[RFC PATCH v1 12/38] coco: host: arm64: CCA host platform device driver

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

This driver registers the pci_tsm_ops with tsm subsystem.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 drivers/virt/coco/Kconfig                |   2 +
 drivers/virt/coco/Makefile               |   1 +
 drivers/virt/coco/arm-cca-host/Kconfig   |  12 ++
 drivers/virt/coco/arm-cca-host/Makefile  |   5 +
 drivers/virt/coco/arm-cca-host/arm-cca.c | 209 +++++++++++++++++++++++
 drivers/virt/coco/arm-cca-host/rmm-da.h  |  29 ++++
 6 files changed, 258 insertions(+)
 create mode 100644 drivers/virt/coco/arm-cca-host/Kconfig
 create mode 100644 drivers/virt/coco/arm-cca-host/Makefile
 create mode 100644 drivers/virt/coco/arm-cca-host/arm-cca.c
 create mode 100644 drivers/virt/coco/arm-cca-host/rmm-da.h

diff --git a/drivers/virt/coco/Kconfig b/drivers/virt/coco/Kconfig
index 57248b088545..43e9508301bf 100644
--- a/drivers/virt/coco/Kconfig
+++ b/drivers/virt/coco/Kconfig
@@ -15,5 +15,7 @@ source "drivers/virt/coco/arm-cca-guest/Kconfig"
 
 source "drivers/virt/coco/guest/Kconfig"
 
+source "drivers/virt/coco/arm-cca-host/Kconfig"
+
 config TSM
 	tristate
diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile
index 04e124b2d7cf..d0a859dd9eaf 100644
--- a/drivers/virt/coco/Makefile
+++ b/drivers/virt/coco/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_ARM_CCA_GUEST)	+= arm-cca-guest/
 
 obj-$(CONFIG_TSM) 		+= tsm-core.o
 obj-y				+= guest/
+obj-$(CONFIG_ARM_CCA_HOST)	+= arm-cca-host/
diff --git a/drivers/virt/coco/arm-cca-host/Kconfig b/drivers/virt/coco/arm-cca-host/Kconfig
new file mode 100644
index 000000000000..0f19fbf47613
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-host/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# TSM (TEE Security Manager) host drivers
+#
+config ARM_CCA_HOST
+	tristate "Arm CCA Host driver"
+	depends on ARM64
+	depends on PCI_TSM
+	select TSM
+
+	help
+	  The driver provides TSM backend for ARM CCA
diff --git a/drivers/virt/coco/arm-cca-host/Makefile b/drivers/virt/coco/arm-cca-host/Makefile
new file mode 100644
index 000000000000..ad353b07e95a
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-host/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+obj-$(CONFIG_ARM_CCA_HOST) += arm-cca-host.o
+
+arm-cca-host-$(CONFIG_TSM) +=  arm-cca.o
diff --git a/drivers/virt/coco/arm-cca-host/arm-cca.c b/drivers/virt/coco/arm-cca-host/arm-cca.c
new file mode 100644
index 000000000000..c8b0e6db1f47
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-host/arm-cca.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 ARM Ltd.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/pci-tsm.h>
+#include <linux/pci-ide.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/tsm.h>
+#include <linux/vmalloc.h>
+
+#include "rmm-da.h"
+
+/* Number of streams that we can support at the hostbridge level */
+#define CCA_HB_PLATFORM_STREAMS 4
+
+/* Total number of stream id supported at root port level */
+#define MAX_STREAM_ID	256
+
+DEFINE_FREE(vfree, void *, if (!IS_ERR_OR_NULL(_T)) vfree(_T))
+static struct pci_tsm *cca_tsm_pci_probe(struct pci_dev *pdev)
+{
+	int rc;
+	struct pci_host_bridge *hb;
+	struct cca_host_dsc_pf0 *dsc_pf0 __free(vfree) = NULL;
+
+	if (pdev->is_virtfn)
+		return NULL;
+
+	if (!is_pci_tsm_pf0(pdev)) {
+		struct pci_tsm *tsm = kzalloc(sizeof(*tsm), GFP_KERNEL);
+
+		if (!tsm)
+			goto err_out;
+
+		pci_tsm_initialize(pdev, tsm);
+		return tsm;
+	}
+
+	if (!pdev->ide_cap)
+		goto err_out;
+
+	dsc_pf0 = vcalloc(sizeof(*dsc_pf0), GFP_KERNEL);
+	if (!dsc_pf0)
+		goto err_out;
+
+	rc = pci_tsm_pf0_initialize(pdev, &dsc_pf0->pci);
+	if (rc)
+		return NULL;
+	/*
+	 * FIXME!!
+	 * update the hostbridge details. This should go into
+	 * some host bridge probe/init routine.
+	 * than the selective index supported by the endpoint
+	 */
+	hb = pci_find_host_bridge(pdev->bus);
+	pci_ide_init_nr_streams(hb, CCA_HB_PLATFORM_STREAMS);
+
+	pci_info(pdev, "tsm enabled\n");
+	return &no_free_ptr(dsc_pf0)->pci.tsm;
+
+err_out:
+	return NULL;
+}
+
+static void cca_tsm_pci_remove(struct pci_tsm *tsm)
+{
+	struct pci_dev *pdev = tsm->pdev;
+	struct cca_host_dsc_pf0 *dsc_pf0;
+
+	if (WARN_ON(pdev->is_virtfn))
+		return;
+
+	if (!is_pci_tsm_pf0(pdev)) {
+
+		pci_dbg(tsm->pdev, "tsm disabled\n");
+		kfree(pdev->tsm);
+		return;
+	}
+
+	dsc_pf0 = to_cca_dsc_pf0(pdev);
+	pci_dbg(tsm->pdev, "tsm disabled\n");
+	vfree(dsc_pf0);
+}
+
+/* per root port unique with multiple restrictions. For now global */
+static DECLARE_BITMAP(cca_stream_ids, MAX_STREAM_ID);
+
+static int cca_tsm_connect(struct pci_dev *pdev)
+{
+	struct pci_dev *rp = pcie_find_root_port(pdev);
+	struct cca_host_dsc_pf0 *dsc_pf0;
+	struct pci_ide *ide;
+	int rc, stream_id;
+
+	/* Only function 0 supports connect in host */
+	if (WARN_ON(!is_pci_tsm_pf0(pdev)))
+		return -EIO;
+
+	dsc_pf0 = to_cca_dsc_pf0(pdev);
+	/* Allocate stream id */
+	stream_id = find_first_zero_bit(cca_stream_ids, MAX_STREAM_ID);
+	if (stream_id == MAX_STREAM_ID)
+		return -EBUSY;
+	set_bit(stream_id, cca_stream_ids);
+
+	ide = pci_ide_stream_alloc(pdev);
+	if (!ide) {
+		rc = -ENOMEM;
+		goto err_stream_alloc;
+	}
+
+	dsc_pf0->sel_stream = ide;
+	ide->stream_id = stream_id;
+	rc = pci_ide_stream_register(ide);
+	if (rc)
+		goto err_stream;
+
+	pci_ide_stream_setup(pdev, ide);
+	pci_ide_stream_setup(rp, ide);
+
+	rc = tsm_ide_stream_register(pdev, ide);
+	if (rc)
+		goto err_tsm;
+
+	/*
+	 * Once ide is setup enable the stream at endpoint
+	 * Root port will be done by RMM
+	 */
+	pci_ide_stream_enable(pdev, ide);
+	return 0;
+
+err_tsm:
+	pci_ide_stream_teardown(rp, ide);
+	pci_ide_stream_teardown(pdev, ide);
+	pci_ide_stream_unregister(ide);
+err_stream:
+	pci_ide_stream_free(ide);
+err_stream_alloc:
+	clear_bit(stream_id, cca_stream_ids);
+
+	return rc;
+}
+
+static void cca_tsm_disconnect(struct pci_dev *pdev)
+{
+	struct pci_dev *rp = pcie_find_root_port(pdev);
+	struct cca_host_dsc_pf0 *dsc_pf0;
+	struct pci_ide *ide;
+
+	if (WARN_ON(!is_pci_tsm_pf0(pdev)))
+		return;
+
+	dsc_pf0 = to_cca_dsc_pf0(pdev);
+	ide = dsc_pf0->sel_stream;
+	dsc_pf0->sel_stream = NULL;
+	pci_ide_stream_disable(pdev, ide);
+	tsm_ide_stream_unregister(ide);
+	pci_ide_stream_teardown(rp, ide);
+	pci_ide_stream_teardown(pdev, ide);
+	pci_ide_stream_unregister(ide);
+	clear_bit(ide->stream_id, cca_stream_ids);
+	pci_ide_stream_free(ide);
+}
+
+static const struct pci_tsm_ops cca_pci_ops = {
+	.probe = cca_tsm_pci_probe,
+	.remove = cca_tsm_pci_remove,
+	.connect = cca_tsm_connect,
+	.disconnect = cca_tsm_disconnect,
+};
+
+static void cca_tsm_remove(void *tsm_core)
+{
+	tsm_unregister(tsm_core);
+}
+
+static int cca_tsm_probe(struct platform_device *pdev)
+{
+	struct tsm_core_dev *tsm_core;
+
+	tsm_core = tsm_register(&pdev->dev, NULL, &cca_pci_ops);
+	if (IS_ERR(tsm_core))
+		return PTR_ERR(tsm_core);
+
+	return devm_add_action_or_reset(&pdev->dev, cca_tsm_remove, tsm_core);
+}
+
+static const struct platform_device_id arm_cca_host_id_table[] = {
+	{ RMI_DEV_NAME, 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, arm_cca_host_id_table);
+
+
+static struct platform_driver cca_tsm_platform_driver = {
+	.probe = cca_tsm_probe,
+	.id_table = arm_cca_host_id_table,
+	.driver = {
+		.name = "cca_tsm",
+	},
+};
+
+MODULE_IMPORT_NS("PCI_IDE");
+module_platform_driver(cca_tsm_platform_driver);
+MODULE_DESCRIPTION("ARM CCA Host TSM driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/virt/coco/arm-cca-host/rmm-da.h b/drivers/virt/coco/arm-cca-host/rmm-da.h
new file mode 100644
index 000000000000..840cb584acdd
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-host/rmm-da.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2024 ARM Ltd.
+ */
+
+#ifndef RMM_DA_H_
+#define RMM_DA_H_
+
+#include <linux/pci.h>
+#include <linux/pci-ide.h>
+#include <linux/pci-tsm.h>
+#include <asm/rmi_smc.h>
+
+struct cca_host_dsc_pf0 {
+	struct pci_tsm_pf0 pci;
+	struct pci_ide *sel_stream;
+};
+
+static inline struct cca_host_dsc_pf0 *to_cca_dsc_pf0(struct pci_dev *pdev)
+{
+	struct pci_tsm *tsm = pdev->tsm;
+
+	if (!tsm || pdev->is_virtfn || !is_pci_tsm_pf0(pdev))
+		return NULL;
+
+	return container_of(tsm, struct cca_host_dsc_pf0, pci.tsm);
+}
+
+#endif
-- 
2.43.0