drm/xe: Introduce a new DRM driver for Intel GPUs

Xe, is a new driver for Intel GPUs that supports both integrated and
discrete platforms starting with Tiger Lake (first Intel Xe Architecture).

The code is at a stage where it is already functional and has experimental
support for multiple platforms starting from Tiger Lake, with initial
support implemented in Mesa (for Iris and Anv, our OpenGL and Vulkan
drivers), as well as in NEO (for OpenCL and Level0).

The new Xe driver leverages a lot from i915.

As for display, the intent is to share the display code with the i915
driver so that there is maximum reuse there. But it is not added
in this patch.

This initial work is a collaboration of many people and unfortunately
the big squashed patch won't fully honor the proper credits. But let's
get some git quick stats so we can at least try to preserve some of the
credits:

Co-developed-by: Matthew Brost <matthew.brost@intel.com>
Co-developed-by: Matthew Auld <matthew.auld@intel.com>
Co-developed-by: Matt Roper <matthew.d.roper@intel.com>
Co-developed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Co-developed-by: Francois Dugast <francois.dugast@intel.com>
Co-developed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Co-developed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Co-developed-by: Philippe Lecluse <philippe.lecluse@intel.com>
Co-developed-by: Nirmoy Das <nirmoy.das@intel.com>
Co-developed-by: Jani Nikula <jani.nikula@intel.com>
Co-developed-by: José Roberto de Souza <jose.souza@intel.com>
Co-developed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Co-developed-by: Dave Airlie <airlied@redhat.com>
Co-developed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Co-developed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Co-developed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_gt_clock.c b/drivers/gpu/drm/xe/xe_gt_clock.c
new file mode 100644
index 000000000000..575433e9718a
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_gt_clock.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "i915_reg.h"
+#include "gt/intel_gt_regs.h"
+
+#include "xe_device.h"
+#include "xe_gt.h"
+#include "xe_gt_clock.h"
+#include "xe_macros.h"
+#include "xe_mmio.h"
+
+static u32 read_reference_ts_freq(struct xe_gt *gt)
+{
+	u32 ts_override = xe_mmio_read32(gt, GEN9_TIMESTAMP_OVERRIDE.reg);
+	u32 base_freq, frac_freq;
+
+	base_freq = ((ts_override & GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_MASK) >>
+		     GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_SHIFT) + 1;
+	base_freq *= 1000000;
+
+	frac_freq = ((ts_override &
+		      GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_MASK) >>
+		     GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_SHIFT);
+	frac_freq = 1000000 / (frac_freq + 1);
+
+	return base_freq + frac_freq;
+}
+
+static u32 get_crystal_clock_freq(u32 rpm_config_reg)
+{
+	const u32 f19_2_mhz = 19200000;
+	const u32 f24_mhz = 24000000;
+	const u32 f25_mhz = 25000000;
+	const u32 f38_4_mhz = 38400000;
+	u32 crystal_clock =
+		(rpm_config_reg & GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
+		GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
+
+	switch (crystal_clock) {
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
+		return f24_mhz;
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
+		return f19_2_mhz;
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ:
+		return f38_4_mhz;
+	case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ:
+		return f25_mhz;
+	default:
+		XE_BUG_ON("NOT_POSSIBLE");
+		return 0;
+	}
+}
+
+int xe_gt_clock_init(struct xe_gt *gt)
+{
+	u32 ctc_reg = xe_mmio_read32(gt, CTC_MODE.reg);
+	u32 freq = 0;
+
+	/* Assuming gen11+ so assert this assumption is correct */
+	XE_BUG_ON(GRAPHICS_VER(gt_to_xe(gt)) < 11);
+
+	if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
+		freq = read_reference_ts_freq(gt);
+	} else {
+		u32 c0 = xe_mmio_read32(gt, RPM_CONFIG0.reg);
+
+		freq = get_crystal_clock_freq(c0);
+
+		/*
+		 * Now figure out how the command stream's timestamp
+		 * register increments from this frequency (it might
+		 * increment only every few clock cycle).
+		 */
+		freq >>= 3 - ((c0 & GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK) >>
+			      GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT);
+	}
+
+	gt->info.clock_freq = freq;
+	return 0;
+}