--- /dev/null
+* IBM Powerpc Virtual Accelerator Switchboard (VAS)
+
+VAS is a hardware mechanism that allows kernel subsystems and user processes
+to directly submit compression and other requests to Nest accelerators (NX)
+or other coprocessors functions.
+
+Required properties:
+- compatible : should be "ibm,vas".
+- ibm,vas-id : A unique identifier for each instance of VAS in the system
+- reg : Should contain 4 pairs of 64-bit fields specifying the Hypervisor
+ window context start and length, OS/User window context start and length,
+ "Paste address" start and length, "Paste window id" start bit and number
+ of bits)
+
+Example:
+
+ vas@6019100000000 {
+ compatible = "ibm,vas", "ibm,power9-vas";
+ reg = <0x6019100000000 0x2000000 0x6019000000000 0x100000000 0x8000000000000 0x100000000 0x20 0x10>;
+ name = "vas";
+ ibm,vas-id = <0x1>;
+ };
--- /dev/null
+/*
+ * 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);
projects / mirror_ubuntu-artful-kernel.git / commitdiff