linux_dsm_epyc7002/arch/powerpc/platforms/powernv/vas.c
Sukadev Bhattiprolu 4dea2d1a92 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>
2017-08-31 14:26:26 +10:00

152 lines
3.1 KiB
C

/*
* 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);