[Intel-xe] [PATCH 5/6] drm/xe/debugfs: Add dump of default LRCs' MI instructions

Matthew Brost matthew.brost at intel.com
Thu Oct 12 04:26:26 UTC 2023


On Wed, Oct 11, 2023 at 04:10:03PM -0700, Matt Roper wrote:
> For non-RCS engines, nearly all of the LRC state is composed of MI
> instructions (specifically MI_LOAD_REGISTER_IMM).  Providing a dump
> interface allows us to verify that the context image layout matches
> what's documented in the bspec, and also allows us to check whether LRC
> workarounds are being properly captured by the default state we record
> at startup.
> 
> For now, the non-MI instructions found in the RCS and CCS engines will
> dump as "unknown;" parsing of those will be added in a follow-up patch.
> 
> Bspec: 64993
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> ---
>  .../gpu/drm/xe/instructions/xe_inst_defs.h    |  1 +
>  .../gpu/drm/xe/instructions/xe_mi_commands.h  |  3 +
>  drivers/gpu/drm/xe/xe_gt_debugfs.c            | 41 +++++++++
>  drivers/gpu/drm/xe/xe_lrc.c                   | 84 +++++++++++++++++++
>  drivers/gpu/drm/xe/xe_lrc.h                   |  5 ++
>  5 files changed, 134 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/instructions/xe_inst_defs.h b/drivers/gpu/drm/xe/instructions/xe_inst_defs.h
> index c992ad767f08..d665a7e21f3b 100644
> --- a/drivers/gpu/drm/xe/instructions/xe_inst_defs.h
> +++ b/drivers/gpu/drm/xe/instructions/xe_inst_defs.h
> @@ -15,6 +15,7 @@
>   */
>  #define XE_INST_CMD_TYPE		GENMASK(31, 29)
>  #define   XE_INST_MI			REG_FIELD_PREP(XE_INST_CMD_TYPE, 0x0)
> +#define   XE_INST_GFXPIPE		REG_FIELD_PREP(XE_INST_CMD_TYPE, 0x3)
>  
>  /*
>   * Most (but not all) instructions have a "length" field in the instruction
> diff --git a/drivers/gpu/drm/xe/instructions/xe_mi_commands.h b/drivers/gpu/drm/xe/instructions/xe_mi_commands.h
> index 4a37b2b86b40..8cd1fc0e4f17 100644
> --- a/drivers/gpu/drm/xe/instructions/xe_mi_commands.h
> +++ b/drivers/gpu/drm/xe/instructions/xe_mi_commands.h
> @@ -30,6 +30,9 @@
>  #define   MI_ARB_DISABLE		0x0
>  
>  #define MI_BATCH_BUFFER_END		__MI_INST(0xA)
> +#define MI_TOPOLOGY_FILTER		__MI_INST(0xD)
> +#define MI_FORCE_WAKEUP			__MI_INST(0x1D)
> +
>  #define MI_STORE_DATA_IMM		__MI_INST(0x20)
>  #define   MI_SDI_GGTT			REG_BIT(22)
>  #define   MI_SDI_LEN_DW			GENMASK(9, 0)
> diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
> index cd6d28c7b923..e2483cb7721a 100644
> --- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
> @@ -15,6 +15,7 @@
>  #include "xe_gt_mcr.h"
>  #include "xe_gt_topology.h"
>  #include "xe_hw_engine.h"
> +#include "xe_lrc.h"
>  #include "xe_macros.h"
>  #include "xe_pat.h"
>  #include "xe_reg_sr.h"
> @@ -149,6 +150,41 @@ static int pat(struct seq_file *m, void *data)
>  	return 0;
>  }
>  
> +static int rcs_default_lrc(struct seq_file *m, void *data) {
> +	struct drm_printer p = drm_seq_file_printer(m);
> +
> +	xe_lrc_dump_default(&p, node_to_gt(m->private), XE_ENGINE_CLASS_RENDER);
> +	return 0;
> +}
> +
> +static int ccs_default_lrc(struct seq_file *m, void *data) {
> +	struct drm_printer p = drm_seq_file_printer(m);
> +
> +	xe_lrc_dump_default(&p, node_to_gt(m->private), XE_ENGINE_CLASS_COMPUTE);
> +	return 0;
> +}
> +
> +static int bcs_default_lrc(struct seq_file *m, void *data) {
> +	struct drm_printer p = drm_seq_file_printer(m);
> +
> +	xe_lrc_dump_default(&p, node_to_gt(m->private), XE_ENGINE_CLASS_COPY);
> +	return 0;
> +}
> +
> +static int vcs_default_lrc(struct seq_file *m, void *data) {
> +	struct drm_printer p = drm_seq_file_printer(m);
> +
> +	xe_lrc_dump_default(&p, node_to_gt(m->private), XE_ENGINE_CLASS_VIDEO_DECODE);
> +	return 0;
> +}
> +
> +static int vecs_default_lrc(struct seq_file *m, void *data) {
> +	struct drm_printer p = drm_seq_file_printer(m);
> +
> +	xe_lrc_dump_default(&p, node_to_gt(m->private), XE_ENGINE_CLASS_VIDEO_ENHANCE);
> +	return 0;
> +}
> +
>  static const struct drm_info_list debugfs_list[] = {
>  	{"hw_engines", hw_engines, 0},
>  	{"force_reset", force_reset, 0},
> @@ -159,6 +195,11 @@ static const struct drm_info_list debugfs_list[] = {
>  	{"register-save-restore", register_save_restore, 0},
>  	{"workarounds", workarounds, 0},
>  	{"pat", pat, 0},
> +	{"default_lrc_rcs", rcs_default_lrc},
> +	{"default_lrc_ccs", ccs_default_lrc},
> +	{"default_lrc_bcs", bcs_default_lrc},
> +	{"default_lrc_vcs", vcs_default_lrc},
> +	{"default_lrc_vecs", vecs_default_lrc},
>  };
>  
>  void xe_gt_debugfs_register(struct xe_gt *gt)
> diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
> index a04867131839..825b229212ae 100644
> --- a/drivers/gpu/drm/xe/xe_lrc.c
> +++ b/drivers/gpu/drm/xe/xe_lrc.c
> @@ -6,6 +6,7 @@
>  #include "xe_lrc.h"
>  
>  #include "instructions/xe_mi_commands.h"
> +#include "instructions/xe_gfxpipe_commands.h"
>  #include "regs/xe_engine_regs.h"
>  #include "regs/xe_gpu_commands.h"
>  #include "regs/xe_gt_regs.h"
> @@ -903,3 +904,86 @@ struct iosys_map xe_lrc_parallel_map(struct xe_lrc *lrc)
>  {
>  	return __xe_lrc_parallel_map(lrc);
>  }
> +
> +static int instr_dw(u32 cmd_header)
> +{
> +	/* Most instructions have the # of dwords (minus 2) in 7:0 */
> +	return REG_FIELD_GET(XE_INST_LEN_MASK, cmd_header) + 2;
> +}
> +
> +static int dump_mi_command(struct drm_printer *p,
> +			   struct xe_gt *gt,
> +			   u32 *dw,
> +			   int remaining_dw)
> +{
> +	u32 numdw = instr_dw(*dw);
> +	u32 opcode = REG_FIELD_GET(MI_OPCODE, *dw);
> +
> +	switch (*dw & MI_OPCODE) {

Drive by comment, 'switch (opcode)'.

Matt

> +	case MI_NOOP:
> +		int num_noop = 1;
> +		while (num_noop < remaining_dw &&
> +		       (*(++dw) & REG_GENMASK(31, 23)) == MI_NOOP)
> +			num_noop++;
> +		drm_printf(p, "MI_NOOP (%d dwords)\n", num_noop);
> +		return num_noop;
> +
> +	case MI_LOAD_REGISTER_IMM:
> +		drm_printf(p, "MI_LOAD_REGISTER_IMM: %d regs\n", (numdw - 1) / 2);
> +		for (int i = 1; i < numdw; i += 2)
> +			drm_printf(p, " - %#6x = %#010x\n", dw[i], dw[i + 1]);
> +		return numdw;
> +
> +	case MI_TOPOLOGY_FILTER:
> +		drm_printf(p, "MI_TOPOLOGY_FILTER\n");
> +		return 1;
> +
> +	case MI_FORCE_WAKEUP:
> +		drm_printf(p, "MI_FORCE_WAKEUP\n");
> +		return numdw;
> +
> +	case MI_BATCH_BUFFER_END:
> +		drm_printf(p, "MI_BATCH_BUFFER_END\n");
> +		return 0;
> +
> +	default:
> +		drm_printf(p, "unknown MI opcode %#x, likely %d dwords\n",
> +			   opcode, numdw);
> +		return numdw;
> +	}
> +}
> +
> +void xe_lrc_dump_default(struct drm_printer *p,
> +			 struct xe_gt *gt,
> +			 enum xe_engine_class hwe_class)
> +{
> +	u32 *dw;
> +	int remaining_dw, num_dw;
> +
> +	if (!gt->default_lrc[hwe_class]) {
> +		drm_printf(p, "No default LRC for class %d\n", hwe_class);
> +		return;
> +	}
> +
> +	/* First page of LRC is a ppHWSP */
> +	dw = gt->default_lrc[hwe_class] + LRC_PPHWSP_SIZE;
> +	remaining_dw = (xe_lrc_size(gt_to_xe(gt), hwe_class) - LRC_PPHWSP_SIZE) / 4;
> +
> +	while (remaining_dw) {
> +		if ((*dw & XE_INST_CMD_TYPE) == XE_INST_MI) {
> +			num_dw = dump_mi_command(p, gt, dw, remaining_dw);
> +		} else {
> +			num_dw = min(instr_dw(*dw), remaining_dw);
> +			drm_printf(p, "Unknown instr <%#x> of type %#x, likely %d dwords\n",
> +				   *dw, REG_FIELD_GET(XE_INST_CMD_TYPE, *dw),
> +				   num_dw);
> +		}
> +
> +		/* 0 is returned on MI_BATCH_BUFFER_END */
> +		if (num_dw == 0)
> +			break;
> +
> +		dw += num_dw;
> +		remaining_dw -= num_dw;
> +	}
> +}
> diff --git a/drivers/gpu/drm/xe/xe_lrc.h b/drivers/gpu/drm/xe/xe_lrc.h
> index 3a6e8fc5a837..a7056eda5e0c 100644
> --- a/drivers/gpu/drm/xe/xe_lrc.h
> +++ b/drivers/gpu/drm/xe/xe_lrc.h
> @@ -7,6 +7,7 @@
>  
>  #include "xe_lrc_types.h"
>  
> +struct drm_printer;
>  struct xe_device;
>  struct xe_exec_queue;
>  enum xe_engine_class;
> @@ -47,4 +48,8 @@ struct iosys_map xe_lrc_parallel_map(struct xe_lrc *lrc);
>  
>  size_t xe_lrc_skip_size(struct xe_device *xe);
>  
> +void xe_lrc_dump_default(struct drm_printer *p,
> +			 struct xe_gt *gt,
> +			 enum xe_engine_class);
> +
>  #endif
> -- 
> 2.41.0
> 


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