[Intel-xe] [PATCH v4 1/2] drm/xe: Skip XY_FAST_COLOR instruction on link copy engines
Lucas De Marchi
lucas.demarchi at intel.com
Fri Mar 17 00:47:21 UTC 2023
On Wed, Mar 15, 2023 at 01:44:59PM +0530, Balasubramani Vivekanandan wrote:
>Link copy engines doesn't support the XY_FAST_COLOR instruction.
>Currently this instruction is used only at one place to clear a ttm
>resource while migrating a BO.
>A new device_info member is created to know if a platform has link copy
>engine. If it supports, then instead of using XY_FAST_COLOR instruction,
>MEM_SET is used which is available both in main and link copy engines.
>
>Since MEM_SET only supports setting 8-bit value, to keep things simple
>emit_clear funciton is restricted only to clear memory address range
>when platform has link copy engine.
>
>BSpec: 68433
>
>Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>
>---
> drivers/gpu/drm/xe/regs/xe_gpu_commands.h | 9 ++++
> drivers/gpu/drm/xe/xe_device_types.h | 2 +
> drivers/gpu/drm/xe/xe_migrate.c | 66 +++++++++++++++++++++--
> drivers/gpu/drm/xe/xe_pci.c | 4 ++
> 4 files changed, 76 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/gpu/drm/xe/regs/xe_gpu_commands.h b/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>index 288576035ce3..e60372a82723 100644
>--- a/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>+++ b/drivers/gpu/drm/xe/regs/xe_gpu_commands.h
>@@ -6,6 +6,8 @@
> #ifndef _XE_GPU_COMMANDS_H_
> #define _XE_GPU_COMMANDS_H_
>
>+#include "regs/xe_reg_defs.h"
>+
> #define INSTR_CLIENT_SHIFT 29
> #define INSTR_MI_CLIENT 0x0
> #define __INSTR(client) ((client) << INSTR_CLIENT_SHIFT)
>@@ -56,6 +58,13 @@
> #define GEN9_XY_FAST_COPY_BLT_CMD (2 << 29 | 0x42 << 22)
> #define BLT_DEPTH_32 (3<<24)
>
>+#define PVC_MEM_SET_CMD (2 << 29 | 0x5b << 22)
>+#define PVC_MEM_SET_CMD_LEN_DW 7
>+#define PVC_MS_MATRIX REG_BIT(17)
>+#define PVC_MS_DATA_FIELD GENMASK(31, 24)
>+/* Bspec lists field as [6:0], but index alone is from [6:1] */
>+#define PVC_MS_MOCS_INDEX_MASK GENMASK(6, 1)
>+
> #define GFX_OP_PIPE_CONTROL(len) ((0x3<<29)|(0x3<<27)|(0x2<<24)|((len)-2))
> #define PIPE_CONTROL_TILE_CACHE_FLUSH (1<<28)
> #define PIPE_CONTROL_AMFS_FLUSH (1<<25)
>diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
>index 034e0956f4ea..46cf37224090 100644
>--- a/drivers/gpu/drm/xe/xe_device_types.h
>+++ b/drivers/gpu/drm/xe/xe_device_types.h
>@@ -95,6 +95,8 @@ struct xe_device {
> bool has_4tile;
> /** @has_range_tlb_invalidation: Has range based TLB invalidations */
> bool has_range_tlb_invalidation;
>+ /** @has_link_copy_engines: Whether the platform has link copy engines */
>+ bool has_link_copy_engine;
> /** @enable_display: display enabled */
> bool enable_display;
>
>diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
>index c0523d8fe944..44a4712f8c83 100644
>--- a/drivers/gpu/drm/xe/xe_migrate.c
>+++ b/drivers/gpu/drm/xe/xe_migrate.c
>@@ -746,14 +746,37 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
> return fence;
> }
>
>-static int emit_clear(struct xe_gt *gt, struct xe_bb *bb, u64 src_ofs,
>- u32 size, u32 pitch, u32 value, bool is_vram)
>+static void emit_clear_link_copy(struct xe_gt *gt, struct xe_bb *bb, u64 src_ofs,
>+ u32 size, u32 pitch)
>+{
>+ u32 *cs = bb->cs + bb->len;
>+ u32 mocs = xe_mocs_index_to_value(gt->mocs.uc_index);
>+ u32 len = PVC_MEM_SET_CMD_LEN_DW;
>+
>+ *cs++ = PVC_MEM_SET_CMD | PVC_MS_MATRIX | (len - 2);
>+ *cs++ = pitch - 1;
>+ *cs++ = (size / pitch) - 1;
>+ *cs++ = pitch - 1;
>+ *cs++ = lower_32_bits(src_ofs);
>+ *cs++ = upper_32_bits(src_ofs);
>+ *cs++ = FIELD_PREP(PVC_MS_MOCS_INDEX_MASK, mocs);
>+
>+ XE_BUG_ON(cs - bb->cs != len + bb->len);
>+
>+ bb->len += len;
>+}
>+
>+static void emit_clear_main_copy(struct xe_gt *gt, struct xe_bb *bb,
>+ u64 src_ofs, u32 size, u32 pitch, u32 value,
>+ bool is_vram)
> {
> u32 *cs = bb->cs + bb->len;
>- u32 len = XY_FAST_COLOR_BLT_DW;
>+ u32 len;
> u32 mocs = xe_mocs_index_to_value(gt->mocs.uc_index);
>+ struct xe_device *xe = gt_to_xe(gt);
>
>- if (GRAPHICS_VERx100(gt->xe) < 1250)
>+ len = XY_FAST_COLOR_BLT_DW;
>+ if (GRAPHICS_VERx100(xe) < 1250)
> len = 11;
>
> *cs++ = XY_FAST_COLOR_BLT_CMD | XY_FAST_COLOR_BLT_DEPTH_32 |
>@@ -779,7 +802,39 @@ static int emit_clear(struct xe_gt *gt, struct xe_bb *bb, u64 src_ofs,
> }
>
> XE_BUG_ON(cs - bb->cs != len + bb->len);
>+
> bb->len += len;
>+}
>+
>+static u32 emit_clear_cmd_len(struct xe_device *xe)
>+{
>+ if (xe->info.has_link_copy_engine)
>+ return PVC_MEM_SET_CMD_LEN_DW;
>+ else
>+ return XY_FAST_COLOR_BLT_DW;
>+}
>+
>+static int emit_clear(struct xe_gt *gt, struct xe_bb *bb, u64 src_ofs,
>+ u32 size, u32 pitch, u32 value, bool is_vram)
>+{
>+ struct xe_device *xe = gt_to_xe(gt);
>+
>+ if (xe->info.has_link_copy_engine) {
>+ /* MEM_SET command supports setting only 8-bit value. So it
>+ * can't be used to set a 32-bit value. And emit_clear function
>+ * is currently used only to clear the address range. Instead
>+ * of limiting value argument to a 8-bit range, for platforms
>+ * with link copy engines, lets not accept any value to set and
>+ * use emit_clear to only clear the memory range.
>+ */
>+ XE_WARN_ON(value);
since this patch comes first, this would create a warning on
uses of emit_clear() not changed in this patch.
Also, this is further exported by xe_migrate_clear(), which received
value as a paramenter. By doing what you are doing here you basically
require every caller of that function to know about the limitation.
Humn... options:
1) Would it be possible to make sure the migrate clear is executed on
the main copy engine? I'm not sure there will be contention on using
that engine, but I think in i915 it was a possible option
2) Remove the value from xe_migrate_clear() and adjust the callers.
Document that this is being cleared with 0.
2b) if there is a need outside of test (why would we test
something that we are not making use of?), then add another
function like xe_migrate_clear_with_val() that may be
implemented differently for PVC or that just returns
-ENOTSUPP. In which case it shoudl be documented that not
all platforms support it.
Lucas De Marchi
>+ emit_clear_link_copy(gt, bb, src_ofs, size, pitch);
>+
>+ } else {
>+ emit_clear_main_copy(gt, bb, src_ofs, size, pitch, value,
>+ is_vram);
>+ }
>+
>
> return 0;
> }
>@@ -836,7 +891,8 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
> batch_size = 2 +
> pte_update_size(m, clear_vram, &src_it,
> &clear_L0, &clear_L0_ofs, &clear_L0_pt,
>- XY_FAST_COLOR_BLT_DW, 0, NUM_PT_PER_BLIT);
>+ emit_clear_cmd_len(xe), 0,
>+ NUM_PT_PER_BLIT);
> if (xe_device_has_flat_ccs(xe) && clear_vram)
> batch_size += EMIT_COPY_CCS_DW;
>
>diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
>index c4d9fd2e7b2b..e555f13395ab 100644
>--- a/drivers/gpu/drm/xe/xe_pci.c
>+++ b/drivers/gpu/drm/xe/xe_pci.c
>@@ -72,6 +72,8 @@ struct xe_device_desc {
> bool has_4tile;
> bool has_range_tlb_invalidation;
> bool has_asid;
>+
>+ bool has_link_copy_engine;
> };
>
> __diag_push();
>@@ -224,6 +226,7 @@ static const struct xe_device_desc pvc_desc = {
> .vm_max_level = 4,
> .supports_usm = true,
> .has_asid = true,
>+ .has_link_copy_engine = true,
> };
>
> #define MTL_MEDIA_ENGINES \
>@@ -413,6 +416,7 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> xe->info.has_flat_ccs = desc->has_flat_ccs;
> xe->info.has_4tile = desc->has_4tile;
> xe->info.has_range_tlb_invalidation = desc->has_range_tlb_invalidation;
>+ xe->info.has_link_copy_engine = desc->has_link_copy_engine;
>
> spd = subplatform_get(xe, desc);
> xe->info.subplatform = spd ? spd->subplatform : XE_SUBPLATFORM_NONE;
>--
>2.25.1
>
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