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/*
* Copyright (C) 2014 Intel Corporation
*
* Authors:
* Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* This device driver implements the TPM interface as defined in
* the TCG CRB 2.0 TPM specification.
*
* 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; version 2
* of the License.
*/
#include <linux/acpi.h>
#include <linux/highmem.h>
#include <linux/rculist.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include "tpm.h"
#define ACPI_SIG_TPM2 "TPM2"
static const u8 CRB_ACPI_START_UUID[] = {
/* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47,
/* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4
};
enum crb_defaults {
CRB_ACPI_START_REVISION_ID = 1,
CRB_ACPI_START_INDEX = 1,
};
enum crb_ca_request {
CRB_CA_REQ_GO_IDLE = BIT(0),
CRB_CA_REQ_CMD_READY = BIT(1),
};
enum crb_ca_status {
CRB_CA_STS_ERROR = BIT(0),
CRB_CA_STS_TPM_IDLE = BIT(1),
};
enum crb_start {
CRB_START_INVOKE = BIT(0),
};
enum crb_cancel {
CRB_CANCEL_INVOKE = BIT(0),
};
struct crb_control_area {
u32 req;
u32 sts;
u32 cancel;
u32 start;
u32 int_enable;
u32 int_sts;
u32 cmd_size;
u32 cmd_pa_low;
u32 cmd_pa_high;
u32 rsp_size;
u64 rsp_pa;
} __packed;
enum crb_status {
CRB_STS_COMPLETE = BIT(0),
};
enum crb_flags {
CRB_FL_ACPI_START = BIT(0),
CRB_FL_CRB_START = BIT(1),
};
struct crb_priv {
unsigned int flags;
void __iomem *iobase;
struct crb_control_area __iomem *cca;
u8 __iomem *cmd;
u8 __iomem *rsp;
};
static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
static u8 crb_status(struct tpm_chip *chip)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
u8 sts = 0;
if ((ioread32(&priv->cca->start) & CRB_START_INVOKE) !=
CRB_START_INVOKE)
sts |= CRB_STS_COMPLETE;
return sts;
}
static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
unsigned int expected;
/* sanity check */
if (count < 6)
return -EIO;
if (ioread32(&priv->cca->sts) & CRB_CA_STS_ERROR)
return -EIO;
memcpy_fromio(buf, priv->rsp, 6);
expected = be32_to_cpup((__be32 *) &buf[2]);
if (expected > count)
return -EIO;
memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
return expected;
}
static int crb_do_acpi_start(struct tpm_chip *chip)
{
union acpi_object *obj;
int rc;
obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
CRB_ACPI_START_UUID,
CRB_ACPI_START_REVISION_ID,
CRB_ACPI_START_INDEX,
NULL);
if (!obj)
return -ENXIO;
rc = obj->integer.value == 0 ? 0 : -ENXIO;
ACPI_FREE(obj);
return rc;
}
static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
int rc = 0;
if (len > ioread32(&priv->cca->cmd_size)) {
dev_err(&chip->dev,
"invalid command count value %x %zx\n",
(unsigned int) len,
(size_t) ioread32(&priv->cca->cmd_size));
return -E2BIG;
}
memcpy_toio(priv->cmd, buf, len);
/* Make sure that cmd is populated before issuing start. */
wmb();
if (priv->flags & CRB_FL_CRB_START)
iowrite32(cpu_to_le32(CRB_START_INVOKE), &priv->cca->start);
if (priv->flags & CRB_FL_ACPI_START)
rc = crb_do_acpi_start(chip);
return rc;
}
static void crb_cancel(struct tpm_chip *chip)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
iowrite32(cpu_to_le32(CRB_CANCEL_INVOKE), &priv->cca->cancel);
/* Make sure that cmd is populated before issuing cancel. */
wmb();
if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
dev_err(&chip->dev, "ACPI Start failed\n");
iowrite32(0, &priv->cca->cancel);
}
static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
{
struct crb_priv *priv = dev_get_drvdata(&chip->dev);
u32 cancel = ioread32(&priv->cca->cancel);
return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
}
static const struct tpm_class_ops tpm_crb = {
.status = crb_status,
.recv = crb_recv,
.send = crb_send,
.cancel = crb_cancel,
.req_canceled = crb_req_canceled,
.req_complete_mask = CRB_STS_COMPLETE,
.req_complete_val = CRB_STS_COMPLETE,
};
static int crb_init(struct acpi_device *device, struct crb_priv *priv)
{
struct tpm_chip *chip;
int rc;
chip = tpmm_chip_alloc(&device->dev, &tpm_crb);
if (IS_ERR(chip))
return PTR_ERR(chip);
dev_set_drvdata(&chip->dev, priv);
chip->acpi_dev_handle = device->handle;
chip->flags = TPM_CHIP_FLAG_TPM2;
rc = tpm_get_timeouts(chip);
if (rc)
return rc;
rc = tpm2_do_selftest(chip);
if (rc)
return rc;
return tpm_chip_register(chip);
}
static int crb_check_resource(struct acpi_resource *ares, void *data)
{
struct resource *io_res = data;
struct resource res;
if (acpi_dev_resource_memory(ares, &res)) {
*io_res = res;
io_res->name = NULL;
}
return 1;
}
static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv,
struct resource *io_res, u64 start, u32 size)
{
struct resource new_res = {
.start = start,
.end = start + size - 1,
.flags = IORESOURCE_MEM,
};
/* Detect a 64 bit address on a 32 bit system */
if (start != new_res.start)
return ERR_PTR(-EINVAL);
if (!resource_contains(io_res, &new_res))
return devm_ioremap_resource(dev, &new_res);
return priv->iobase + (new_res.start - io_res->start);
}
static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
struct acpi_table_tpm2 *buf)
{
struct list_head resources;
struct resource io_res;
struct device *dev = &device->dev;
u64 cmd_pa;
u32 cmd_size;
u64 rsp_pa;
u32 rsp_size;
int ret;
INIT_LIST_HEAD(&resources);
ret = acpi_dev_get_resources(device, &resources, crb_check_resource,
&io_res);
if (ret < 0)
return ret;
acpi_dev_free_resource_list(&resources);
if (resource_type(&io_res) != IORESOURCE_MEM) {
dev_err(dev,
FW_BUG "TPM2 ACPI table does not define a memory resource\n");
return -EINVAL;
}
priv->iobase = devm_ioremap_resource(dev, &io_res);
if (IS_ERR(priv->iobase))
return PTR_ERR(priv->iobase);
priv->cca = crb_map_res(dev, priv, &io_res, buf->control_address,
sizeof(struct crb_control_area));
if (IS_ERR(priv->cca))
return PTR_ERR(priv->cca);
cmd_pa = ((u64) ioread32(&priv->cca->cmd_pa_high) << 32) |
(u64) ioread32(&priv->cca->cmd_pa_low);
cmd_size = ioread32(&priv->cca->cmd_size);
priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size);
if (IS_ERR(priv->cmd))
return PTR_ERR(priv->cmd);
memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8);
rsp_pa = le64_to_cpu(rsp_pa);
rsp_size = ioread32(&priv->cca->rsp_size);
if (cmd_pa != rsp_pa) {
priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size);
return PTR_ERR_OR_ZERO(priv->rsp);
}
/* According to the PTP specification, overlapping command and response
* buffer sizes must be identical.
*/
if (cmd_size != rsp_size) {
dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
return -EINVAL;
}
priv->rsp = priv->cmd;
return 0;
}
static int crb_acpi_add(struct acpi_device *device)
{
struct acpi_table_tpm2 *buf;
struct crb_priv *priv;
struct device *dev = &device->dev;
acpi_status status;
u32 sm;
int rc;
status = acpi_get_table(ACPI_SIG_TPM2, 1,
(struct acpi_table_header **) &buf);
if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
return -EINVAL;
}
/* Should the FIFO driver handle this? */
sm = buf->start_method;
if (sm == ACPI_TPM2_MEMORY_MAPPED)
return -ENODEV;
priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
* report only ACPI start but in practice seems to require both
* ACPI start and CRB start.
*/
if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED ||
!strcmp(acpi_device_hid(device), "MSFT0101"))
priv->flags |= CRB_FL_CRB_START;
if (sm == ACPI_TPM2_START_METHOD ||
sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
priv->flags |= CRB_FL_ACPI_START;
rc = crb_map_io(device, priv, buf);
if (rc)
return rc;
return crb_init(device, priv);
}
static int crb_acpi_remove(struct acpi_device *device)
{
struct device *dev = &device->dev;
struct tpm_chip *chip = dev_get_drvdata(dev);
tpm_chip_unregister(chip);
return 0;
}
static struct acpi_device_id crb_device_ids[] = {
{"MSFT0101", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, crb_device_ids);
static struct acpi_driver crb_acpi_driver = {
.name = "tpm_crb",
.ids = crb_device_ids,
.ops = {
.add = crb_acpi_add,
.remove = crb_acpi_remove,
},
.drv = {
.pm = &crb_pm,
},
};
module_acpi_driver(crb_acpi_driver);
MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
MODULE_DESCRIPTION("TPM2 Driver");
MODULE_VERSION("0.1");
MODULE_LICENSE("GPL");
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