testing/nvdimm: Add test module for non-nfit platforms

The current test module cannot be used for testing platforms (make check)
that do not have support for NFIT. In order to get the ndctl tests working,
we need a module which can emulate NVDIMM devices without relying on
ACPI/NFIT.

The aim of this proposed module is to implement a similar functionality to
the existing module but without the ACPI dependencies.

This RFC series is split into reviewable and compilable chunks.

This patch adds a new driver and registers two nvdimm bus needed for ndctl
make check.

Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Link: https://lore.kernel.org/r/20201222042240.2983755-2-santosh@fossix.org
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/nvdimm/config_check.c

@@ -12,7 +12,8 @@ void check(void)
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_BTT));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_PFN));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_BLK));
-	BUILD_BUG_ON(!IS_MODULE(CONFIG_ACPI_NFIT));
+	if (IS_ENABLED(CONFIG_ACPI_NFIT))
+		BUILD_BUG_ON(!IS_MODULE(CONFIG_ACPI_NFIT));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_DEV_DAX));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_DEV_DAX_PMEM));
 }

tools/testing/nvdimm/test/Kbuild

@@ -5,5 +5,9 @@ ccflags-y += -I$(srctree)/drivers/acpi/nfit/
 obj-m += nfit_test.o
 obj-m += nfit_test_iomap.o
 
-nfit_test-y := nfit.o
+ifeq  ($(CONFIG_ACPI_NFIT),m)
+	nfit_test-y := nfit.o
+else
+	nfit_test-y := ndtest.o
+endif
 nfit_test_iomap-y := iomap.o

tools/testing/nvdimm/test/ndtest.c

@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/genalloc.h>
+#include <linux/vmalloc.h>
+#include <linux/dma-mapping.h>
+#include <linux/list_sort.h>
+#include <linux/libnvdimm.h>
+#include <linux/ndctl.h>
+#include <nd-core.h>
+#include <linux/printk.h>
+#include <linux/seq_buf.h>
+
+#include "../watermark.h"
+#include "nfit_test.h"
+#include "ndtest.h"
+
+enum {
+	DIMM_SIZE = SZ_32M,
+	LABEL_SIZE = SZ_128K,
+	NUM_INSTANCES = 2,
+	NUM_DCR = 4,
+};
+
+static struct ndtest_priv *instances[NUM_INSTANCES];
+static struct class *ndtest_dimm_class;
+
+static inline struct ndtest_priv *to_ndtest_priv(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	return container_of(pdev, struct ndtest_priv, pdev);
+}
+
+static int ndtest_ctl(struct nvdimm_bus_descriptor *nd_desc,
+		      struct nvdimm *nvdimm, unsigned int cmd, void *buf,
+		      unsigned int buf_len, int *cmd_rc)
+{
+	struct ndtest_dimm *dimm;
+	int _cmd_rc;
+
+	if (!cmd_rc)
+		cmd_rc = &_cmd_rc;
+
+	*cmd_rc = 0;
+
+	if (!nvdimm)
+		return -EINVAL;
+
+	dimm = nvdimm_provider_data(nvdimm);
+	if (!dimm)
+		return -EINVAL;
+
+	switch (cmd) {
+	case ND_CMD_GET_CONFIG_SIZE:
+	case ND_CMD_GET_CONFIG_DATA:
+	case ND_CMD_SET_CONFIG_DATA:
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ndtest_bus_register(struct ndtest_priv *p)
+{
+	p->bus_desc.ndctl = ndtest_ctl;
+	p->bus_desc.module = THIS_MODULE;
+	p->bus_desc.provider_name = NULL;
+
+	p->bus = nvdimm_bus_register(&p->pdev.dev, &p->bus_desc);
+	if (!p->bus) {
+		dev_err(&p->pdev.dev, "Error creating nvdimm bus %pOF\n", p->dn);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int ndtest_remove(struct platform_device *pdev)
+{
+	struct ndtest_priv *p = to_ndtest_priv(&pdev->dev);
+
+	nvdimm_bus_unregister(p->bus);
+	return 0;
+}
+
+static int ndtest_probe(struct platform_device *pdev)
+{
+	struct ndtest_priv *p;
+
+	p = to_ndtest_priv(&pdev->dev);
+	if (ndtest_bus_register(p))
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, p);
+
+	return 0;
+}
+
+static const struct platform_device_id ndtest_id[] = {
+	{ KBUILD_MODNAME },
+	{ },
+};
+
+static struct platform_driver ndtest_driver = {
+	.probe = ndtest_probe,
+	.remove = ndtest_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+	},
+	.id_table = ndtest_id,
+};
+
+static void ndtest_release(struct device *dev)
+{
+	struct ndtest_priv *p = to_ndtest_priv(dev);
+
+	kfree(p);
+}
+
+static void cleanup_devices(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_INSTANCES; i++)
+		if (instances[i])
+			platform_device_unregister(&instances[i]->pdev);
+
+	nfit_test_teardown();
+
+	if (ndtest_dimm_class)
+		class_destroy(ndtest_dimm_class);
+}
+
+static __init int ndtest_init(void)
+{
+	int rc, i;
+
+	pmem_test();
+	libnvdimm_test();
+	device_dax_test();
+	dax_pmem_test();
+	dax_pmem_core_test();
+#ifdef CONFIG_DEV_DAX_PMEM_COMPAT
+	dax_pmem_compat_test();
+#endif
+
+	ndtest_dimm_class = class_create(THIS_MODULE, "nfit_test_dimm");
+	if (IS_ERR(ndtest_dimm_class)) {
+		rc = PTR_ERR(ndtest_dimm_class);
+		goto err_register;
+	}
+
+	/* Each instance can be taken as a bus, which can have multiple dimms */
+	for (i = 0; i < NUM_INSTANCES; i++) {
+		struct ndtest_priv *priv;
+		struct platform_device *pdev;
+
+		priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+		if (!priv) {
+			rc = -ENOMEM;
+			goto err_register;
+		}
+
+		INIT_LIST_HEAD(&priv->resources);
+		pdev = &priv->pdev;
+		pdev->name = KBUILD_MODNAME;
+		pdev->id = i;
+		pdev->dev.release = ndtest_release;
+		rc = platform_device_register(pdev);
+		if (rc) {
+			put_device(&pdev->dev);
+			goto err_register;
+		}
+		get_device(&pdev->dev);
+
+		instances[i] = priv;
+	}
+
+	rc = platform_driver_register(&ndtest_driver);
+	if (rc)
+		goto err_register;
+
+	return 0;
+
+err_register:
+	pr_err("Error registering platform device\n");
+	cleanup_devices();
+
+	return rc;
+}
+
+static __exit void ndtest_exit(void)
+{
+	cleanup_devices();
+	platform_driver_unregister(&ndtest_driver);
+}
+
+module_init(ndtest_init);
+module_exit(ndtest_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("IBM Corporation");

tools/testing/nvdimm/test/ndtest.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef NDTEST_H
+#define NDTEST_H
+
+#include <linux/platform_device.h>
+#include <linux/libnvdimm.h>
+
+struct ndtest_priv {
+	struct platform_device pdev;
+	struct device_node *dn;
+	struct list_head resources;
+	struct nvdimm_bus_descriptor bus_desc;
+	struct nvdimm_bus *bus;
+};
+
+#endif /* NDTEST_H */