[RFC PATCH 4/4] cxl/pci: Add really basic CMA authentication support.

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

This is just for purposes of poking the CMA / SPDM code.
What exactly the model in the driver looks like is still to
be worked out.

Note the PROBE_FORCE_SYNCHRONOUS is a workaround to avoid warnings
about trying to load an additional crypto module whilst doing an
asychronous probe.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/cxl/Kconfig |  1 +
 drivers/cxl/mem.h   |  2 ++
 drivers/cxl/pci.c   | 13 ++++++++++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig
index e2bca26eb879..c726cc9adddb 100644
--- a/drivers/cxl/Kconfig
+++ b/drivers/cxl/Kconfig
@@ -17,6 +17,7 @@ config CXL_MEM
 	tristate "CXL.mem: Memory Devices"
 	default CXL_BUS
 	select PCI_DOE
+	select PCI_CMA
 	help
 	  The CXL.mem protocol allows a device to act as a provider of
 	  "System RAM" and/or "Persistent Memory" that is fully coherent
diff --git a/drivers/cxl/mem.h b/drivers/cxl/mem.h
index f626aa7eb389..cb8c2dfda277 100644
--- a/drivers/cxl/mem.h
+++ b/drivers/cxl/mem.h
@@ -57,6 +57,7 @@ struct cxl_memdev {
  * @pdev: The PCI device associated with this CXL device.
  * @cxlmd: Logical memory device chardev / interface
  * @table_doe: Data exchange object mailbox used to read tables
+ * @cma_doe: Component measurement and authentication mailbox
  * @regs: Parsed register blocks
  * @payload_size: Size of space for payload
  *                (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
@@ -73,6 +74,7 @@ struct cxl_mem {
 	struct cxl_memdev *cxlmd;
 
 	struct pci_doe *table_doe;
+	struct pci_doe *cma_doe;
 	struct cxl_regs regs;
 
 	size_t payload_size;
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 471bddc9d167..e6ca84cc6fff 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -2,10 +2,12 @@
 /* Copyright(c) 2020 Intel Corporation. All rights reserved. */
 #include <uapi/linux/cxl_mem.h>
 #include <linux/security.h>
+#include <linux/pci-cma.h>
 #include <linux/debugfs.h>
 #include <linux/module.h>
 #include <linux/sizes.h>
 #include <linux/mutex.h>
+#include <linux/spdm.h>
 #include <linux/list.h>
 #include <linux/cdev.h>
 #include <linux/idr.h>
@@ -1723,6 +1725,7 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct cxl_memdev *cxlmd;
 	struct cxl_mem *cxlm;
+	struct spdm_state spdm_state;
 	int rc, irqs;
 
 	rc = pcim_enable_device(pdev);
@@ -1770,6 +1773,14 @@ static int cxl_mem_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	cxlm->table_doe = pci_doe_find(pdev, PCI_DVSEC_VENDOR_ID_CXL,
 				       CXL_DOE_PROTOCOL_TABLE_ACCESS);
 
+	cxlm->cma_doe = pci_doe_find(pdev, PCI_VENDOR_ID_PCI_SIG,
+				     PCI_DOE_PROTOCOL_CMA);
+
+	pci_cma_init(cxlm->cma_doe, &spdm_state);
+	rc = pci_cma_authenticate(&spdm_state);
+	if (rc)
+		return rc;
+
 	rc = cxl_mem_setup_regs(cxlm);
 	if (rc)
 		return rc;
@@ -1808,7 +1819,7 @@ static struct pci_driver cxl_mem_driver = {
 	.id_table		= cxl_mem_pci_tbl,
 	.probe			= cxl_mem_probe,
 	.driver	= {
-		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
+		.probe_type	= PROBE_FORCE_SYNCHRONOUS,
 	},
 };
 
-- 
2.19.1