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SubjectRe: [PATCH v2 07/11] powerpc: add a shared interface to get gpci version and capabilities
On 02/24/2014 07:33 PM, Michael Ellerman wrote:
> [PATCH v2 07/11] powerpc: add a shared interface to get gpci version and capabilities
>
> All the patches that touch perf should be "powerpc/perf: foo"

Ok.

> On Fri, 2014-14-02 at 22:02:11 UTC, Cody P Schafer wrote:
>> ...
>
> I realise this is a fairly small patch but a changelog is still nice. You could
> for example mention that we don't currently use .ga, .expanded or .lab but
> we're adding the logic anyway because ...
>

Well, we do use them to expose some more information to the user (via
sysfs attributes). Always nice to know what capabilities are enabled.

But sure, I can explain why each bit in that structure is a good idea.

>
>> Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
>> ---
>> arch/powerpc/perf/hv-common.c | 39 +++++++++++++++++++++++++++++++++++++++
>> arch/powerpc/perf/hv-common.h | 17 +++++++++++++++++
>> 2 files changed, 56 insertions(+)
>> create mode 100644 arch/powerpc/perf/hv-common.c
>> create mode 100644 arch/powerpc/perf/hv-common.h
>>
>> diff --git a/arch/powerpc/perf/hv-common.c b/arch/powerpc/perf/hv-common.c
>> new file mode 100644
>> index 0000000..47e02b3
>> --- /dev/null
>> +++ b/arch/powerpc/perf/hv-common.c
>> @@ -0,0 +1,39 @@
>> +#include <asm/io.h>
>> +#include <asm/hvcall.h>
>> +
>> +#include "hv-gpci.h"
>> +#include "hv-common.h"
>> +
>> +unsigned long hv_perf_caps_get(struct hv_perf_caps *caps)
>> +{
>> + unsigned long r;
>> + struct p {
>> + struct hv_get_perf_counter_info_params params;
>> + struct cv_system_performance_capabilities caps;
>> + } __packed __aligned(sizeof(uint64_t));
>> +
>> + struct p arg = {
>> + .params = {
>> + .counter_request = cpu_to_be32(
>> + CIR_SYSTEM_PERFORMANCE_CAPABILITIES),
>> + .starting_index = cpu_to_be32(-1),
>> + .counter_info_version_in = 0,
>> + }
>> + };
>> +
>> + r = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
>> + virt_to_phys(&arg), sizeof(arg));
>> +
>> + if (r)
>> + return r;
>> +
>> + pr_devel("capability_mask: 0x%x\n", arg.caps.capability_mask);
>> +
>> + caps->version = arg.params.counter_info_version_out;
>> + caps->collect_privileged = !!arg.caps.perf_collect_privileged;
>> + caps->ga = !!(arg.caps.capability_mask & CV_CM_GA);
>> + caps->expanded = !!(arg.caps.capability_mask & CV_CM_EXPANDED);
>> + caps->lab = !!(arg.caps.capability_mask & CV_CM_LAB);
>> +
>> + return r;
>> +}
>> diff --git a/arch/powerpc/perf/hv-common.h b/arch/powerpc/perf/hv-common.h
>> new file mode 100644
>> index 0000000..7e615bd
>> --- /dev/null
>> +++ b/arch/powerpc/perf/hv-common.h
>> @@ -0,0 +1,17 @@
>> +#ifndef LINUX_POWERPC_PERF_HV_COMMON_H_
>> +#define LINUX_POWERPC_PERF_HV_COMMON_H_
>> +
>> +#include <linux/types.h>
>> +
>> +struct hv_perf_caps {
>> + u16 version;
>> + u16 collect_privileged:1,
>> + ga:1,
>> + expanded:1,
>> + lab:1,
>> + unused:12;
>> +};
>> +
>> +unsigned long hv_perf_caps_get(struct hv_perf_caps *caps);
>> +
>> +#endif
>> --
>> 1.8.5.4
>>
>>
>



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