[PATCH v2 07/10] drm/xe: Move GFX_MODE programming to RTP

Matt Roper
2026-04-24T20:50:35Z

The write GFX_MODE to disable engine "legacy mode" and to enable MSI-X
support was unnecessarily open-coded in xe_hw_engine_enable_ring();
it's preferable to do such programming in the engine_entries[] RTP table
since gets reflected/verified in debugfs, and will also automatically
ensure that the register is properly saved/restored around engine
resets. This also helps consolidate common logic that was duplicated
between the main driver initialization path and the dead-code execlist
initialization path.

This also allows us to drop GFX_MODE from the list of extra registers to
be added to the GuC ADS' save-restore list since all registers on the
RTP table are added automatically.

v2:
- Actually use the xe_rtp_match_has_msix match function added.
(Shuicheng)

Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
---
drivers/gpu/drm/xe/xe_execlist.c | 5 -----
drivers/gpu/drm/xe/xe_guc_ads.c | 1 -
drivers/gpu/drm/xe/xe_hw_engine.c | 16 ++++++++++------
drivers/gpu/drm/xe/xe_rtp.c | 8 ++++++++
drivers/gpu/drm/xe/xe_rtp.h | 12 ++++++++++++
5 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_execlist.c b/drivers/gpu/drm/xe/xe_execlist.c
index 337b9b4e8b4a..9fb99c038ea8 100644
--- a/drivers/gpu/drm/xe/xe_execlist.c
+++ b/drivers/gpu/drm/xe/xe_execlist.c
@@ -47,7 +47,6 @@ static void __start_lrc(struct xe_hw_engine *hwe, struct xe_lrc *lrc,
struct xe_mmio *mmio = &gt->mmio;
struct xe_device *xe = gt_to_xe(gt);
u64 lrc_desc;
- u32 ring_mode = REG_MASKED_FIELD_ENABLE(GFX_DISABLE_LEGACY_MODE);

lrc_desc = xe_lrc_descriptor(lrc);

@@ -78,10 +77,6 @@ static void __start_lrc(struct xe_hw_engine *hwe, struct xe_lrc *lrc,
xe_bo_ggtt_addr(hwe->hwsp));
xe_mmio_read32(mmio, RING_HWS_PGA(hwe->mmio_base));

- if (xe_device_has_msix(gt_to_xe(hwe->gt)))
- ring_mode |= REG_MASKED_FIELD_ENABLE(GFX_MSIX_INTERRUPT_ENABLE);
- xe_mmio_write32(mmio, GFX_MODE(hwe->mmio_base), ring_mode);
-
xe_mmio_write32(mmio, RING_EXECLIST_SQ_CONTENTS_LO(hwe->mmio_base),
lower_32_bits(lrc_desc));
xe_mmio_write32(mmio, RING_EXECLIST_SQ_CONTENTS_HI(hwe->mmio_base),
diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
index b403ee0b5e74..ce651da6f318 100644
--- a/drivers/gpu/drm/xe/xe_guc_ads.c
+++ b/drivers/gpu/drm/xe/xe_guc_ads.c
@@ -745,7 +745,6 @@ static unsigned int guc_mmio_regset_write(struct xe_guc_ads *ads,
struct xe_reg reg;
bool skip;
} *e, extra_regs[] = {
- { .reg = GFX_MODE(hwe->mmio_base), },
{ .reg = RING_HWS_PGA(hwe->mmio_base), },
{ .reg = RING_IMR(hwe->mmio_base), },
{ .reg = CCS_MODE,
diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
index 60af395d031c..b380d3cf6d3a 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine.c
@@ -325,14 +325,8 @@ u32 xe_hw_engine_mmio_read32(struct xe_hw_engine *hwe, struct xe_reg reg)

void xe_hw_engine_enable_ring(struct xe_hw_engine *hwe)
{
- u32 ring_mode = REG_MASKED_FIELD_ENABLE(GFX_DISABLE_LEGACY_MODE);
-
xe_hw_engine_mmio_write32(hwe, RING_HWS_PGA(0),
xe_bo_ggtt_addr(hwe->hwsp));
-
- if (xe_device_has_msix(gt_to_xe(hwe->gt)))
- ring_mode |= REG_MASKED_FIELD_ENABLE(GFX_MSIX_INTERRUPT_ENABLE);
- xe_hw_engine_mmio_write32(hwe, GFX_MODE(0), ring_mode);
xe_hw_engine_mmio_write32(hwe, RING_MI_MODE(0),
REG_MASKED_FIELD_DISABLE(STOP_RING));
xe_hw_engine_mmio_read32(hwe, RING_MI_MODE(0));
@@ -441,6 +435,11 @@ hw_engine_setup_default_state(struct xe_hw_engine *hwe)
XE_RTP_ACTIONS(SET(RING_HWSTAM(0), ~0x0,
XE_RTP_ACTION_FLAG(ENGINE_BASE)))
},
+ { XE_RTP_NAME("Disable engine 'legacy' mode"),
+ XE_RTP_RULES(FUNC(xe_rtp_match_always)),
+ XE_RTP_ACTIONS(SET(GFX_MODE(0), GFX_DISABLE_LEGACY_MODE,
+ XE_RTP_ACTION_FLAG(ENGINE_BASE)))
+ },
/*
* To allow the GSC engine to go idle on MTL we need to enable
* idle messaging and set the hysteresis value (we use 0xA=5us
@@ -474,6 +473,11 @@ hw_engine_setup_default_state(struct xe_hw_engine *hwe)
XE_RTP_ACTIONS(FIELD_SET(RCU_MODE, RCU_MODE_FIXED_SLICE_CCS_MODE,
RCU_MODE_FIXED_SLICE_CCS_MODE))
},
+ { XE_RTP_NAME("Enable MSI-X interrupt support"),
+ XE_RTP_RULES(FUNC(xe_rtp_match_has_msix)),
+ XE_RTP_ACTIONS(SET(GFX_MODE(0), GFX_MSIX_INTERRUPT_ENABLE,
+ XE_RTP_ACTION_FLAG(ENGINE_BASE)))
+ },
};

xe_rtp_process_to_sr(&ctx, engine_entries, ARRAY_SIZE(engine_entries),
diff --git a/drivers/gpu/drm/xe/xe_rtp.c b/drivers/gpu/drm/xe/xe_rtp.c
index 728933a1c34f..1a4dcbbbc176 100644
--- a/drivers/gpu/drm/xe/xe_rtp.c
+++ b/drivers/gpu/drm/xe/xe_rtp.c
@@ -10,6 +10,7 @@
#include <uapi/drm/xe_drm.h>

#include "xe_configfs.h"
+#include "xe_device.h"
#include "xe_gt.h"
#include "xe_gt_topology.h"
#include "xe_reg_sr.h"
@@ -404,3 +405,10 @@ bool xe_rtp_match_has_flat_ccs(const struct xe_device *xe,
{
return xe->info.has_flat_ccs;
}
+
+bool xe_rtp_match_has_msix(const struct xe_device *xe,
+ const struct xe_gt *gt,
+ const struct xe_hw_engine *hwe)
+{
+ return xe_device_has_msix(xe);
+}
diff --git a/drivers/gpu/drm/xe/xe_rtp.h b/drivers/gpu/drm/xe/xe_rtp.h
index d058a629cd3e..562082b18d7b 100644
--- a/drivers/gpu/drm/xe/xe_rtp.h
+++ b/drivers/gpu/drm/xe/xe_rtp.h
@@ -536,4 +536,16 @@ bool xe_rtp_match_has_flat_ccs(const struct xe_device *xe,
const struct xe_gt *gt,
const struct xe_hw_engine *hwe);

+/**
+ * xe_rtp_match_has_msix - Match when platform has MSI-X
+ * @xe: Device structure
+ * @gt: GT structure
+ * @hwe: Engine instance
+ *
+ * Returns: true if platform has MSI-X interrupt support
+ */
+bool xe_rtp_match_has_msix(const struct xe_device *xe,
+ const struct xe_gt *gt,
+ const struct xe_hw_engine *hwe);
+
#endif

--
2.53.0