[PATCH v4 06/28] drm/xe/pf: Add helpers for migration data packet allocation / free

["Michał Winiarski" <michal.winiarski@intel.com>]

Now that it's possible to free the packets - connect the restore
handling logic with the ring.
The helpers will also be used in upcoming changes that will start
producing migration data packets.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
---
 drivers/gpu/drm/xe/Makefile                   |   1 +
 drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c   |  11 +-
 drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c |  33 ++++-
 drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h |   1 +
 drivers/gpu/drm/xe/xe_sriov_packet.c          | 129 ++++++++++++++++++
 drivers/gpu/drm/xe/xe_sriov_packet.h          |  30 ++++
 6 files changed, 202 insertions(+), 3 deletions(-)
 create mode 100644 drivers/gpu/drm/xe/xe_sriov_packet.c
 create mode 100644 drivers/gpu/drm/xe/xe_sriov_packet.h

diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index cb6b30fd8c2d8..e4b273b025d2a 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -174,6 +174,7 @@ xe-$(CONFIG_PCI_IOV) += \
 	xe_lmtt_2l.o \
 	xe_lmtt_ml.o \
 	xe_pci_sriov.o \
+	xe_sriov_packet.o \
 	xe_sriov_pf.o \
 	xe_sriov_pf_control.o \
 	xe_sriov_pf_debugfs.o \
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
index db57f9d9b491f..25937592bc42f 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_control.c
@@ -18,6 +18,7 @@
 #include "xe_gt_sriov_printk.h"
 #include "xe_guc_ct.h"
 #include "xe_sriov.h"
+#include "xe_sriov_packet.h"
 #include "xe_sriov_pf_control.h"
 #include "xe_sriov_pf_migration.h"
 #include "xe_sriov_pf_service.h"
@@ -852,6 +853,8 @@ int xe_gt_sriov_pf_control_resume_vf(struct xe_gt *gt, unsigned int vfid)
 static void pf_exit_vf_save_wip(struct xe_gt *gt, unsigned int vfid)
 {
 	if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WIP)) {
+		xe_gt_sriov_pf_migration_ring_free(gt, vfid);
+
 		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_PROCESS_DATA);
 		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_WAIT_DATA);
 		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_SAVE_DATA_DONE);
@@ -1074,6 +1077,8 @@ int xe_gt_sriov_pf_control_finish_save_vf(struct xe_gt *gt, unsigned int vfid)
 static void pf_exit_vf_restore_wip(struct xe_gt *gt, unsigned int vfid)
 {
 	if (pf_exit_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WIP)) {
+		xe_gt_sriov_pf_migration_ring_free(gt, vfid);
+
 		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_PROCESS_DATA);
 		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_WAIT_DATA);
 		pf_escape_vf_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_DATA_DONE);
@@ -1108,6 +1113,8 @@ static int pf_handle_vf_restore_data(struct xe_gt *gt, unsigned int vfid)
 
 	xe_gt_sriov_notice(gt, "Skipping VF%u unknown data type: %d\n", vfid, data->type);
 
+	xe_sriov_packet_free(data);
+
 	return 0;
 }
 
@@ -1201,8 +1208,10 @@ int xe_gt_sriov_pf_control_restore_data_done(struct xe_gt *gt, unsigned int vfid
  */
 int xe_gt_sriov_pf_control_process_restore_data(struct xe_gt *gt, unsigned int vfid)
 {
-	if (!pf_expect_vf_not_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_FAILED))
+	if (!pf_expect_vf_not_state(gt, vfid, XE_GT_SRIOV_STATE_RESTORE_FAILED)) {
+		xe_gt_sriov_pf_migration_ring_free(gt, vfid);
 		return -EIO;
+	}
 
 	pf_exit_vf_restore_wait_data(gt, vfid);
 
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
index d9ca9ea737dcc..c492677db28d9 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.c
@@ -14,6 +14,7 @@
 #include "xe_guc.h"
 #include "xe_guc_ct.h"
 #include "xe_sriov.h"
+#include "xe_sriov_packet.h"
 #include "xe_sriov_pf_migration.h"
 
 #define XE_GT_SRIOV_PF_MIGRATION_RING_SIZE 5
@@ -418,6 +419,25 @@ bool xe_gt_sriov_pf_migration_ring_full(struct xe_gt *gt, unsigned int vfid)
 	return ptr_ring_full(&pf_pick_gt_migration(gt, vfid)->ring);
 }
 
+/**
+ * xe_gt_sriov_pf_migration_ring_free() - Consume and free all data in migration ring
+ * @gt: the &xe_gt
+ * @vfid: the VF identifier
+ */
+void xe_gt_sriov_pf_migration_ring_free(struct xe_gt *gt, unsigned int vfid)
+{
+	struct xe_gt_sriov_migration_data *migration = pf_pick_gt_migration(gt, vfid);
+	struct xe_sriov_packet *data;
+
+	if (ptr_ring_empty(&migration->ring))
+		return;
+
+	xe_gt_sriov_notice(gt, "VF%u unprocessed migration data left in the ring!\n", vfid);
+
+	while ((data = ptr_ring_consume(&migration->ring)))
+		xe_sriov_packet_free(data);
+}
+
 /**
  * xe_gt_sriov_pf_migration_save_produce() - Add VF save data packet to migration ring.
  * @gt: the &xe_gt
@@ -544,8 +564,10 @@ xe_gt_sriov_pf_migration_save_consume(struct xe_gt *gt, unsigned int vfid)
 	data = ptr_ring_consume(&migration->ring);
 	if (data) {
 		ret = xe_gt_sriov_pf_control_process_save_data(gt, vfid);
-		if (ret)
+		if (ret) {
+			xe_sriov_packet_free(data);
 			return ERR_PTR(ret);
+		}
 
 		return data;
 	}
@@ -559,11 +581,18 @@ xe_gt_sriov_pf_migration_save_consume(struct xe_gt *gt, unsigned int vfid)
 	return ERR_PTR(-EAGAIN);
 }
 
+static void pf_mig_packet_destroy(void *ptr)
+{
+	struct xe_sriov_packet *data = ptr;
+
+	xe_sriov_packet_free(data);
+}
+
 static void action_ring_cleanup(void *arg)
 {
 	struct ptr_ring *r = arg;
 
-	ptr_ring_cleanup(r, NULL);
+	ptr_ring_cleanup(r, pf_mig_packet_destroy);
 }
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
index b29d34a835b71..b4c7b5dc9e914 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_migration.h
@@ -17,6 +17,7 @@ int xe_gt_sriov_pf_migration_restore_guc_state(struct xe_gt *gt, unsigned int vf
 
 bool xe_gt_sriov_pf_migration_ring_empty(struct xe_gt *gt, unsigned int vfid);
 bool xe_gt_sriov_pf_migration_ring_full(struct xe_gt *gt, unsigned int vfid);
+void xe_gt_sriov_pf_migration_ring_free(struct xe_gt *gt, unsigned int vfid);
 
 int xe_gt_sriov_pf_migration_save_produce(struct xe_gt *gt, unsigned int vfid,
 					  struct xe_sriov_packet *data);
diff --git a/drivers/gpu/drm/xe/xe_sriov_packet.c b/drivers/gpu/drm/xe/xe_sriov_packet.c
new file mode 100644
index 0000000000000..2cdcfb2073d00
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_sriov_packet.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include "xe_bo.h"
+#include "xe_device.h"
+#include "xe_sriov_packet.h"
+
+static bool pkt_needs_bo(struct xe_sriov_packet *data)
+{
+	return data->type == XE_SRIOV_PACKET_TYPE_VRAM;
+}
+
+/**
+ * xe_sriov_packet_alloc() - Allocate migration data packet
+ * @xe: the &xe_device
+ *
+ * Only allocates the "outer" structure, without initializing the migration
+ * data backing storage.
+ *
+ * Return: Pointer to &xe_sriov_packet on success,
+ *         NULL in case of error.
+ */
+struct xe_sriov_packet *xe_sriov_packet_alloc(struct xe_device *xe)
+{
+	struct xe_sriov_packet *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return NULL;
+
+	data->xe = xe;
+	data->hdr_remaining = sizeof(data->hdr);
+
+	return data;
+}
+
+/**
+ * xe_sriov_packet_free() - Free migration data packet.
+ * @data: the &xe_sriov_packet
+ */
+void xe_sriov_packet_free(struct xe_sriov_packet *data)
+{
+	if (IS_ERR_OR_NULL(data))
+		return;
+
+	if (pkt_needs_bo(data))
+		xe_bo_unpin_map_no_vm(data->bo);
+	else
+		kvfree(data->buff);
+
+	kfree(data);
+}
+
+static int mig_pkt_init(struct xe_sriov_packet *data)
+{
+	struct xe_gt *gt = xe_device_get_gt(data->xe, data->gt);
+
+	if (data->size == 0)
+		return 0;
+
+	if (pkt_needs_bo(data)) {
+		struct xe_bo *bo;
+
+		bo = xe_bo_create_pin_map_novm(data->xe, gt->tile, PAGE_ALIGN(data->size),
+					       ttm_bo_type_kernel,
+					       XE_BO_FLAG_SYSTEM | XE_BO_FLAG_PINNED, false);
+		if (IS_ERR(bo))
+			return PTR_ERR(bo);
+
+		data->bo = bo;
+		data->vaddr = bo->vmap.vaddr;
+	} else {
+		void *buff = kvzalloc(data->size, GFP_KERNEL);
+
+		if (!buff)
+			return -ENOMEM;
+
+		data->buff = buff;
+		data->vaddr = buff;
+	}
+
+	return 0;
+}
+
+#define XE_SRIOV_PACKET_SUPPORTED_VERSION 1
+/**
+ * xe_sriov_packet_init() - Initialize migration packet header and backing storage.
+ * @data: the &xe_sriov_packet
+ * @tile_id: tile identifier
+ * @gt_id: GT identifier
+ * @type: &xe_sriov_packet_type
+ * @offset: offset of data packet payload (within wider resource)
+ * @size: size of data packet payload
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_sriov_packet_init(struct xe_sriov_packet *data, u8 tile_id, u8 gt_id,
+			 enum xe_sriov_packet_type type, loff_t offset, size_t size)
+{
+	data->version = XE_SRIOV_PACKET_SUPPORTED_VERSION;
+	data->type = type;
+	data->tile = tile_id;
+	data->gt = gt_id;
+	data->offset = offset;
+	data->size = size;
+	data->remaining = size;
+
+	return mig_pkt_init(data);
+}
+
+/**
+ * xe_sriov_packet_init_from_hdr() - Initialize migration packet backing storage based on header.
+ * @data: the &xe_sriov_packet
+ *
+ * Header data is expected to be filled prior to calling this function.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int xe_sriov_packet_init_from_hdr(struct xe_sriov_packet *data)
+{
+	if (data->version != XE_SRIOV_PACKET_SUPPORTED_VERSION)
+		return -EINVAL;
+
+	data->remaining = data->size;
+
+	return mig_pkt_init(data);
+}
diff --git a/drivers/gpu/drm/xe/xe_sriov_packet.h b/drivers/gpu/drm/xe/xe_sriov_packet.h
new file mode 100644
index 0000000000000..2c5a49897d763
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_sriov_packet.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#ifndef _XE_SRIOV_PACKET_H_
+#define _XE_SRIOV_PACKET_H_
+
+#include <linux/types.h>
+
+struct xe_device;
+
+enum xe_sriov_packet_type {
+	/* Skipping 0 to catch uninitialized data */
+	XE_SRIOV_PACKET_TYPE_DESCRIPTOR = 1,
+	XE_SRIOV_PACKET_TYPE_TRAILER,
+	XE_SRIOV_PACKET_TYPE_GGTT,
+	XE_SRIOV_PACKET_TYPE_MMIO,
+	XE_SRIOV_PACKET_TYPE_GUC,
+	XE_SRIOV_PACKET_TYPE_VRAM,
+};
+
+struct xe_sriov_packet *xe_sriov_packet_alloc(struct xe_device *xe);
+void xe_sriov_packet_free(struct xe_sriov_packet *data);
+
+int xe_sriov_packet_init(struct xe_sriov_packet *data, u8 tile_id, u8 gt_id,
+			 enum xe_sriov_packet_type, loff_t offset, size_t size);
+int xe_sriov_packet_init_from_hdr(struct xe_sriov_packet *data);
+
+#endif
-- 
2.51.2