Re: [Intel-gfx] [PATCH v2 08/18] drm/i915/guc: Convert engine record to iosys_map

On Tue, Feb 08, 2022 at 02:45:14AM -0800, Lucas De Marchi wrote:

Use iosys_map to read fields from the dma_blob so access to IO and system memory is abstracted away.

Cc: Matt Roper matthew.d.roper@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Cc: Daniel Vetter daniel@ffwll.ch Cc: John Harrison John.C.Harrison@Intel.com Cc: Matthew Brost matthew.brost@intel.com Cc: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com

Reviewed-by: Matt Atwoodmatthew.s.atwood@intel.com

Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com

drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c | 14 ++++++-------- drivers/gpu/drm/i915/gt/uc/intel_guc_ads.h | 3 ++- .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 17 ++++++++++------- 3 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c index 6a34ab38b45f..383c5994d4ef 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.c @@ -695,18 +695,16 @@ void intel_guc_ads_reset(struct intel_guc *guc)

u32 intel_guc_engine_usage_offset(struct intel_guc *guc) {

• struct __guc_ads_blob *blob = guc->ads_blob;
• u32 base = intel_guc_ggtt_offset(guc, guc->ads_vma);
• u32 offset = base + ptr_offset(blob, engine_usage);
• return offset;

• return intel_guc_ggtt_offset(guc, guc->ads_vma) +

• offsetof(struct __guc_ads_blob, engine_usage);
  

}

-struct guc_engine_usage_record *intel_guc_engine_usage(struct intel_engine_cs *engine) +struct iosys_map intel_guc_engine_usage_record_map(struct intel_engine_cs *engine) { struct intel_guc *guc = &engine->gt->uc.guc;

• struct __guc_ads_blob *blob = guc->ads_blob; u8 guc_class = engine_class_to_guc_class(engine->class);

• size_t offset = offsetof(struct __guc_ads_blob,

• 		 engine_usage.engines[guc_class][ilog2(engine->logical_mask)]);
  
  

• return &blob->engine_usage.engines[guc_class][ilog2(engine->logical_mask)];

• return IOSYS_MAP_INIT_OFFSET(&guc->ads_map, offset);

} diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.h index e74c110facff..1c64f4d6ea21 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ads.h @@ -7,6 +7,7 @@ #define _INTEL_GUC_ADS_H_

#include <linux/types.h> +#include <linux/iosys-map.h>

struct intel_guc; struct drm_printer; @@ -18,7 +19,7 @@ void intel_guc_ads_init_late(struct intel_guc *guc); void intel_guc_ads_reset(struct intel_guc *guc); void intel_guc_ads_print_policy_info(struct intel_guc *guc, struct drm_printer *p); -struct guc_engine_usage_record *intel_guc_engine_usage(struct intel_engine_cs *engine); +struct iosys_map intel_guc_engine_usage_record_map(struct intel_engine_cs *engine); u32 intel_guc_engine_usage_offset(struct intel_guc *guc);

#endif diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index b3a429a92c0d..ab3cea352fb3 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1139,6 +1139,9 @@ __extend_last_switch(struct intel_guc *guc, u64 *prev_start, u32 new_start) *prev_start = ((u64)gt_stamp_hi << 32) | new_start; }

+#define record_read(map_, field_) \

• iosys_map_rd_field(map_, 0, struct guc_engine_usage_record, field_)

/*

• GuC updates shared memory and KMD reads it. Since this is not synchronized,
• we run into a race where the value read is inconsistent. Sometimes the

@@ -1153,17 +1156,17 @@ __extend_last_switch(struct intel_guc *guc, u64 *prev_start, u32 new_start) static void __get_engine_usage_record(struct intel_engine_cs *engine, u32 *last_in, u32 *id, u32 *total) {

• struct guc_engine_usage_record *rec = intel_guc_engine_usage(engine);

• struct iosys_map rec_map = intel_guc_engine_usage_record_map(engine); int i = 0;

  do {

• *last_in = READ_ONCE(rec->last_switch_in_stamp);
  

• *id = READ_ONCE(rec->current_context_index);
  

• *total = READ_ONCE(rec->total_runtime);
  

• *last_in = record_read(&rec_map, last_switch_in_stamp);
  

• *id = record_read(&rec_map, current_context_index);
  

• *total = record_read(&rec_map, total_runtime);
  
  

• if (READ_ONCE(rec->last_switch_in_stamp) == *last_in &&
  

•     READ_ONCE(rec->current_context_index) == *id &&
  

•     READ_ONCE(rec->total_runtime) == *total)
  

• if (record_read(&rec_map, last_switch_in_stamp) == *last_in &&
  

•     record_read(&rec_map, current_context_index) == *id &&
  

•     record_read(&rec_map, total_runtime) == *total)
  break;
  

  } while (++i < 6);

}

2.35.1