[PATCH v4 10/10] samples/devsec: Add sample IDE establishment

[Dan Williams <dan.j.williams@intel.com>]

Exercise common setup and teardown flows for a sample platform TSM
driver that implements the TSM 'connect' and 'disconnect' flows.

This is both a template for platform specific implementations and a
simple integration test for the PCI core infrastructure + ABI.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Samuel Ortiz <sameo@rivosinc.com>
Cc: Alexey Kardashevskiy <aik@amd.com>
Cc: Xu Yilun <yilun.xu@linux.intel.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 samples/devsec/bus.c |  3 ++
 samples/devsec/tsm.c | 70 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 72 insertions(+), 1 deletion(-)

diff --git a/samples/devsec/bus.c b/samples/devsec/bus.c
index 675e185fcf79..efd7a650b20d 100644
--- a/samples/devsec/bus.c
+++ b/samples/devsec/bus.c
@@ -15,6 +15,7 @@
 
 #define NR_DEVSEC_BUSES 1
 #define NR_DEVSEC_ROOT_PORTS 1
+#define NR_PLATFORM_STREAMS 4
 #define NR_PORT_STREAMS 1
 #define NR_ADDR_ASSOC 1
 #define NR_DEVSEC_DEVS 1
@@ -662,6 +663,7 @@ static int __init devsec_bus_probe(struct platform_device *pdev)
 	hb->dev.parent = dev;
 	hb->sysdata = sd;
 	hb->ops = &devsec_ops;
+	pci_ide_init_nr_streams(hb, NR_PLATFORM_STREAMS);
 
 	rc = pci_scan_root_bus_bridge(hb);
 	if (rc)
@@ -704,5 +706,6 @@ static void __exit devsec_bus_exit(void)
 }
 module_exit(devsec_bus_exit);
 
+MODULE_IMPORT_NS("PCI_IDE");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Device Security Sample Infrastructure: TDISP Device Emulation");
diff --git a/samples/devsec/tsm.c b/samples/devsec/tsm.c
index a4705212a7e4..b93396ca0c92 100644
--- a/samples/devsec/tsm.c
+++ b/samples/devsec/tsm.c
@@ -4,6 +4,7 @@
 #define dev_fmt(fmt) "devsec: " fmt
 #include <linux/device/faux.h>
 #include <linux/pci-tsm.h>
+#include <linux/pci-ide.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/tsm.h>
@@ -92,6 +93,23 @@ static void devsec_tsm_pci_remove(struct pci_tsm *tsm)
 	}
 }
 
+/* protected by tsm_ops lock */
+static DECLARE_BITMAP(devsec_stream_ids, NR_TSM_STREAMS);
+static struct pci_ide *devsec_streams[NR_TSM_STREAMS];
+
+static unsigned long *alloc_devsec_stream_id(unsigned long *stream_id)
+{
+	unsigned long id;
+
+	id = find_first_zero_bit(devsec_stream_ids, NR_TSM_STREAMS);
+	if (id == NR_TSM_STREAMS)
+		return NULL;
+	set_bit(id, devsec_stream_ids);
+	*stream_id = id;
+	return stream_id;
+}
+DEFINE_FREE(free_devsec_stream, unsigned long *, if (_T) clear_bit(*_T, devsec_stream_ids))
+
 /*
  * Reference consumer for a TSM driver "connect" operation callback. The
  * low-level TSM driver understands details about the platform the PCI
@@ -116,11 +134,61 @@ static void devsec_tsm_pci_remove(struct pci_tsm *tsm)
  */
 static int devsec_tsm_connect(struct pci_dev *pdev)
 {
-	return -ENXIO;
+	struct pci_dev *rp = pcie_find_root_port(pdev);
+	unsigned long __stream_id;
+	int rc;
+
+	unsigned long *stream_id __free(free_devsec_stream) =
+		alloc_devsec_stream_id(&__stream_id);
+	if (!stream_id)
+		return -EBUSY;
+
+	struct pci_ide *ide __free(pci_ide_stream_release) =
+		pci_ide_stream_alloc(pdev);
+	if (!ide)
+		return -ENOMEM;
+
+	ide->stream_id = *stream_id;
+	rc = pci_ide_stream_register(ide);
+	if (rc)
+		return rc;
+
+	pci_ide_stream_setup(pdev, ide);
+	pci_ide_stream_setup(rp, ide);
+
+	rc = tsm_ide_stream_register(ide);
+	if (rc)
+		return rc;
+
+	/*
+	 * Model a TSM that handled enabling the stream at
+	 * tsm_ide_stream_register() time
+	 */
+	rc = pci_ide_stream_enable(pdev, ide);
+	if (rc)
+		return rc;
+
+	devsec_streams[*no_free_ptr(stream_id)] = no_free_ptr(ide);
+
+	return 0;
 }
 
 static void devsec_tsm_disconnect(struct pci_dev *pdev)
 {
+	struct pci_ide *ide;
+	unsigned long i;
+
+	for_each_set_bit(i, devsec_stream_ids, NR_TSM_STREAMS)
+		if (devsec_streams[i]->pdev == pdev)
+			break;
+
+	if (i >= NR_TSM_STREAMS)
+		return;
+
+	ide = devsec_streams[i];
+	devsec_streams[i] = NULL;
+	pci_ide_stream_release(ide);
+	clear_bit(i, devsec_stream_ids);
 }
 
 static struct pci_tsm_ops devsec_pci_ops = {
-- 
2.50.1