linux/linux-5.18.11/drivers/platform/x86/intel/pmt/telemetry.c

151 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Intel Platform Monitory Technology Telemetry driver
*
* Copyright (c) 2020, Intel Corporation.
* All Rights Reserved.
*
* Author: "David E. Box" <david.e.box@linux.intel.com>
*/
#include <linux/auxiliary_bus.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/overflow.h>
#include "../vsec.h"
#include "class.h"
#define TELEM_SIZE_OFFSET 0x0
#define TELEM_GUID_OFFSET 0x4
#define TELEM_BASE_OFFSET 0x8
#define TELEM_ACCESS(v) ((v) & GENMASK(3, 0))
/* size is in bytes */
#define TELEM_SIZE(v) (((v) & GENMASK(27, 12)) >> 10)
/* Used by client hardware to identify a fixed telemetry entry*/
#define TELEM_CLIENT_FIXED_BLOCK_GUID 0x10000000
struct pmt_telem_priv {
int num_entries;
struct intel_pmt_entry entry[];
};
static bool pmt_telem_region_overlaps(struct intel_pmt_entry *entry,
struct device *dev)
{
u32 guid = readl(entry->disc_table + TELEM_GUID_OFFSET);
if (guid != TELEM_CLIENT_FIXED_BLOCK_GUID)
return false;
return intel_pmt_is_early_client_hw(dev);
}
static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
struct intel_pmt_header *header,
struct device *dev)
{
void __iomem *disc_table = entry->disc_table;
if (pmt_telem_region_overlaps(entry, dev))
return 1;
header->access_type = TELEM_ACCESS(readl(disc_table));
header->guid = readl(disc_table + TELEM_GUID_OFFSET);
header->base_offset = readl(disc_table + TELEM_BASE_OFFSET);
/* Size is measured in DWORDS, but accessor returns bytes */
header->size = TELEM_SIZE(readl(disc_table));
/*
* Some devices may expose non-functioning entries that are
* reserved for future use. They have zero size. Do not fail
* probe for these. Just ignore them.
*/
if (header->size == 0)
return 1;
return 0;
}
static DEFINE_XARRAY_ALLOC(telem_array);
static struct intel_pmt_namespace pmt_telem_ns = {
.name = "telem",
.xa = &telem_array,
.pmt_header_decode = pmt_telem_header_decode,
};
static void pmt_telem_remove(struct auxiliary_device *auxdev)
{
struct pmt_telem_priv *priv = auxiliary_get_drvdata(auxdev);
int i;
for (i = 0; i < priv->num_entries; i++)
intel_pmt_dev_destroy(&priv->entry[i], &pmt_telem_ns);
}
static int pmt_telem_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
{
struct intel_vsec_device *intel_vsec_dev = auxdev_to_ivdev(auxdev);
struct pmt_telem_priv *priv;
size_t size;
int i, ret;
size = struct_size(priv, entry, intel_vsec_dev->num_resources);
priv = devm_kzalloc(&auxdev->dev, size, GFP_KERNEL);
if (!priv)
return -ENOMEM;
auxiliary_set_drvdata(auxdev, priv);
for (i = 0; i < intel_vsec_dev->num_resources; i++) {
struct intel_pmt_entry *entry = &priv->entry[priv->num_entries];
ret = intel_pmt_dev_create(entry, &pmt_telem_ns, intel_vsec_dev, i);
if (ret < 0)
goto abort_probe;
if (ret)
continue;
priv->num_entries++;
}
return 0;
abort_probe:
pmt_telem_remove(auxdev);
return ret;
}
static const struct auxiliary_device_id pmt_telem_id_table[] = {
{ .name = "intel_vsec.telemetry" },
{}
};
MODULE_DEVICE_TABLE(auxiliary, pmt_telem_id_table);
static struct auxiliary_driver pmt_telem_aux_driver = {
.id_table = pmt_telem_id_table,
.remove = pmt_telem_remove,
.probe = pmt_telem_probe,
};
static int __init pmt_telem_init(void)
{
return auxiliary_driver_register(&pmt_telem_aux_driver);
}
module_init(pmt_telem_init);
static void __exit pmt_telem_exit(void)
{
auxiliary_driver_unregister(&pmt_telem_aux_driver);
xa_destroy(&telem_array);
}
module_exit(pmt_telem_exit);
MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
MODULE_DESCRIPTION("Intel PMT Telemetry driver");
MODULE_LICENSE("GPL v2");