// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012-2020 IBM Corporation
*
* Author: Ashley Lai <[email protected]>
*
* Maintained by: <[email protected]>
*
* Device driver for TCG/TCPA TPM (trusted platform module).
* Specifications at www.trustedcomputinggroup.org
*/
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/slab.h>
#include <asm/vio.h>
#include <asm/irq.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <asm/prom.h>
#include "tpm.h"
#include "tpm_ibmvtpm.h"
static const char tpm_ibmvtpm_driver_name[] = "tpm_ibmvtpm";
static const struct vio_device_id tpm_ibmvtpm_device_table[] = {
{ "IBM,vtpm", "IBM,vtpm"},
{ "IBM,vtpm", "IBM,vtpm20"},
{ "", "" }
};
MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table);
/**
* ibmvtpm_send_crq_word() - Send a CRQ request
* @vdev: vio device struct
* @w1: pre-constructed first word of tpm crq (second word is reserved)
*
* Return:
* 0 - Success
* Non-zero - Failure
*/
static int ibmvtpm_send_crq_word(struct vio_dev *vdev, u64 w1)
{
return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, 0);
}
/**
* ibmvtpm_send_crq() - Send a CRQ request
*
* @vdev: vio device struct
* @valid: Valid field
* @msg: Type field
* @len: Length field
* @data: Data field
*
* The ibmvtpm crq is defined as follows:
*
* Byte | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7
* -----------------------------------------------------------------------
* Word0 | Valid | Type | Length | Data
* -----------------------------------------------------------------------
* Word1 | Reserved
* -----------------------------------------------------------------------
*
* Which matches the following structure (on bigendian host):
*
* struct ibmvtpm_crq {
* u8 valid;
* u8 msg;
* __be16 len;
* __be32 data;
* __be64 reserved;
* } __attribute__((packed, aligned(8)));
*
* However, the value is passed in a register so just compute the numeric value
* to load into the register avoiding byteswap altogether. Endian only affects
* memory loads and stores - registers are internally represented the same.
*
* Return:
* 0 (H_SUCCESS) - Success
* Non-zero - Failure
*/
static int ibmvtpm_send_crq(struct vio_dev *vdev,
u8 valid, u8 msg, u16 len, u32 data)
{
u64 w1 = ((u64)valid << 56) | ((u64)msg << 48) | ((u64)len << 32) |
(u64)data;
return ibmvtpm_send_crq_word(vdev, w1);
}
/**
* tpm_ibmvtpm_recv - Receive data after send
*
* @chip: tpm chip struct
* @buf: buffer to read
* @count: size of buffer
*
* Return:
* Number of bytes read
*/
static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
u16 len;
if (!ibmvtpm->rtce_buf) {
dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
return 0;
}
len = ibmvtpm->res_len;
if (count < len) {
dev_err(ibmvtpm->dev,
"Invalid size in recv: count=%zd, crq_size=%d\n",
count, len);
return -EIO;
}
spin_lock(&ibmvtpm->rtce_lock);
memcpy((void *)buf, (void *)ibmvtpm->rtce_buf, len);
memset(ibmvtpm->rtce_buf, 0, len);
ibmvtpm->res_len = 0;
spin_unlock(&ibmvtpm->rtce_lock);
return len;
}
/**
* ibmvtpm_crq_send_init - Send a CRQ initialize message
* @ibmvtpm: vtpm device struct
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
{
int rc;
rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_CMD);
if (rc != H_SUCCESS)
dev_err(ibmvtpm->dev,
"%s failed rc=%d\n", __func__, rc);
return rc;
}
/**
* tpm_ibmvtpm_resume - Resume from suspend
*
* @dev: device struct
*
* Return: Always 0.
*/
static int tpm_ibmvtpm_resume(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
int rc = 0;
do {
if (rc)
msleep(100);
rc = plpar_hcall_norets(H_ENABLE_CRQ,
ibmvtpm->vdev->unit_address);
} while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));
if (rc) {
dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
return rc;
}
rc = vio_enable_interrupts(ibmvtpm->vdev);
if (rc) {
dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
return rc;
}
rc = ibmvtpm_crq_send_init(ibmvtpm);
if (rc)
dev_err(dev, "Error send_init rc=%d\n", rc);
return rc;
}
/**
* tpm_ibmvtpm_send() - Send a TPM command
* @chip: tpm chip struct
* @buf: buffer contains data to send
* @count: size of buffer
*
* Return:
* 0 on success,
* -errno on error
*/
static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
{
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
bool retry = true;
int rc, sig;
if (!ibmvtpm->rtce_buf) {
dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n");
return 0;
}
if (count > ibmvtpm->rtce_size) {
dev_err(ibmvtpm->dev,
"Invalid size in send: count=%zd, rtce_size=%d\n",
count, ibmvtpm->rtce_size);
return -EIO;
}
if (ibmvtpm->tpm_processing_cmd) {
dev_info(ibmvtpm->dev,
"Need to wait for TPM to finish\n");
/* wait for previous command to finish */
sig = wait_event_interruptible(ibmvtpm->wq, !ibmvtpm->tpm_processing_cmd);
if (sig)
return -EINTR;
}
spin_lock(&ibmvtpm->rtce_lock);
ibmvtpm->res_len = 0;
memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count);
/*
* set the processing flag before the Hcall, since we may get the
* result (interrupt) before even being able to check rc.
*/
ibmvtpm->tpm_processing_cmd = 1;
again:
rc = ibmvtpm_send_crq(ibmvtpm->vdev,
IBMVTPM_VALID_CMD, VTPM_TPM_COMMAND,
count, ibmvtpm->rtce_dma_handle);
if (rc != H_SUCCESS) {
/*
* H_CLOSED can be returned after LPM resume. Call
* tpm_ibmvtpm_resume() to re-enable the CRQ then retry
* ibmvtpm_send_crq() once before failing.
*/
if (rc == H_CLOSED && retry) {
tpm_ibmvtpm_resume(ibmvtpm->dev);
retry = false;
goto again;
}
dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
ibmvtpm->tpm_processing_cmd = 0;
}
spin_unlock(&ibmvtpm->rtce_lock);
return 0;
}
static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
{
return;
}
static u8 tpm_ibmvtpm_status(struct tpm_chip *chip)
{
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
return ibmvtpm->tpm_processing_cmd;
}
/**
* ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size
*
* @ibmvtpm: vtpm device struct
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm)
{
int rc;
rc = ibmvtpm_send_crq(ibmvtpm->vdev,
IBMVTPM_VALID_CMD, VTPM_GET_RTCE_BUFFER_SIZE, 0, 0);
if (rc != H_SUCCESS)
dev_err(ibmvtpm->dev,
"ibmvtpm_crq_get_rtce_size failed rc=%d\n", rc);
return rc;
}
/**
* ibmvtpm_crq_get_version - Send a CRQ request to get vtpm version
* - Note that this is vtpm version and not tpm version
*
* @ibmvtpm: vtpm device struct
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm)
{
int rc;
rc = ibmvtpm_send_crq(ibmvtpm->vdev,
IBMVTPM_VALID_CMD, VTPM_GET_VERSION, 0, 0);
if (rc != H_SUCCESS)
dev_err(ibmvtpm->dev,
"ibmvtpm_crq_get_version failed rc=%d\n", rc);
return rc;
}
/**
* ibmvtpm_crq_send_init_complete - Send a CRQ initialize complete message
* @ibmvtpm: vtpm device struct
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
{
int rc;
rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_COMP_CMD);
if (rc != H_SUCCESS)
dev_err(ibmvtpm->dev,
"ibmvtpm_crq_send_init_complete failed rc=%d\n", rc);
return rc;
}
/**
* tpm_ibmvtpm_remove - ibm vtpm remove entry point
* @vdev: vio device struct
*
* Return: Always 0.
*/
static void tpm_ibmvtpm_remove(struct vio_dev *vdev)
{
struct tpm_chip *chip = dev_get_drvdata(&vdev->dev);
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
int rc = 0;
tpm_chip_unregister(chip);
free_irq(vdev->irq, ibmvtpm);
do {
if (rc)
msleep(100);
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle,
CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL);
free_page((unsigned long)ibmvtpm->crq_queue.crq_addr);
if (ibmvtpm->rtce_buf) {
dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle,
ibmvtpm->rtce_size, DMA_BIDIRECTIONAL);
kfree(ibmvtpm->rtce_buf);
}
kfree(ibmvtpm);
/* For tpm_ibmvtpm_get_desired_dma */
dev_set_drvdata(&vdev->dev, NULL);
}
/**
* tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver
* @vdev: vio device struct
*
* Return:
* Number of bytes the driver needs to DMA map.
*/
static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev)
{
struct tpm_chip *chip = dev_get_drvdata(&vdev->dev);
struct ibmvtpm_dev *ibmvtpm;
/*
* ibmvtpm initializes at probe time, so the data we are
* asking for may not be set yet. Estimate that 4K required
* for TCE-mapped buffer in addition to CRQ.
*/
if (chip)
ibmvtpm = dev_get_drvdata(&chip->dev);
else
return CRQ_RES_BUF_SIZE + PAGE_SIZE;
return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size;
}
/**
* tpm_ibmvtpm_suspend - Suspend
* @dev: device struct
*
* Return: Always 0.
*/
static int tpm_ibmvtpm_suspend(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
int rc = 0;
rc = ibmvtpm_send_crq(ibmvtpm->vdev,
IBMVTPM_VALID_CMD, VTPM_PREPARE_TO_SUSPEND, 0, 0);
if (rc != H_SUCCESS)
dev_err(ibmvtpm->dev,
"tpm_ibmvtpm_suspend failed rc=%d\n", rc);
return rc;
}
/**
* ibmvtpm_reset_crq - Reset CRQ
*
* @ibmvtpm: ibm vtpm struct
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
{
int rc = 0;
do {
if (rc)
msleep(100);
rc = plpar_hcall_norets(H_FREE_CRQ,
ibmvtpm->vdev->unit_address);
} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));
memset(ibmvtpm->crq_queue.crq_addr, 0, CRQ_RES_BUF_SIZE);
ibmvtpm->crq_queue.index = 0;
return plpar_hcall_norets(H_REG_CRQ, ibmvtpm->vdev->unit_address,
ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
}
static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status)
{
return (status == 0);
}
static const struct tpm_class_ops tpm_ibmvtpm = {
.recv = tpm_ibmvtpm_recv,
.send = tpm_ibmvtpm_send,
.cancel = tpm_ibmvtpm_cancel,
.status = tpm_ibmvtpm_status,
.req_complete_mask = 1,
.req_complete_val = 0,
.req_canceled = tpm_ibmvtpm_req_canceled,
};
static const struct dev_pm_ops tpm_ibmvtpm_pm_ops = {
.suspend = tpm_ibmvtpm_suspend,
.resume = tpm_ibmvtpm_resume,
};
/**
* ibmvtpm_crq_get_next - Get next responded crq
*
* @ibmvtpm: vtpm device struct
*
* Return: vtpm crq pointer or NULL.
*/
static struct ibmvtpm_crq *ibmvtpm_crq_get_next(struct ibmvtpm_dev *ibmvtpm)
{
struct ibmvtpm_crq_queue *crq_q = &ibmvtpm->crq_queue;
struct ibmvtpm_crq *crq = &crq_q->crq_addr[crq_q->index];
if (crq->valid & VTPM_MSG_RES) {
if (++crq_q->index == crq_q->num_entry)
crq_q->index = 0;
smp_rmb();
} else
crq = NULL;
return crq;
}
/**
* ibmvtpm_crq_process - Process responded crq
*
* @crq: crq to be processed
* @ibmvtpm: vtpm device struct
*
*/
static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
struct ibmvtpm_dev *ibmvtpm)
{
int rc = 0;
switch (crq->valid) {
case VALID_INIT_CRQ:
switch (crq->msg) {
case INIT_CRQ_RES:
dev_info(ibmvtpm->dev, "CRQ initialized\n");
rc = ibmvtpm_crq_send_init_complete(ibmvtpm);
if (rc)
dev_err(ibmvtpm->dev, "Unable to send CRQ init complete rc=%d\n", rc);
return;
case INIT_CRQ_COMP_RES:
dev_info(ibmvtpm->dev,
"CRQ initialization completed\n");
return;
default:
dev_err(ibmvtpm->dev, "Unknown crq message type: %d\n", crq->msg);
return;
}
case IBMVTPM_VALID_CMD:
switch (crq->msg) {
case VTPM_GET_RTCE_BUFFER_SIZE_RES:
if (be16_to_cpu(crq->len) <= 0) {
dev_err(ibmvtpm->dev, "Invalid rtce size\n");
return;
}
ibmvtpm->rtce_size = be16_to_cpu(crq->len);
ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size,
GFP_ATOMIC);
if (!ibmvtpm->rtce_buf) {
dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n");
return;
}
ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev,
ibmvtpm->rtce_buf, ibmvtpm->rtce_size,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(ibmvtpm->dev,
ibmvtpm->rtce_dma_handle)) {
kfree(ibmvtpm->rtce_buf);
ibmvtpm->rtce_buf = NULL;
dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n");
}
return;
case VTPM_GET_VERSION_RES:
ibmvtpm->vtpm_version = be32_to_cpu(crq->data);
return;
case VTPM_TPM_COMMAND_RES:
/* len of the data in rtce buffer */
ibmvtpm->res_len = be16_to_cpu(crq->len);
ibmvtpm->tpm_processing_cmd = 0;
wake_up_interruptible(&ibmvtpm->wq);
return;
default:
return;
}
}
return;
}
/**
* ibmvtpm_interrupt - Interrupt handler
*
* @irq: irq number to handle
* @vtpm_instance: vtpm that received interrupt
*
* Returns:
* IRQ_HANDLED
**/
static irqreturn_t ibmvtpm_interrupt(int irq, void *vtpm_instance)
{
struct ibmvtpm_dev *ibmvtpm = (struct ibmvtpm_dev *) vtpm_instance;
struct ibmvtpm_crq *crq;
/* while loop is needed for initial setup (get version and
* get rtce_size). There should be only one tpm request at any
* given time.
*/
while ((crq = ibmvtpm_crq_get_next(ibmvtpm)) != NULL) {
ibmvtpm_crq_process(crq, ibmvtpm);
wake_up_interruptible(&ibmvtpm->crq_queue.wq);
crq->valid = 0;
smp_wmb();
}
return IRQ_HANDLED;
}
/**
* tpm_ibmvtpm_probe - ibm vtpm initialize entry point
*
* @vio_dev: vio device struct
* @id: vio device id struct
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
const struct vio_device_id *id)
{
struct ibmvtpm_dev *ibmvtpm;
struct device *dev = &vio_dev->dev;
struct ibmvtpm_crq_queue *crq_q;
struct tpm_chip *chip;
int rc = -ENOMEM, rc1;
chip = tpmm_chip_alloc(dev, &tpm_ibmvtpm);
if (IS_ERR(chip))
return PTR_ERR(chip);
ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL);
if (!ibmvtpm) {
dev_err(dev, "kzalloc for ibmvtpm failed\n");
goto cleanup;
}
ibmvtpm->dev = dev;
ibmvtpm->vdev = vio_dev;
crq_q = &ibmvtpm->crq_queue;
crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL);
if (!crq_q->crq_addr) {
dev_err(dev, "Unable to allocate memory for crq_addr\n");
goto cleanup;
}
crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
init_waitqueue_head(&crq_q->wq);
ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
CRQ_RES_BUF_SIZE,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) {
dev_err(dev, "dma mapping failed\n");
goto cleanup;
}
rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address,
ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
if (rc == H_RESOURCE)
rc = ibmvtpm_reset_crq(ibmvtpm);
if (rc) {
dev_err(dev, "Unable to register CRQ rc=%d\n", rc);
goto reg_crq_cleanup;
}
rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
tpm_ibmvtpm_driver_name, ibmvtpm);
if (rc) {
dev_err(dev, "Error %d register irq 0x%x\n", rc, vio_dev->irq);
goto init_irq_cleanup;
}
rc = vio_enable_interrupts(vio_dev);
if (rc) {
dev_err(dev, "Error %d enabling interrupts\n", rc);
goto init_irq_cleanup;
}
init_waitqueue_head(&ibmvtpm->wq);
crq_q->index = 0;
dev_set_drvdata(&chip->dev, ibmvtpm);
spin_lock_init(&ibmvtpm->rtce_lock);
rc = ibmvtpm_crq_send_init(ibmvtpm);
if (rc)
goto init_irq_cleanup;
rc = ibmvtpm_crq_get_version(ibmvtpm);
if (rc)
goto init_irq_cleanup;
rc = ibmvtpm_crq_get_rtce_size(ibmvtpm);
if (rc)
goto init_irq_cleanup;
if (!wait_event_timeout(ibmvtpm->crq_queue.wq,
ibmvtpm->rtce_buf != NULL,
HZ)) {
rc = -ENODEV;
dev_err(dev, "CRQ response timed out\n");
goto init_irq_cleanup;
}
if (!strcmp(id->compat, "IBM,vtpm20"))
chip->flags |= TPM_CHIP_FLAG_TPM2;
rc = tpm_get_timeouts(chip);
if (rc)
goto init_irq_cleanup;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm2_get_cc_attrs_tbl(chip);
if (rc)
goto init_irq_cleanup;
rc = tpm2_sessions_init(chip);
if (rc)
goto init_irq_cleanup;
}
return tpm_chip_register(chip);
init_irq_cleanup:
do {
rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
} while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
reg_crq_cleanup:
dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE,
DMA_BIDIRECTIONAL);
cleanup:
if (ibmvtpm) {
if (crq_q->crq_addr)
free_page((unsigned long)crq_q->crq_addr);
kfree(ibmvtpm);
}
return rc;
}
static struct vio_driver ibmvtpm_driver = {
.id_table = tpm_ibmvtpm_device_table,
.probe = tpm_ibmvtpm_probe,
.remove = tpm_ibmvtpm_remove,
.get_desired_dma = tpm_ibmvtpm_get_desired_dma,
.name = tpm_ibmvtpm_driver_name,
.pm = &tpm_ibmvtpm_pm_ops,
};
/**
* ibmvtpm_module_init - Initialize ibm vtpm module.
*
*
* Return:
* 0 on success.
* Non-zero on failure.
*/
static int __init ibmvtpm_module_init(void)
{
return vio_register_driver(&ibmvtpm_driver);
}
/**
* ibmvtpm_module_exit - Tear down ibm vtpm module.
*/
static void __exit ibmvtpm_module_exit(void)
{
vio_unregister_driver(&ibmvtpm_driver);
}
module_init(ibmvtpm_module_init);
module_exit(ibmvtpm_module_exit);
MODULE_AUTHOR("[email protected]");
MODULE_DESCRIPTION("IBM vTPM Driver");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");
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