blob: 9e0ea2cdd7042b402e1617424b24802bd9fe0ace [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Intel On Demand (Software Defined Silicon) driver
*
* Copyright (c) 2022, Intel Corporation.
* All Rights Reserved.
*
* Author: "David E. Box" <david.e.box@linux.intel.com>
*/
#include <linux/auxiliary_bus.h>
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/device.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "vsec.h"
#define ACCESS_TYPE_BARID 2
#define ACCESS_TYPE_LOCAL 3
#define SDSI_MIN_SIZE_DWORDS 276
#define SDSI_SIZE_MAILBOX 1024
#define SDSI_SIZE_REGS 80
#define SDSI_SIZE_CMD sizeof(u64)
/*
* Write messages are currently up to the size of the mailbox
* while read messages are up to 4 times the size of the
* mailbox, sent in packets
*/
#define SDSI_SIZE_WRITE_MSG SDSI_SIZE_MAILBOX
#define SDSI_SIZE_READ_MSG (SDSI_SIZE_MAILBOX * 4)
#define SDSI_ENABLED_FEATURES_OFFSET 16
#define SDSI_FEATURE_SDSI BIT(3)
#define SDSI_FEATURE_METERING BIT(26)
#define SDSI_SOCKET_ID_OFFSET 64
#define SDSI_SOCKET_ID GENMASK(3, 0)
#define SDSI_MBOX_CMD_SUCCESS 0x40
#define SDSI_MBOX_CMD_TIMEOUT 0x80
#define MBOX_TIMEOUT_US 2000
#define MBOX_TIMEOUT_ACQUIRE_US 1000
#define MBOX_POLLING_PERIOD_US 100
#define MBOX_ACQUIRE_NUM_RETRIES 5
#define MBOX_ACQUIRE_RETRY_DELAY_MS 500
#define MBOX_MAX_PACKETS 4
#define MBOX_OWNER_NONE 0x00
#define MBOX_OWNER_INBAND 0x01
#define CTRL_RUN_BUSY BIT(0)
#define CTRL_READ_WRITE BIT(1)
#define CTRL_SOM BIT(2)
#define CTRL_EOM BIT(3)
#define CTRL_OWNER GENMASK(5, 4)
#define CTRL_COMPLETE BIT(6)
#define CTRL_READY BIT(7)
#define CTRL_STATUS GENMASK(15, 8)
#define CTRL_PACKET_SIZE GENMASK(31, 16)
#define CTRL_MSG_SIZE GENMASK(63, 48)
#define DISC_TABLE_SIZE 12
#define DT_ACCESS_TYPE GENMASK(3, 0)
#define DT_SIZE GENMASK(27, 12)
#define DT_TBIR GENMASK(2, 0)
#define DT_OFFSET(v) ((v) & GENMASK(31, 3))
#define SDSI_GUID_V1 0x006DD191
#define GUID_V1_CNTRL_SIZE 8
#define GUID_V1_REGS_SIZE 72
#define SDSI_GUID_V2 0xF210D9EF
#define GUID_V2_CNTRL_SIZE 16
#define GUID_V2_REGS_SIZE 80
enum sdsi_command {
SDSI_CMD_PROVISION_AKC = 0x0004,
SDSI_CMD_PROVISION_CAP = 0x0008,
SDSI_CMD_READ_STATE = 0x0010,
SDSI_CMD_READ_METER = 0x0014,
};
struct sdsi_mbox_info {
u64 *payload;
void *buffer;
int size;
};
struct disc_table {
u32 access_info;
u32 guid;
u32 offset;
};
struct sdsi_priv {
struct mutex mb_lock; /* Mailbox access lock */
struct device *dev;
void __iomem *control_addr;
void __iomem *mbox_addr;
void __iomem *regs_addr;
int control_size;
int maibox_size;
int registers_size;
u32 guid;
u32 features;
};
/* SDSi mailbox operations must be performed using 64bit mov instructions */
static __always_inline void
sdsi_memcpy64_toio(u64 __iomem *to, const u64 *from, size_t count_bytes)
{
size_t count = count_bytes / sizeof(*to);
int i;
for (i = 0; i < count; i++)
writeq(from[i], &to[i]);
}
static __always_inline void
sdsi_memcpy64_fromio(u64 *to, const u64 __iomem *from, size_t count_bytes)
{
size_t count = count_bytes / sizeof(*to);
int i;
for (i = 0; i < count; i++)
to[i] = readq(&from[i]);
}
static inline void sdsi_complete_transaction(struct sdsi_priv *priv)
{
u64 control = FIELD_PREP(CTRL_COMPLETE, 1);
lockdep_assert_held(&priv->mb_lock);
writeq(control, priv->control_addr);
}
static int sdsi_status_to_errno(u32 status)
{
switch (status) {
case SDSI_MBOX_CMD_SUCCESS:
return 0;
case SDSI_MBOX_CMD_TIMEOUT:
return -ETIMEDOUT;
default:
return -EIO;
}
}
static int sdsi_mbox_cmd_read(struct sdsi_priv *priv, struct sdsi_mbox_info *info,
size_t *data_size)
{
struct device *dev = priv->dev;
u32 total, loop, eom, status, message_size;
u64 control;
int ret;
lockdep_assert_held(&priv->mb_lock);
/* Format and send the read command */
control = FIELD_PREP(CTRL_EOM, 1) |
FIELD_PREP(CTRL_SOM, 1) |
FIELD_PREP(CTRL_RUN_BUSY, 1) |
FIELD_PREP(CTRL_PACKET_SIZE, info->size);
writeq(control, priv->control_addr);
/* For reads, data sizes that are larger than the mailbox size are read in packets. */
total = 0;
loop = 0;
do {
void *buf = info->buffer + (SDSI_SIZE_MAILBOX * loop);
u32 packet_size;
/* Poll on ready bit */
ret = readq_poll_timeout(priv->control_addr, control, control & CTRL_READY,
MBOX_POLLING_PERIOD_US, MBOX_TIMEOUT_US);
if (ret)
break;
eom = FIELD_GET(CTRL_EOM, control);
status = FIELD_GET(CTRL_STATUS, control);
packet_size = FIELD_GET(CTRL_PACKET_SIZE, control);
message_size = FIELD_GET(CTRL_MSG_SIZE, control);
ret = sdsi_status_to_errno(status);
if (ret)
break;
/* Only the last packet can be less than the mailbox size. */
if (!eom && packet_size != SDSI_SIZE_MAILBOX) {
dev_err(dev, "Invalid packet size\n");
ret = -EPROTO;
break;
}
if (packet_size > SDSI_SIZE_MAILBOX) {
dev_err(dev, "Packet size too large\n");
ret = -EPROTO;
break;
}
sdsi_memcpy64_fromio(buf, priv->mbox_addr, round_up(packet_size, SDSI_SIZE_CMD));
total += packet_size;
sdsi_complete_transaction(priv);
} while (!eom && ++loop < MBOX_MAX_PACKETS);
if (ret) {
sdsi_complete_transaction(priv);
return ret;
}
if (!eom) {
dev_err(dev, "Exceeded read attempts\n");
return -EPROTO;
}
/* Message size check is only valid for multi-packet transfers */
if (loop && total != message_size)
dev_warn(dev, "Read count %u differs from expected count %u\n",
total, message_size);
*data_size = total;
return 0;
}
static int sdsi_mbox_cmd_write(struct sdsi_priv *priv, struct sdsi_mbox_info *info)
{
u64 control;
u32 status;
int ret;
lockdep_assert_held(&priv->mb_lock);
/* Write rest of the payload */
sdsi_memcpy64_toio(priv->mbox_addr + SDSI_SIZE_CMD, info->payload + 1,
info->size - SDSI_SIZE_CMD);
/* Format and send the write command */
control = FIELD_PREP(CTRL_EOM, 1) |
FIELD_PREP(CTRL_SOM, 1) |
FIELD_PREP(CTRL_RUN_BUSY, 1) |
FIELD_PREP(CTRL_READ_WRITE, 1) |
FIELD_PREP(CTRL_PACKET_SIZE, info->size);
writeq(control, priv->control_addr);
/* Poll on ready bit */
ret = readq_poll_timeout(priv->control_addr, control, control & CTRL_READY,
MBOX_POLLING_PERIOD_US, MBOX_TIMEOUT_US);
if (ret)
goto release_mbox;
status = FIELD_GET(CTRL_STATUS, control);
ret = sdsi_status_to_errno(status);
release_mbox:
sdsi_complete_transaction(priv);
return ret;
}
static int sdsi_mbox_acquire(struct sdsi_priv *priv, struct sdsi_mbox_info *info)
{
u64 control;
u32 owner;
int ret, retries = 0;
lockdep_assert_held(&priv->mb_lock);
/* Check mailbox is available */
control = readq(priv->control_addr);
owner = FIELD_GET(CTRL_OWNER, control);
if (owner != MBOX_OWNER_NONE)
return -EBUSY;
/*
* If there has been no recent transaction and no one owns the mailbox,
* we should acquire it in under 1ms. However, if we've accessed it
* recently it may take up to 2.1 seconds to acquire it again.
*/
do {
/* Write first qword of payload */
writeq(info->payload[0], priv->mbox_addr);
/* Check for ownership */
ret = readq_poll_timeout(priv->control_addr, control,
FIELD_GET(CTRL_OWNER, control) == MBOX_OWNER_INBAND,
MBOX_POLLING_PERIOD_US, MBOX_TIMEOUT_ACQUIRE_US);
if (FIELD_GET(CTRL_OWNER, control) == MBOX_OWNER_NONE &&
retries++ < MBOX_ACQUIRE_NUM_RETRIES) {
msleep(MBOX_ACQUIRE_RETRY_DELAY_MS);
continue;
}
/* Either we got it or someone else did. */
break;
} while (true);
return ret;
}
static int sdsi_mbox_write(struct sdsi_priv *priv, struct sdsi_mbox_info *info)
{
int ret;
lockdep_assert_held(&priv->mb_lock);
ret = sdsi_mbox_acquire(priv, info);
if (ret)
return ret;
return sdsi_mbox_cmd_write(priv, info);
}
static int sdsi_mbox_read(struct sdsi_priv *priv, struct sdsi_mbox_info *info, size_t *data_size)
{
int ret;
lockdep_assert_held(&priv->mb_lock);
ret = sdsi_mbox_acquire(priv, info);
if (ret)
return ret;
return sdsi_mbox_cmd_read(priv, info, data_size);
}
static ssize_t sdsi_provision(struct sdsi_priv *priv, char *buf, size_t count,
enum sdsi_command command)
{
struct sdsi_mbox_info info;
int ret;
if (count > (SDSI_SIZE_WRITE_MSG - SDSI_SIZE_CMD))
return -EOVERFLOW;
/* Qword aligned message + command qword */
info.size = round_up(count, SDSI_SIZE_CMD) + SDSI_SIZE_CMD;
info.payload = kzalloc(info.size, GFP_KERNEL);
if (!info.payload)
return -ENOMEM;
/* Copy message to payload buffer */
memcpy(info.payload, buf, count);
/* Command is last qword of payload buffer */
info.payload[(info.size - SDSI_SIZE_CMD) / SDSI_SIZE_CMD] = command;
ret = mutex_lock_interruptible(&priv->mb_lock);
if (ret)
goto free_payload;
ret = sdsi_mbox_write(priv, &info);
mutex_unlock(&priv->mb_lock);
free_payload:
kfree(info.payload);
if (ret)
return ret;
return count;
}
static ssize_t provision_akc_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
if (off)
return -ESPIPE;
return sdsi_provision(priv, buf, count, SDSI_CMD_PROVISION_AKC);
}
static BIN_ATTR_WO(provision_akc, SDSI_SIZE_WRITE_MSG);
static ssize_t provision_cap_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
if (off)
return -ESPIPE;
return sdsi_provision(priv, buf, count, SDSI_CMD_PROVISION_CAP);
}
static BIN_ATTR_WO(provision_cap, SDSI_SIZE_WRITE_MSG);
static ssize_t
certificate_read(u64 command, struct sdsi_priv *priv, char *buf, loff_t off,
size_t count)
{
struct sdsi_mbox_info info;
size_t size;
int ret;
if (off)
return 0;
/* Buffer for return data */
info.buffer = kmalloc(SDSI_SIZE_READ_MSG, GFP_KERNEL);
if (!info.buffer)
return -ENOMEM;
info.payload = &command;
info.size = sizeof(command);
ret = mutex_lock_interruptible(&priv->mb_lock);
if (ret)
goto free_buffer;
ret = sdsi_mbox_read(priv, &info, &size);
mutex_unlock(&priv->mb_lock);
if (ret < 0)
goto free_buffer;
if (size > count)
size = count;
memcpy(buf, info.buffer, size);
free_buffer:
kfree(info.buffer);
if (ret)
return ret;
return size;
}
static ssize_t
state_certificate_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
return certificate_read(SDSI_CMD_READ_STATE, priv, buf, off, count);
}
static BIN_ATTR_ADMIN_RO(state_certificate, SDSI_SIZE_READ_MSG);
static ssize_t
meter_certificate_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
return certificate_read(SDSI_CMD_READ_METER, priv, buf, off, count);
}
static BIN_ATTR_ADMIN_RO(meter_certificate, SDSI_SIZE_READ_MSG);
static ssize_t registers_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
void __iomem *addr = priv->regs_addr;
int size = priv->registers_size;
/*
* The check below is performed by the sysfs caller based on the static
* file size. But this may be greater than the actual size which is based
* on the GUID. So check here again based on actual size before reading.
*/
if (off >= size)
return 0;
if (off + count > size)
count = size - off;
memcpy_fromio(buf, addr + off, count);
return count;
}
static BIN_ATTR_ADMIN_RO(registers, SDSI_SIZE_REGS);
static struct bin_attribute *sdsi_bin_attrs[] = {
&bin_attr_registers,
&bin_attr_state_certificate,
&bin_attr_meter_certificate,
&bin_attr_provision_akc,
&bin_attr_provision_cap,
NULL
};
static umode_t
sdsi_battr_is_visible(struct kobject *kobj, struct bin_attribute *attr, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct sdsi_priv *priv = dev_get_drvdata(dev);
/* Registers file is always readable if the device is present */
if (attr == &bin_attr_registers)
return attr->attr.mode;
/* All other attributes not visible if BIOS has not enabled On Demand */
if (!(priv->features & SDSI_FEATURE_SDSI))
return 0;
if (attr == &bin_attr_meter_certificate)
return (priv->features & SDSI_FEATURE_METERING) ?
attr->attr.mode : 0;
return attr->attr.mode;
}
static ssize_t guid_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct sdsi_priv *priv = dev_get_drvdata(dev);
return sysfs_emit(buf, "0x%x\n", priv->guid);
}
static DEVICE_ATTR_RO(guid);
static struct attribute *sdsi_attrs[] = {
&dev_attr_guid.attr,
NULL
};
static const struct attribute_group sdsi_group = {
.attrs = sdsi_attrs,
.bin_attrs = sdsi_bin_attrs,
.is_bin_visible = sdsi_battr_is_visible,
};
__ATTRIBUTE_GROUPS(sdsi);
static int sdsi_get_layout(struct sdsi_priv *priv, struct disc_table *table)
{
switch (table->guid) {
case SDSI_GUID_V1:
priv->control_size = GUID_V1_CNTRL_SIZE;
priv->registers_size = GUID_V1_REGS_SIZE;
break;
case SDSI_GUID_V2:
priv->control_size = GUID_V2_CNTRL_SIZE;
priv->registers_size = GUID_V2_REGS_SIZE;
break;
default:
dev_err(priv->dev, "Unrecognized GUID 0x%x\n", table->guid);
return -EINVAL;
}
return 0;
}
static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *parent,
struct disc_table *disc_table, struct resource *disc_res)
{
u32 access_type = FIELD_GET(DT_ACCESS_TYPE, disc_table->access_info);
u32 size = FIELD_GET(DT_SIZE, disc_table->access_info);
u32 tbir = FIELD_GET(DT_TBIR, disc_table->offset);
u32 offset = DT_OFFSET(disc_table->offset);
struct resource res = {};
/* Starting location of SDSi MMIO region based on access type */
switch (access_type) {
case ACCESS_TYPE_LOCAL:
if (tbir) {
dev_err(priv->dev, "Unsupported BAR index %u for access type %u\n",
tbir, access_type);
return -EINVAL;
}
/*
* For access_type LOCAL, the base address is as follows:
* base address = end of discovery region + base offset + 1
*/
res.start = disc_res->end + offset + 1;
break;
case ACCESS_TYPE_BARID:
res.start = pci_resource_start(parent, tbir) + offset;
break;
default:
dev_err(priv->dev, "Unrecognized access_type %u\n", access_type);
return -EINVAL;
}
res.end = res.start + size * sizeof(u32) - 1;
res.flags = IORESOURCE_MEM;
priv->control_addr = devm_ioremap_resource(priv->dev, &res);
if (IS_ERR(priv->control_addr))
return PTR_ERR(priv->control_addr);
priv->mbox_addr = priv->control_addr + priv->control_size;
priv->regs_addr = priv->mbox_addr + SDSI_SIZE_MAILBOX;
priv->features = readq(priv->regs_addr + SDSI_ENABLED_FEATURES_OFFSET);
return 0;
}
static int sdsi_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
{
struct intel_vsec_device *intel_cap_dev = auxdev_to_ivdev(auxdev);
struct disc_table disc_table;
struct resource *disc_res;
void __iomem *disc_addr;
struct sdsi_priv *priv;
int ret;
priv = devm_kzalloc(&auxdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = &auxdev->dev;
mutex_init(&priv->mb_lock);
auxiliary_set_drvdata(auxdev, priv);
/* Get the SDSi discovery table */
disc_res = &intel_cap_dev->resource[0];
disc_addr = devm_ioremap_resource(&auxdev->dev, disc_res);
if (IS_ERR(disc_addr))
return PTR_ERR(disc_addr);
memcpy_fromio(&disc_table, disc_addr, DISC_TABLE_SIZE);
priv->guid = disc_table.guid;
/* Get guid based layout info */
ret = sdsi_get_layout(priv, &disc_table);
if (ret)
return ret;
/* Map the SDSi mailbox registers */
ret = sdsi_map_mbox_registers(priv, intel_cap_dev->pcidev, &disc_table, disc_res);
if (ret)
return ret;
return 0;
}
static const struct auxiliary_device_id sdsi_aux_id_table[] = {
{ .name = "intel_vsec.sdsi" },
{}
};
MODULE_DEVICE_TABLE(auxiliary, sdsi_aux_id_table);
static struct auxiliary_driver sdsi_aux_driver = {
.driver = {
.dev_groups = sdsi_groups,
},
.id_table = sdsi_aux_id_table,
.probe = sdsi_probe,
/* No remove. All resources are handled under devm */
};
module_auxiliary_driver(sdsi_aux_driver);
MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
MODULE_DESCRIPTION("Intel On Demand (SDSi) driver");
MODULE_LICENSE("GPL");