drm/xe/gsc: Query GSC compatibility version

The version is obtained via a dedicated MKHI GSC HECI command.
The compatibility version is what we want to match against for the GSC,
so we need to call the FW version checker after obtaining the version.

Since this is the first time we send a GSC HECI command via the GSCCS,
this patch also introduces common infrastructure to send such commands
to the GSC. Communication with the GSC FW is done via input/output
buffers, whose addresses are provided via a GSCCS command. The buffers
contain a generic header and a client-specific packet (e.g. PXP, HDCP);
the clients don't care about the header format and/or the GSCCS command
in the batch, they only care about their client-specific header. This
patch therefore introduces helpers that allow the callers to
automatically fill in the input header, submit the GSCCS job and decode
the output header, to make it so that the caller only needs to worry about
their client-specific input and output messages.

v3: squash of 2 separate patches ahead of merge, so that the common
functions and their first user are added at the same time

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: Suraj Kandpal <suraj.kandpal@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.Com> #v1
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 184 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_gsc_submit.c b/drivers/gpu/drm/xe/xe_gsc_submit.c
new file mode 100644
index 000000000000..8c5381e5913f
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_gsc_submit.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include "xe_gsc_submit.h"
+
+#include "abi/gsc_command_header_abi.h"
+#include "xe_bb.h"
+#include "xe_exec_queue.h"
+#include "xe_gt_printk.h"
+#include "xe_gt_types.h"
+#include "xe_map.h"
+#include "xe_sched_job.h"
+#include "instructions/xe_gsc_commands.h"
+#include "regs/xe_gsc_regs.h"
+
+#define GSC_HDR_SIZE (sizeof(struct intel_gsc_mtl_header)) /* shorthand define */
+
+#define mtl_gsc_header_wr(xe_, map_, offset_, field_, val_) \
+	xe_map_wr_field(xe_, map_, offset_, struct intel_gsc_mtl_header, field_, val_)
+
+#define mtl_gsc_header_rd(xe_, map_, offset_, field_) \
+	xe_map_rd_field(xe_, map_, offset_, struct intel_gsc_mtl_header, field_)
+
+/*
+ * GSC FW allows us to define the host_session_handle as we see fit, as long
+ * as we use unique identifier for each user, with handle 0 being reserved for
+ * kernel usage.
+ * To be able to differentiate which client subsystem owns the given session, we
+ * include the client id in the top 8 bits of the handle.
+ */
+#define HOST_SESSION_CLIENT_MASK GENMASK_ULL(63, 56)
+
+static struct xe_gt *
+gsc_to_gt(struct xe_gsc *gsc)
+{
+	return container_of(gsc, struct xe_gt, uc.gsc);
+}
+
+/**
+ * xe_gsc_emit_header - write the MTL GSC header in memory
+ * @xe: the Xe device
+ * @map: the iosys map to write to
+ * @offset: offset from the start of the map at which to write the header
+ * @heci_client_id: client id identifying the type of command (see abi for values)
+ * @host_session_id: host session ID of the caller
+ * @payload_size: size of the payload that follows the header
+ *
+ * Returns: offset memory location following the header
+ */
+u32 xe_gsc_emit_header(struct xe_device *xe, struct iosys_map *map, u32 offset,
+		       u8 heci_client_id, u64 host_session_id, u32 payload_size)
+{
+	xe_assert(xe, !(host_session_id & HOST_SESSION_CLIENT_MASK));
+
+	if (host_session_id)
+		host_session_id |= FIELD_PREP(HOST_SESSION_CLIENT_MASK, heci_client_id);
+
+	xe_map_memset(xe, map, offset, 0, GSC_HDR_SIZE);
+
+	mtl_gsc_header_wr(xe, map, offset, validity_marker, GSC_HECI_VALIDITY_MARKER);
+	mtl_gsc_header_wr(xe, map, offset, heci_client_id, heci_client_id);
+	mtl_gsc_header_wr(xe, map, offset, host_session_handle, host_session_id);
+	mtl_gsc_header_wr(xe, map, offset, header_version, MTL_GSC_HEADER_VERSION);
+	mtl_gsc_header_wr(xe, map, offset, message_size, payload_size + GSC_HDR_SIZE);
+
+	return offset + GSC_HDR_SIZE;
+};
+
+/**
+ * xe_gsc_check_and_update_pending - check the pending bit and update the input
+ * header with the retry handle from the output header
+ * @xe: the Xe device
+ * @in: the iosys map containing the input buffer
+ * @offset_in: offset within the iosys at which the input buffer is located
+ * @out: the iosys map containing the output buffer
+ * @offset_out: offset within the iosys at which the output buffer is located
+ *
+ * Returns: true if the pending bit was set, false otherwise
+ */
+bool xe_gsc_check_and_update_pending(struct xe_device *xe,
+				     struct iosys_map *in, u32 offset_in,
+				     struct iosys_map *out, u32 offset_out)
+{
+	if (mtl_gsc_header_rd(xe, out, offset_out, flags) & GSC_OUTFLAG_MSG_PENDING) {
+		u64 handle = mtl_gsc_header_rd(xe, out, offset_out, gsc_message_handle);
+
+		mtl_gsc_header_wr(xe, in, offset_in, gsc_message_handle, handle);
+
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * xe_gsc_read_out_header - reads and validates the output header and returns
+ * the offset of the reply following the header
+ * @xe: the Xe device
+ * @map: the iosys map containing the output buffer
+ * @offset: offset within the iosys at which the output buffer is located
+ * @min_payload_size: minimum size of the message excluding the gsc header
+ * @payload_offset: optional pointer to be set to the payload offset
+ *
+ * Returns: -errno value on failure, 0 otherwise
+ */
+int xe_gsc_read_out_header(struct xe_device *xe,
+			   struct iosys_map *map, u32 offset,
+			   u32 min_payload_size,
+			   u32 *payload_offset)
+{
+	u32 marker = mtl_gsc_header_rd(xe, map, offset, validity_marker);
+	u32 size = mtl_gsc_header_rd(xe, map, offset, message_size);
+	u32 payload_size = size - GSC_HDR_SIZE;
+
+	if (marker != GSC_HECI_VALIDITY_MARKER)
+		return -EPROTO;
+
+	if (size < GSC_HDR_SIZE || payload_size < min_payload_size)
+		return -ENODATA;
+
+	if (payload_offset)
+		*payload_offset = offset + GSC_HDR_SIZE;
+
+	return 0;
+}
+
+/**
+ * xe_gsc_pkt_submit_kernel - submit a kernel heci pkt to the GSC
+ * @gsc: the GSC uC
+ * @addr_in: GGTT address of the message to send to the GSC
+ * @size_in: size of the message to send to the GSC
+ * @addr_out: GGTT address for the GSC to write the reply to
+ * @size_out: size of the memory reserved for the reply
+ */
+int xe_gsc_pkt_submit_kernel(struct xe_gsc *gsc, u64 addr_in, u32 size_in,
+			     u64 addr_out, u32 size_out)
+{
+	struct xe_gt *gt = gsc_to_gt(gsc);
+	struct xe_bb *bb;
+	struct xe_sched_job *job;
+	struct dma_fence *fence;
+	long timeout;
+
+	if (size_in < GSC_HDR_SIZE)
+		return -ENODATA;
+
+	if (size_out < GSC_HDR_SIZE)
+		return -ENOMEM;
+
+	bb = xe_bb_new(gt, 8, false);
+	if (IS_ERR(bb))
+		return PTR_ERR(bb);
+
+	bb->cs[bb->len++] = GSC_HECI_CMD_PKT;
+	bb->cs[bb->len++] = lower_32_bits(addr_in);
+	bb->cs[bb->len++] = upper_32_bits(addr_in);
+	bb->cs[bb->len++] = size_in;
+	bb->cs[bb->len++] = lower_32_bits(addr_out);
+	bb->cs[bb->len++] = upper_32_bits(addr_out);
+	bb->cs[bb->len++] = size_out;
+	bb->cs[bb->len++] = 0;
+
+	job = xe_bb_create_job(gsc->q, bb);
+	if (IS_ERR(job)) {
+		xe_bb_free(bb, NULL);
+		return PTR_ERR(job);
+	}
+
+	xe_sched_job_arm(job);
+	fence = dma_fence_get(&job->drm.s_fence->finished);
+	xe_sched_job_push(job);
+
+	timeout = dma_fence_wait_timeout(fence, false, HZ);
+	dma_fence_put(fence);
+	xe_bb_free(bb, NULL);
+	if (timeout < 0)
+		return timeout;
+	else if (!timeout)
+		return -ETIME;
+
+	return 0;
+}