powerpc/powernv/vas: Define vas_init() and vas_exit()

Implement vas_init() and vas_exit() functions for a new VAS module.
This VAS module is essentially a library for other device drivers
and kernel users of the NX coprocessors like NX-842 and NX-GZIP.
In the future this will be extended to add support for user space
to access the NX coprocessors.

VAS is currently only supported with 64K page size.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 151 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
new file mode 100644
index 000000000000..565a4878fefa
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/vas.c
@@ -0,0 +1,151 @@
+/*
+ * Copyright 2016-17 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "vas: " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+
+#include "vas.h"
+
+static DEFINE_MUTEX(vas_mutex);
+static LIST_HEAD(vas_instances);
+
+static int init_vas_instance(struct platform_device *pdev)
+{
+	int rc, vasid;
+	struct resource *res;
+	struct vas_instance *vinst;
+	struct device_node *dn = pdev->dev.of_node;
+
+	rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
+	if (rc) {
+		pr_err("No ibm,vas-id property for %s?\n", pdev->name);
+		return -ENODEV;
+	}
+
+	if (pdev->num_resources != 4) {
+		pr_err("Unexpected DT configuration for [%s, %d]\n",
+				pdev->name, vasid);
+		return -ENODEV;
+	}
+
+	vinst = kzalloc(sizeof(*vinst), GFP_KERNEL);
+	if (!vinst)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&vinst->node);
+	ida_init(&vinst->ida);
+	mutex_init(&vinst->mutex);
+	vinst->vas_id = vasid;
+	vinst->pdev = pdev;
+
+	res = &pdev->resource[0];
+	vinst->hvwc_bar_start = res->start;
+
+	res = &pdev->resource[1];
+	vinst->uwc_bar_start = res->start;
+
+	res = &pdev->resource[2];
+	vinst->paste_base_addr = res->start;
+
+	res = &pdev->resource[3];
+	if (res->end > 62) {
+		pr_err("Bad 'paste_win_id_shift' in DT, %llx\n", res->end);
+		goto free_vinst;
+	}
+
+	vinst->paste_win_id_shift = 63 - res->end;
+
+	pr_devel("Initialized instance [%s, %d], paste_base 0x%llx, "
+			"paste_win_id_shift 0x%llx\n", pdev->name, vasid,
+			vinst->paste_base_addr, vinst->paste_win_id_shift);
+
+	mutex_lock(&vas_mutex);
+	list_add(&vinst->node, &vas_instances);
+	mutex_unlock(&vas_mutex);
+
+	dev_set_drvdata(&pdev->dev, vinst);
+
+	return 0;
+
+free_vinst:
+	kfree(vinst);
+	return -ENODEV;
+
+}
+
+/*
+ * Although this is read/used multiple times, it is written to only
+ * during initialization.
+ */
+struct vas_instance *find_vas_instance(int vasid)
+{
+	struct list_head *ent;
+	struct vas_instance *vinst;
+
+	mutex_lock(&vas_mutex);
+	list_for_each(ent, &vas_instances) {
+		vinst = list_entry(ent, struct vas_instance, node);
+		if (vinst->vas_id == vasid) {
+			mutex_unlock(&vas_mutex);
+			return vinst;
+		}
+	}
+	mutex_unlock(&vas_mutex);
+
+	pr_devel("Instance %d not found\n", vasid);
+	return NULL;
+}
+
+static int vas_probe(struct platform_device *pdev)
+{
+	return init_vas_instance(pdev);
+}
+
+static const struct of_device_id powernv_vas_match[] = {
+	{ .compatible = "ibm,vas",},
+	{},
+};
+
+static struct platform_driver vas_driver = {
+	.driver = {
+		.name = "vas",
+		.of_match_table = powernv_vas_match,
+	},
+	.probe = vas_probe,
+};
+
+static int __init vas_init(void)
+{
+	int found = 0;
+	struct device_node *dn;
+
+	platform_driver_register(&vas_driver);
+
+	for_each_compatible_node(dn, NULL, "ibm,vas") {
+		of_platform_device_create(dn, NULL, NULL);
+		found++;
+	}
+
+	if (!found)
+		return -ENODEV;
+
+	pr_devel("Found %d instances\n", found);
+
+	return 0;
+}
+device_initcall(vas_init);