Subject: Re: [PATCH v4 2/3] powerpc/powernv: Move cpuidle related code from setup.c to new file

From: Preeti U Murthy <[email-masked]>
Date: Tue, 14 Apr 2015 10:37:31 +0530

On 04/14/2015 07:26 AM, Shreyas B. Prabhu wrote:
> This is a cleanup patch; doesn't change any functionality. Moves
> all cpuidle related code from setup.c to a new file.
> 
> Signed-off-by: Shreyas B. Prabhu <[email-masked]>

Reviewed-by: Preeti U Murthy <[email-masked]>

Regards
Preeti U Murthy
> ---
>  arch/powerpc/platforms/powernv/Makefile |   2 +-
>  arch/powerpc/platforms/powernv/idle.c   | 191 ++++++++++++++++++++++++++++++++
>  arch/powerpc/platforms/powernv/setup.c  | 171 ----------------------------
>  3 files changed, 192 insertions(+), 172 deletions(-)
>  create mode 100644 arch/powerpc/platforms/powernv/idle.c
> 
> diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
> index 33e44f3..bee9235 100644
> --- a/arch/powerpc/platforms/powernv/Makefile
> +++ b/arch/powerpc/platforms/powernv/Makefile
> @@ -1,4 +1,4 @@
> -obj-y			+= setup.o opal-wrappers.o opal.o opal-async.o
> +obj-y			+= setup.o opal-wrappers.o opal.o opal-async.o idle.o
>  obj-y			+= opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
>  obj-y			+= rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
>  obj-y			+= opal-msglog.o opal-hmi.o opal-power.o
> diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
> new file mode 100644
> index 0000000..104235a
> --- /dev/null
> +++ b/arch/powerpc/platforms/powernv/idle.c
> @@ -0,0 +1,191 @@
> +/*
> + * PowerNV cpuidle code
> + *
> + * Copyright 2015 IBM Corp.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#include <linux/types.h>
> +#include <linux/mm.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +
> +#include <asm/firmware.h>
> +#include <asm/opal.h>
> +#include <asm/cputhreads.h>
> +#include <asm/cpuidle.h>
> +#include <asm/code-patching.h>
> +
> +#include "powernv.h"
> +#include "subcore.h"
> +
> +static u32 supported_cpuidle_states;
> +
> +int pnv_save_sprs_for_winkle(void)
> +{
> +	int cpu;
> +	int rc;
> +
> +	/*
> +	 * hid0, hid1, hid4, hid5, hmeer and lpcr values are symmetric accross
> +	 * all cpus at boot. Get these reg values of current cpu and use the
> +	 * same accross all cpus.
> +	 */
> +	uint64_t lpcr_val = mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1;
> +	uint64_t hid0_val = mfspr(SPRN_HID0);
> +	uint64_t hid1_val = mfspr(SPRN_HID1);
> +	uint64_t hid4_val = mfspr(SPRN_HID4);
> +	uint64_t hid5_val = mfspr(SPRN_HID5);
> +	uint64_t hmeer_val = mfspr(SPRN_HMEER);
> +
> +	for_each_possible_cpu(cpu) {
> +		uint64_t pir = get_hard_smp_processor_id(cpu);
> +		uint64_t hsprg0_val = (uint64_t)&paca[cpu];
> +
> +		/*
> +		 * HSPRG0 is used to store the cpu's pointer to paca. Hence last
> +		 * 3 bits are guaranteed to be 0. Program slw to restore HSPRG0
> +		 * with 63rd bit set, so that when a thread wakes up at 0x100 we
> +		 * can use this bit to distinguish between fastsleep and
> +		 * deep winkle.
> +		 */
> +		hsprg0_val |= 1;
> +
> +		rc = opal_slw_set_reg(pir, SPRN_HSPRG0, hsprg0_val);
> +		if (rc != 0)
> +			return rc;
> +
> +		rc = opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
> +		if (rc != 0)
> +			return rc;
> +
> +		/* HIDs are per core registers */
> +		if (cpu_thread_in_core(cpu) == 0) {
> +
> +			rc = opal_slw_set_reg(pir, SPRN_HMEER, hmeer_val);
> +			if (rc != 0)
> +				return rc;
> +
> +			rc = opal_slw_set_reg(pir, SPRN_HID0, hid0_val);
> +			if (rc != 0)
> +				return rc;
> +
> +			rc = opal_slw_set_reg(pir, SPRN_HID1, hid1_val);
> +			if (rc != 0)
> +				return rc;
> +
> +			rc = opal_slw_set_reg(pir, SPRN_HID4, hid4_val);
> +			if (rc != 0)
> +				return rc;
> +
> +			rc = opal_slw_set_reg(pir, SPRN_HID5, hid5_val);
> +			if (rc != 0)
> +				return rc;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static void pnv_alloc_idle_core_states(void)
> +{
> +	int i, j;
> +	int nr_cores = cpu_nr_cores();
> +	u32 *core_idle_state;
> +
> +	/*
> +	 * core_idle_state - First 8 bits track the idle state of each thread
> +	 * of the core. The 8th bit is the lock bit. Initially all thread bits
> +	 * are set. They are cleared when the thread enters deep idle state
> +	 * like sleep and winkle. Initially the lock bit is cleared.
> +	 * The lock bit has 2 purposes
> +	 * a. While the first thread is restoring core state, it prevents
> +	 * other threads in the core from switching to process context.
> +	 * b. While the last thread in the core is saving the core state, it
> +	 * prevents a different thread from waking up.
> +	 */
> +	for (i = 0; i < nr_cores; i++) {
> +		int first_cpu = i * threads_per_core;
> +		int node = cpu_to_node(first_cpu);
> +
> +		core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
> +		*core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
> +
> +		for (j = 0; j < threads_per_core; j++) {
> +			int cpu = first_cpu + j;
> +
> +			paca[cpu].core_idle_state_ptr = core_idle_state;
> +			paca[cpu].thread_idle_state = PNV_THREAD_RUNNING;
> +			paca[cpu].thread_mask = 1 << j;
> +		}
> +	}
> +
> +	update_subcore_sibling_mask();
> +
> +	if (supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED)
> +		pnv_save_sprs_for_winkle();
> +}
> +
> +u32 pnv_get_supported_cpuidle_states(void)
> +{
> +	return supported_cpuidle_states;
> +}
> +EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states);
> +
> +static int __init pnv_init_idle_states(void)
> +{
> +	struct device_node *power_mgt;
> +	int dt_idle_states;
> +	u32 *flags;
> +	int i;
> +
> +	supported_cpuidle_states = 0;
> +
> +	if (cpuidle_disable != IDLE_NO_OVERRIDE)
> +		goto out;
> +
> +	if (!firmware_has_feature(FW_FEATURE_OPALv3))
> +		goto out;
> +
> +	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
> +	if (!power_mgt) {
> +		pr_warn("opal: PowerMgmt Node not found\n");
> +		goto out;
> +	}
> +	dt_idle_states = of_property_count_u32_elems(power_mgt,
> +			"ibm,cpu-idle-state-flags");
> +	if (dt_idle_states < 0) {
> +		pr_warn("cpuidle-powernv: no idle states found in the DT\n");
> +		goto out;
> +	}
> +
> +	flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
> +	if (of_property_read_u32_array(power_mgt,
> +			"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
> +		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n");
> +		goto out_free;
> +	}
> +
> +	for (i = 0; i < dt_idle_states; i++)
> +		supported_cpuidle_states |= flags[i];
> +
> +	if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
> +		patch_instruction(
> +			(unsigned int *)pnv_fastsleep_workaround_at_entry,
> +			PPC_INST_NOP);
> +		patch_instruction(
> +			(unsigned int *)pnv_fastsleep_workaround_at_exit,
> +			PPC_INST_NOP);
> +	}
> +	pnv_alloc_idle_core_states();
> +out_free:
> +	kfree(flags);
> +out:
> +	return 0;
> +}
> +
> +subsys_initcall(pnv_init_idle_states);
> diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
> index 16fdcb2..509cdd2 100644
> --- a/arch/powerpc/platforms/powernv/setup.c
> +++ b/arch/powerpc/platforms/powernv/setup.c
> @@ -35,12 +35,8 @@
>  #include <asm/opal.h>
>  #include <asm/kexec.h>
>  #include <asm/smp.h>
> -#include <asm/cputhreads.h>
> -#include <asm/cpuidle.h>
> -#include <asm/code-patching.h>
>  
>  #include "powernv.h"
> -#include "subcore.h"
>  
>  static void __init pnv_setup_arch(void)
>  {
> @@ -277,173 +273,6 @@ static void __init pnv_setup_machdep_opal(void)
>  	ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
>  }
>  
> -static u32 supported_cpuidle_states;
> -
> -int pnv_save_sprs_for_winkle(void)
> -{
> -	int cpu;
> -	int rc;
> -
> -	/*
> -	 * hid0, hid1, hid4, hid5, hmeer and lpcr values are symmetric accross
> -	 * all cpus at boot. Get these reg values of current cpu and use the
> -	 * same accross all cpus.
> -	 */
> -	uint64_t lpcr_val = mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1;
> -	uint64_t hid0_val = mfspr(SPRN_HID0);
> -	uint64_t hid1_val = mfspr(SPRN_HID1);
> -	uint64_t hid4_val = mfspr(SPRN_HID4);
> -	uint64_t hid5_val = mfspr(SPRN_HID5);
> -	uint64_t hmeer_val = mfspr(SPRN_HMEER);
> -
> -	for_each_possible_cpu(cpu) {
> -		uint64_t pir = get_hard_smp_processor_id(cpu);
> -		uint64_t hsprg0_val = (uint64_t)&paca[cpu];
> -
> -		/*
> -		 * HSPRG0 is used to store the cpu's pointer to paca. Hence last
> -		 * 3 bits are guaranteed to be 0. Program slw to restore HSPRG0
> -		 * with 63rd bit set, so that when a thread wakes up at 0x100 we
> -		 * can use this bit to distinguish between fastsleep and
> -		 * deep winkle.
> -		 */
> -		hsprg0_val |= 1;
> -
> -		rc = opal_slw_set_reg(pir, SPRN_HSPRG0, hsprg0_val);
> -		if (rc != 0)
> -			return rc;
> -
> -		rc = opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
> -		if (rc != 0)
> -			return rc;
> -
> -		/* HIDs are per core registers */
> -		if (cpu_thread_in_core(cpu) == 0) {
> -
> -			rc = opal_slw_set_reg(pir, SPRN_HMEER, hmeer_val);
> -			if (rc != 0)
> -				return rc;
> -
> -			rc = opal_slw_set_reg(pir, SPRN_HID0, hid0_val);
> -			if (rc != 0)
> -				return rc;
> -
> -			rc = opal_slw_set_reg(pir, SPRN_HID1, hid1_val);
> -			if (rc != 0)
> -				return rc;
> -
> -			rc = opal_slw_set_reg(pir, SPRN_HID4, hid4_val);
> -			if (rc != 0)
> -				return rc;
> -
> -			rc = opal_slw_set_reg(pir, SPRN_HID5, hid5_val);
> -			if (rc != 0)
> -				return rc;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
> -static void pnv_alloc_idle_core_states(void)
> -{
> -	int i, j;
> -	int nr_cores = cpu_nr_cores();
> -	u32 *core_idle_state;
> -
> -	/*
> -	 * core_idle_state - First 8 bits track the idle state of each thread
> -	 * of the core. The 8th bit is the lock bit. Initially all thread bits
> -	 * are set. They are cleared when the thread enters deep idle state
> -	 * like sleep and winkle. Initially the lock bit is cleared.
> -	 * The lock bit has 2 purposes
> -	 * a. While the first thread is restoring core state, it prevents
> -	 * other threads in the core from switching to process context.
> -	 * b. While the last thread in the core is saving the core state, it
> -	 * prevents a different thread from waking up.
> -	 */
> -	for (i = 0; i < nr_cores; i++) {
> -		int first_cpu = i * threads_per_core;
> -		int node = cpu_to_node(first_cpu);
> -
> -		core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
> -		*core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
> -
> -		for (j = 0; j < threads_per_core; j++) {
> -			int cpu = first_cpu + j;
> -
> -			paca[cpu].core_idle_state_ptr = core_idle_state;
> -			paca[cpu].thread_idle_state = PNV_THREAD_RUNNING;
> -			paca[cpu].thread_mask = 1 << j;
> -		}
> -	}
> -
> -	update_subcore_sibling_mask();
> -
> -	if (supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED)
> -		pnv_save_sprs_for_winkle();
> -}
> -
> -u32 pnv_get_supported_cpuidle_states(void)
> -{
> -	return supported_cpuidle_states;
> -}
> -EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states);
> -
> -static int __init pnv_init_idle_states(void)
> -{
> -	struct device_node *power_mgt;
> -	int dt_idle_states;
> -	u32 *flags;
> -	int i;
> -
> -	supported_cpuidle_states = 0;
> -
> -	if (cpuidle_disable != IDLE_NO_OVERRIDE)
> -		goto out;
> -
> -	if (!firmware_has_feature(FW_FEATURE_OPALv3))
> -		goto out;
> -
> -	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
> -	if (!power_mgt) {
> -		pr_warn("opal: PowerMgmt Node not found\n");
> -		goto out;
> -	}
> -	dt_idle_states = of_property_count_u32_elems(power_mgt,
> -			"ibm,cpu-idle-state-flags");
> -	if (dt_idle_states < 0) {
> -		pr_warn("cpuidle-powernv: no idle states found in the DT\n");
> -		goto out;
> -	}
> -
> -	flags = kzalloc(sizeof(*flags) * dt_idle_states, GFP_KERNEL);
> -	if (of_property_read_u32_array(power_mgt,
> -			"ibm,cpu-idle-state-flags", flags, dt_idle_states)) {
> -		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n");
> -		goto out_free;
> -	}
> -
> -	for (i = 0; i < dt_idle_states; i++)
> -		supported_cpuidle_states |= flags[i];
> -
> -	if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
> -		patch_instruction(
> -			(unsigned int *)pnv_fastsleep_workaround_at_entry,
> -			PPC_INST_NOP);
> -		patch_instruction(
> -			(unsigned int *)pnv_fastsleep_workaround_at_exit,
> -			PPC_INST_NOP);
> -	}
> -	pnv_alloc_idle_core_states();
> -out_free:
> -	kfree(flags);
> -out:
> -	return 0;
> -}
> -
> -subsys_initcall(pnv_init_idle_states);
> -
>  static int __init pnv_probe(void)
>  {
>  	unsigned long root = of_get_flat_dt_root();
>