[Intel-gfx] [PATCH] drm/i915/dsb: DSB code refactoring

Jani Nikula jani.nikula at linux.intel.com
Mon Sep 25 12:30:04 UTC 2023


On Sat, 23 Sep 2023, Animesh Manna <animesh.manna at intel.com> wrote:
> Refactor DSB implementation to be compatible with Xe driver.

Sad trombone.

struct intel_dsb should remain an opaque type. I put effort into hiding
its definition, so its guts wouldn't be accessed nilly-willy all over
the place. If it's not hidden, it just will get accessed.

BR,
Jani.

>
> Signed-off-by: Animesh Manna <animesh.manna at intel.com>
> ---
>  drivers/gpu/drm/i915/Makefile                |   1 +
>  drivers/gpu/drm/i915/display/intel_dsb.c     | 115 ++++---------------
>  drivers/gpu/drm/i915/display/intel_dsb.h     |  41 ++++++-
>  drivers/gpu/drm/i915/display/intel_dsb_ops.c |  67 +++++++++++
>  4 files changed, 130 insertions(+), 94 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/display/intel_dsb_ops.c
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 1b2e02e9d92c..7fbb5055b85b 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -256,6 +256,7 @@ i915-y += \
>  	display/intel_dpt.o \
>  	display/intel_drrs.o \
>  	display/intel_dsb.o \
> +	display/intel_dsb_ops.o \
>  	display/intel_fb.o \
>  	display/intel_fb_pin.o \
>  	display/intel_fbc.o \
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
> index 9a507b9ad82c..f7c6b9aa130f 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.c
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.c
> @@ -4,8 +4,6 @@
>   *
>   */
>  
> -#include "gem/i915_gem_internal.h"
> -
>  #include "i915_drv.h"
>  #include "i915_reg.h"
>  #include "intel_de.h"
> @@ -13,41 +11,7 @@
>  #include "intel_dsb.h"
>  #include "intel_dsb_regs.h"
>  
> -struct i915_vma;
> -
> -enum dsb_id {
> -	INVALID_DSB = -1,
> -	DSB1,
> -	DSB2,
> -	DSB3,
> -	MAX_DSB_PER_PIPE
> -};
> -
> -struct intel_dsb {
> -	enum dsb_id id;
> -
> -	u32 *cmd_buf;
> -	struct i915_vma *vma;
> -	struct intel_crtc *crtc;
> -
> -	/*
> -	 * maximum number of dwords the buffer will hold.
> -	 */
> -	unsigned int size;
> -
> -	/*
> -	 * free_pos will point the first free dword and
> -	 * help in calculating tail of command buffer.
> -	 */
> -	unsigned int free_pos;
> -
> -	/*
> -	 * ins_start_offset will help to store start dword of the dsb
> -	 * instuction and help in identifying the batch of auto-increment
> -	 * register.
> -	 */
> -	unsigned int ins_start_offset;
> -};
> +#define CACHELINE_BYTES 64
>  
>  /**
>   * DOC: DSB
> @@ -117,8 +81,6 @@ static bool is_dsb_busy(struct drm_i915_private *i915, enum pipe pipe,
>  
>  static void intel_dsb_emit(struct intel_dsb *dsb, u32 ldw, u32 udw)
>  {
> -	u32 *buf = dsb->cmd_buf;
> -
>  	if (!assert_dsb_has_room(dsb))
>  		return;
>  
> @@ -127,14 +89,13 @@ static void intel_dsb_emit(struct intel_dsb *dsb, u32 ldw, u32 udw)
>  
>  	dsb->ins_start_offset = dsb->free_pos;
>  
> -	buf[dsb->free_pos++] = ldw;
> -	buf[dsb->free_pos++] = udw;
> +	intel_dsb_write(dsb, dsb->free_pos++, ldw);
> +	intel_dsb_write(dsb, dsb->free_pos++, udw);
>  }
>  
>  static bool intel_dsb_prev_ins_is_write(struct intel_dsb *dsb,
>  					u32 opcode, i915_reg_t reg)
>  {
> -	const u32 *buf = dsb->cmd_buf;
>  	u32 prev_opcode, prev_reg;
>  
>  	/*
> @@ -145,8 +106,8 @@ static bool intel_dsb_prev_ins_is_write(struct intel_dsb *dsb,
>  	if (dsb->free_pos == 0)
>  		return false;
>  
> -	prev_opcode = buf[dsb->ins_start_offset + 1] & ~DSB_REG_VALUE_MASK;
> -	prev_reg = buf[dsb->ins_start_offset + 1] & DSB_REG_VALUE_MASK;
> +	prev_opcode = intel_dsb_read(dsb, dsb->ins_start_offset + 1) >> DSB_OPCODE_SHIFT;
> +	prev_reg =  intel_dsb_read(dsb, dsb->ins_start_offset + 1) & DSB_REG_VALUE_MASK;
>  
>  	return prev_opcode == opcode && prev_reg == i915_mmio_reg_offset(reg);
>  }
> @@ -179,6 +140,8 @@ static bool intel_dsb_prev_ins_is_indexed_write(struct intel_dsb *dsb, i915_reg_
>  void intel_dsb_reg_write(struct intel_dsb *dsb,
>  			 i915_reg_t reg, u32 val)
>  {
> +	u32 old_val;
> +
>  	/*
>  	 * For example the buffer will look like below for 3 dwords for auto
>  	 * increment register:
> @@ -202,31 +165,30 @@ void intel_dsb_reg_write(struct intel_dsb *dsb,
>  			       (DSB_BYTE_EN << DSB_BYTE_EN_SHIFT) |
>  			       i915_mmio_reg_offset(reg));
>  	} else {
> -		u32 *buf = dsb->cmd_buf;
> -
>  		if (!assert_dsb_has_room(dsb))
>  			return;
>  
>  		/* convert to indexed write? */
>  		if (intel_dsb_prev_ins_is_mmio_write(dsb, reg)) {
> -			u32 prev_val = buf[dsb->ins_start_offset + 0];
> +			u32 prev_val = intel_dsb_read(dsb, dsb->ins_start_offset + 0);
>  
> -			buf[dsb->ins_start_offset + 0] = 1; /* count */
> -			buf[dsb->ins_start_offset + 1] =
> -				(DSB_OPCODE_INDEXED_WRITE << DSB_OPCODE_SHIFT) |
> -				i915_mmio_reg_offset(reg);
> -			buf[dsb->ins_start_offset + 2] = prev_val;
> +			intel_dsb_write(dsb, dsb->ins_start_offset + 0, 1); /* count */
> +			intel_dsb_write(dsb, dsb->ins_start_offset + 1,
> +					(DSB_OPCODE_INDEXED_WRITE << DSB_OPCODE_SHIFT) |
> +					i915_mmio_reg_offset(reg));
> +			intel_dsb_write(dsb, dsb->ins_start_offset + 2, prev_val);
>  
>  			dsb->free_pos++;
>  		}
>  
> -		buf[dsb->free_pos++] = val;
> +		intel_dsb_write(dsb, dsb->free_pos++, val);
>  		/* Update the count */
> -		buf[dsb->ins_start_offset]++;
> +		old_val = intel_dsb_read(dsb, dsb->ins_start_offset);
> +		intel_dsb_write(dsb, dsb->ins_start_offset, old_val + 1);
>  
>  		/* if number of data words is odd, then the last dword should be 0.*/
>  		if (dsb->free_pos & 0x1)
> -			buf[dsb->free_pos] = 0;
> +			intel_dsb_write(dsb, dsb->free_pos, 0);
>  	}
>  }
>  
> @@ -238,8 +200,8 @@ static void intel_dsb_align_tail(struct intel_dsb *dsb)
>  	aligned_tail = ALIGN(tail, CACHELINE_BYTES);
>  
>  	if (aligned_tail > tail)
> -		memset(&dsb->cmd_buf[dsb->free_pos], 0,
> -		       aligned_tail - tail);
> +		intel_dsb_memset(dsb, dsb->free_pos, 0,
> +				 aligned_tail - tail);
>  
>  	dsb->free_pos = aligned_tail / 4;
>  }
> @@ -277,9 +239,9 @@ void intel_dsb_commit(struct intel_dsb *dsb, bool wait_for_vblank)
>  		       (wait_for_vblank ? DSB_WAIT_FOR_VBLANK : 0) |
>  		       DSB_ENABLE);
>  	intel_de_write(dev_priv, DSB_HEAD(pipe, dsb->id),
> -		       i915_ggtt_offset(dsb->vma));
> +		       intel_dsb_ggtt_offset(dsb));
>  	intel_de_write(dev_priv, DSB_TAIL(pipe, dsb->id),
> -		       i915_ggtt_offset(dsb->vma) + tail);
> +		       intel_dsb_ggtt_offset(dsb) + tail);
>  }
>  
>  void intel_dsb_wait(struct intel_dsb *dsb)
> @@ -325,12 +287,9 @@ struct intel_dsb *intel_dsb_prepare(struct intel_crtc *crtc,
>  				    unsigned int max_cmds)
>  {
>  	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> -	struct drm_i915_gem_object *obj;
>  	intel_wakeref_t wakeref;
>  	struct intel_dsb *dsb;
> -	struct i915_vma *vma;
>  	unsigned int size;
> -	u32 *buf;
>  
>  	if (!HAS_DSB(i915))
>  		return NULL;
> @@ -344,28 +303,11 @@ struct intel_dsb *intel_dsb_prepare(struct intel_crtc *crtc,
>  	/* ~1 qword per instruction, full cachelines */
>  	size = ALIGN(max_cmds * 8, CACHELINE_BYTES);
>  
> -	obj = i915_gem_object_create_internal(i915, PAGE_ALIGN(size));
> -	if (IS_ERR(obj))
> -		goto out_put_rpm;
> -
> -	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
> -	if (IS_ERR(vma)) {
> -		i915_gem_object_put(obj);
> +	if (!intel_dsb_buffer_create(crtc, dsb, size))
>  		goto out_put_rpm;
> -	}
> -
> -	buf = i915_gem_object_pin_map_unlocked(vma->obj, I915_MAP_WC);
> -	if (IS_ERR(buf)) {
> -		i915_vma_unpin_and_release(&vma, I915_VMA_RELEASE_MAP);
> -		goto out_put_rpm;
> -	}
>  
>  	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
>  
> -	dsb->id = DSB1;
> -	dsb->vma = vma;
> -	dsb->crtc = crtc;
> -	dsb->cmd_buf = buf;
>  	dsb->size = size / 4; /* in dwords */
>  	dsb->free_pos = 0;
>  	dsb->ins_start_offset = 0;
> @@ -382,16 +324,3 @@ struct intel_dsb *intel_dsb_prepare(struct intel_crtc *crtc,
>  
>  	return NULL;
>  }
> -
> -/**
> - * intel_dsb_cleanup() - To cleanup DSB context.
> - * @dsb: DSB context
> - *
> - * This function cleanup the DSB context by unpinning and releasing
> - * the VMA object associated with it.
> - */
> -void intel_dsb_cleanup(struct intel_dsb *dsb)
> -{
> -	i915_vma_unpin_and_release(&dsb->vma, I915_VMA_RELEASE_MAP);
> -	kfree(dsb);
> -}
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
> index b8148b47022d..7feeb37e00a5 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.h
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.h
> @@ -11,7 +11,41 @@
>  #include "i915_reg_defs.h"
>  
>  struct intel_crtc;
> -struct intel_dsb;
> +struct i915_vma;
> +
> +enum dsb_id {
> +	INVALID_DSB = -1,
> +	DSB1,
> +	DSB2,
> +	DSB3,
> +	MAX_DSB_PER_PIPE
> +};
> +
> +struct intel_dsb {
> +	enum dsb_id id;
> +
> +	u32 *cmd_buf;
> +	struct i915_vma *vma;
> +	struct intel_crtc *crtc;
> +
> +	/*
> +	 * maximum number of dwords the buffer will hold.
> +	 */
> +	unsigned int size;
> +
> +	/*
> +	 * free_pos will point the first free dword and
> +	 * help in calculating tail of command buffer.
> +	 */
> +	unsigned int free_pos;
> +
> +	/*
> +	 * ins_start_offset will help to store start dword of the dsb
> +	 * instuction and help in identifying the batch of auto-increment
> +	 * register.
> +	 */
> +	unsigned int ins_start_offset;
> +};
>  
>  struct intel_dsb *intel_dsb_prepare(struct intel_crtc *crtc,
>  				    unsigned int max_cmds);
> @@ -22,5 +56,10 @@ void intel_dsb_reg_write(struct intel_dsb *dsb,
>  void intel_dsb_commit(struct intel_dsb *dsb,
>  		      bool wait_for_vblank);
>  void intel_dsb_wait(struct intel_dsb *dsb);
> +u32 intel_dsb_ggtt_offset(struct intel_dsb *dsb);
> +void intel_dsb_write(struct intel_dsb *dsb, u32 idx, u32 val);
> +u32 intel_dsb_read(struct intel_dsb *dsb, u32 idx);
> +void intel_dsb_memset(struct intel_dsb *dsb, u32 idx, u32 val, u32 sz);
> +bool intel_dsb_buffer_create(struct intel_crtc *crtc, struct intel_dsb *dsb, u32 size);
>  
>  #endif
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb_ops.c b/drivers/gpu/drm/i915/display/intel_dsb_ops.c
> new file mode 100644
> index 000000000000..9fe125abb890
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/display/intel_dsb_ops.c
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright 2023, Intel Corporation.
> + */
> +
> +#include "gem/i915_gem_internal.h"
> +#include "i915_drv.h"
> +#include "i915_vma.h"
> +#include "intel_display_types.h"
> +#include "intel_dsb.h"
> +
> +u32 intel_dsb_ggtt_offset(struct intel_dsb *dsb)
> +{
> +	return i915_ggtt_offset(dsb->vma);
> +}
> +
> +void intel_dsb_write(struct intel_dsb *dsb, u32 idx, u32 val)
> +{
> +	dsb->cmd_buf[idx] = val;
> +}
> +
> +u32 intel_dsb_read(struct intel_dsb *dsb, u32 idx)
> +{
> +	return dsb->cmd_buf[idx];
> +}
> +
> +void intel_dsb_memset(struct intel_dsb *dsb, u32 idx, u32 val, u32 sz)
> +{
> +	memset(&dsb->cmd_buf[idx], val, sz);
> +}
> +
> +bool intel_dsb_buffer_create(struct intel_crtc *crtc, struct intel_dsb *dsb, u32 size)
> +{
> +	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> +	struct drm_i915_gem_object *obj;
> +	struct i915_vma *vma;
> +	u32 *buf;
> +
> +	obj = i915_gem_object_create_internal(i915, PAGE_ALIGN(size));
> +	if (IS_ERR(obj))
> +		return false;
> +
> +	vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
> +	if (IS_ERR(vma)) {
> +		i915_gem_object_put(obj);
> +		return false;
> +	}
> +
> +	buf = i915_gem_object_pin_map_unlocked(vma->obj, I915_MAP_WC);
> +	if (IS_ERR(buf)) {
> +		i915_vma_unpin_and_release(&vma, I915_VMA_RELEASE_MAP);
> +		return false;
> +	}
> +
> +	dsb->id = DSB1;
> +	dsb->vma = vma;
> +	dsb->crtc = crtc;
> +	dsb->cmd_buf = buf;
> +
> +	return true;
> +}
> +
> +void intel_dsb_cleanup(struct intel_dsb *dsb)
> +{
> +	i915_vma_unpin_and_release(&dsb->vma, I915_VMA_RELEASE_MAP);
> +	kfree(dsb);
> +}

-- 
Jani Nikula, Intel


More information about the Intel-gfx mailing list