diff options
Diffstat (limited to 'drivers/crypto/ccp/ccp-dev.c')
| -rw-r--r-- | drivers/crypto/ccp/ccp-dev.c | 670 |
1 files changed, 670 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/ccp-dev.c b/drivers/crypto/ccp/ccp-dev.c new file mode 100644 index 000000000..c531d13d9 --- /dev/null +++ b/drivers/crypto/ccp/ccp-dev.c @@ -0,0 +1,670 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD Cryptographic Coprocessor (CCP) driver + * + * Copyright (C) 2013,2019 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lendacky@amd.com> + * Author: Gary R Hook <gary.hook@amd.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/kthread.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/spinlock_types.h> +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/delay.h> +#include <linux/hw_random.h> +#include <linux/cpu.h> +#include <linux/atomic.h> +#ifdef CONFIG_X86 +#include <asm/cpu_device_id.h> +#endif +#include <linux/ccp.h> + +#include "ccp-dev.h" + +#define MAX_CCPS 32 + +/* Limit CCP use to a specifed number of queues per device */ +static unsigned int nqueues; +module_param(nqueues, uint, 0444); +MODULE_PARM_DESC(nqueues, "Number of queues per CCP (minimum 1; default: all available)"); + +/* Limit the maximum number of configured CCPs */ +static atomic_t dev_count = ATOMIC_INIT(0); +static unsigned int max_devs = MAX_CCPS; +module_param(max_devs, uint, 0444); +MODULE_PARM_DESC(max_devs, "Maximum number of CCPs to enable (default: all; 0 disables all CCPs)"); + +struct ccp_tasklet_data { + struct completion completion; + struct ccp_cmd *cmd; +}; + +/* Human-readable error strings */ +#define CCP_MAX_ERROR_CODE 64 +static char *ccp_error_codes[] = { + "", + "ILLEGAL_ENGINE", + "ILLEGAL_KEY_ID", + "ILLEGAL_FUNCTION_TYPE", + "ILLEGAL_FUNCTION_MODE", + "ILLEGAL_FUNCTION_ENCRYPT", + "ILLEGAL_FUNCTION_SIZE", + "Zlib_MISSING_INIT_EOM", + "ILLEGAL_FUNCTION_RSVD", + "ILLEGAL_BUFFER_LENGTH", + "VLSB_FAULT", + "ILLEGAL_MEM_ADDR", + "ILLEGAL_MEM_SEL", + "ILLEGAL_CONTEXT_ID", + "ILLEGAL_KEY_ADDR", + "0xF Reserved", + "Zlib_ILLEGAL_MULTI_QUEUE", + "Zlib_ILLEGAL_JOBID_CHANGE", + "CMD_TIMEOUT", + "IDMA0_AXI_SLVERR", + "IDMA0_AXI_DECERR", + "0x15 Reserved", + "IDMA1_AXI_SLAVE_FAULT", + "IDMA1_AIXI_DECERR", + "0x18 Reserved", + "ZLIBVHB_AXI_SLVERR", + "ZLIBVHB_AXI_DECERR", + "0x1B Reserved", + "ZLIB_UNEXPECTED_EOM", + "ZLIB_EXTRA_DATA", + "ZLIB_BTYPE", + "ZLIB_UNDEFINED_SYMBOL", + "ZLIB_UNDEFINED_DISTANCE_S", + "ZLIB_CODE_LENGTH_SYMBOL", + "ZLIB _VHB_ILLEGAL_FETCH", + "ZLIB_UNCOMPRESSED_LEN", + "ZLIB_LIMIT_REACHED", + "ZLIB_CHECKSUM_MISMATCH0", + "ODMA0_AXI_SLVERR", + "ODMA0_AXI_DECERR", + "0x28 Reserved", + "ODMA1_AXI_SLVERR", + "ODMA1_AXI_DECERR", +}; + +void ccp_log_error(struct ccp_device *d, unsigned int e) +{ + if (WARN_ON(e >= CCP_MAX_ERROR_CODE)) + return; + + if (e < ARRAY_SIZE(ccp_error_codes)) + dev_err(d->dev, "CCP error %d: %s\n", e, ccp_error_codes[e]); + else + dev_err(d->dev, "CCP error %d: Unknown Error\n", e); +} + +/* List of CCPs, CCP count, read-write access lock, and access functions + * + * Lock structure: get ccp_unit_lock for reading whenever we need to + * examine the CCP list. While holding it for reading we can acquire + * the RR lock to update the round-robin next-CCP pointer. The unit lock + * must be acquired before the RR lock. + * + * If the unit-lock is acquired for writing, we have total control over + * the list, so there's no value in getting the RR lock. + */ +static DEFINE_RWLOCK(ccp_unit_lock); +static LIST_HEAD(ccp_units); + +/* Round-robin counter */ +static DEFINE_SPINLOCK(ccp_rr_lock); +static struct ccp_device *ccp_rr; + +/** + * ccp_add_device - add a CCP device to the list + * + * @ccp: ccp_device struct pointer + * + * Put this CCP on the unit list, which makes it available + * for use. + * + * Returns zero if a CCP device is present, -ENODEV otherwise. + */ +void ccp_add_device(struct ccp_device *ccp) +{ + unsigned long flags; + + write_lock_irqsave(&ccp_unit_lock, flags); + list_add_tail(&ccp->entry, &ccp_units); + if (!ccp_rr) + /* We already have the list lock (we're first) so this + * pointer can't change on us. Set its initial value. + */ + ccp_rr = ccp; + write_unlock_irqrestore(&ccp_unit_lock, flags); +} + +/** + * ccp_del_device - remove a CCP device from the list + * + * @ccp: ccp_device struct pointer + * + * Remove this unit from the list of devices. If the next device + * up for use is this one, adjust the pointer. If this is the last + * device, NULL the pointer. + */ +void ccp_del_device(struct ccp_device *ccp) +{ + unsigned long flags; + + write_lock_irqsave(&ccp_unit_lock, flags); + if (ccp_rr == ccp) { + /* ccp_unit_lock is read/write; any read access + * will be suspended while we make changes to the + * list and RR pointer. + */ + if (list_is_last(&ccp_rr->entry, &ccp_units)) + ccp_rr = list_first_entry(&ccp_units, struct ccp_device, + entry); + else + ccp_rr = list_next_entry(ccp_rr, entry); + } + list_del(&ccp->entry); + if (list_empty(&ccp_units)) + ccp_rr = NULL; + write_unlock_irqrestore(&ccp_unit_lock, flags); +} + + + +int ccp_register_rng(struct ccp_device *ccp) +{ + int ret = 0; + + dev_dbg(ccp->dev, "Registering RNG...\n"); + /* Register an RNG */ + ccp->hwrng.name = ccp->rngname; + ccp->hwrng.read = ccp_trng_read; + ret = hwrng_register(&ccp->hwrng); + if (ret) + dev_err(ccp->dev, "error registering hwrng (%d)\n", ret); + + return ret; +} + +void ccp_unregister_rng(struct ccp_device *ccp) +{ + if (ccp->hwrng.name) + hwrng_unregister(&ccp->hwrng); +} + +static struct ccp_device *ccp_get_device(void) +{ + unsigned long flags; + struct ccp_device *dp = NULL; + + /* We round-robin through the unit list. + * The (ccp_rr) pointer refers to the next unit to use. + */ + read_lock_irqsave(&ccp_unit_lock, flags); + if (!list_empty(&ccp_units)) { + spin_lock(&ccp_rr_lock); + dp = ccp_rr; + if (list_is_last(&ccp_rr->entry, &ccp_units)) + ccp_rr = list_first_entry(&ccp_units, struct ccp_device, + entry); + else + ccp_rr = list_next_entry(ccp_rr, entry); + spin_unlock(&ccp_rr_lock); + } + read_unlock_irqrestore(&ccp_unit_lock, flags); + + return dp; +} + +/** + * ccp_present - check if a CCP device is present + * + * Returns zero if a CCP device is present, -ENODEV otherwise. + */ +int ccp_present(void) +{ + unsigned long flags; + int ret; + + read_lock_irqsave(&ccp_unit_lock, flags); + ret = list_empty(&ccp_units); + read_unlock_irqrestore(&ccp_unit_lock, flags); + + return ret ? -ENODEV : 0; +} +EXPORT_SYMBOL_GPL(ccp_present); + +/** + * ccp_version - get the version of the CCP device + * + * Returns the version from the first unit on the list; + * otherwise a zero if no CCP device is present + */ +unsigned int ccp_version(void) +{ + struct ccp_device *dp; + unsigned long flags; + int ret = 0; + + read_lock_irqsave(&ccp_unit_lock, flags); + if (!list_empty(&ccp_units)) { + dp = list_first_entry(&ccp_units, struct ccp_device, entry); + ret = dp->vdata->version; + } + read_unlock_irqrestore(&ccp_unit_lock, flags); + + return ret; +} +EXPORT_SYMBOL_GPL(ccp_version); + +/** + * ccp_enqueue_cmd - queue an operation for processing by the CCP + * + * @cmd: ccp_cmd struct to be processed + * + * Queue a cmd to be processed by the CCP. If queueing the cmd + * would exceed the defined length of the cmd queue the cmd will + * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will + * result in a return code of -EBUSY. + * + * The callback routine specified in the ccp_cmd struct will be + * called to notify the caller of completion (if the cmd was not + * backlogged) or advancement out of the backlog. If the cmd has + * advanced out of the backlog the "err" value of the callback + * will be -EINPROGRESS. Any other "err" value during callback is + * the result of the operation. + * + * The cmd has been successfully queued if: + * the return code is -EINPROGRESS or + * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set + */ +int ccp_enqueue_cmd(struct ccp_cmd *cmd) +{ + struct ccp_device *ccp; + unsigned long flags; + unsigned int i; + int ret; + + /* Some commands might need to be sent to a specific device */ + ccp = cmd->ccp ? cmd->ccp : ccp_get_device(); + + if (!ccp) + return -ENODEV; + + /* Caller must supply a callback routine */ + if (!cmd->callback) + return -EINVAL; + + cmd->ccp = ccp; + + spin_lock_irqsave(&ccp->cmd_lock, flags); + + i = ccp->cmd_q_count; + + if (ccp->cmd_count >= MAX_CMD_QLEN) { + if (cmd->flags & CCP_CMD_MAY_BACKLOG) { + ret = -EBUSY; + list_add_tail(&cmd->entry, &ccp->backlog); + } else { + ret = -ENOSPC; + } + } else { + ret = -EINPROGRESS; + ccp->cmd_count++; + list_add_tail(&cmd->entry, &ccp->cmd); + + /* Find an idle queue */ + if (!ccp->suspending) { + for (i = 0; i < ccp->cmd_q_count; i++) { + if (ccp->cmd_q[i].active) + continue; + + break; + } + } + } + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); + + /* If we found an idle queue, wake it up */ + if (i < ccp->cmd_q_count) + wake_up_process(ccp->cmd_q[i].kthread); + + return ret; +} +EXPORT_SYMBOL_GPL(ccp_enqueue_cmd); + +static void ccp_do_cmd_backlog(struct work_struct *work) +{ + struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work); + struct ccp_device *ccp = cmd->ccp; + unsigned long flags; + unsigned int i; + + cmd->callback(cmd->data, -EINPROGRESS); + + spin_lock_irqsave(&ccp->cmd_lock, flags); + + ccp->cmd_count++; + list_add_tail(&cmd->entry, &ccp->cmd); + + /* Find an idle queue */ + for (i = 0; i < ccp->cmd_q_count; i++) { + if (ccp->cmd_q[i].active) + continue; + + break; + } + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); + + /* If we found an idle queue, wake it up */ + if (i < ccp->cmd_q_count) + wake_up_process(ccp->cmd_q[i].kthread); +} + +static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q) +{ + struct ccp_device *ccp = cmd_q->ccp; + struct ccp_cmd *cmd = NULL; + struct ccp_cmd *backlog = NULL; + unsigned long flags; + + spin_lock_irqsave(&ccp->cmd_lock, flags); + + cmd_q->active = 0; + + if (ccp->suspending) { + cmd_q->suspended = 1; + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); + wake_up_interruptible(&ccp->suspend_queue); + + return NULL; + } + + if (ccp->cmd_count) { + cmd_q->active = 1; + + cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry); + list_del(&cmd->entry); + + ccp->cmd_count--; + } + + if (!list_empty(&ccp->backlog)) { + backlog = list_first_entry(&ccp->backlog, struct ccp_cmd, + entry); + list_del(&backlog->entry); + } + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); + + if (backlog) { + INIT_WORK(&backlog->work, ccp_do_cmd_backlog); + schedule_work(&backlog->work); + } + + return cmd; +} + +static void ccp_do_cmd_complete(unsigned long data) +{ + struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data; + struct ccp_cmd *cmd = tdata->cmd; + + cmd->callback(cmd->data, cmd->ret); + + complete(&tdata->completion); +} + +/** + * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue + * + * @data: thread-specific data + */ +int ccp_cmd_queue_thread(void *data) +{ + struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data; + struct ccp_cmd *cmd; + struct ccp_tasklet_data tdata; + struct tasklet_struct tasklet; + + tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata); + + set_current_state(TASK_INTERRUPTIBLE); + while (!kthread_should_stop()) { + schedule(); + + set_current_state(TASK_INTERRUPTIBLE); + + cmd = ccp_dequeue_cmd(cmd_q); + if (!cmd) + continue; + + __set_current_state(TASK_RUNNING); + + /* Execute the command */ + cmd->ret = ccp_run_cmd(cmd_q, cmd); + + /* Schedule the completion callback */ + tdata.cmd = cmd; + init_completion(&tdata.completion); + tasklet_schedule(&tasklet); + wait_for_completion(&tdata.completion); + } + + __set_current_state(TASK_RUNNING); + + return 0; +} + +/** + * ccp_alloc_struct - allocate and initialize the ccp_device struct + * + * @sp: sp_device struct of the CCP + */ +struct ccp_device *ccp_alloc_struct(struct sp_device *sp) +{ + struct device *dev = sp->dev; + struct ccp_device *ccp; + + ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL); + if (!ccp) + return NULL; + ccp->dev = dev; + ccp->sp = sp; + ccp->axcache = sp->axcache; + + INIT_LIST_HEAD(&ccp->cmd); + INIT_LIST_HEAD(&ccp->backlog); + + spin_lock_init(&ccp->cmd_lock); + mutex_init(&ccp->req_mutex); + mutex_init(&ccp->sb_mutex); + ccp->sb_count = KSB_COUNT; + ccp->sb_start = 0; + + /* Initialize the wait queues */ + init_waitqueue_head(&ccp->sb_queue); + init_waitqueue_head(&ccp->suspend_queue); + + snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord); + snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord); + + return ccp; +} + +int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng); + u32 trng_value; + int len = min_t(int, sizeof(trng_value), max); + + /* Locking is provided by the caller so we can update device + * hwrng-related fields safely + */ + trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG); + if (!trng_value) { + /* Zero is returned if not data is available or if a + * bad-entropy error is present. Assume an error if + * we exceed TRNG_RETRIES reads of zero. + */ + if (ccp->hwrng_retries++ > TRNG_RETRIES) + return -EIO; + + return 0; + } + + /* Reset the counter and save the rng value */ + ccp->hwrng_retries = 0; + memcpy(data, &trng_value, len); + + return len; +} + +bool ccp_queues_suspended(struct ccp_device *ccp) +{ + unsigned int suspended = 0; + unsigned long flags; + unsigned int i; + + spin_lock_irqsave(&ccp->cmd_lock, flags); + + for (i = 0; i < ccp->cmd_q_count; i++) + if (ccp->cmd_q[i].suspended) + suspended++; + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); + + return ccp->cmd_q_count == suspended; +} + +void ccp_dev_suspend(struct sp_device *sp) +{ + struct ccp_device *ccp = sp->ccp_data; + unsigned long flags; + unsigned int i; + + /* If there's no device there's nothing to do */ + if (!ccp) + return; + + spin_lock_irqsave(&ccp->cmd_lock, flags); + + ccp->suspending = 1; + + /* Wake all the queue kthreads to prepare for suspend */ + for (i = 0; i < ccp->cmd_q_count; i++) + wake_up_process(ccp->cmd_q[i].kthread); + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); + + /* Wait for all queue kthreads to say they're done */ + while (!ccp_queues_suspended(ccp)) + wait_event_interruptible(ccp->suspend_queue, + ccp_queues_suspended(ccp)); +} + +void ccp_dev_resume(struct sp_device *sp) +{ + struct ccp_device *ccp = sp->ccp_data; + unsigned long flags; + unsigned int i; + + /* If there's no device there's nothing to do */ + if (!ccp) + return; + + spin_lock_irqsave(&ccp->cmd_lock, flags); + + ccp->suspending = 0; + + /* Wake up all the kthreads */ + for (i = 0; i < ccp->cmd_q_count; i++) { + ccp->cmd_q[i].suspended = 0; + wake_up_process(ccp->cmd_q[i].kthread); + } + + spin_unlock_irqrestore(&ccp->cmd_lock, flags); +} + +int ccp_dev_init(struct sp_device *sp) +{ + struct device *dev = sp->dev; + struct ccp_device *ccp; + int ret; + + /* + * Check how many we have so far, and stop after reaching + * that number + */ + if (atomic_inc_return(&dev_count) > max_devs) + return 0; /* don't fail the load */ + + ret = -ENOMEM; + ccp = ccp_alloc_struct(sp); + if (!ccp) + goto e_err; + sp->ccp_data = ccp; + + if (!nqueues || (nqueues > MAX_HW_QUEUES)) + ccp->max_q_count = MAX_HW_QUEUES; + else + ccp->max_q_count = nqueues; + + ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata; + if (!ccp->vdata || !ccp->vdata->version) { + ret = -ENODEV; + dev_err(dev, "missing driver data\n"); + goto e_err; + } + + ccp->use_tasklet = sp->use_tasklet; + + ccp->io_regs = sp->io_map + ccp->vdata->offset; + if (ccp->vdata->setup) + ccp->vdata->setup(ccp); + + ret = ccp->vdata->perform->init(ccp); + if (ret) { + /* A positive number means that the device cannot be initialized, + * but no additional message is required. + */ + if (ret > 0) + goto e_quiet; + + /* An unexpected problem occurred, and should be reported in the log */ + goto e_err; + } + + dev_notice(dev, "ccp enabled\n"); + + return 0; + +e_err: + dev_notice(dev, "ccp initialization failed\n"); + +e_quiet: + sp->ccp_data = NULL; + + return ret; +} + +void ccp_dev_destroy(struct sp_device *sp) +{ + struct ccp_device *ccp = sp->ccp_data; + + if (!ccp) + return; + + ccp->vdata->perform->destroy(ccp); +} |