[Intel-gfx] [PATCH v10 6/6] drm/i915: expose rcs topology through query uAPI
Lionel Landwerlin
lionel.g.landwerlin at intel.com
Fri Jan 19 14:58:58 UTC 2018
On 19/01/18 14:24, Tvrtko Ursulin wrote:
>
> On 19/01/2018 13:22, Lionel Landwerlin wrote:
>> With the introduction of asymmetric slices in CNL, we cannot rely on
>> the previous SUBSLICE_MASK getparam to tell userspace what subslices
>> are available. Here we introduce a more detailed way of querying the
>> Gen's GPU topology that doesn't aggregate numbers.
>>
>> This is essential for monitoring parts of the GPU with the OA unit,
>> because counters need to be normalized to the number of
>> EUs/subslices/slices. The current aggregated numbers like EU_TOTAL do
>> not gives us sufficient information.
>>
>> As a bonus we can draw representations of the GPU :
>>
>> https://imgur.com/a/vuqpa
>>
>> v2: Rename uapi struct s/_mask/_info/ (Tvrtko)
>> Report max_slice/subslice/eus_per_subslice rather than strides
>> (Tvrtko)
>> Add uapi macros to read data from *_info structs (Tvrtko)
>>
>> v3: Use !!(v & DRM_I915_BIT()) for uapi macros instead of custom
>> shifts (Tvrtko)
>>
>> v4: factorize query item writting (Tvrtko)
>> tweak uapi struct/define names (Tvrtko)
>>
>> v5: Replace ALIGN() macro (Chris)
>>
>> v6: Updated uapi comments (Tvrtko)
>> Moved flags != 0 checks into vfuncs (Tvrtko)
>>
>> v7: Use access_ok() before copying anything, to avoid overflows (Chris)
>> Switch BUG_ON() to GEM_WARN_ON() (Tvrtko)
>>
>> v8: Tweak uapi comments style to match the coding style (Lionel)
>>
>> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> ---
>> drivers/gpu/drm/i915/i915_query.c | 110
>> ++++++++++++++++++++++++++++++++++++++
>> include/uapi/drm/i915_drm.h | 71 ++++++++++++++++++++++++
>> 2 files changed, 181 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_query.c
>> b/drivers/gpu/drm/i915/i915_query.c
>> index 5aa886313cf9..ff87ec8a321a 100644
>> --- a/drivers/gpu/drm/i915/i915_query.c
>> +++ b/drivers/gpu/drm/i915/i915_query.c
>> @@ -25,8 +25,118 @@
>> #include "i915_drv.h"
>> #include <uapi/drm/i915_drm.h>
>>
>> +static int copy_query_data(struct drm_i915_query_item *query_item,
>> + const void *item_ptr, u32 item_length,
>> + const void *data_ptr, u32 data_length)
>> +{
>> + u32 total_length = item_length + data_length;
>> +
>> + if (GEM_WARN_ON(add_overflows(item_length, data_length)))
>> + return -EINVAL;
>> +
>> + if (query_item->length == 0)
>> + return total_length;
>> +
>> + if (query_item->length < total_length)
>> + return -EINVAL;
>> +
>> + if (!access_ok(VERIFY_WRITE, u64_to_user_ptr(query_item->data_ptr),
>> + total_length))
>> + return -EFAULT;
>> +
>> + if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr),
>> + item_ptr, item_length))
>> + return -EFAULT;
>> +
>> + if (__copy_to_user(u64_to_user_ptr(query_item->data_ptr +
>> item_length),
>> + data_ptr, data_length))
>> + return -EFAULT;
>> +
>> + return total_length;
>> +}
>> +
>> +static int query_slice_info(struct drm_i915_private *dev_priv,
>> + struct drm_i915_query_item *query_item)
>> +{
>> + const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
>> + struct drm_i915_query_slice_info slice_info;
>> +
>> + if (query_item->flags != 0)
>> + return -EINVAL;
>> +
>> + if (sseu->max_slices == 0)
>> + return -ENODEV;
>> +
>> + /*
>> + * If we ever change the internal slice mask data type, we'll
>> need to
>> + * update this function.
>> + */
>> + BUILD_BUG_ON(sizeof(u8) != sizeof(sseu->slice_mask));
>> +
>> + memset(&slice_info, 0, sizeof(slice_info));
>> + slice_info.max_slices = sseu->max_slices;
>> +
>> + return copy_query_data(query_item, &slice_info, sizeof(slice_info),
>> + &sseu->slice_mask, sizeof(sseu->slice_mask));
>> +}
>> +
>> +static int query_subslice_info(struct drm_i915_private *dev_priv,
>> + struct drm_i915_query_item *query_item)
>> +{
>> + const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
>> + struct drm_i915_query_subslice_info subslice_info;
>> + u32 data_length;
>> +
>> + if (query_item->flags != 0)
>> + return -EINVAL;
>> +
>> + if (sseu->max_slices == 0)
>> + return -ENODEV;
>> +
>> + memset(&subslice_info, 0, sizeof(subslice_info));
>> + subslice_info.max_slices = sseu->max_slices;
>> + subslice_info.max_subslices = sseu->max_subslices;
>> +
>> + data_length = subslice_info.max_slices *
>> + DIV_ROUND_UP(subslice_info.max_subslices,
>> + sizeof(sseu->subslice_mask[0]) * BITS_PER_BYTE);
>> +
>> + return copy_query_data(query_item,
>> + &subslice_info, sizeof(subslice_info),
>> + sseu->subslice_mask, data_length);
>> +}
>> +
>> +static int query_eu_info(struct drm_i915_private *dev_priv,
>> + struct drm_i915_query_item *query_item)
>> +{
>> + const struct sseu_dev_info *sseu = &INTEL_INFO(dev_priv)->sseu;
>> + struct drm_i915_query_eu_info eu_info;
>> + u32 data_length;
>> +
>> + if (query_item->flags != 0)
>> + return -EINVAL;
>> +
>> + if (sseu->max_slices == 0)
>> + return -ENODEV;
>> +
>> + memset(&eu_info, 0, sizeof(eu_info));
>> + eu_info.max_slices = sseu->max_slices;
>> + eu_info.max_subslices = sseu->max_subslices;
>> + eu_info.max_eus_per_subslice = sseu->max_eus_per_subslice;
>> +
>> + data_length = eu_info.max_slices * eu_info.max_subslices *
>> + DIV_ROUND_UP(eu_info.max_eus_per_subslice, BITS_PER_BYTE);
>> +
>> + return copy_query_data(query_item,
>> + &eu_info, sizeof(eu_info),
>> + sseu->eu_mask, data_length);
>> +}
>> +
>> static int (* const i915_query_funcs[])(struct drm_i915_private
>> *dev_priv,
>> struct drm_i915_query_item *query_item) = {
>> + query_slice_info,
>> + query_subslice_info,
>> + query_eu_info,
>> };
>>
>> int i915_query_ioctl(struct drm_device *dev, void *data, struct
>> drm_file *file)
>> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>> index 03f031652d86..0a4f4cdd7e92 100644
>> --- a/include/uapi/drm/i915_drm.h
>> +++ b/include/uapi/drm/i915_drm.h
>> @@ -1618,6 +1618,9 @@ struct drm_i915_perf_oa_config {
>>
>> struct drm_i915_query_item {
>> __u64 query_id;
>> +#define DRM_I915_QUERY_SLICE_INFO 0x01
>> +#define DRM_I915_QUERY_SUBSLICE_INFO 0x02
>> +#define DRM_I915_QUERY_EU_INFO 0x03
>>
>> /*
>> * When set to zero by userspace, this is filled with the size
>> of the
>> @@ -1654,6 +1657,74 @@ struct drm_i915_query {
>> __u64 items_ptr;
>> };
>>
>> +#define DRM_I915_BIT(bit) ((__u32)1 << (bit))
>> +#define DRM_I915_DIV_ROUND_UP(val, div) (((val) + (div) - 1) / (div))
>> +
>> +/*
>> + * Data written by the kernel with query DRM_I915_QUERY_SLICE_INFO :
>> + *
>> + * data: each bit indicates whether a slice is available (1) or
>> fused off (0).
>> + * Formula to tell if slice X is available :
>> + *
>> + * (data[X / 8] >> (X % 8)) & 1
>> + *
>> + * Alternatively, use DRM_I915_QUERY_SLICE_AVAILABLE() to query a
>> + * given subslice's availability.
>> + */
>> +struct drm_i915_query_slice_info {
>> + __u32 max_slices;
>
> Would it be worth also returning num_slices? I have no idea, just
> wondering if userspace cares more about the mask or count of enabled
> ones. Probably not worth it since doing the similar in other queries
> would be much harder.
I just count the bits in userspace.
>
>> +
>> +#define DRM_I915_QUERY_SLICE_AVAILABLE(info, slice) \
>> + !!((info)->data[(slice) / 8] & DRM_I915_BIT((slice) % 8))
>> + __u8 data[];
>> +};
>> +
>> +/*
>> + * Data written by the kernel with query DRM_I915_QUERY_SUBSLICE_INFO :
>> + *
>> + * data: each bit indicates whether a subslice is available (1) or
>> fused off
>> + * (0). Formula to tell if slice X subslice Y is available :
>> + *
>> + * (data[(X * max_subslices) + Y / 8] >> (Y % 8)) & 1
>
> "X * max_subslices" is I think wrong, need to express the DIV_ROUND_UP
> in this comment somehow. Ah, "X * ALIGN(max_subslices, 8) / 8", as in
> the EU query?
Oops indeed... The macro got it right.
>
>> + *
>> + * Alternatively, use DRM_I915_QUERY_SUBSLICE_AVAILABLE() to
>> query a
>> + * given subslice's availability.
>> + */
>> +struct drm_i915_query_subslice_info {
>> + __u32 max_slices;
>> + __u32 max_subslices;
>> +
>> +#define DRM_I915_QUERY_SUBSLICE_AVAILABLE(info, slice, subslice) \
>> + !!((info)->data[(slice) *
>> DRM_I915_DIV_ROUND_UP((info)->max_subslices, 8) + \
>> + (subslice) / 8] & DRM_I915_BIT((subslice) % 8))
>> + __u8 data[];
>> +};
>> +
>> +/*
>> + * Data written by the kernel with query DRM_I915_QUERY_EU_INFO :
>> + *
>> + * data: Each bit indicates whether an EU is available (1) or fused
>> off (0).
>> + * Formula to tell if slice X subslice Y eu Z is available :
>> + *
>> + * (data[X * max_subslices * ALIGN(max_eus_per_subslice,
>> 8) / 8 +
>> + * Y * ALIGN(max_eus_per_subslice, 8) / 8 +
>> + * Z / 8] >> (Z % 8)) & 1
>> + *
>> + * Alternatively, use DRM_I915_QUERY_EU_AVAILABLE() to query a
>> given
>> + * EU's availability.
>> + */
>> +struct drm_i915_query_eu_info {
>> + __u32 max_slices;
>> + __u32 max_subslices;
>> + __u32 max_eus_per_subslice;
>> +
>> +#define DRM_I915_QUERY_EU_AVAILABLE(info, slice, subslice, eu) \
>> + !!((info)->data[(slice) *
>> DRM_I915_DIV_ROUND_UP((info)->max_eus_per_subslice, 8) *
>> (info)->max_subslices + \
>> + (subslice) *
>> DRM_I915_DIV_ROUND_UP((info)->max_eus_per_subslice, 8) + \
>> + (eu) / 8] & DRM_I915_BIT((eu) % 8))
>> + __u8 data[];
>> +};
>> +
>> #if defined(__cplusplus)
>> }
>> #endif
>
> Regards,
>
> Tvrtko
>
>
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