From: Michael Bringmann <mwb@linux.vnet.ibm.com>
To: Nathan Fontenot <nfont@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: RESEND [PATCH V3 2/4] pseries/drc-info: Search DRC properties for CPU indexes
Date: Thu, 16 Nov 2017 11:43:02 -0600 [thread overview]
Message-ID: <d57df38b-7373-0ccc-a514-1b8772d6be5a@linux.vnet.ibm.com> (raw)
In-Reply-To: <0c12e74e-771a-6a85-175b-15bb9476be99@linux.vnet.ibm.com>
See below.
On 11/16/2017 11:34 AM, Nathan Fontenot wrote:
> On 11/15/2017 12:09 PM, Michael Bringmann wrote:
>> pseries/drc-info: Provide parallel routines to convert between
>> drc_index and CPU numbers at runtime, using 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".
>>
>> Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
>> ---
>> Changes in V3:
>> -- Some code compression and use of data structures for value passing.
>> ---
>> arch/powerpc/include/asm/prom.h | 15 ++
>> arch/powerpc/platforms/pseries/of_helpers.c | 60 ++++++++++
>> arch/powerpc/platforms/pseries/pseries_energy.c | 139 ++++++++++++++++++-----
>> 3 files changed, 186 insertions(+), 28 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
>> index 3243455..007430a 100644
>> --- a/arch/powerpc/include/asm/prom.h
>> +++ b/arch/powerpc/include/asm/prom.h
>> @@ -96,6 +96,21 @@ struct of_drconf_cell {
>> #define DRCONF_MEM_AI_INVALID 0x00000040
>> #define DRCONF_MEM_RESERVED 0x00000080
>>
>> +struct of_drc_info {
>> + char *drc_type;
>> + char *drc_name_prefix;
>> + u32 drc_index_start;
>> + u32 drc_name_suffix_start;
>> + u32 num_sequential_elems;
>> + u32 sequential_inc;
>> + u32 drc_power_domain;
>> + u32 last_drc_index;
>> +};
>> +
>> +extern int of_one_drc_info(struct property **prop, void **curval,
>> + struct of_drc_info *data);
>
> I'm not sure if prom.h is where this really belongs but I also do
> not see an existing header file that it really makes sense to put it in.
If you think of a better place, please let me know.
>
>> +
>> +
>> /*
>> * There are two methods for telling firmware what our capabilities are.
>> * Newer machines have an "ibm,client-architecture-support" method on the
>> diff --git a/arch/powerpc/platforms/pseries/of_helpers.c b/arch/powerpc/platforms/pseries/of_helpers.c
>> index 2798933..62dc8e9 100644
>> --- a/arch/powerpc/platforms/pseries/of_helpers.c
>> +++ b/arch/powerpc/platforms/pseries/of_helpers.c
>> @@ -2,6 +2,7 @@
>> #include <linux/err.h>
>> #include <linux/slab.h>
>> #include <linux/of.h>
>> +#include <asm/prom.h>
>>
>> #include "of_helpers.h"
>>
>> @@ -36,3 +37,62 @@ struct device_node *pseries_of_derive_parent(const char *path)
>> kfree(parent_path);
>> return parent ? parent : ERR_PTR(-EINVAL);
>> }
>> +
>> +
>> +/* Helper Routines to convert between drc_index to cpu numbers */
>> +
>> +int of_one_drc_info(struct property **prop, void **curval,
>> + struct of_drc_info *data)
>
> Small nit, this should probably be of_read_drc_info_cell.
Okay. Will change.
>
>> +{
>> + const char *p;
>> + const __be32 *p2;
>> +
>> + if (!data)
>> + return -EINVAL;
>> +
>> + /* Get drc-type:encode-string */
>> + p = data->drc_type = (*curval);
>> + p = of_prop_next_string(*prop, p);
>> + if (!p)
>> + return -EINVAL;
>> +
>> + /* Get drc-name-prefix:encode-string */
>> + data->drc_name_prefix = (char *)p;
>> + p = of_prop_next_string(*prop, p);
>> + if (!p)
>> + return -EINVAL;
>> +
>> + /* Get drc-index-start:encode-int */
>> + p2 = (const __be32 *)p;
>> + p2 = of_prop_next_u32(*prop, p2, &data->drc_index_start);
>> + if (!p2)
>> + return -EINVAL;
>> +
>> + /* Get/skip drc-name-suffix-start:encode-int */
>
> You're getting the suffix, should probably drop 'skip' in the comment.
Okay.
>
>> + p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
>> + if (!p2)
>> + return -EINVAL;
>> +
>> + /* Get number-sequential-elements:encode-int */
>> + p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
>> + if (!p2)
>> + return -EINVAL;
>> +
>> + /* Get sequential-increment:encode-int */
>> + p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
>> + if (!p2)
>> + return -EINVAL;
>> +
>> + /* Get/skip drc-power-domain:encode-int */
>
> Same here.
Okay.
>
>> + p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
>> + if (!p2)
>> + return -EINVAL;
>> +
>> + /* Should now know end of current entry */
>> + (*curval) = (void *)p2;
>> + data->last_drc_index = data->drc_index_start +
>> + ((data->num_sequential_elems-1)*data->sequential_inc);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(of_one_drc_info);
>> diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
>> index 35c891a..7160855 100644
>> --- a/arch/powerpc/platforms/pseries/pseries_energy.c
>> +++ b/arch/powerpc/platforms/pseries/pseries_energy.c
>> @@ -22,6 +22,7 @@
>> #include <asm/page.h>
>> #include <asm/hvcall.h>
>> #include <asm/firmware.h>
>> +#include <asm/prom.h>
>>
>>
>> #define MODULE_VERS "1.0"
>> @@ -38,26 +39,65 @@
>> static u32 cpu_to_drc_index(int cpu)
>> {
>> struct device_node *dn = NULL;
>> - const int *indexes;
>> - int i;
>> + int thread_index;
>> int rc = 1;
>> u32 ret = 0;
>>
>> dn = of_find_node_by_path("/cpus");
>> if (dn == NULL)
>> goto err;
>> - indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
>> - if (indexes == NULL)
>> - goto err_of_node_put;
>> +
>> /* Convert logical cpu number to core number */
>> - i = cpu_core_index_of_thread(cpu);
>> - /*
>> - * The first element indexes[0] is the number of drc_indexes
>> - * returned in the list. Hence i+1 will get the drc_index
>> - * corresponding to core number i.
>> - */
>> - WARN_ON(i > indexes[0]);
>> - ret = indexes[i + 1];
>> + thread_index = cpu_core_index_of_thread(cpu);
>> +
>> + if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
>> + struct property *info = NULL;
>
> No need to set this to NULL here.
Okay.
>
>> + struct of_drc_info drc;
>> + int j;
>> + u32 num_set_entries;
>> + void *value;
>
> For device tree values, which are BE by design, this would be better as
> const __be32 *value;
Okay.
>
>> +
>> + info = of_find_property(dn, "ibm,drc-info", NULL);
>> + if (info == NULL)
>> + goto err_of_node_put;
>> +
>> + value = info->value;
>> + value = (void *)of_prop_next_u32(info, value, &num_set_entries);
>> + if (!value)
>> + goto err_of_node_put;
>> +
>> + for (j = 0; j < num_set_entries; j++) {
>> +
>> + of_one_drc_info(&info, &value, &drc);
>> + if (strncmp(drc.drc_type, "CPU", 3))
>> + goto err;
>> +
>> + if (thread_index < drc.last_drc_index)
>> + break;
>> +
>> + WARN_ON(((thread_index-drc.drc_index_start)%
>
> Spaces around the '-' sign please.
Okay. Missed that one.
>
>> + drc.sequential_inc) != 0);
>> + }
>> + WARN_ON((drc.num_sequential_elems == 0) ||
>> + (drc.sequential_inc == 0));
>
> This warning seems like it would fit better in the routine that reads the
> drc-info property values.
Wanted to have minimal impact on original calling code. Will remove this one.
>
>> +
>> + ret = drc.drc_index_start + (thread_index*drc.sequential_inc);
>
> Spaces... '*'
Okay.
>
>> + } else {
>> + const __be32 *indexes;
>> +
>> + indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
>> + if (indexes == NULL)
>> + goto err_of_node_put;
>> +
>> + /*
>> + * The first element indexes[0] is the number of drc_indexes
>> + * returned in the list. Hence thread_index+1 will get the
>> + * drc_index corresponding to core number thread_index.
>> + */
>> + WARN_ON(thread_index > indexes[0]);
>> + ret = indexes[thread_index + 1];
>> + }
>> +
>> rc = 0;
>>
>> err_of_node_put:
>> @@ -72,34 +112,77 @@ static int drc_index_to_cpu(u32 drc_index)
>> {
>> struct device_node *dn = NULL;
>> const int *indexes;
>> - int i, cpu = 0;
>> + int thread_index = 0, cpu = 0;
>> int rc = 1;
>>
>> dn = of_find_node_by_path("/cpus");
>> if (dn == NULL)
>> goto err;
>> - indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
>> - if (indexes == NULL)
>> - goto err_of_node_put;
>> - /*
>> - * First element in the array is the number of drc_indexes
>> - * returned. Search through the list to find the matching
>> - * drc_index and get the core number
>> - */
>> - for (i = 0; i < indexes[0]; i++) {
>> - if (indexes[i + 1] == drc_index)
>> +
>> + if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
>> + struct property *info = NULL;
>> + struct of_drc_info drc;
>> + int j;
>> + u32 num_set_entries;
>> + void *value;
>> +
>> + info = of_find_property(dn, "ibm,drc-info", NULL);
>> + if (info == NULL)
>> + goto err_of_node_put;
>> +
>> + value = info->value;
>> + value = (void *)of_prop_next_u32(info, value, &num_set_entries);
>> + if (!value)
>> + goto err_of_node_put;
>> +
>> + for (j = 0; j < num_set_entries; j++) {
>> +
>> + of_one_drc_info(&info, &value, &drc);
>> + if (strncmp(drc.drc_type, "CPU", 3))
>> + goto err;
>> +
>> + WARN_ON(drc_index < drc.drc_index_start);
>> + WARN_ON(((drc_index-drc.drc_index_start)%
>> + drc.sequential_inc) != 0);
>> +
>> + if (drc_index > drc.last_drc_index) {
>> + cpu += drc.num_sequential_elems;
>> + continue;
>> + } else {
>
> Since you do a continue in the if() part above you shouldn't need to
> put this in an else block.
Okay.
>
> -Nathan
>
>> + cpu += ((drc_index-drc.drc_index_start)/
>> + drc.sequential_inc);
>> + }
>> +
>> + thread_index = cpu_first_thread_of_core(cpu);
>> + rc = 0;
>> break;
>> + }
>> + } else {
>> + unsigned long int i;
>> +
>> + indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
>> + if (indexes == NULL)
>> + goto err_of_node_put;
>> + /*
>> + * First element in the array is the number of drc_indexes
>> + * returned. Search through the list to find the matching
>> + * drc_index and get the core number
>> + */
>> + for (i = 0; i < indexes[0]; i++) {
>> + if (indexes[i + 1] == drc_index)
>> + break;
>> + }
>> + /* Convert core number to logical cpu number */
>> + thread_index = cpu_first_thread_of_core(i);
>> + rc = 0;
>> }
>> - /* Convert core number to logical cpu number */
>> - cpu = cpu_first_thread_of_core(i);
>> - rc = 0;
>>
>> err_of_node_put:
>> of_node_put(dn);
>> err:
>> if (rc)
>> printk(KERN_WARNING "drc_index_to_cpu(%d) failed", drc_index);
>> - return cpu;
>> + return thread_index;
>> }
>>
>> /*
>>
>
--
Michael W. Bringmann
Linux Technology Center
IBM Corporation
Tie-Line 363-5196
External: (512) 286-5196
Cell: (512) 466-0650
mwb@linux.vnet.ibm.com
next prev parent reply other threads:[~2017-11-16 17:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-15 18:08 RESEND [PATCH V3 0/4] powerpc/devtree: Add support for 'ibm, drc-info' property Michael Bringmann
2017-11-15 18:09 ` RESEND [PATCH V3 1/4] powerpc/firmware: Add definitions for new drc-info firmware feature Michael Bringmann
2017-11-16 17:06 ` Nathan Fontenot
2017-11-16 17:37 ` Michael Bringmann
2017-11-15 18:09 ` RESEND [PATCH V3 2/4] pseries/drc-info: Search DRC properties for CPU indexes Michael Bringmann
2017-11-16 17:34 ` Nathan Fontenot
2017-11-16 17:43 ` Michael Bringmann [this message]
2017-11-15 18:09 ` RESEND [PATCH V3 3/4] hotplug/drc-info: Add code to search ibm,drc-info property Michael Bringmann
2017-11-16 17:50 ` Nathan Fontenot
2017-11-16 18:33 ` Michael Bringmann
2017-11-15 18:09 ` RESEND [PATCH V3 4/4] powerpc: Enable support for ibm,drc-info devtree property Michael Bringmann
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