[PATCH v2 03/11] coco: guest: arm64: Add support for guest initiated TDI bind/unbind

["Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>]

Add RHI for VDEV_SET_TDI_STATE

Note: This is not part of RHI spec. This is a POC implementation
and will be later converted to correct interface defined by RHI.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 drivers/virt/coco/arm-cca-guest/Makefile  |  2 +-
 drivers/virt/coco/arm-cca-guest/arm-cca.c |  8 ++++-
 drivers/virt/coco/arm-cca-guest/rsi-da.c  | 36 +++++++++++++++++++++++
 drivers/virt/coco/arm-cca-guest/rsi-da.h  |  2 ++
 4 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 drivers/virt/coco/arm-cca-guest/rsi-da.c

diff --git a/drivers/virt/coco/arm-cca-guest/Makefile b/drivers/virt/coco/arm-cca-guest/Makefile
index 04d26e398a1d..146af69d0362 100644
--- a/drivers/virt/coco/arm-cca-guest/Makefile
+++ b/drivers/virt/coco/arm-cca-guest/Makefile
@@ -2,4 +2,4 @@
 #
 obj-$(CONFIG_ARM_CCA_GUEST) += arm-cca-guest.o
 
-arm-cca-guest-y +=  arm-cca.o rhi-da.o
+arm-cca-guest-y +=  arm-cca.o rhi-da.o rsi-da.o
diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca.c b/drivers/virt/coco/arm-cca-guest/arm-cca.c
index 26be2e8fe182..f4c9e529c43e 100644
--- a/drivers/virt/coco/arm-cca-guest/arm-cca.c
+++ b/drivers/virt/coco/arm-cca-guest/arm-cca.c
@@ -208,13 +208,19 @@ static struct pci_tsm *cca_tsm_lock(struct tsm_dev *tsm_dev, struct pci_dev *pde
 	if (ret)
 		return ERR_PTR(ret);
 
-	return ERR_PTR(-EIO);
+	ret = cca_device_lock(pdev);
+	if (ret)
+		return ERR_PTR(-EIO);
+
+	return &no_free_ptr(cca_dsc)->pci.base_tsm;
 }
 
 static void cca_tsm_unlock(struct pci_tsm *tsm)
 {
 	struct cca_guest_dsc *cca_dsc = to_cca_guest_dsc(tsm->pdev);
 
+	cca_device_unlock(tsm->pdev);
+
 	kfree(cca_dsc);
 }
 
diff --git a/drivers/virt/coco/arm-cca-guest/rsi-da.c b/drivers/virt/coco/arm-cca-guest/rsi-da.c
new file mode 100644
index 000000000000..6770861629f2
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-guest/rsi-da.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 ARM Ltd.
+ */
+
+#include <linux/pci.h>
+#include <asm/rsi_cmds.h>
+
+#include "rsi-da.h"
+#include "rhi-da.h"
+
+#define PCI_TDISP_MESSAGE_VERSION_10	0x10
+
+int cca_device_lock(struct pci_dev *pdev)
+{
+	int ret;
+
+	ret = rhi_vdev_set_tdi_state(pdev, RHI_DA_TDI_CONFIG_LOCKED);
+	if (ret) {
+		pci_err(pdev, "failed to lock the device (%u)\n", ret);
+		return -EIO;
+	}
+	return 0;
+}
+
+int cca_device_unlock(struct pci_dev *pdev)
+{
+	int ret;
+
+	ret = rhi_vdev_set_tdi_state(pdev, RHI_DA_TDI_CONFIG_UNLOCKED);
+	if (ret) {
+		pci_err(pdev, "failed to unlock the device (%u)\n", ret);
+		return -EIO;
+	}
+	return 0;
+}
diff --git a/drivers/virt/coco/arm-cca-guest/rsi-da.h b/drivers/virt/coco/arm-cca-guest/rsi-da.h
index 5ad3b740710e..d1f4641a0fa1 100644
--- a/drivers/virt/coco/arm-cca-guest/rsi-da.h
+++ b/drivers/virt/coco/arm-cca-guest/rsi-da.h
@@ -29,4 +29,6 @@ static inline int rsi_vdev_id(struct pci_dev *pdev)
 	       PCI_DEVID(pdev->bus->number, pdev->devfn);
 }
 
+int cca_device_lock(struct pci_dev *pdev);
+int cca_device_unlock(struct pci_dev *pdev);
 #endif
-- 
2.43.0