Re: RESEND [PATCH V3 3/4] hotplug/drc-info: Add code to search ibm,drc-info property

[Nathan Fontenot <nfont@linux.vnet.ibm.com>]

On 11/15/2017 12:09 PM, Michael Bringmann wrote:
> rpadlpar_core.c: Provide parallel routines to search the older device-
> tree properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
> and "ibm,drc-power-domains"), or the new property "ibm,drc-info".
> 
> The interface to examine the DRC information is changed from a "get"
> function that returns values for local verification elsewhere, to a
> "check" function that validates the 'name' and/or 'type' of a device
> node.  This update hides the format of the underlying device-tree
> properties, and concentrates the value checks into a single function
> without requiring the user to verify whether a search was successful.
> 
> Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
> ---
> Changes in V3:
>   -- Now passing more values by structure reducing use of local
>      declarations / initialization.
>   -- Improve some code spacing for better clarity.
> ---
>  drivers/pci/hotplug/rpadlpar_core.c |   13 ++--
>  drivers/pci/hotplug/rpaphp.h        |    4 +
>  drivers/pci/hotplug/rpaphp_core.c   |  110 +++++++++++++++++++++++++++--------
>  3 files changed, 92 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
> index a3449d7..fc01d7d 100644
> --- a/drivers/pci/hotplug/rpadlpar_core.c
> +++ b/drivers/pci/hotplug/rpadlpar_core.c
> @@ -27,6 +27,7 @@
>  #include <linux/mutex.h>
>  #include <asm/rtas.h>
>  #include <asm/vio.h>
> +#include <linux/firmware.h>
> 
>  #include "../pci.h"
>  #include "rpaphp.h"
> @@ -44,15 +45,14 @@ static struct device_node *find_vio_slot_node(char *drc_name)
>  {
>  	struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
>  	struct device_node *dn = NULL;
> -	char *name;
>  	int rc;
> 
>  	if (!parent)
>  		return NULL;
> 
>  	while ((dn = of_get_next_child(parent, dn))) {
> -		rc = rpaphp_get_drc_props(dn, NULL, &name, NULL, NULL);
> -		if ((rc == 0) && (!strcmp(drc_name, name)))
> +		rc = rpaphp_check_drc_props(dn, drc_name, NULL);
> +		if (rc == 0)
>  			break;
>  	}
> 
> @@ -64,15 +64,12 @@ static struct device_node *find_php_slot_pci_node(char *drc_name,
>  						  char *drc_type)
>  {
>  	struct device_node *np = NULL;
> -	char *name;
> -	char *type;
>  	int rc;
> 
>  	while ((np = of_find_node_by_name(np, "pci"))) {
> -		rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL);
> +		rc = rpaphp_check_drc_props(np, drc_name, drc_type);
>  		if (rc == 0)
> -			if (!strcmp(drc_name, name) && !strcmp(drc_type, type))
> -				break;
> +			break;
>  	}
> 
>  	return np;
> diff --git a/drivers/pci/hotplug/rpaphp.h b/drivers/pci/hotplug/rpaphp.h
> index 7db024e..8db5f2e 100644
> --- a/drivers/pci/hotplug/rpaphp.h
> +++ b/drivers/pci/hotplug/rpaphp.h
> @@ -91,8 +91,8 @@ struct slot {
> 
>  /* rpaphp_core.c */
>  int rpaphp_add_slot(struct device_node *dn);
> -int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
> -		char **drc_name, char **drc_type, int *drc_power_domain);
> +int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
> +		char *drc_type);
> 
>  /* rpaphp_slot.c */
>  void dealloc_slot_struct(struct slot *slot);
> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
> index 1e29aba..6606175 100644
> --- a/drivers/pci/hotplug/rpaphp_core.c
> +++ b/drivers/pci/hotplug/rpaphp_core.c
> @@ -30,6 +30,7 @@
>  #include <linux/smp.h>
>  #include <linux/init.h>
>  #include <linux/vmalloc.h>
> +#include <asm/firmware.h>
>  #include <asm/eeh.h>       /* for eeh_add_device() */
>  #include <asm/rtas.h>		/* rtas_call */
>  #include <asm/pci-bridge.h>	/* for pci_controller */
> @@ -196,25 +197,21 @@ static int get_children_props(struct device_node *dn, const int **drc_indexes,
>  	return 0;
>  }
> 
> -/* To get the DRC props describing the current node, first obtain it's
> - * my-drc-index property.  Next obtain the DRC list from it's parent.  Use
> - * the my-drc-index for correlation, and obtain the requested properties.
> +
> +/* Verify the existence of 'drc_name' and/or 'drc_type' within the
> + * current node.  First obtain it's my-drc-index property.  Next,
> + * obtain the DRC info from it's parent.  Use the my-drc-index for
> + * correlation, and obtain/validate the requested properties.
>   */
> -int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
> -		char **drc_name, char **drc_type, int *drc_power_domain)
> +
> +static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
> +				char *drc_type, unsigned int my_index)
>  {
> +	char *name_tmp, *type_tmp;
>  	const int *indexes, *names;
>  	const int *types, *domains;
> -	const unsigned int *my_index;
> -	char *name_tmp, *type_tmp;
>  	int i, rc;
> 
> -	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
> -	if (!my_index) {
> -		/* Node isn't DLPAR/hotplug capable */
> -		return -EINVAL;
> -	}
> -
>  	rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
>  	if (rc < 0) {
>  		return -EINVAL;
> @@ -225,24 +222,87 @@ int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
> 
>  	/* Iterate through parent properties, looking for my-drc-index */
>  	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
> -		if ((unsigned int) indexes[i + 1] == *my_index) {
> -			if (drc_name)
> -				*drc_name = name_tmp;
> -			if (drc_type)
> -				*drc_type = type_tmp;
> -			if (drc_index)
> -				*drc_index = be32_to_cpu(*my_index);
> -			if (drc_power_domain)
> -				*drc_power_domain = be32_to_cpu(domains[i+1]);
> -			return 0;
> -		}
> +		if ((unsigned int) indexes[i + 1] == my_index)
> +			break;
> +
>  		name_tmp += (strlen(name_tmp) + 1);
>  		type_tmp += (strlen(type_tmp) + 1);
>  	}
> 
> +	if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
> +	    ((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
> +		return 0;
> +
> +	return -EINVAL;
> +}
> +
> +static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
> +				char *drc_type, unsigned int my_index)
> +{
> +	struct property *info;
> +	unsigned int entries;
> +	struct of_drc_info drc;
> +	void *value;

This should be __be32 *

> +	int j;
> +
> +	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
> +	if (info == NULL)
> +		return -EINVAL;
> +
> +	value = info->value;
> +	value = (void *)of_prop_next_u32(info, value, &entries);
> +	if (!value)
> +		return -EINVAL;
> +
> +	for (j = 0; j < entries; j++) {
> +		of_one_drc_info(&info, &value, &drc);
> +
> +		/* Should now know end of current entry */
> +
> +		WARN_ON((my_index < drc.drc_index_start) ||
> +			(((my_index-drc.drc_index_start)%
> +				drc.sequential_inc) != 0));
> +
> +		if (my_index > drc.last_drc_index)
> +			continue;
> +
> +		break;
> +	}
> +	/* Found it */
> +
> +	if (((drc_name == NULL) ||
> +	     (drc_name && !strncmp(drc_name,
> +				drc.drc_name_prefix,
> +				strlen(drc.drc_name_prefix)))) &&

Shouldn't we be doing a string compare on the entire name, not just the prefix?

If I remember correctly the prefix is the same for every cpu.

-Nathan

> +	    ((drc_type == NULL) ||
> +	     (drc_type && !strncmp(drc_type,
> +				drc.drc_type,
> +				strlen(drc.drc_type)))))
> +		return 0;
> +
>  	return -EINVAL;
>  }
> -EXPORT_SYMBOL_GPL(rpaphp_get_drc_props);
> +
> +int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
> +			char *drc_type)
> +{
> +	const unsigned int *my_index;
> +
> +	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
> +	if (!my_index) {
> +		/* Node isn't DLPAR/hotplug capable */
> +		return -EINVAL;
> +	}
> +
> +	if (firmware_has_feature(FW_FEATURE_DRC_INFO))
> +		return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
> +						*my_index);
> +	else
> +		return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
> +						*my_index);
> +}
> +EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
> +
> 
>  static int is_php_type(char *drc_type)
>  {
>