Merge miscellaneous libnvdimm updates for 4.21

* Use common helpers, bitmap_zalloc() and kstrndup(), to replace open
  coded versions.
* Clarify the comments around hotplug vs initial init case for the nfit
  driver.
* Cleanup the libnvdimm init path.

tools/testing/nvdimm/test/nfit.c

@@ -15,6 +15,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/workqueue.h>
 #include <linux/libnvdimm.h>
+#include <linux/genalloc.h>
 #include <linux/vmalloc.h>
 #include <linux/device.h>
 #include <linux/module.h>
@@ -222,6 +223,8 @@ struct nfit_test {
 
 static struct workqueue_struct *nfit_wq;
 
+static struct gen_pool *nfit_pool;
+
 static struct nfit_test *to_nfit_test(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
@@ -1415,6 +1418,9 @@ static void release_nfit_res(void *data)
 	list_del(&nfit_res->list);
 	spin_unlock(&nfit_test_lock);
 
+	if (resource_size(&nfit_res->res) >= DIMM_SIZE)
+		gen_pool_free(nfit_pool, nfit_res->res.start,
+				resource_size(&nfit_res->res));
 	vfree(nfit_res->buf);
 	kfree(nfit_res);
 }
@@ -1427,7 +1433,7 @@ static void *__test_alloc(struct nfit_test *t, size_t size, dma_addr_t *dma,
 			GFP_KERNEL);
 	int rc;
 
-	if (!buf || !nfit_res)
+	if (!buf || !nfit_res || !*dma)
 		goto err;
 	rc = devm_add_action(dev, release_nfit_res, nfit_res);
 	if (rc)
@@ -1447,6 +1453,8 @@ static void *__test_alloc(struct nfit_test *t, size_t size, dma_addr_t *dma,
 
 	return nfit_res->buf;
  err:
+	if (*dma && size >= DIMM_SIZE)
+		gen_pool_free(nfit_pool, *dma, size);
 	if (buf)
 		vfree(buf);
 	kfree(nfit_res);
@@ -1455,9 +1463,16 @@ static void *__test_alloc(struct nfit_test *t, size_t size, dma_addr_t *dma,
 
 static void *test_alloc(struct nfit_test *t, size_t size, dma_addr_t *dma)
 {
+	struct genpool_data_align data = {
+		.align = SZ_128M,
+	};
 	void *buf = vmalloc(size);
 
-	*dma = (unsigned long) buf;
+	if (size >= DIMM_SIZE)
+		*dma = gen_pool_alloc_algo(nfit_pool, size,
+				gen_pool_first_fit_align, &data);
+	else
+		*dma = (unsigned long) buf;
 	return __test_alloc(t, size, dma, buf);
 }
 
@@ -3160,6 +3175,17 @@ static __init int nfit_test_init(void)
 		goto err_register;
 	}
 
+	nfit_pool = gen_pool_create(ilog2(SZ_4M), NUMA_NO_NODE);
+	if (!nfit_pool) {
+		rc = -ENOMEM;
+		goto err_register;
+	}
+
+	if (gen_pool_add(nfit_pool, SZ_4G, SZ_4G, NUMA_NO_NODE)) {
+		rc = -ENOMEM;
+		goto err_register;
+	}
+
 	for (i = 0; i < NUM_NFITS; i++) {
 		struct nfit_test *nfit_test;
 		struct platform_device *pdev;
@@ -3215,6 +3241,9 @@ static __init int nfit_test_init(void)
 	return 0;
 
  err_register:
+	if (nfit_pool)
+		gen_pool_destroy(nfit_pool);
+
 	destroy_workqueue(nfit_wq);
 	for (i = 0; i < NUM_NFITS; i++)
 		if (instances[i])
@@ -3238,6 +3267,8 @@ static __exit void nfit_test_exit(void)
 	platform_driver_unregister(&nfit_test_driver);
 	nfit_test_teardown();
 
+	gen_pool_destroy(nfit_pool);
+
 	for (i = 0; i < NUM_NFITS; i++)
 		put_device(&instances[i]->pdev.dev);
 	class_destroy(nfit_test_dimm);