[Intel-xe] [PATCH 5/6] drm/xe/wa: Apply tile workarounds at probe/resume

[Matt Roper]

Although the vast majority of workarounds the driver needs to implement
are either GT-based or display-based, there are occasionally workarounds
that reside outside those parts of the hardware (i.e., in they target
registers in the sgunit/soc); we can consider these to be "tile"
workarounds since there will be instance of these registers per tile.
The registers in question should only lose their values during a
function-level reset, so they only need to be applied during probe and
resume; the registers will not be affected by GT/engine resets.

Tile workarounds are rare (there's only one, 22010954014, that's
relevant to Xe at the moment) so it's probably not worth updating the
xe_rtp design to handle tile-level workarounds yet, although we may want
to consider that in the future if/when more of these show up on future
platforms.

Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/xe/regs/xe_regs.h  |  3 +++
 drivers/gpu/drm/xe/xe_pm.c         |  5 +++++
 drivers/gpu/drm/xe/xe_tile.c       |  3 +++
 drivers/gpu/drm/xe/xe_wa.c         | 20 ++++++++++++++++++++
 drivers/gpu/drm/xe/xe_wa.h         |  2 ++
 drivers/gpu/drm/xe/xe_wa_oob.rules |  1 +
 6 files changed, 34 insertions(+)

diff --git a/drivers/gpu/drm/xe/regs/xe_regs.h b/drivers/gpu/drm/xe/regs/xe_regs.h
index 39d7b0740bf0..8a93ab169e04 100644
--- a/drivers/gpu/drm/xe/regs/xe_regs.h
+++ b/drivers/gpu/drm/xe/regs/xe_regs.h
@@ -56,6 +56,9 @@
 #define GU_CNTL					XE_REG(0x101010)
 #define   LMEM_INIT				REG_BIT(7)
 
+#define XEHP_CLOCK_GATE_DIS			XE_REG(0x101014)
+#define   SGSI_SIDECLK_DIS			REG_BIT(17)
+
 #define GGC					XE_REG(0x108040)
 #define   GMS_MASK				REG_GENMASK(15, 8)
 #define   GGMS_MASK				REG_GENMASK(7, 6)
diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 0f06d8304e17..ad3c08c4ff22 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -20,6 +20,7 @@
 #include "xe_guc.h"
 #include "xe_irq.h"
 #include "xe_pcode.h"
+#include "xe_wa.h"
 
 /**
  * DOC: Xe Power Management
@@ -86,10 +87,14 @@ int xe_pm_suspend(struct xe_device *xe)
  */
 int xe_pm_resume(struct xe_device *xe)
 {
+	struct xe_tile *tile;
 	struct xe_gt *gt;
 	u8 id;
 	int err;
 
+	for_each_tile(tile, xe, id)
+		xe_wa_apply_tile_workarounds(tile);
+
 	for_each_gt(gt, xe, id) {
 		err = xe_pcode_init(gt);
 		if (err)
diff --git a/drivers/gpu/drm/xe/xe_tile.c b/drivers/gpu/drm/xe/xe_tile.c
index e0bc2b60ab09..131752a57f65 100644
--- a/drivers/gpu/drm/xe/xe_tile.c
+++ b/drivers/gpu/drm/xe/xe_tile.c
@@ -12,6 +12,7 @@
 #include "xe_tile.h"
 #include "xe_tile_sysfs.h"
 #include "xe_ttm_vram_mgr.h"
+#include "xe_wa.h"
 
 /**
  * DOC: Multi-tile Design
@@ -143,6 +144,8 @@ int xe_tile_init_noalloc(struct xe_tile *tile)
 	if (IS_ERR(tile->mem.kernel_bb_pool))
 		err = PTR_ERR(tile->mem.kernel_bb_pool);
 
+	xe_wa_apply_tile_workarounds(tile);
+
 	xe_tile_sysfs_init(tile);
 
 err_mem_access:
diff --git a/drivers/gpu/drm/xe/xe_wa.c b/drivers/gpu/drm/xe/xe_wa.c
index f45e9452ba0e..d84e67a9af07 100644
--- a/drivers/gpu/drm/xe/xe_wa.c
+++ b/drivers/gpu/drm/xe/xe_wa.c
@@ -753,3 +753,23 @@ void xe_wa_dump(struct xe_gt *gt, struct drm_printer *p)
 		if (oob_was[idx].name)
 			drm_printf_indent(p, 1, "%s\n", oob_was[idx].name);
 }
+
+/*
+ * Apply tile (non-GT, non-display) workarounds.  Think very carefully before
+ * adding anything to this function; most workarounds should be implemented
+ * elsewhere.  The programming here is primarily for sgunit/soc workarounds,
+ * which are relatively rare.  Since the registers these workarounds target are
+ * outside the GT, they should only need to be applied once at device
+ * probe/resume; they will not lose their values on any kind of GT or engine
+ * reset.
+ *
+ * TODO:  We may want to move this over to xe_rtp in the future once we have
+ * enough workarounds to justify the work.
+ */
+void xe_wa_apply_tile_workarounds(struct xe_tile *tile)
+{
+	struct xe_gt *mmio = tile->primary_gt;
+
+	if (XE_WA(mmio, 22010954014))
+		xe_mmio_rmw32(mmio, XEHP_CLOCK_GATE_DIS, 0, SGSI_SIDECLK_DIS);
+}
diff --git a/drivers/gpu/drm/xe/xe_wa.h b/drivers/gpu/drm/xe/xe_wa.h
index cfe685989524..1b24d66f9d80 100644
--- a/drivers/gpu/drm/xe/xe_wa.h
+++ b/drivers/gpu/drm/xe/xe_wa.h
@@ -9,12 +9,14 @@
 struct drm_printer;
 struct xe_gt;
 struct xe_hw_engine;
+struct xe_tile;
 
 int xe_wa_init(struct xe_gt *gt);
 void xe_wa_process_oob(struct xe_gt *gt);
 void xe_wa_process_gt(struct xe_gt *gt);
 void xe_wa_process_engine(struct xe_hw_engine *hwe);
 void xe_wa_process_lrc(struct xe_hw_engine *hwe);
+void xe_wa_apply_tile_workarounds(struct xe_tile *tile);
 
 void xe_reg_whitelist_process_engine(struct xe_hw_engine *hwe);
 void xe_wa_dump(struct xe_gt *gt, struct drm_printer *p);
diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules b/drivers/gpu/drm/xe/xe_wa_oob.rules
index 599e67169dae..f3ff774dc4aa 100644
--- a/drivers/gpu/drm/xe/xe_wa_oob.rules
+++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
@@ -18,3 +18,4 @@
 14016763929	SUBPLATFORM(DG2, G10)
 		SUBPLATFORM(DG2, G12)
 16017236439	PLATFORM(PVC)
+22010954014	PLATFORM(DG2)
-- 
2.41.0