[RFC v4 4/4] hotplug/drcinfo: Code cleanup for devices

Nathan Fontenot nfont at linux.vnet.ibm.com
Wed May 23 07:39:35 AEST 2018


On 05/22/2018 11:37 AM, Michael Bringmann wrote:
> This patch extends the use of a common parse function for the
> ibm,drc-info property that can be modified by a callback function
> to the hotplug device processing.  Candidate code is replaced by
> a call to the parser including a pointer to a local context-specific
> functions, and local data.
> 
> In addition, several more opportunities to compress and reuse
> common code between the old and new property parsers were applied.
> 
> Finally, a bug with the registration of slots was observed on some
> systems, and the code was rewritten to prevent its reoccurrence.
> 
> Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
> Fixes: 3f38000eda48 ("powerpc/firmware: Add definitions for new drc-info firmwar
> e feature" -- end of patch series applied to powerpc next)
> ---
> Changes in V4:
>   -- Update code to account for latest kernel checkins.
>   -- Fix bug searching for virtual device slots.
>   -- Rebased to 4.17-rc5 kernel
>   -- Patch cleanup
> ---
>  drivers/pci/hotplug/rpaphp_core.c |  181 ++++++++++++++++++++++++++-----------
>  1 file changed, 126 insertions(+), 55 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
> index 435c1a0..dc4ec68 100644
> --- a/drivers/pci/hotplug/rpaphp_core.c
> +++ b/drivers/pci/hotplug/rpaphp_core.c
> @@ -222,47 +222,51 @@ static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
>  	return -EINVAL;
>  }
> 
> -static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
> -				char *drc_type, unsigned int my_index)
> +struct check_drc_props_v2_struct {
> +	char *drc_name;
> +	char *drc_type;
> +	unsigned int my_index;
> +};
> +
> +static int check_drc_props_v2_cb(struct of_drc_info *drc, void *idata,
> +				void *not_used, int *ret_code)
>  {
> -	struct property *info;
> -	unsigned int entries;
> -	struct of_drc_info drc;
> -	const __be32 *value;
> +	struct check_drc_props_v2_struct *cdata = idata;
>  	char cell_drc_name[MAX_DRC_NAME_LEN];
> -	int j, fndit;
> 
> -	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
> -	if (info == NULL)
> -		return -EINVAL;
> +	(*ret_code) = -EINVAL;
> 
> -	value = info->value;
> -	entries = of_read_number(value++, 1);
> -
> -	for (j = 0; j < entries; j++) {
> -		of_read_drc_info_cell(&info, &value, &drc);
> -
> -		/* Should now know end of current entry */
> -
> -		if (my_index > drc.last_drc_index)
> -			continue;
> +	if (cdata->my_index > drc->last_drc_index)
> +		return 0;
> 
> -		fndit = 1;
> -		break;
> +	/* Found drc_index.  Now match the rest. */
> +	sprintf(cell_drc_name, "%s%d", drc->drc_name_prefix,
> +		cdata->my_index - drc->drc_index_start +
> +		drc->drc_name_suffix_start);
> +
> +	if (((cdata->drc_name == NULL) ||
> +	     (cdata->drc_name && !strcmp(cdata->drc_name, cell_drc_name))) &&
> +	    ((cdata->drc_type == NULL) ||
> +	     (cdata->drc_type && !strcmp(cdata->drc_type, drc->drc_type)))) {
> +		(*ret_code) = 0;
> +		return 1;
>  	}
> -	/* Found it */
> 
> -	if (fndit)
> -		sprintf(cell_drc_name, "%s%d", drc.drc_name_prefix, 
> -			my_index);
> +	return 0;
> +}
> 
> -	if (((drc_name == NULL) ||
> -	     (drc_name && !strcmp(drc_name, cell_drc_name))) &&
> -	    ((drc_type == NULL) ||
> -	     (drc_type && !strcmp(drc_type, drc.drc_type))))
> -		return 0;
> +static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
> +				char *drc_type, unsigned int my_index)
> +{
> +	struct device_node *root = dn;
> +	struct check_drc_props_v2_struct cdata = {
> +		drc_name, drc_type, be32_to_cpu(my_index) };
> 
> -	return -EINVAL;
> +	if (!drc_type || (drc_type && strcmp(drc_type, "SLOT")))
> +		root = dn->parent;
> +
> +	return drc_info_parser(root, check_drc_props_v2_cb,
> +				drc_type, &cdata);
>  }
> 
>  int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
> @@ -285,7 +289,6 @@ int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
>  }
>  EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
> 
> -
>  static int is_php_type(char *drc_type)
>  {
>  	unsigned long value;
> @@ -345,17 +348,41 @@ static int is_php_dn(struct device_node *dn, const int **indexes,
>   *
>   * To remove a slot, it suffices to call rpaphp_deregister_slot().
>   */
> -int rpaphp_add_slot(struct device_node *dn)
> +
> +static int rpaphp_add_slot_common(struct device_node *dn,
> +			u32 drc_index, char *drc_name, char *drc_type,
> +			u32 drc_power_domain)
>  {
>  	struct slot *slot;
>  	int retval = 0;
> -	int i;
> +
> +	slot = alloc_slot_struct(dn, drc_index, drc_name, drc_power_domain);
> +	if (!slot)
> +		return -ENOMEM;
> +
> +	slot->type = simple_strtoul(drc_type, NULL, 10);
> +	if (retval)
> +		return -EINVAL;
> +
> +	dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
> +		drc_index, drc_name, drc_type);
> +
> +	retval = rpaphp_enable_slot(slot);
> +	if (!retval)
> +		retval = rpaphp_register_slot(slot);
> +
> +	if (retval)
> +		dealloc_slot_struct(slot);
> +
> +	return retval;
> +}
> +
> +static int rpaphp_add_slot_v1(struct device_node *dn)
> +{
> +	int i, retval = 0;
>  	const int *indexes, *names, *types, *power_domains;
>  	char *name, *type;
> 
> -	if (!dn->name || strcmp(dn->name, "pci"))
> -		return 0;
> -
>  	/* If this is not a hotplug slot, return without doing anything. */
>  	if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
>  		return 0;
> @@ -366,25 +393,12 @@ int rpaphp_add_slot(struct device_node *dn)
>  	name = (char *) &names[1];
>  	type = (char *) &types[1];
>  	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
> -		int index;
> -
> -		index = be32_to_cpu(indexes[i + 1]);
> -		slot = alloc_slot_struct(dn, index, name,
> -					 be32_to_cpu(power_domains[i + 1]));
> -		if (!slot)
> -			return -ENOMEM;
> -
> -		slot->type = simple_strtoul(type, NULL, 10);
> 
> -		dbg("Found drc-index:0x%x drc-name:%s drc-type:%s\n",
> -				index, name, type);
> -
> -		retval = rpaphp_enable_slot(slot);
> +		retval = rpaphp_add_slot_common(dn,
> +				be32_to_cpu(indexes[i + 1]), name, type,
> +				be32_to_cpu(power_domains[i + 1]));
>  		if (!retval)
> -			retval = rpaphp_register_slot(slot);
> -
> -		if (retval)
> -			dealloc_slot_struct(slot);
> +			return retval;
> 
>  		name += strlen(name) + 1;
>  		type += strlen(type) + 1;
> @@ -394,6 +408,63 @@ int rpaphp_add_slot(struct device_node *dn)
>  	/* XXX FIXME: reports a failure only if last entry in loop failed */
>  	return retval;
>  }
> +
> +struct rpaphp_add_slot_v2_struct {
> +	struct device_node *dn;
> +};
> +
> +static int rpaphp_add_slot_v2_cb(struct of_drc_info *drc, void *idata,
> +				void *not_used, int *ret_code)
> +{
> +	struct rpaphp_add_slot_v2_struct *cdata = idata;
> +	u32 drc_index;
> +	char drc_name[MAX_DRC_NAME_LEN];
> +	int i, retval;
> +
> +	(*ret_code) = -EINVAL;
> +
> +	if (!is_php_type((char *) drc->drc_type)) {
> +		(*ret_code) = 0;
> +		return 1;
> +	}
> +
> +	for (i = 0, drc_index = drc->drc_index_start;
> +		i < drc->num_sequential_elems; i++, drc_index++) {
> +
> +		sprintf(drc_name, "%s%d", drc->drc_name_prefix,
> +			drc_index - drc->drc_index_start +
> +			drc->drc_name_suffix_start);
> +
> +		retval = rpaphp_add_slot_common(cdata->dn,
> +				drc_index, drc_name, drc->drc_type,
> +				drc->drc_power_domain);
> +		if (!retval) {
> +			(*ret_code) = retval;
> +			return 1;
> +		}
> +	}

I may be reading this loop wrong, but it appears that it will add all drc indexes
for all drc_info entries to the specified device node, minus drc-types that don't match.

-Nathan

> +
> +	(*ret_code) = retval;
> +	return 0;
> +}
> +
> +static int rpaphp_add_slot_v2(struct device_node *dn)
> +{
> +	struct rpaphp_add_slot_v2_struct cdata = { dn };
> +
> +	return drc_info_parser(dn, rpaphp_add_slot_v2_cb, NULL, &cdata);
> +}
> +
> +int rpaphp_add_slot(struct device_node *dn)
> +{
> +	if (!dn->name || strcmp(dn->name, "pci"))
> +		return 0;
> +
> +	if (firmware_has_feature(FW_FEATURE_DRC_INFO))
> +		return rpaphp_add_slot_v2(dn);
> +	else
> +		return rpaphp_add_slot_v1(dn);
> +}
>  EXPORT_SYMBOL_GPL(rpaphp_add_slot);
> 
>  static void __exit cleanup_slots(void)
> 



More information about the Linuxppc-dev mailing list