[PATCH V2 5/8] pseries/drc-info: Search new DRC properties for CPU indexes
Michael Bringmann
mwb at linux.vnet.ibm.com
Tue Aug 2 06:17:46 AEST 2016
On 08/01/2016 10:23 AM, Nathan Fontenot wrote:
> On 07/27/2016 09:23 AM, 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 at linux.vnet.ibm.com>
>> ---
>> diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
>> index 9276779..10c4200 100644
>> --- a/arch/powerpc/platforms/pseries/pseries_energy.c
>> +++ b/arch/powerpc/platforms/pseries/pseries_energy.c
>> @@ -35,10 +35,68 @@ static int sysfs_entries;
>>
>> /* Helper Routines to convert between drc_index to cpu numbers */
>>
>> +void read_one_drc_info(int **info, char **dtype, char **dname,
>> + unsigned long int *fdi_p, unsigned long int *nsl_p,
>> + unsigned long int *si_p, unsigned long int *ldi_p)
>> +{
>> + char *drc_type, *drc_name, *pc;
>> + u32 fdi, nsl, si, ldi;
>> +
>> + fdi = nsl = si = ldi = 0;
>> +
>> + /* Get drc-type:encode-string */
>> + pc = (char *)info;
>> + drc_type = pc;
>> + pc += (strlen(drc_type) + 1);
>> +
>> + /* Get drc-name-prefix:encode-string */
>> + drc_name = (char *)pc;
>> + pc += (strlen(drc_name) + 1);
>> +
>> + /* Get drc-index-start:encode-int */
>> + memcpy(&fdi, pc, 4);
>> + fdi = be32_to_cpu(fdi);
>
> Could this be done with just using the drc-start-index directly? Such
> as fdi = be32_to_cpu(*(u32 *)pc)? Just curious if the memcpy could be avoided.
Will try it again. I thought that I had a runtime problem, but maybe that
has gone away.
>
>> + pc += 4;
>> +
>> + /* Get/skip drc-name-suffix-start:encode-int */
>> + pc += 4;
>> +
>> + /* Get number-sequential-elements:encode-int */
>> + memcpy(&nsl, pc, 4);
>> + nsl = be32_to_cpu(nsl);
>> + pc += 4;
>> +
>> + /* Get sequential-increment:encode-int */
>> + memcpy(&si, pc, 4);
>> + si = be32_to_cpu(si);
>> + pc += 4;
>> +
>> + /* Get/skip drc-power-domain:encode-int */
>> + pc += 4;
>> +
>> + /* Should now know end of current entry */
>> + ldi = fdi + ((nsl-1)*si);
>> +
>> + (*info) = (int *)pc;
>> +
>> + if (dtype)
>> + *dtype = drc_type;
>> + if (dname)
>> + *dname = drc_name;
>> + if (fdi_p)
>> + *fdi_p = fdi;
>> + if (nsl_p)
>> + *nsl_p = nsl;
>> + if (si_p)
>> + *si_p = si;
>> + if (ldi_p)
>> + *ldi_p = ldi;
>> +}
>> +EXPORT_SYMBOL(read_one_drc_info);
>> +
>> static u32 cpu_to_drc_index(int cpu)
>> {
>> struct device_node *dn = NULL;
>> - const int *indexes;
>> int i;
>> int rc = 1;
>> u32 ret = 0;
>> @@ -46,18 +104,54 @@ static u32 cpu_to_drc_index(int cpu)
>> 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];
>> +
>> + if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
>> + int *info = (int *)4;
>
> Why initialize info to this?
The GCC compiler kept giving me fatal errors when this variable was not
initialized. I chose the value from "out of the hat". Will retry again.
>
>> + unsigned long int num_set_entries, j, iw = i, fdi = 0;
>> + unsigned long int ldi = 0, nsl = 0, si = 0;
>> + char *dtype;
>> + char *dname;
>> +
>> + info = (int *)of_get_property(dn, "ibm,drc-info", NULL);
>> + if (info == NULL)
>> + goto err_of_node_put;
>> +
>> + num_set_entries = be32_to_cpu(*info++);
>> +
>> + for (j = 0; j < num_set_entries; j++) {
>> +
>> + read_one_drc_info(&info, &dtype, &dname, &fdi,
>> + &nsl, &si, &ldi);
>> + if (strcmp(dtype, "CPU"))
>> + goto err;
>> +
>> + if (iw < ldi)
>> + break;
>> +
>> + WARN_ON(((iw-fdi)%si) != 0);
>> + }
>> + WARN_ON((nsl == 0) | (si == 0));
>> +
>> + ret = ldi + (iw*si);
>
> I think some variable names other than the very short ones used would make
> this code a lot easier to understand, otherwise it is not very clear exactly
> what is being calculated here.
Okay.
>
> -Nathan
>
>> + } else {
>> + const int *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 i+1 will get the drc_index
>> + * corresponding to core number i.
>> + */
>> + WARN_ON(i > indexes[0]);
>> + ret = indexes[i + 1];
>> + }
>> +
>> rc = 0;
>>
>> err_of_node_put:
>> @@ -78,21 +172,51 @@ static int drc_index_to_cpu(u32 drc_index)
>> 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)) {
>> + int *info = (int *)dn;
>> + unsigned long int num_set_entries, j, ret;
>> + unsigned long int fdi = 0, ldi = 0, nsl = 0, si = 0;
>> + char *dtype, *dname;
>> +
>> + info = (int *)of_get_property(dn, "ibm,drc-info", NULL);
>> + if (info == NULL)
>> + goto err_of_node_put;
>> +
>> + num_set_entries = be32_to_cpu(*info++);
>> +
>> + for (j = 0; j < num_set_entries; j++) {
>> + read_one_drc_info(&info, &dtype, &dname, &fdi,
>> + &nsl, &si, &ldi);
>> + if (strcmp(dtype, "CPU"))
>> + goto err;
>> +
>> + WARN_ON(drc_index < fdi);
>> + if (drc_index > ldi)
>> + continue;
>> +
>> + WARN_ON(((drc_index-fdi)%si) != 0);
>> +
>> + ret = ((drc_index-fdi)/si);
>> break;
>> + }
>> + } else {
>> + 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 */
>> + cpu = 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);
>>
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>>
>
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>
--
Michael W. Bringmann
Linux Technology Center
IBM Corporation
Tie-Line 363-5196
External: (512) 286-5196
Cell: (512) 466-0650
mwb at linux.vnet.ibm.com
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