[Intel-gfx] [PATCH 02/19] drm/i915/perf: Add OA formats for DG2
Lionel Landwerlin
lionel.g.landwerlin at intel.com
Tue Sep 6 19:59:16 UTC 2022
On 06/09/2022 22:46, Umesh Nerlige Ramappa wrote:
> On Tue, Sep 06, 2022 at 10:35:16PM +0300, Lionel Landwerlin wrote:
>> On 23/08/2022 23:41, Umesh Nerlige Ramappa wrote:
>>> Add new OA formats for DG2. Some of the newer OA formats are not
>>> multples of 64 bytes and are not powers of 2. For those formats, adjust
>>> hw_tail accordingly when checking for new reports.
>>>
>>> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramampa at intel.com>
>>
>> Apart from the coding style issue :
>>
>>
>> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>>
>>
>>> ---
>>> drivers/gpu/drm/i915/i915_perf.c | 63 ++++++++++++++++++++------------
>>> include/uapi/drm/i915_drm.h | 6 +++
>>> 2 files changed, 46 insertions(+), 23 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_perf.c
>>> b/drivers/gpu/drm/i915/i915_perf.c
>>> index 735244a3aedd..c8331b549d31 100644
>>> --- a/drivers/gpu/drm/i915/i915_perf.c
>>> +++ b/drivers/gpu/drm/i915/i915_perf.c
>>> @@ -306,7 +306,8 @@ static u32 i915_oa_max_sample_rate = 100000;
>>> /* XXX: beware if future OA HW adds new report formats that the
>>> current
>>> * code assumes all reports have a power-of-two size and ~(size -
>>> 1) can
>>> - * be used as a mask to align the OA tail pointer.
>>> + * be used as a mask to align the OA tail pointer. In some of the
>>> + * formats, R is used to denote reserved field.
>>> */
>>> static const struct i915_oa_format oa_formats[I915_OA_FORMAT_MAX] = {
>>> [I915_OA_FORMAT_A13] = { 0, 64 },
>>> @@ -320,6 +321,10 @@ static const struct i915_oa_format
>>> oa_formats[I915_OA_FORMAT_MAX] = {
>>> [I915_OA_FORMAT_A12] = { 0, 64 },
>>> [I915_OA_FORMAT_A12_B8_C8] = { 2, 128 },
>>> [I915_OA_FORMAT_A32u40_A4u32_B8_C8] = { 5, 256 },
>>> + [I915_OAR_FORMAT_A32u40_A4u32_B8_C8] = { 5, 256 },
>>> + [I915_OA_FORMAT_A24u40_A14u32_B8_C8] = { 5, 256 },
>>> + [I915_OAR_FORMAT_A36u64_B8_C8] = { 1, 384 },
>>> + [I915_OA_FORMAT_A38u64_R2u64_B8_C8] = { 1, 448 },
>>> };
>>> #define SAMPLE_OA_REPORT (1<<0)
>>> @@ -467,6 +472,7 @@ static bool oa_buffer_check_unlocked(struct
>>> i915_perf_stream *stream)
>>> bool pollin;
>>> u32 hw_tail;
>>> u64 now;
>>> + u32 partial_report_size;
>>> /* We have to consider the (unlikely) possibility that read()
>>> errors
>>> * could result in an OA buffer reset which might reset the
>>> head and
>>> @@ -476,10 +482,16 @@ static bool oa_buffer_check_unlocked(struct
>>> i915_perf_stream *stream)
>>> hw_tail = stream->perf->ops.oa_hw_tail_read(stream);
>>> - /* The tail pointer increases in 64 byte increments,
>>> - * not in report_size steps...
>>> + /* The tail pointer increases in 64 byte increments, whereas
>>> report
>>> + * sizes need not be integral multiples or 64 or powers of 2.
>>> + * Compute potentially partially landed report in the OA buffer
>>> */
>>> - hw_tail &= ~(report_size - 1);
>>> + partial_report_size = OA_TAKEN(hw_tail, stream->oa_buffer.tail);
>>> + partial_report_size %= report_size;
>>> +
>>> + /* Subtract partial amount off the tail */
>>> + hw_tail = gtt_offset + ((hw_tail - partial_report_size) &
>>> + (stream->oa_buffer.vma->size - 1));
>>> now = ktime_get_mono_fast_ns();
>>> @@ -601,6 +613,8 @@ static int append_oa_sample(struct
>>> i915_perf_stream *stream,
>>> {
>>> int report_size = stream->oa_buffer.format_size;
>>> struct drm_i915_perf_record_header header;
>>> + int report_size_partial;
>>> + u8 *oa_buf_end;
>>> header.type = DRM_I915_PERF_RECORD_SAMPLE;
>>> header.pad = 0;
>>> @@ -614,7 +628,19 @@ static int append_oa_sample(struct
>>> i915_perf_stream *stream,
>>> return -EFAULT;
>>> buf += sizeof(header);
>>> - if (copy_to_user(buf, report, report_size))
>>> + oa_buf_end = stream->oa_buffer.vaddr +
>>> + stream->oa_buffer.vma->size;
>>> + report_size_partial = oa_buf_end - report;
>>> +
>>> + if (report_size_partial < report_size) {
>>> + if(copy_to_user(buf, report, report_size_partial))
>>> + return -EFAULT;
>>> + buf += report_size_partial;
>>> +
>>> + if(copy_to_user(buf, stream->oa_buffer.vaddr,
>>> + report_size - report_size_partial))
>>> + return -EFAULT;
>>
>> I think the coding style requires you to use if () not if()
>>
>
> Will fix.
>
>>
>> Just a suggestion : you could make this code deal with the partial
>> bit as the main bit of the function :
>>
>>
>> oa_buf_end = stream->oa_buffer.vaddr +
>> stream->oa_buffer.vma->size;
>>
>> report_size_partial = oa_buf_end - report;
>>
>> if (copy_to_user(buf, report, report_size_partial))
>> return -EFAULT;
>> buf += report_size_partial;
>
> This ^ may not work because append_oa_sample is appending exactly one
> report to the user buffer, whereas the above may append more than one.
>
> Thanks,
> Umesh
Ah I see, thanks for pointing this out.
-Lionel
>
>>
>> if (report_size_partial < report_size &&
>> copy_to_user(buf, stream->oa_buffer.vaddr,
>> report_size - report_size_partial))
>> return -EFAULT;
>> buf += report_size - report_size_partial;
>>
>>
>>> + } else if (copy_to_user(buf, report, report_size))
>>> return -EFAULT;
>>> (*offset) += header.size;
>>> @@ -684,8 +710,8 @@ static int gen8_append_oa_reports(struct
>>> i915_perf_stream *stream,
>>> * all a power of two).
>>> */
>>> if (drm_WARN_ONCE(&uncore->i915->drm,
>>> - head > OA_BUFFER_SIZE || head % report_size ||
>>> - tail > OA_BUFFER_SIZE || tail % report_size,
>>> + head > stream->oa_buffer.vma->size ||
>>> + tail > stream->oa_buffer.vma->size,
>>> "Inconsistent OA buffer pointers: head = %u, tail =
>>> %u\n",
>>> head, tail))
>>> return -EIO;
>>> @@ -699,22 +725,6 @@ static int gen8_append_oa_reports(struct
>>> i915_perf_stream *stream,
>>> u32 ctx_id;
>>> u32 reason;
>>> - /*
>>> - * All the report sizes factor neatly into the buffer
>>> - * size so we never expect to see a report split
>>> - * between the beginning and end of the buffer.
>>> - *
>>> - * Given the initial alignment check a misalignment
>>> - * here would imply a driver bug that would result
>>> - * in an overrun.
>>> - */
>>> - if (drm_WARN_ON(&uncore->i915->drm,
>>> - (OA_BUFFER_SIZE - head) < report_size)) {
>>> - drm_err(&uncore->i915->drm,
>>> - "Spurious OA head ptr: non-integral report offset\n");
>>> - break;
>>> - }
>>> -
>>> /*
>>> * The reason field includes flags identifying what
>>> * triggered this specific report (mostly timer
>>> @@ -4513,6 +4523,13 @@ static void oa_init_supported_formats(struct
>>> i915_perf *perf)
>>> oa_format_add(perf, I915_OA_FORMAT_C4_B8);
>>> break;
>>> + case INTEL_DG2:
>>> + oa_format_add(perf, I915_OAR_FORMAT_A32u40_A4u32_B8_C8);
>>> + oa_format_add(perf, I915_OA_FORMAT_A24u40_A14u32_B8_C8);
>>> + oa_format_add(perf, I915_OAR_FORMAT_A36u64_B8_C8);
>>> + oa_format_add(perf, I915_OA_FORMAT_A38u64_R2u64_B8_C8);
>>> + break;
>>> +
>>> default:
>>> MISSING_CASE(platform);
>>> }
>>> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>>> index 520ad2691a99..d20d723925b5 100644
>>> --- a/include/uapi/drm/i915_drm.h
>>> +++ b/include/uapi/drm/i915_drm.h
>>> @@ -2650,6 +2650,12 @@ enum drm_i915_oa_format {
>>> I915_OA_FORMAT_A12_B8_C8,
>>> I915_OA_FORMAT_A32u40_A4u32_B8_C8,
>>> + /* DG2 */
>>> + I915_OAR_FORMAT_A32u40_A4u32_B8_C8,
>>> + I915_OA_FORMAT_A24u40_A14u32_B8_C8,
>>> + I915_OAR_FORMAT_A36u64_B8_C8,
>>> + I915_OA_FORMAT_A38u64_R2u64_B8_C8,
>>> +
>>> I915_OA_FORMAT_MAX /* non-ABI */
>>> };
>>
>>
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