On Tue, 26 Sep 2023, "Manna, Animesh" <animesh.manna@xxxxxxxxx> wrote:
>> -----Original Message-----
>> From: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
>> Sent: Monday, September 25, 2023 6:00 PM
>> To: Manna, Animesh <animesh.manna@xxxxxxxxx>; intel-
>> gfx@xxxxxxxxxxxxxxxxxxxxx
>> Subject: Re: [PATCH] drm/i915/dsb: DSB code refactoring
>>
>> On Sat, 23 Sep 2023, Animesh Manna <animesh.manna@xxxxxxxxx> 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.
>
> Hi Jani,
>
> Xe driver need access to intel_dsb structure, so I can create a new header file intel_dsb_ops.h and keep intel_dsb structure in it. Is it ok?
I just think you need to find a different abstraction level that doesn't
involve exposing struct intel_dsb.
The stuff you're putting in intel_dsb_ops.[ch] don't really need to
operate on intel_dsb at all.
BR,
Jani.
>
> Regards,
> Animesh
>>
>> BR,
>> Jani.
>>
>> >
>> > Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
>> > ---
>> > 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
--
Jani Nikula, Intel
