[PATCH] arm-cci: simplify sysfs attr handling

[mark.rutland@arm.com (Mark Rutland)]

On Tue, Sep 29, 2015 at 11:41:23AM +0100, Mark Rutland wrote:
> There's no need to dynamically initialise attribute pointers when we can
> get the compiler to do it for us. We also don't need a dev_ext_attribute
> for the cpumask, as the drvdata for a PMU device is a pointer to struct
> pmu.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Acked-by: Punit Agrawal <punit.agrawal@arm.com>
> Reviewed-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
> Tested-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Olof Johansson <olof@lixom.net>
> ---
>  drivers/bus/arm-cci.c | 100 +++++++++++++-------------------------------------
>  1 file changed, 25 insertions(+), 75 deletions(-)

Arnd/Olof, are you happy to pick this up?

I don't believe there are any other pending changes to the CCI code, and
haven't been since I posted this so it still applies atop of v4.3.

Thanks,
Mark.

> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
> index 577cc4b..10511b0 100644
> --- a/drivers/bus/arm-cci.c
> +++ b/drivers/bus/arm-cci.c
> @@ -121,10 +121,8 @@ struct cci_pmu_model {
>  	u32 fixed_hw_cntrs;
>  	u32 num_hw_cntrs;
>  	u32 cntr_size;
> -	u64 nformat_attrs;
> -	u64 nevent_attrs;
> -	struct dev_ext_attribute *format_attrs;
> -	struct dev_ext_attribute *event_attrs;
> +	struct attribute **format_attrs;
> +	struct attribute **event_attrs;
>  	struct event_range event_ranges[CCI_IF_MAX];
>  	int (*validate_hw_event)(struct cci_pmu *, unsigned long);
>  	int (*get_event_idx)(struct cci_pmu *, struct cci_pmu_hw_events *, unsigned long);
> @@ -166,8 +164,10 @@ static ssize_t cci_pmu_format_show(struct device *dev,
>  static ssize_t cci_pmu_event_show(struct device *dev,
>  			struct device_attribute *attr, char *buf);
>  
> -#define CCI_EXT_ATTR_ENTRY(_name, _func, _config) \
> -	{ __ATTR(_name, S_IRUGO, _func, NULL), (void *)_config }
> +#define CCI_EXT_ATTR_ENTRY(_name, _func, _config) 				\
> +	&((struct dev_ext_attribute[]) {					\
> +		{ __ATTR(_name, S_IRUGO, _func, NULL), (void *)_config }	\
> +	})[0].attr.attr
>  
>  #define CCI_FORMAT_EXT_ATTR_ENTRY(_name, _config) \
>  	CCI_EXT_ATTR_ENTRY(_name, cci_pmu_format_show, (char *)_config)
> @@ -242,12 +242,13 @@ enum cci400_perf_events {
>  static ssize_t cci400_pmu_cycle_event_show(struct device *dev,
>  			struct device_attribute *attr, char *buf);
>  
> -static struct dev_ext_attribute cci400_pmu_format_attrs[] = {
> +static struct attribute *cci400_pmu_format_attrs[] = {
>  	CCI_FORMAT_EXT_ATTR_ENTRY(event, "config:0-4"),
>  	CCI_FORMAT_EXT_ATTR_ENTRY(source, "config:5-7"),
> +	NULL
>  };
>  
> -static struct dev_ext_attribute cci400_r0_pmu_event_attrs[] = {
> +static struct attribute *cci400_r0_pmu_event_attrs[] = {
>  	/* Slave events */
>  	CCI_EVENT_EXT_ATTR_ENTRY(si_rrq_hs_any, 0x0),
>  	CCI_EVENT_EXT_ATTR_ENTRY(si_rrq_hs_device, 0x01),
> @@ -279,9 +280,10 @@ static struct dev_ext_attribute cci400_r0_pmu_event_attrs[] = {
>  	CCI_EVENT_EXT_ATTR_ENTRY(mi_wrq_stall_tt_full, 0x1A),
>  	/* Special event for cycles counter */
>  	CCI400_CYCLE_EVENT_EXT_ATTR_ENTRY(cycles, 0xff),
> +	NULL
>  };
>  
> -static struct dev_ext_attribute cci400_r1_pmu_event_attrs[] = {
> +static struct attribute *cci400_r1_pmu_event_attrs[] = {
>  	/* Slave events */
>  	CCI_EVENT_EXT_ATTR_ENTRY(si_rrq_hs_any, 0x0),
>  	CCI_EVENT_EXT_ATTR_ENTRY(si_rrq_hs_device, 0x01),
> @@ -325,6 +327,7 @@ static struct dev_ext_attribute cci400_r1_pmu_event_attrs[] = {
>  	CCI_EVENT_EXT_ATTR_ENTRY(mi_wrq_unique_or_line_unique_addr_hazard, 0x11),
>  	/* Special event for cycles counter */
>  	CCI400_CYCLE_EVENT_EXT_ATTR_ENTRY(cycles, 0xff),
> +	NULL
>  };
>  
>  static ssize_t cci400_pmu_cycle_event_show(struct device *dev,
> @@ -480,12 +483,13 @@ static inline struct cci_pmu_model *probe_cci_model(struct platform_device *pdev
>  static ssize_t cci500_pmu_global_event_show(struct device *dev,
>  				struct device_attribute *attr, char *buf);
>  
> -static struct dev_ext_attribute cci500_pmu_format_attrs[] = {
> +static struct attribute *cci500_pmu_format_attrs[] = {
>  	CCI_FORMAT_EXT_ATTR_ENTRY(event, "config:0-4"),
>  	CCI_FORMAT_EXT_ATTR_ENTRY(source, "config:5-8"),
> +	NULL
>  };
>  
> -static struct dev_ext_attribute cci500_pmu_event_attrs[] = {
> +static struct attribute *cci500_pmu_event_attrs[] = {
>  	/* Slave events */
>  	CCI_EVENT_EXT_ATTR_ENTRY(si_rrq_hs_arvalid, 0x0),
>  	CCI_EVENT_EXT_ATTR_ENTRY(si_rrq_dev, 0x1),
> @@ -546,6 +550,7 @@ static struct dev_ext_attribute cci500_pmu_event_attrs[] = {
>  	CCI500_GLOBAL_EVENT_EXT_ATTR_ENTRY(cci_rq_stall_addr_hazard, 0xD),
>  	CCI500_GLOBAL_EVENT_EXT_ATTR_ENTRY(cci_snopp_rq_stall_tt_full, 0xE),
>  	CCI500_GLOBAL_EVENT_EXT_ATTR_ENTRY(cci_snoop_rq_tzmp1_prot, 0xF),
> +	NULL
>  };
>  
>  static ssize_t cci500_pmu_global_event_show(struct device *dev,
> @@ -1176,9 +1181,8 @@ static int cci_pmu_event_init(struct perf_event *event)
>  static ssize_t pmu_cpumask_attr_show(struct device *dev,
>  				     struct device_attribute *attr, char *buf)
>  {
> -	struct dev_ext_attribute *eattr = container_of(attr,
> -					struct dev_ext_attribute, attr);
> -	struct cci_pmu *cci_pmu = eattr->var;
> +	struct pmu *pmu = dev_get_drvdata(dev);
> +	struct cci_pmu *cci_pmu = to_cci_pmu(pmu);
>  
>  	int n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
>  			  cpumask_pr_args(&cci_pmu->cpus));
> @@ -1187,13 +1191,11 @@ static ssize_t pmu_cpumask_attr_show(struct device *dev,
>  	return n;
>  }
>  
> -static struct dev_ext_attribute pmu_cpumask_attr = {
> -	__ATTR(cpumask, S_IRUGO, pmu_cpumask_attr_show, NULL),
> -	NULL,		/* Populated in cci_pmu_init */
> -};
> +static struct device_attribute pmu_cpumask_attr =
> +	__ATTR(cpumask, S_IRUGO, pmu_cpumask_attr_show, NULL);
>  
>  static struct attribute *pmu_attrs[] = {
> -	&pmu_cpumask_attr.attr.attr,
> +	&pmu_cpumask_attr.attr,
>  	NULL,
>  };
>  
> @@ -1218,60 +1220,14 @@ static const struct attribute_group *pmu_attr_groups[] = {
>  	NULL
>  };
>  
> -static struct attribute **alloc_attrs(struct platform_device *pdev,
> -				int n, struct dev_ext_attribute *source)
> -{
> -	int i;
> -	struct attribute **attrs;
> -
> -	/* Alloc n + 1 (for terminating NULL) */
> -	attrs  = devm_kcalloc(&pdev->dev, n + 1, sizeof(struct attribute *),
> -								GFP_KERNEL);
> -	if (!attrs)
> -		return attrs;
> -	for(i = 0; i < n; i++)
> -		attrs[i] = &source[i].attr.attr;
> -	return attrs;
> -}
> -
> -static int cci_pmu_init_attrs(struct cci_pmu *cci_pmu, struct platform_device *pdev)
> -{
> -	const struct cci_pmu_model *model = cci_pmu->model;
> -	struct attribute **attrs;
> -
> -	/*
> -	 * All allocations below are managed, hence doesn't need to be
> -	 * free'd explicitly in case of an error.
> -	 */
> -
> -	if (model->nevent_attrs) {
> -		attrs = alloc_attrs(pdev, model->nevent_attrs,
> -						model->event_attrs);
> -		if (!attrs)
> -			return -ENOMEM;
> -		pmu_event_attr_group.attrs = attrs;
> -	}
> -	if (model->nformat_attrs) {
> -		attrs = alloc_attrs(pdev, model->nformat_attrs,
> -						 model->format_attrs);
> -		if (!attrs)
> -			return -ENOMEM;
> -		pmu_format_attr_group.attrs = attrs;
> -	}
> -	pmu_cpumask_attr.var = cci_pmu;
> -
> -	return 0;
> -}
> -
>  static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
>  {
> -	char *name = cci_pmu->model->name;
> +	const struct cci_pmu_model *model = cci_pmu->model;
> +	char *name = model->name;
>  	u32 num_cntrs;
> -	int rc;
>  
> -	rc = cci_pmu_init_attrs(cci_pmu, pdev);
> -	if (rc)
> -		return rc;
> +	pmu_event_attr_group.attrs = model->event_attrs;
> +	pmu_format_attr_group.attrs = model->format_attrs;
>  
>  	cci_pmu->pmu = (struct pmu) {
>  		.name		= cci_pmu->model->name,
> @@ -1336,9 +1292,7 @@ static struct cci_pmu_model cci_pmu_models[] = {
>  		.num_hw_cntrs = 4,
>  		.cntr_size = SZ_4K,
>  		.format_attrs = cci400_pmu_format_attrs,
> -		.nformat_attrs = ARRAY_SIZE(cci400_pmu_format_attrs),
>  		.event_attrs = cci400_r0_pmu_event_attrs,
> -		.nevent_attrs = ARRAY_SIZE(cci400_r0_pmu_event_attrs),
>  		.event_ranges = {
>  			[CCI_IF_SLAVE] = {
>  				CCI400_R0_SLAVE_PORT_MIN_EV,
> @@ -1358,9 +1312,7 @@ static struct cci_pmu_model cci_pmu_models[] = {
>  		.num_hw_cntrs = 4,
>  		.cntr_size = SZ_4K,
>  		.format_attrs = cci400_pmu_format_attrs,
> -		.nformat_attrs = ARRAY_SIZE(cci400_pmu_format_attrs),
>  		.event_attrs = cci400_r1_pmu_event_attrs,
> -		.nevent_attrs = ARRAY_SIZE(cci400_r1_pmu_event_attrs),
>  		.event_ranges = {
>  			[CCI_IF_SLAVE] = {
>  				CCI400_R1_SLAVE_PORT_MIN_EV,
> @@ -1382,9 +1334,7 @@ static struct cci_pmu_model cci_pmu_models[] = {
>  		.num_hw_cntrs = 8,
>  		.cntr_size = SZ_64K,
>  		.format_attrs = cci500_pmu_format_attrs,
> -		.nformat_attrs = ARRAY_SIZE(cci500_pmu_format_attrs),
>  		.event_attrs = cci500_pmu_event_attrs,
> -		.nevent_attrs = ARRAY_SIZE(cci500_pmu_event_attrs),
>  		.event_ranges = {
>  			[CCI_IF_SLAVE] = {
>  				CCI500_SLAVE_PORT_MIN_EV,
> -- 
> 1.9.1
>