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, 296 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_pcode.c b/drivers/gpu/drm/xe/xe_pcode.c
new file mode 100644
index 000000000000..236159c8a6c0
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_pcode.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "xe_pcode_api.h"
+#include "xe_pcode.h"
+
+#include "xe_gt.h"
+#include "xe_mmio.h"
+
+#include <linux/errno.h>
+
+/**
+ * DOC: PCODE
+ *
+ * Xe PCODE is the component responsible for interfacing with the PCODE
+ * firmware.
+ * It shall provide a very simple ABI to other Xe components, but be the
+ * single and consolidated place that will communicate with PCODE. All read
+ * and write operations to PCODE will be internal and private to this component.
+ *
+ * What's next:
+ * - PCODE hw metrics
+ * - PCODE for display operations
+ */
+
+static int pcode_mailbox_status(struct xe_gt *gt)
+{
+	u32 err;
+	static const struct pcode_err_decode err_decode[] = {
+		[PCODE_ILLEGAL_CMD] = {-ENXIO, "Illegal Command"},
+		[PCODE_TIMEOUT] = {-ETIMEDOUT, "Timed out"},
+		[PCODE_ILLEGAL_DATA] = {-EINVAL, "Illegal Data"},
+		[PCODE_ILLEGAL_SUBCOMMAND] = {-ENXIO, "Illegal Subcommand"},
+		[PCODE_LOCKED] = {-EBUSY, "PCODE Locked"},
+		[PCODE_GT_RATIO_OUT_OF_RANGE] = {-EOVERFLOW,
+			"GT ratio out of range"},
+		[PCODE_REJECTED] = {-EACCES, "PCODE Rejected"},
+		[PCODE_ERROR_MASK] = {-EPROTO, "Unknown"},
+	};
+
+	lockdep_assert_held(&gt->pcode.lock);
+
+	err = xe_mmio_read32(gt, PCODE_MAILBOX.reg) & PCODE_ERROR_MASK;
+	if (err) {
+		drm_err(&gt_to_xe(gt)->drm, "PCODE Mailbox failed: %d %s", err,
+			err_decode[err].str ?: "Unknown");
+		return err_decode[err].errno ?: -EPROTO;
+	}
+
+	return 0;
+}
+
+static bool pcode_mailbox_done(struct xe_gt *gt)
+{
+	lockdep_assert_held(&gt->pcode.lock);
+	return (xe_mmio_read32(gt, PCODE_MAILBOX.reg) & PCODE_READY) == 0;
+}
+
+static int pcode_mailbox_rw(struct xe_gt *gt, u32 mbox, u32 *data0, u32 *data1,
+			    unsigned int timeout, bool return_data, bool atomic)
+{
+	lockdep_assert_held(&gt->pcode.lock);
+
+	if (!pcode_mailbox_done(gt))
+		return -EAGAIN;
+
+	xe_mmio_write32(gt, PCODE_DATA0.reg, *data0);
+	xe_mmio_write32(gt, PCODE_DATA1.reg, data1 ? *data1 : 0);
+	xe_mmio_write32(gt, PCODE_MAILBOX.reg, PCODE_READY | mbox);
+
+	if (atomic)
+		_wait_for_atomic(pcode_mailbox_done(gt), timeout * 1000, 1);
+	else
+		wait_for(pcode_mailbox_done(gt), timeout);
+
+	if (return_data) {
+		*data0 = xe_mmio_read32(gt, PCODE_DATA0.reg);
+		if (data1)
+			*data1 = xe_mmio_read32(gt, PCODE_DATA1.reg);
+	}
+
+	return pcode_mailbox_status(gt);
+}
+
+int xe_pcode_write_timeout(struct xe_gt *gt, u32 mbox, u32 data, int timeout)
+{
+	int err;
+
+	mutex_lock(&gt->pcode.lock);
+	err = pcode_mailbox_rw(gt, mbox, &data, NULL, timeout, false, false);
+	mutex_unlock(&gt->pcode.lock);
+
+	return err;
+}
+
+int xe_pcode_read(struct xe_gt *gt, u32 mbox, u32 *val, u32 *val1)
+{
+	int err;
+
+	mutex_lock(&gt->pcode.lock);
+	err = pcode_mailbox_rw(gt, mbox, val, val1, 1, true, false);
+	mutex_unlock(&gt->pcode.lock);
+
+	return err;
+}
+
+static bool xe_pcode_try_request(struct xe_gt *gt, u32 mbox,
+				  u32 request, u32 reply_mask, u32 reply,
+				  u32 *status, bool atomic)
+{
+	*status = pcode_mailbox_rw(gt, mbox, &request, NULL, 1, true, atomic);
+
+	return (*status == 0) && ((request & reply_mask) == reply);
+}
+
+/**
+ * xe_pcode_request - send PCODE request until acknowledgment
+ * @gt: gt
+ * @mbox: PCODE mailbox ID the request is targeted for
+ * @request: request ID
+ * @reply_mask: mask used to check for request acknowledgment
+ * @reply: value used to check for request acknowledgment
+ * @timeout_base_ms: timeout for polling with preemption enabled
+ *
+ * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
+ * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
+ * The request is acknowledged once the PCODE reply dword equals @reply after
+ * applying @reply_mask. Polling is first attempted with preemption enabled
+ * for @timeout_base_ms and if this times out for another 50 ms with
+ * preemption disabled.
+ *
+ * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
+ * other error as reported by PCODE.
+ */
+int xe_pcode_request(struct xe_gt *gt, u32 mbox, u32 request,
+		      u32 reply_mask, u32 reply, int timeout_base_ms)
+{
+	u32 status;
+	int ret;
+	bool atomic = false;
+
+	mutex_lock(&gt->pcode.lock);
+
+#define COND \
+	xe_pcode_try_request(gt, mbox, request, reply_mask, reply, &status, atomic)
+
+	/*
+	 * Prime the PCODE by doing a request first. Normally it guarantees
+	 * that a subsequent request, at most @timeout_base_ms later, succeeds.
+	 * _wait_for() doesn't guarantee when its passed condition is evaluated
+	 * first, so send the first request explicitly.
+	 */
+	if (COND) {
+		ret = 0;
+		goto out;
+	}
+	ret = _wait_for(COND, timeout_base_ms * 1000, 10, 10);
+	if (!ret)
+		goto out;
+
+	/*
+	 * The above can time out if the number of requests was low (2 in the
+	 * worst case) _and_ PCODE was busy for some reason even after a
+	 * (queued) request and @timeout_base_ms delay. As a workaround retry
+	 * the poll with preemption disabled to maximize the number of
+	 * requests. Increase the timeout from @timeout_base_ms to 50ms to
+	 * account for interrupts that could reduce the number of these
+	 * requests, and for any quirks of the PCODE firmware that delays
+	 * the request completion.
+	 */
+	drm_err(&gt_to_xe(gt)->drm,
+		"PCODE timeout, retrying with preemption disabled\n");
+	drm_WARN_ON_ONCE(&gt_to_xe(gt)->drm, timeout_base_ms > 1);
+	preempt_disable();
+	atomic = true;
+	ret = wait_for_atomic(COND, 50);
+	atomic = false;
+	preempt_enable();
+
+out:
+	mutex_unlock(&gt->pcode.lock);
+	return status ? status : ret;
+#undef COND
+}
+/**
+ * xe_pcode_init_min_freq_table - Initialize PCODE's QOS frequency table
+ * @gt: gt instance
+ * @min_gt_freq: Minimal (RPn) GT frequency in units of 50MHz.
+ * @max_gt_freq: Maximal (RP0) GT frequency in units of 50MHz.
+ *
+ * This function initialize PCODE's QOS frequency table for a proper minimal
+ * frequency/power steering decision, depending on the current requested GT
+ * frequency. For older platforms this was a more complete table including
+ * the IA freq. However for the latest platforms this table become a simple
+ * 1-1 Ring vs GT frequency. Even though, without setting it, PCODE might
+ * not take the right decisions for some memory frequencies and affect latency.
+ *
+ * It returns 0 on success, and -ERROR number on failure, -EINVAL if max
+ * frequency is higher then the minimal, and other errors directly translated
+ * from the PCODE Error returs:
+ * - -ENXIO: "Illegal Command"
+ * - -ETIMEDOUT: "Timed out"
+ * - -EINVAL: "Illegal Data"
+ * - -ENXIO, "Illegal Subcommand"
+ * - -EBUSY: "PCODE Locked"
+ * - -EOVERFLOW, "GT ratio out of range"
+ * - -EACCES, "PCODE Rejected"
+ * - -EPROTO, "Unknown"
+ */
+int xe_pcode_init_min_freq_table(struct xe_gt *gt, u32 min_gt_freq,
+				 u32 max_gt_freq)
+{
+	int ret;
+	u32 freq;
+
+	if (IS_DGFX(gt_to_xe(gt)))
+		return 0;
+
+	if (max_gt_freq <= min_gt_freq)
+		return -EINVAL;
+
+	mutex_lock(&gt->pcode.lock);
+	for (freq = min_gt_freq; freq <= max_gt_freq; freq++) {
+		u32 data = freq << PCODE_FREQ_RING_RATIO_SHIFT | freq;
+
+		ret = pcode_mailbox_rw(gt, PCODE_WRITE_MIN_FREQ_TABLE,
+				       &data, NULL, 1, false, false);
+		if (ret)
+			goto unlock;
+	}
+
+unlock:
+	mutex_unlock(&gt->pcode.lock);
+	return ret;
+}
+
+static bool pcode_dgfx_status_complete(struct xe_gt *gt)
+{
+	u32 data = DGFX_GET_INIT_STATUS;
+	int status = pcode_mailbox_rw(gt, DGFX_PCODE_STATUS,
+				      &data, NULL, 1, true, false);
+
+	return status == 0 &&
+		(data & DGFX_INIT_STATUS_COMPLETE) == DGFX_INIT_STATUS_COMPLETE;
+}
+
+/**
+ * xe_pcode_init - Ensure PCODE is initialized
+ * @gt: gt instance
+ *
+ * This function ensures that PCODE is properly initialized. To be called during
+ * probe and resume paths.
+ *
+ * It returns 0 on success, and -error number on failure.
+ */
+int xe_pcode_init(struct xe_gt *gt)
+{
+	int timeout = 180000; /* 3 min */
+	int ret;
+
+	if (!IS_DGFX(gt_to_xe(gt)))
+		return 0;
+
+	mutex_lock(&gt->pcode.lock);
+	ret = wait_for(pcode_dgfx_status_complete(gt), timeout);
+	mutex_unlock(&gt->pcode.lock);
+
+	if (ret)
+		drm_err(&gt_to_xe(gt)->drm,
+			"PCODE initialization timedout after: %d min\n",
+			timeout / 60000);
+
+	return ret;
+}
+
+/**
+ * xe_pcode_probe - Prepare xe_pcode and also ensure PCODE is initialized.
+ * @gt: gt instance
+ *
+ * This function initializes the xe_pcode component, and when needed, it ensures
+ * that PCODE has properly performed its initialization and it is really ready
+ * to go. To be called once only during probe.
+ *
+ * It returns 0 on success, and -error number on failure.
+ */
+int xe_pcode_probe(struct xe_gt *gt)
+{
+	mutex_init(&gt->pcode.lock);
+
+	if (!IS_DGFX(gt_to_xe(gt)))
+		return 0;
+
+	return xe_pcode_init(gt);
+}