> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Sent: Thursday, October 26, 2023 8:03 PM
> To: Manna, Animesh <animesh.manna@xxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Nikula, Jani <jani.nikula@xxxxxxxxx>
> Subject: Re: [PATCH v3] drm/i915/dsb: DSB code refactoring
>
> On Sun, Oct 08, 2023 at 03:42:06PM +0530, Animesh Manna wrote:
> > Refactor DSB implementation to be compatible with Xe driver.
> >
> > v1: RFC version.
> > v2: Make intel_dsb structure opaque from external usage. [Jani]
> > v3: Rebased on latest.
> >
> > Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> > Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/Makefile | 1 +
> > drivers/gpu/drm/i915/display/intel_dsb.c | 84 ++++++++-----------
> > .../gpu/drm/i915/display/intel_dsb_buffer.c | 64 ++++++++++++++
> > .../gpu/drm/i915/display/intel_dsb_buffer.h | 26 ++++++
> > 4 files changed, 126 insertions(+), 49 deletions(-) create mode
> > 100644 drivers/gpu/drm/i915/display/intel_dsb_buffer.c
> > create mode 100644 drivers/gpu/drm/i915/display/intel_dsb_buffer.h
> >
> > diff --git a/drivers/gpu/drm/i915/Makefile
> > b/drivers/gpu/drm/i915/Makefile index dec78efa452a..7c3f91c2375a
> > 100644
> > --- a/drivers/gpu/drm/i915/Makefile
> > +++ b/drivers/gpu/drm/i915/Makefile
> > @@ -260,6 +260,7 @@ i915-y += \
> > display/intel_dpt.o \
> > display/intel_drrs.o \
> > display/intel_dsb.o \
> > + display/intel_dsb_buffer.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 3e32aa49b8eb..ec89d968a873 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dsb.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dsb.c
> > @@ -13,12 +13,13 @@
> > #include "intel_de.h"
> > #include "intel_display_types.h"
> > #include "intel_dsb.h"
> > +#include "intel_dsb_buffer.h"
> > #include "intel_dsb_regs.h"
> > #include "intel_vblank.h"
> > #include "intel_vrr.h"
> > #include "skl_watermark.h"
> >
> > -struct i915_vma;
> > +#define CACHELINE_BYTES 64
> >
> > enum dsb_id {
> > INVALID_DSB = -1,
> > @@ -31,8 +32,7 @@ enum dsb_id {
> > struct intel_dsb {
> > enum dsb_id id;
> >
> > - u32 *cmd_buf;
> > - struct i915_vma *vma;
> > + struct intel_dsb_buffer dsb_buf;
> > struct intel_crtc *crtc;
> >
> > /*
> > @@ -108,15 +108,17 @@ static void intel_dsb_dump(struct intel_dsb
> > *dsb) {
> > struct intel_crtc *crtc = dsb->crtc;
> > struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> > - const u32 *buf = dsb->cmd_buf;
> > int i;
> >
> > drm_dbg_kms(&i915->drm, "[CRTC:%d:%s] DSB %d commands {\n",
> > crtc->base.base.id, crtc->base.name, dsb->id);
> > for (i = 0; i < ALIGN(dsb->free_pos, 64 / 4); i += 4)
> > drm_dbg_kms(&i915->drm,
> > - " 0x%08x: 0x%08x 0x%08x 0x%08x 0x%08x\n",
> > - i * 4, buf[i], buf[i+1], buf[i+2], buf[i+3]);
> > + " 0x%08x: 0x%08x 0x%08x 0x%08x 0x%08x\n", i * 4,
> > + intel_dsb_buffer_read(&dsb->dsb_buf, i),
> > + intel_dsb_buffer_read(&dsb->dsb_buf, i + 1),
> > + intel_dsb_buffer_read(&dsb->dsb_buf, i + 2),
> > + intel_dsb_buffer_read(&dsb->dsb_buf, i + 3));
> > drm_dbg_kms(&i915->drm, "}\n");
> > }
> >
> > @@ -128,8 +130,6 @@ 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;
> >
> > @@ -138,14 +138,13 @@ 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_buffer_write(&dsb->dsb_buf, dsb->free_pos++, ldw);
> > + intel_dsb_buffer_write(&dsb->dsb_buf, 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;
> >
> > /*
> > @@ -156,8 +155,10 @@ 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_buffer_read(&dsb->dsb_buf,
> > + dsb->ins_start_offset + 1) >>
> DSB_OPCODE_SHIFT;
> > + prev_reg = intel_dsb_buffer_read(&dsb->dsb_buf,
> > + dsb->ins_start_offset + 1) &
> DSB_REG_VALUE_MASK;
> >
> > return prev_opcode == opcode && prev_reg ==
> > i915_mmio_reg_offset(reg); } @@ -190,6 +191,8 @@ 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:
> > @@ -213,31 +216,32 @@ 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_buffer_read(&dsb-
> >dsb_buf,
> > + 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_buffer_write(&dsb->dsb_buf,
> > + dsb->ins_start_offset + 0, 1); /*
> count */
> > + intel_dsb_buffer_write(&dsb->dsb_buf, dsb-
> >ins_start_offset + 1,
> > + (DSB_OPCODE_INDEXED_WRITE
> << DSB_OPCODE_SHIFT) |
> > + i915_mmio_reg_offset(reg));
> > + intel_dsb_buffer_write(&dsb->dsb_buf, dsb-
> >ins_start_offset + 2,
> > +prev_val);
> >
> > dsb->free_pos++;
> > }
> >
> > - buf[dsb->free_pos++] = val;
> > + intel_dsb_buffer_write(&dsb->dsb_buf, dsb->free_pos++,
> val);
> > /* Update the count */
> > - buf[dsb->ins_start_offset]++;
> > + old_val = intel_dsb_buffer_read(&dsb->dsb_buf, dsb-
> >ins_start_offset);
> > + intel_dsb_buffer_write(&dsb->dsb_buf, 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_buffer_write(&dsb->dsb_buf, dsb-
> >free_pos, 0);
> > }
> > }
> >
> > @@ -296,8 +300,8 @@ 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_buffer_memset(&dsb->dsb_buf, dsb->free_pos, 0,
> > + aligned_tail - tail);
> >
> > dsb->free_pos = aligned_tail / 4;
> > }
> > @@ -358,7 +362,7 @@ static void _intel_dsb_commit(struct intel_dsb
> *dsb, u32 ctrl,
> > ctrl | DSB_ENABLE);
> >
> > intel_de_write_fw(dev_priv, DSB_HEAD(pipe, dsb->id),
> > - i915_ggtt_offset(dsb->vma));
> > + intel_dsb_buffer_ggtt_offset(&dsb->dsb_buf));
> >
> > if (dewake_scanline >= 0) {
> > int diff, hw_dewake_scanline;
> > @@ -380,7 +384,7 @@ static void _intel_dsb_commit(struct intel_dsb
> *dsb, u32 ctrl,
> > }
> >
> > intel_de_write_fw(dev_priv, DSB_TAIL(pipe, dsb->id),
> > - i915_ggtt_offset(dsb->vma) + tail);
> > + intel_dsb_buffer_ggtt_offset(&dsb->dsb_buf) + tail);
> > }
> >
> > /**
> > @@ -405,7 +409,7 @@ void intel_dsb_wait(struct intel_dsb *dsb)
> > enum pipe pipe = crtc->pipe;
> >
> > if (wait_for(!is_dsb_busy(dev_priv, pipe, dsb->id), 1)) {
> > - u32 offset = i915_ggtt_offset(dsb->vma);
> > + u32 offset = intel_dsb_buffer_ggtt_offset(&dsb->dsb_buf);
> >
> > intel_de_write_fw(dev_priv, DSB_CTRL(pipe, dsb->id),
> > DSB_ENABLE | DSB_HALT);
> > @@ -442,12 +446,9 @@ struct intel_dsb *intel_dsb_prepare(const struct
> > intel_crtc_state *crtc_state, {
> > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > 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;
> > @@ -461,28 +462,13 @@ struct intel_dsb *intel_dsb_prepare(const struct
> intel_crtc_state *crtc_state,
> > /* ~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->dsb_buf, 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;
> > @@ -510,6 +496,6 @@ struct intel_dsb *intel_dsb_prepare(const struct
> intel_crtc_state *crtc_state,
> > */
> > void intel_dsb_cleanup(struct intel_dsb *dsb) {
> > - i915_vma_unpin_and_release(&dsb->vma,
> I915_VMA_RELEASE_MAP);
> > + intel_dsb_buffer_cleanup(&dsb->dsb_buf);
> > kfree(dsb);
> > }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dsb_buffer.c
> > b/drivers/gpu/drm/i915/display/intel_dsb_buffer.c
> > new file mode 100644
> > index 000000000000..723937591831
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/display/intel_dsb_buffer.c
> > @@ -0,0 +1,64 @@
> > +// 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_buffer.h"
> > +
> > +u32 intel_dsb_buffer_ggtt_offset(struct intel_dsb_buffer *dsb_buf) {
> > + return i915_ggtt_offset(dsb_buf->vma); }
> > +
> > +void intel_dsb_buffer_write(struct intel_dsb_buffer *dsb_buf, u32
> > +idx, u32 val) {
> > + dsb_buf->cmd_buf[idx] = val;
> > +}
> > +
> > +u32 intel_dsb_buffer_read(struct intel_dsb_buffer *dsb_buf, u32 idx)
> > +{
> > + return dsb_buf->cmd_buf[idx];
> > +}
> > +
> > +void intel_dsb_buffer_memset(struct intel_dsb_buffer *dsb_buf, u32
> > +idx, u32 val, u32 sz) {
> > + memset(&dsb_buf->cmd_buf[idx], val, sz); }
>
> What's the point in abstracting that stuff?
For xe driver the memset implementation will be done differently, so created this abstraction. The same thing is followed other xe-refactoring code as well.
If you want me to change the code any specific way please let me, will try to modify accordingly.
Regards,
Animesh
>
> > +
> > +bool intel_dsb_buffer_create(struct intel_crtc *crtc, struct
> > +intel_dsb_buffer *dsb_buf, 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_buf->vma = vma;
> > + dsb_buf->cmd_buf = buf;
> > +
> > + return true;
> > +}
> > +
> > +void intel_dsb_buffer_cleanup(struct intel_dsb_buffer *dsb_buf) {
> > + i915_vma_unpin_and_release(&dsb_buf->vma,
> I915_VMA_RELEASE_MAP); }
> > diff --git a/drivers/gpu/drm/i915/display/intel_dsb_buffer.h
> > b/drivers/gpu/drm/i915/display/intel_dsb_buffer.h
> > new file mode 100644
> > index 000000000000..7dbfd23b52a9
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/display/intel_dsb_buffer.h
> > @@ -0,0 +1,26 @@
> > +/* SPDX-License-Identifier: MIT
> > + *
> > + * Copyright © 2023 Intel Corporation */
> > +
> > +#ifndef _INTEL_DSB_BUFFER_H
> > +#define _INTEL_DSB_BUFFER_H
> > +
> > +#include <linux/types.h>
> > +
> > +struct intel_crtc;
> > +struct i915_vma;
> > +
> > +struct intel_dsb_buffer {
> > + u32 *cmd_buf;
> > + struct i915_vma *vma;
> > +};
> > +
> > +u32 intel_dsb_buffer_ggtt_offset(struct intel_dsb_buffer *dsb_buf);
> > +void intel_dsb_buffer_write(struct intel_dsb_buffer *dsb_buf, u32
> > +idx, u32 val);
> > +u32 intel_dsb_buffer_read(struct intel_dsb_buffer *dsb_buf, u32 idx);
> > +void intel_dsb_buffer_memset(struct intel_dsb_buffer *dsb_buf, u32
> > +idx, u32 val, u32 sz); bool intel_dsb_buffer_create(struct intel_crtc
> > +*crtc, struct intel_dsb_buffer *dsb_buf, u32 size); void
> > +intel_dsb_buffer_cleanup(struct intel_dsb_buffer *dsb_buf);
> > +
> > +#endif
> > --
> > 2.29.0
>
> --
> Ville Syrjälä
> Intel
