[Intel-xe] [RFC v2 2/6] drm/xe/xe2: Determine bios enablement for flat ccs on igfx.

[Himal Prasad Ghimiray]

If bios disables flat ccs on igfx  make has_flat_ccs as 0 and notify
via drm_info.

Bspec:59255

Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 drivers/gpu/drm/xe/regs/xe_gt_regs.h |  3 +++
 drivers/gpu/drm/xe/xe_device.c       | 30 ++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/gpu/drm/xe/regs/xe_gt_regs.h b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
index cc27fe8fc363..b642301947f5 100644
--- a/drivers/gpu/drm/xe/regs/xe_gt_regs.h
+++ b/drivers/gpu/drm/xe/regs/xe_gt_regs.h
@@ -142,6 +142,9 @@
 #define XEHP_SLICE_COMMON_ECO_CHICKEN1		XE_REG_MCR(0x731c, XE_REG_OPTION_MASKED)
 #define   MSC_MSAA_REODER_BUF_BYPASS_DISABLE	REG_BIT(14)
 
+#define XE2_FLAT_CCS_BASE_RANGE_LOWER		XE_REG_MCR(0x8800)
+#define   XE2_FLAT_CCS_ENABLE			REG_BIT(0)
+
 #define VF_PREEMPTION				XE_REG(0x83a4, XE_REG_OPTION_MASKED)
 #define   PREEMPTION_VERTEX_COUNT		REG_GENMASK(15, 0)
 
diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index 8be765adf702..07a3e4cf48d1 100644
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -16,6 +16,7 @@
 #include <drm/xe_drm.h>
 
 #include "regs/xe_regs.h"
+#include "regs/xe_gt_regs.h"
 #include "xe_bo.h"
 #include "xe_debugfs.h"
 #include "xe_display.h"
@@ -25,6 +26,7 @@
 #include "xe_exec_queue.h"
 #include "xe_exec.h"
 #include "xe_gt.h"
+#include "xe_gt_mcr.h"
 #include "xe_irq.h"
 #include "xe_mmio.h"
 #include "xe_module.h"
@@ -342,6 +344,29 @@ static void xe_device_sanitize(struct drm_device *drm, void *arg)
 		xe_gt_sanitize(gt);
 }
 
+static int xe_device_set_has_flat_ccs(struct  xe_device *xe)
+{
+	u32 reg;
+	int err;
+
+	if (IS_DGFX(xe) || GRAPHICS_VER(xe) < 20 || !xe->info.has_flat_ccs)
+		return 0;
+
+	struct xe_gt *gt = xe_root_mmio_gt(xe);
+
+	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
+	if (err)
+		return err;
+
+	reg = xe_gt_mcr_unicast_read_any(gt, XE2_FLAT_CCS_BASE_RANGE_LOWER);
+	xe->info.has_flat_ccs = (reg & XE2_FLAT_CCS_ENABLE);
+
+	if (!xe->info.has_flat_ccs)
+		drm_info(&xe->drm,
+			 "Flat CCS has been disabled in bios, May lead to performance impact");
+	return 0;
+}
+
 int xe_device_probe(struct xe_device *xe)
 {
 	struct xe_tile *tile;
@@ -352,6 +377,7 @@ int xe_device_probe(struct xe_device *xe)
 	xe_pat_init_early(xe);
 
 	xe->info.mem_region_mask = 1;
+
 	err = xe_display_init_nommio(xe);
 	if (err)
 		return err;
@@ -390,6 +416,10 @@ int xe_device_probe(struct xe_device *xe)
 			goto err_irq_shutdown;
 	}
 
+	err = xe_device_set_has_flat_ccs(xe);
+	if (err)
+		return err;
+
 	err = xe_mmio_probe_vram(xe);
 	if (err)
 		goto err_irq_shutdown;
-- 
2.25.1