diff options
Diffstat (limited to 'drivers/char/tpm/tpm_ibmvtpm.c')
| -rw-r--r-- | drivers/char/tpm/tpm_ibmvtpm.c | 700 |
1 files changed, 700 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c new file mode 100644 index 000000000..27ebf9511 --- /dev/null +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -0,0 +1,700 @@ +/* + * Copyright (C) 2012 IBM Corporation + * + * Author: Ashley Lai <ashleydlai@gmail.com> + * + * Maintained by: <tpmdd-devel@lists.sourceforge.net> + * + * Device driver for TCG/TCPA TPM (trusted platform module). + * Specifications at www.trustedcomputinggroup.org + * + * 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/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 struct vio_device_id tpm_ibmvtpm_device_table[] = { + { "IBM,vtpm", "IBM,vtpm"}, + { "", "" } +}; +MODULE_DEVICE_TABLE(vio, tpm_ibmvtpm_device_table); + +/** + * ibmvtpm_send_crq - Send a CRQ request + * @vdev: vio device struct + * @w1: first word + * @w2: second word + * + * Return value: + * 0 -Sucess + * Non-zero - Failure + */ +static int ibmvtpm_send_crq(struct vio_dev *vdev, u64 w1, u64 w2) +{ + return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, w1, w2); +} + +/** + * ibmvtpm_get_data - Retrieve ibm vtpm data + * @dev: device struct + * + * Return value: + * vtpm device struct + */ +static struct ibmvtpm_dev *ibmvtpm_get_data(const struct device *dev) +{ + struct tpm_chip *chip = dev_get_drvdata(dev); + if (chip) + return (struct ibmvtpm_dev *)TPM_VPRIV(chip); + return NULL; +} + +/** + * tpm_ibmvtpm_recv - Receive data after send + * @chip: tpm chip struct + * @buf: buffer to read + * count: size of buffer + * + * Return value: + * Number of bytes read + */ +static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct ibmvtpm_dev *ibmvtpm; + u16 len; + int sig; + + ibmvtpm = (struct ibmvtpm_dev *)TPM_VPRIV(chip); + + if (!ibmvtpm->rtce_buf) { + dev_err(ibmvtpm->dev, "ibmvtpm device is not ready\n"); + return 0; + } + + sig = wait_event_interruptible(ibmvtpm->wq, ibmvtpm->res_len != 0); + if (sig) + return -EINTR; + + 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; +} + +/** + * tpm_ibmvtpm_send - Send tpm request + * @chip: tpm chip struct + * @buf: buffer contains data to send + * count: size of buffer + * + * Return value: + * Number of bytes sent + */ +static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct ibmvtpm_dev *ibmvtpm; + struct ibmvtpm_crq crq; + __be64 *word = (__be64 *)&crq; + int rc; + + ibmvtpm = (struct ibmvtpm_dev *)TPM_VPRIV(chip); + + 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; + } + + spin_lock(&ibmvtpm->rtce_lock); + memcpy((void *)ibmvtpm->rtce_buf, (void *)buf, count); + crq.valid = (u8)IBMVTPM_VALID_CMD; + crq.msg = (u8)VTPM_TPM_COMMAND; + crq.len = cpu_to_be16(count); + crq.data = cpu_to_be32(ibmvtpm->rtce_dma_handle); + + rc = ibmvtpm_send_crq(ibmvtpm->vdev, be64_to_cpu(word[0]), + be64_to_cpu(word[1])); + if (rc != H_SUCCESS) { + dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc); + rc = 0; + } else + rc = count; + + spin_unlock(&ibmvtpm->rtce_lock); + return rc; +} + +static void tpm_ibmvtpm_cancel(struct tpm_chip *chip) +{ + return; +} + +static u8 tpm_ibmvtpm_status(struct tpm_chip *chip) +{ + return 0; +} + +/** + * ibmvtpm_crq_get_rtce_size - Send a CRQ request to get rtce size + * @ibmvtpm: vtpm device struct + * + * Return value: + * 0 - Success + * Non-zero - Failure + */ +static int ibmvtpm_crq_get_rtce_size(struct ibmvtpm_dev *ibmvtpm) +{ + struct ibmvtpm_crq crq; + u64 *buf = (u64 *) &crq; + int rc; + + crq.valid = (u8)IBMVTPM_VALID_CMD; + crq.msg = (u8)VTPM_GET_RTCE_BUFFER_SIZE; + + rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]), + cpu_to_be64(buf[1])); + 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 value: + * 0 - Success + * Non-zero - Failure + */ +static int ibmvtpm_crq_get_version(struct ibmvtpm_dev *ibmvtpm) +{ + struct ibmvtpm_crq crq; + u64 *buf = (u64 *) &crq; + int rc; + + crq.valid = (u8)IBMVTPM_VALID_CMD; + crq.msg = (u8)VTPM_GET_VERSION; + + rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]), + cpu_to_be64(buf[1])); + 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 value: + * 0 - Success + * Non-zero - Failure + */ +static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm) +{ + int rc; + + rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_COMP_CMD, 0); + if (rc != H_SUCCESS) + dev_err(ibmvtpm->dev, + "ibmvtpm_crq_send_init_complete failed rc=%d\n", rc); + + return rc; +} + +/** + * ibmvtpm_crq_send_init - Send a CRQ initialize message + * @ibmvtpm: vtpm device struct + * + * Return value: + * 0 - Success + * Non-zero - Failure + */ +static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm) +{ + int rc; + + rc = ibmvtpm_send_crq(ibmvtpm->vdev, INIT_CRQ_CMD, 0); + if (rc != H_SUCCESS) + dev_err(ibmvtpm->dev, + "ibmvtpm_crq_send_init failed rc=%d\n", rc); + + return rc; +} + +/** + * tpm_ibmvtpm_remove - ibm vtpm remove entry point + * @vdev: vio device struct + * + * Return value: + * 0 + */ +static int tpm_ibmvtpm_remove(struct vio_dev *vdev) +{ + struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev); + struct tpm_chip *chip = dev_get_drvdata(ibmvtpm->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); + + return 0; +} + +/** + * tpm_ibmvtpm_get_desired_dma - Get DMA size needed by this driver + * @vdev: vio device struct + * + * Return value: + * Number of bytes the driver needs to DMA map + */ +static unsigned long tpm_ibmvtpm_get_desired_dma(struct vio_dev *vdev) +{ + struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev); + + /* 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 (!ibmvtpm) + return CRQ_RES_BUF_SIZE + PAGE_SIZE; + + return CRQ_RES_BUF_SIZE + ibmvtpm->rtce_size; +} + +/** + * tpm_ibmvtpm_suspend - Suspend + * @dev: device struct + * + * Return value: + * 0 + */ +static int tpm_ibmvtpm_suspend(struct device *dev) +{ + struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(dev); + struct ibmvtpm_crq crq; + u64 *buf = (u64 *) &crq; + int rc = 0; + + crq.valid = (u8)IBMVTPM_VALID_CMD; + crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND; + + rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]), + cpu_to_be64(buf[1])); + 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 value: + * 0 - Success + * Non-zero - 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); +} + +/** + * tpm_ibmvtpm_resume - Resume from suspend + * @dev: device struct + * + * Return value: + * 0 + */ +static int tpm_ibmvtpm_resume(struct device *dev) +{ + struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(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; +} + +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 = 0, + .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 value: + * vtpm crq pointer + */ +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 + * + * Return value: + * Nothing + */ +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_KERNEL); + 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); + 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); + 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 value: + * 0 - Success + * Non-zero - 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); + 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; + + TPM_VPRIV(chip) = (void *)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; + + 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 value: + * 0 -Success + * Non-zero - Failure + */ +static int __init ibmvtpm_module_init(void) +{ + return vio_register_driver(&ibmvtpm_driver); +} + +/** + * ibmvtpm_module_exit - Teardown ibm vtpm module + * + * Return value: + * Nothing + */ +static void __exit ibmvtpm_module_exit(void) +{ + vio_unregister_driver(&ibmvtpm_driver); +} + +module_init(ibmvtpm_module_init); +module_exit(ibmvtpm_module_exit); + +MODULE_AUTHOR("adlai@us.ibm.com"); +MODULE_DESCRIPTION("IBM vTPM Driver"); +MODULE_VERSION("1.0"); +MODULE_LICENSE("GPL"); |