name, show_state_name);
> define_one_state_ro(desc, show_state_desc);
> @@ -256,7 +261,11 @@ define_one_state_ro(latency, show_state_exit_latency);
> define_one_state_ro(power, show_state_power_usage);
> define_one_state_ro(usage, show_state_usage);
> define_one_state_ro(time, show_state_time);
> -
> +#ifdef CONFIG_CPU_IDLE_PROF
> +define_one_state_ro(actual_latency, show_state_actual_latency);
> +define_one_state_ro(sleep_latency, show_state_sleep_latency);
> +define_one_state_ro(wkup_latency, show_state_wkup_latency);
> +#endif
> static struct attribute *cpuidle_state_default_attrs[] = {
> &attr_name.attr,
> &attr_desc.attr,
> @@ -264,6 +273,11 @@ static struct attribute *cpuidle_state_default_attrs[] =
> {
> &attr_power.attr,
> &attr_usage.attr,
> &attr_time.attr,
> +#ifdef CONFIG_CPU_IDLE_PROF
> + &attr_actual_latency.attr,
> + &attr_sleep_latency.attr,
> + &attr_wkup_latency.attr,
> +#endif
> NULL
> };
>
> diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> index 55215cc..6474f6a 100644
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -43,6 +43,9 @@ struct cpuidle_state {
>
> int (*enter) (struct cpuidle_device *dev,
> struct cpuidle_state *state);
> +#ifdef CONFIG_CPU_IDLE_PROF
> + u32 actual_latency, sleep_latency, wkup_latency;
> +#endif
> };
>
> /* Idle State Flags */
> --
> 1.7.0.4
>
> --
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>
--
Silesh
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